A novel derivatization-free method of formaldehyde and propylene glycol determination in hydrogels by liquid chromatography with refractometric detection.

PubMed

Isakau, Henadz; Robert, Marielle; Shingel, Kirill I

2009-04-05

The paper describes the development and validation of a new derivatization-free liquid chromatography method for simultaneous determination of propylene glycol and formaldehyde in the formulations containing formaldehyde-releasing preservative. Highly swollen hydrogel made of poly(ethylene glycol)-protein conjugates was taken as a model formulation for integration of the propylene glycol and the diazolydinyl urea as formaldehyde releaser. The method is shown to be simple and selective and, more importantly, allows determining an existing level of formaldehyde at the moment of analysis instead of all available formaldehyde that might be released during chemical derivatization. After liquid extraction the propylene glycol (PG) and formaldehyde (FA) amounts are determined chromatographically on a Shodex SH 1011 ligand-exchange column using 0.01 M sulfuric acid mobile phase, a flow rate of 1.0 ml/min and RI detection. The assay is validated showing good linearity, precision, and accuracy. The limits of detection of formaldehyde and propylene glycol in the analyzed solutions were estimated to be 25 ng and 87 ng, respectively. This analytical assay is considered useful for product stability studies and in developing new formaldehyde releaser-containing formulations where the concentration of formaldehyde is a presumable subject of labeling requirements. This method can also provide a rapid and convenient alternative to gas chromatography method of propylene glycol quantification.

Comparison of ethylene glycol and propylene glycol for the vitrification of immature porcine oocytes.

PubMed

Somfai, Tamás; Nakai, Michiko; Tanihara, Fuminori; Noguchi, Junko; Kaneko, Hiroyuki; Kashiwazaki, Naomi; Egerszegi, István; Nagai, Takashi; Kikuchi, Kazuhiro

2013-01-01

Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35% ethylene glycol (EG), 35% propylene glycol (PG) or a combination of 17.5% EG and 17.5% PG. After warming, the COCs were in vitro matured (IVM), and surviving oocytes were in vitro fertilized (IVF) and cultured. The mean survival rate of vitrified oocytes in 35% PG (73.9%) was higher (P<0.05) than that in 35% EG (27.8%). Oocyte maturation rates did not differ among vitrified and non-vitrified control groups. Blastocyst formation in the vitrified EG group (10.8%) was higher (P<0.05) than that in the vitrified PG group (2.0%) but was lower than that in the control group (25.0%). Treatment of oocytes with 35% of each cryoprotectant without vitrification revealed a higher toxicity of PG on subsequent blastocyst development compared with EG. The combination of EG and PG resulted in 42.6% survival after vitrification. The maturation and fertilization rates of the surviving oocytes were similar in the vitrified, control and toxicity control (TC; treated with EG+PG combination without cooling) groups. Blastocyst development in the vitrified group was lower (P<0.05) than that in the control and TC groups, which in turn had similar development rates (10.7%, 18.1% and 23.3%, respectively). In conclusion, 35% PG enabled a higher oocyte survival rate after vitrification compared with 35% EG. However, PG was greatly toxic to oocytes. The combination of 17.5% EG and 17.5% PG yielded reasonable survival rates without toxic effects on embryo development.

Ruminal and intermediary metabolism of propylene glycol in lactating Holstein cows.

PubMed

Kristensen, N B; Raun, B M L

2007-10-01

Four lactating Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in the mesenteric artery, mesenteric vein, hepatic portal vein, and hepatic vein were used in a cross-over design to study the metabolism of propylene glycol (PG). Each cow received 2 treatments: control (no infusion) and infusion of 650 g of PG into the rumen at the time of the morning feeding. Propylene glycol was infused on the day of sampling only. Samples of arterial, portal, and hepatic blood as well as ruminal fluid were obtained at 0.5 h before feeding and at 0.5, 1.5, 2.5, 3.5, 5, 7, 9, and 11 h after feeding. Infusion of PG did not affect ruminal pH or the total concentration of ruminal volatile fatty acids, but did decrease the molar proportion of ruminal acetate. The ruminal concentrations of PG, propanol, and propanal as well as the molar proportion of propionate increased with PG infusion. The plasma concentrations of PG, ethanol, propanol, propanal, glucose, L-lactate, propionate, and insulin increased with PG and the plasma concentrations of acetate and beta-hydroxybutyrate decreased. The net portal flux of PG, propanol, and propanal increased with PG. The hepatic uptake of PG was equivalent to 19% of the intraruminal dose. When cows were dosed with PG, the hepatic extraction of PG was between 0 and 10% depending on the plasma concentration of PG, explaining the slow decrease in arterial PG. The increased net hepatic flux of L-lactate with PG could account for the entire hepatic uptake of PG, which suggests that the primary hepatic pathway for PG is oxidation to l-lactate. The hepatic uptake of propanol increased with PG, but no effects of PG on the net hepatic and net splanchnic flux of glucose were observed. Despite no effect of PG on net portal flux and net hepatic flux of propionate, the net splanchnic flux of propionate increased and the data suggest that propionate produced from hepatic metabolism of propanol is partly released to the blood. The data suggest that PG affects metabolism of the cows by 2 modes of action: 1) increased supply of l-lactate and propionate to gluconeogenesis and 2) insulin resistance of peripheral tissues induced by increased concentrations of PG and propanol as well as a decreased ratio of ketogenic to glucogenic metabolites in arterial blood plasma.

Safety and efficacy of a hydroxypropyl guar/polyethylene glycol/propylene glycol-based lubricant eye-drop in patients with dry eye.

PubMed

Labetoulle, Marc; Messmer, Elisabeth M; Pisella, Pierre-Jean; Ogundele, Abayomi; Baudouin, Christophe

2017-04-01

To demonstrate non-inferiority of a hydroxypropyl guar/polyethylene glycol/propylene glycol lubricating eye-drop (HPG/PEG/PG) compared with an osmoprotective carboxymethylcellulose/glycerine eye-drop (O/CMC) for ocular surface staining. This was a multicentre, randomised, observer-masked, parallel-group study. Adults with dry eye instilled HPG/PEG/PG/ or O/CMC 4 times daily for 35 days and then as needed through day 90. Total ocular surface staining (TOSS) score changes from baseline and Impact of Dry Eye on Everyday Life (IDEEL) treatment satisfaction module scores were assessed. Non-inferiority, based on TOSS score change from baseline, was concluded if the upper limit of the 2-sided CI was <2 units. Mean±SD patient age was 64.4±13.7 years; 94 patients were randomised to treatment (HPG/PEG/PG, n=46; O/CMC, n=48). Mean±SE TOSS score change from baseline to day 35 was -2.2±0.33 with HPG/PEG/PG and -1.7±0.47 with O/CMC (treatment difference, -0.47±0.47; p=0.38), and the non-inferiority criterion was met. IDEEL treatment satisfaction scores were similar between groups at day 35 and day 90. The most frequently reported adverse event was eye irritation (HPG/PEG/PG, n=2; O/CMC, n=3). HPG/PEG/PG and O/CMC reduced ocular surface damage, and HPG/PEG/PG was non-inferior to O/CMC. Both treatments were effective, convenient and well tolerated. NCT01863368, Results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

The effect of different treatments for early-lactation hyperketonemia on blood β-hydroxybutyrate, plasma nonesterified fatty acids, glucose, insulin, and glucagon in dairy cattle.

PubMed

Mann, S; Yepes, F A Leal; Behling-Kelly, E; McArt, J A A

2017-08-01

Despite increased efforts in preventing the occurrence of metabolic disorders in transition cows, hyperketonemia remains a frequent early-lactation metabolic disease affecting an average of 40% of cows in herds in the United States. Despite the demonstrated economic effect of this disorder, controlled clinical trials comparing different treatment strategies in affected cows are lacking. The objective of our study was to investigate the effect of treatment with intravenous glucose, oral propylene glycol, or a combination of both on the reduction in blood β-hydroxybutyrate (BHB) concentrations of early-lactation hyperketonemic dairy cows. Multiparous Holstein cows between 3 to 9 d in milk were screened for hyperketonemia using a handheld meter 3 times per week, and enrolled at whole blood BHB concentration ≥1.2 mmol/L to 1 of 4 treatment groups: (1) 500 mL of a 50% dextrose solution i.v. once daily for 3 d (GLU, n = 9), (2) 300 mL of propylene glycol as a drench once daily for 3 d (PG, n = 9), (3) a combination treatment of a 500 mL of 50% dextrose solution i.v. and 300 mL of propylene glycol orally once daily for 3 d (GLU+PG, n = 8), or (4) an untreated control group (CTRL, n = 8). Blood samples were collected immediately before as well as at 1, 2, 4, 8, 12, 24, 36, 48, 60, and 72 h after administration of the first treatment through a jugular catheter and 3 times per week thereafter from coccygeal vessels. Concentrations of BHB were measured in whole blood, and plasma samples were analyzed for glucose, fatty acid (NEFA), insulin, glucagon, and electrolyte concentrations. The EDTA-anticoagulated blood samples were assessed for red blood cell indices, and smears were made for evaluation of red blood cell morphology. Outcomes were analyzed using repeated measures analysis. Overall least squares means (95% CI) of whole blood BHB concentrations between 1 h and d 11 relative to first treatment were 1.11 (0.95 to 1.30), 1.26 (1.07 to 1.47), 0.96 (0.81 to 1.13), and 1.53 (1.30 to 1.80) mmol/L for the GLU, PG, GLU+PG, and CTRL groups, respectively. Treatment with both glucose and propylene glycol led to a greater magnitude and more prolonged decrease in BHB concentrations compared with individual treatments. The NEFA and glucagon concentrations were lower immediately after treatment in GLU and GLU+PG groups compared with CTRL, and treatment with both glucose and propylene glycol was associated with a greater increase in glucose and insulin concentrations immediately after treatment compared with CTRL and GLU treatment alone. Treatments did not lead to differences in plasma mineral concentrations. We conclude that treatments varied in the magnitude of decreasing blood BHB concentrations in hyperketonemic postpartum cows, with the greatest decline after treatment with a combination of intravenous glucose and oral propylene glycol. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Broadband terahertz dynamics of propylene glycol monomer and oligomers

NASA Astrophysics Data System (ADS)

Koda, Shota; Mori, Tatsuya; Kojima, Seiji

2016-12-01

We investigated the broadband terahertz spectra (0.1-5.0 THz) of glass-forming liquids, propylene glycol (PG), its oligomers poly (propylene glycol)s (PPGs), and poly (propylene glycol) diglycidyl ether (PPG-de) using broadband terahertz time-domain spectroscopy and low-frequency Raman scattering. The numerical value of the dielectric loss at around 1.5 THz, which is the peak position of broad peaks in all samples, decreased as the molecular weight increased. Furthermore, the peak at around 1.5 THz is insensitive to the molecular weight. For PPGs, the side chain effect of the oligomer was observed in the terahertz region. Based on the experimental and calculation results for the PPGs and PPG-de, whose end groups are epoxy groups, the beginnings of the increases in the observed dielectric loss above 3.5 THz of the PPGs are assigned to the OH bending vibration. The higher value of the dielectric loss in the terahertz region for the PPG-de can be the tail of a broad peak located in the MHz region. The difference between the Raman susceptibility and dielectric loss reflects the difference in the observable molecular dynamics between the infrared and Raman spectroscopies.

Impact of flavour solvent (propylene glycol or triacetin) on vanillin, 5-(hydroxymethyl)furfural, 2,4-decadienal, 2,4-heptadienal, structural parameters and sensory perception of shortcake biscuits over accelerated shelf life testing.

PubMed

Yang, Ni; Hort, Joanne; Linforth, Robert; Brown, Keith; Walsh, Stuart; Fisk, Ian D

2013-11-15

The influence of choice of flavour solvent, propylene glycol (PG) or triacetin (TA), was investigated during accelerated shelf life (ASL) testing of shortcake biscuits. Specifically, the differential effect on the stability of added vanillin, the natural baked marker compound 5-(hydroxymethyl)furfural (HMF), specific markers of oxidative rancidity (2,4-decadienal, 2,4-heptadienal), and the structural parameters of hardness and fracturability. Significantly more HMF was formed during baking of biscuits prepared with TA; these biscuits were also more stable to oxidative degradation and loss of vanillin during ageing than biscuits prepared with PG. Fresh TA biscuits were significantly more brittle than fresh PG biscuits. There was no impact of solvent choice on hardness. Sensory evaluation of hardness, vanilla flavour and oily off-note was tested during ASL testing. There was no significant impact of storage on sensory ratings for either the PG or TA biscuits. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of different dosages of propylene glycol in dry cows and cows in early lactation.

PubMed

Maurer, Michaela; Peinhopf, Walter; Gottschalk, Jutta; Einspanier, Almut; Koeller, Gabor; Wittek, Thomas

2017-11-01

In this Research Paper we hypothesised that the temporary insulin resistance seen during the transition period in dairy cows may cause significant differences in the efficacy of PG at different sampling periods and that in some cases this effect will be dose dependent. Eighty four sampling sets were generated by studying 7 multiparous Holstein cows repeatedly at 4 sampling periods of 3 d length (dry cows: days 40, 39 and 38 antepartum; close up cows: days 10, 9 and 8 antepartum; fresh cows: days 3, 4 and 5 post-partum; lactating cows: days 38, 39 and 40 post-partum). On each of these days 3 h after morning feeding propylene glycol was drenched in different dosages of 100, 300 or 500 ml once per day (cross over study). The different doses were applied in an alternating order (Latin square). Blood samples were taken before, every 30 min up to 4 h, after 6 and 12 h after PG application. Following parameters have been measured: insulin, non-esterified fatty acids (NEFA), betahydroxybutyrate (BHB), bilirubin, cholesterol, potassium, aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH). Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) was calculated. It was found that glucose, insulin, NEFA, BHB, bilirubin and potassium concentrations were influenced differently by the three defined dosages of propylene glycol at four different sampling periods. Whereas RQUICKI, cholesterol, AST and GLDH did not differ between the sampling periods and treatments. The major results of the study are that the effect of PG is dose-dependent and that the effect of PG is depending on the time of application according to calving. It can be concluded that in fresh cows higher dosages are necessary to provoke similar effects in comparison to dry, close up and lactating cows. Although the study did not compare to topdressing of PG from the results it is reasonable to believe that bolus application of a specific PG volume is necessary to provoke the effect.

Natural and enhanced biodegradation of propylene glycol in airport soil.

PubMed

Toscano, Giuseppe; Colarieti, M Letizia; Anton, Attila; Greco, Guido; Biró, Borbála

2014-01-01

Aircraft de-icing fluids (ADF) are a source of water and soil pollution in airport sites. Propylene glycol (PG) is a main component in several commercial formulations of ADFs. Even though PG is biodegradable in soil, seasonal overloads may result in occasional groundwater contamination. Feasibility studies for the biostimulation of PG degradation in soil have been carried out in soil slurries, soil microcosms and enrichment cultures with and without the addition of nutrients (N and P sources, oligoelements), alternative electron acceptors (nitrate, oxygen releasing compounds) and adsorbents (activated carbon). Soil samples have been taken from the contaminated area of Gardermoen Airport Oslo. Under aerobic conditions and in the absence of added nutrients, no or scarce biomass growth is observed and PG degradation occurs by maintenance metabolism at constant removal rate by the original population of PG degraders. With the addition of nutrient, biomass exponential growth enhances aerobic PG degradation also at low temperatures (4 ° C) that occur at the high season of snowmelt. Anaerobic PG degradation without added nutrients still proceeds at constant rate (i.e. no biomass growth) and gives rise to reduced fermentation product (propionic acid, reduced Fe and Mn, methane). The addition of nitrate does not promote biomass growth but allows full PG mineralization without reduced by-products. Further exploitation on the field is necessary to fully evaluate the effect of oxygen releasing compounds and adsorbents.

Assessment of the dietary intake of propylene glycol in the Korean population.

PubMed

Lim, Ho Soo; Hwang, Ju Young; Choi, EunA; Lee, Gun Young; Yun, Sang Soon; Kang, TaeSeok

2016-08-01

An improved method for the analysis of propylene glycol (PG) in foods using a gas chromatography-flame ionisation detector (GC-FID), with confirmation by GC-MS, was validated by measuring several analytical parameters. The PG concentrations in 1073 products available in Korean markets were determined. PG was detected in 74.1% of the samples, in a concentration range from the limit of detection (n.d., 0.39 μg ml(-1)) to 12,819.9 mg kg(-1). The Korea National Health and Nutrition Examination Survey (KNHANES) 2011-2013 reported the mean intake levels of PG from all sources by the general population and consumers were 26.3 mg day(-1) (0.52 mg kg(-1) day(-1)) and 34.3 mg day(-1) (0.67 mg kg(-1) day(-1)), respectively. The 95th percentile intake levels of the general population and consumers were 123.6 mg day(-1) (2.39 mg kg(-1) day(-1)) and 146.3 mg day(-1) (2.86 mg kg(-1) day(-1)), respectively. In all groups of the general population, breads were the main contributors to the total PG intake. These reports provide a current perspective on the daily intake of PG in the Korean population.

Formulation and in vitro/in vivo evaluation of levodopa transdermal delivery systems.

PubMed

Lee, Kyung Eun; Choi, Yun Jung; Oh, Byu Ree; Chun, In Koo; Gwak, Hye Sun

2013-11-18

This study aims to investigate the feasibility of Levodopa transdermal delivery systems (TDSs). Levodopa TDSs were formulated using various vehicles and permeation enhancers, and in vitro permeation and in vivo pharmacokinetic studies were carried out. In the in vitro study, ester-type vehicles showed relatively high enhancing effects; propylene glycol monocaprylate and propylene glycol monolaurate showed the highest permeation fluxes from both solution and pressure sensitive adhesive (PSA) TDS formulations. Lag time was dramatically shortened with PSA TDS formulations as compared with solution formulations. In the in vivo study, the addition of fatty acids increased blood drug concentrations regardless of the kind or concentration of fatty acid; the AUCinf increased up to 8.7 times as compared with propylene glycol (PG) alone. PSA TDS containing 10% linoleic acid exhibited prolonged Tmax as compared with oral form. Total clearance of L-dopa from PSA TDSs was significantly lower than from oral form (up to 86.8 times). Especially, PSA TDS containing 10% linoleic acid (LOA) revealed 76.2 fold higher AUCinf than oral administration. Based on our results, the L-dopa PSA TDS containing PG with 10% LOA could be used as a good adjuvant therapy for Parkinson's disease patients who experience symptom fluctuation by L-dopa oral administration. Copyright © 2013 Elsevier B.V. All rights reserved.

Skin deposition and permeation of finasteride in vitro: effects of propylene glycol, ethanol and sodium lauryl sulfate.

PubMed

Limpongsa, Ekapol; Jaipakdee, Napaphak; Pongjanyakul, Thaned

2014-08-27

Abstract The objective of this study was to investigate the effects of propylene glycol (PG), ethanol (EtOH) and sodium lauryl sulfate (SLS) on the in vitro deposition and permeation of finasteride (FNS). A side-by-side diffusion cell mounted with a pig ear skin and a saturated solution of FNS in PG (10, 20% v/v), EtOH (10, 20% v/v) or SLS (0.5, 1% w/v) vehicles were used. Incorporation of PG, EtOH or SLS caused a significant increase in FNS solubility both in the solution and on the skin with SLS > EtOH > PG. The results obtained from skin deposition studies showed that the FNS deposition rate and time increased in the same order as that of the solubility. The deposition kinetics of FNS solubilized in PG, EtOH and SLS vehicles followed either zero-order, square-root-of-time or pseudo-first-order kinetic models depending on the type and concentration of the enhancer. The permeation studies demonstrated that FNS permeation fluxes were enhanced only by EtOH vehicles. These results suggest that PG and SLS could be used as deposition enhancers, while EtOH could be the effective permeation enhancer of FNS. The obtained results can be used as the considerable insights for formulating the topical and transdermal products of FNS.

Photoresponsive Release from Azobenzene-Modified Single Cubic Crystal NaCl/Silica Particles

DOE PAGES

Jiang, Xingmao; Liu, Nanguo; Assink, Roger A.; ...

2011-01-01

Azobenzene ligands were uniformly anchored to the pore surfaces of nanoporous silica particles with single crystal NaCl using 4-(3-triethoxysilylpropylureido)azobenzene (TSUA). The functionalization delayed the release of NaCl significantly. The modified particles demonstrated a photocontrolled release by trans/cis isomerization of azobenzene moieties. The addition of amphiphilic solvents, propylene glycol (PG), propylene glycol propyl ether (PGPE), and dipropylene glycol propyl ether (DPGPE) delayed the release in water, although the wetting behavior was improved and the delay is the most for the block molecules with the longest carbon chain. The speedup by UV irradiation suggests a strong dependence of diffusion on the switchablemore » pore size. TGA, XRD, FTIR, and NMR techniques were used to characterize the structures.« less

Using Raman Spectroscopy in Studying the Effect of Propylene Glycol, Oleic Acid, and Their Combination on the Rat Skin.

PubMed

Atef, Eman; Altuwaijri, Njoud

2018-01-01

The permeability enhancement effect of oleic acid (OA) and propylene glycol (PG) as well as their (1:1 v/v) combined mixture was studied using rat skin. The percutaneous drug administration is a challenge and an opportunity for drug delivery. To date, there is limited research that illustrates the mechanism of penetration enhancers and their combinations on the skin. This project aims to explore the skin diffusion and penetration enhancement of PG, OA, and a combination of PG-OA (1:1 v/v) on rat skin and to identify the potential synergistic effect of the two enhancers utilizing Raman spectroscopy. Dissected dorsal skin was treated with either PG or OA or their combination for predetermined time intervals after which the Raman spectra of the treated skin were collected with the enhancer. A spectrum of the wiped and the washed skin were also collected. The skin integrity was tested before and after exposure to PG. The skin histology proved that the skin integrity has been maintained during experiments and the results indicated that OA disrupted rat skin lipid as evident by changes in the lipid peak. The results also showed that PG and OA improved the diffusion of each other and created faster, yet reversible changes of the skin peaks. In conclusion, Raman spectroscopy is a potential tool for ex vivo skin diffusion studies. We also concluded that PG and OA have potential synergistic reversible effect on the skin.

Hexagonal spherical Ln3+-doped NaGdF4: A facile double solvent hydrothermal synthesis and luminescent properties

NASA Astrophysics Data System (ADS)

Wu, Kelu; Huang, Zhuanzhuan; Yu, Qiao-He; Wang, Yi-Yan; Xia, Tian-Long

2017-04-01

Different sizes of hexagonal spherical NaGdF4:Eu3+ particles are synthesized via a facile hydrothermal method with the use of ethylene glycol (EG), propylene glycol (PG) or butylene glycol (BG) as another solvent. The particle size decreases with the addition of EG, PG or BG and the decreasing trend in BG/H2O system is significantly more than that in the other two systems. Meanwhile, results show that luminescent properties of NaGdF4:Eu3+ are enhanced along with the decrease of particle size. Besides, the energy transfer from Dy3+ to Eu3+ is directly observed in the PL spectra of NaGdF4:Eu3+/Dy3+.

Low but inducible contribution of renal elimination to clearance of propylene glycol in preterm and term neonates.

PubMed

De Cock, Roosmarijn F W; Allegaert, Karel; Vanhaesebrouck, Sophie; de Hoon, Jan; Verbesselt, Rene; Danhof, Meindert; Knibbe, Catherijne A J

2014-06-01

Despite limited information being available on the pharmacokinetics of excipients, propylene glycol (PG) is often used as an excipient in both adults and children. The aim of this study is to characterize the renal and hepatic elimination of PG in preterm and term neonates. The pharmacokinetic analysis of PG was performed in NONMEM 6.2. on the basis of PG concentrations in plasma and/or urine samples for a total of 69 (pre)term neonates (birth weight 630-3980 g, gestational age 24-41 weeks, postnatal age 1-29 days) who received PG coadministered with intravenous paracetamol (5-10 mg/kg per 6 hours), phenobarbital (5 mg·kg(-1)·d(-1)), or both. To capture the time-dependent trend in the renal excretion of PG, different models based on time after the first dose, urine volume, and creatinine amount in urine were tested. A one-compartment model parameterized in terms of renal clearance, hepatic clearance, and volume of distribution was found to adequately describe the observations in both plasma and urine. After the first dose was administered, the renal elimination of PG was 15% of total clearance, which increased over time to 25% at 24 hours after the first dose of PG. This increase was best described using a hyperbolic function based on time after the first dose. Renal elimination of PG in (pre)term neonates is low, particularly compared with the reported percentage of 45% in adults, but it may increase with time after the first dose of PG. To study whether this increase is caused by an autoinduced increase in the renal secretion or a reduction of tubular reabsorption of PG, further research is needed.

UV stabilization of wood by nano metal oxides dispersed in propylene glycol.

PubMed

Nair, Sreeja; Nagarajappa, Giridhar B; Pandey, Krishna K

2018-06-01

Nanoparticles of some of the metal oxides are known to have high UV protective efficiency. The UV filtering efficiency of nanoparticles invariably depends on their size and stability in the dispersion. In the present work, a stable dispersion of nanoparticles of three metal oxides, zinc oxide (ZnO), cerium oxide (CeO 2 ) and titanium dioxide (TiO 2 ), was prepared in propylene glycol (PG) using ultrasonication. The method is easy and useful as no additional surfactant or dispersant is needed. The particle size and its distribution was confirmed by Scanning Electron Microscopy and Dynamic Light Scattering. The stability of dispersion was assessed by UV-visible absorption spectroscopy. The UV stability of wood surfaces of Wrightia tinctoria coated with nanodispersions of ZnO, CeO 2 and TiO 2 was evaluated under laboratory conditions in an accelerated weathering tester. Changes in the colour and FTIR spectra of exposed specimens were measured periodically. Rapid colour darkening (yellowing) was observed in uncoated and PG coated specimens. In contrast, nanodispersion coated specimens prevented photo-yellowing considerably with significant reduction in colour changes examined by CIE L*, a*, b* and ΔE*. Increase in concentration of nanoparticles in the dispersion imparted higher resistance to UV induced degradation. However, increased concentration of nanoparticles reduced the transparency of the coating. FTIR analysis indicated rapid degradation of lignin in uncoated and PG coated specimens due to UV exposure. Coating of wood surfaces with nanodispersions restricted lignin degradation. The study also demonstrates the potential of propylene glycol as a dispersant for developing stable and efficient UV protective nanodispersions for wood coating. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of Environmentally Benign and Reduced Corrosion Runway Deicing Fluid

DTIC Science & Technology

2009-08-01

PCNA Peter Cremer North America PG Propylene glycol P&G Proctor and Gamble Inc. PNNL Pacific Northwest National Laboratory RDF Runway Deicing...Navy/NAVAIR Defining Navy needs Mack Findley Peter Cremer North America (PCNA) Bio-based raw materials selection Pat Viani SMI AMS 1435 testing...SMI), and other laboratories under the leadership of SAE G-12 Fluids Subcommittee, and is expected to provide a better indication of compatibility with

Mixing with propylene glycol enhances the bond strength of mineral trioxide aggregate to dentin.

PubMed

Salem Milani, Amin; Froughreyhani, Mohammad; Charchi Aghdam, Saeed; Pournaghiazar, Fatemeh; Asghari Jafarabadi, Mohammad

2013-11-01

Mixing mineral trioxide aggregate (MTA) with different proportions of propylene glycol (PG) improves its handling property. The aim of this study was to evaluate the effect of PG on MTA-dentin push-out bond strength. Seventy-five 2-mm-thick midroot sections were prepared from single-rooted human extracted teeth. The lumen of each slice was enlarged with Gates-Glidden burs. The slices were randomly divided into 3 groups (n = 25). In each group, 0.3 mL of the liquid was mixed with 1 g MTA (Angelus, Londrina, Brazil). The liquid vehicles used in groups 1-3 were 100% distilled water (DW), 20% PG-80% DW, and 100% PG, respectively. After incubation, the push-out strength of the samples was measured using a universal testing machine. The samples were then cut in halves and examined under a stereomicroscope to determine the failure pattern. One-way analysis of variance followed by the Tukey post hoc test was used to compare the push-out strength among groups. There were statistically significant differences between groups (P < .001). The push-out strength in group 1 (DW) was significantly lower than groups 2 and 3 (P < .001 and P = .022, respectively). However, there was no significant difference between groups 2 (DW-PG) and 3 (PG). Mixing MTA with PG increased its push-out bond strength to dentin. In the present study, the most suitable ratio was 80% DW-20% PG. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Cellular component of lavage fluid from broilers with normal versus aerosol-primed airways

USDA-ARS?s Scientific Manuscript database

Previously we reported that intratracheal administration of lipopolysaccharide (LPS) elicits pulmonary hypertension (PH) in broilers reared under commercial conditions, in broilers reared in environmental chambers and pre-treated with aerosolized red food colorant # 3 and propylene glycol (Red#3+PG)...

Biodegradability relationships among propylene glycol substances in the Organization for Economic Cooperation and Development ready- and seawater biodegradability tests.

PubMed

West, Robert J; Davis, John W; Pottenger, Lynn H; Banton, Marcy I; Graham, Cynthia

2007-05-01

Eight propylene glycol substances, ranging from 1,2-propanediol to a poly(propylene glycol) (PPG) having number-average molecular weight (M(n)) of 2,700 (i.e., PPG 2700), were evaluated in the Organization for Economic Cooperation and Development (OECD) ready- and seawater biodegradability tests. Uniformity in test parameters, such as inoculum source/density and test substance concentrations, combined with frequent measurements of O2 consumption and CO2 evolution, revealed unexpected biodegradability trends across this family of substances. Biodegradability in both tests decreased with increased number of oxy-propylene repeating units (n = 1, 2, 3, 4) of the oligomeric propylene glycols (PGs). However, this trend was reversed for the PPG polymers, and increased biodegradability was observed with increases of average n to seven, 17, and 34 (M(n) = 425, 1,000, and 2,000, respectively). This relationship between molecular weight and biodegradability was reversed again when average n was incremented from 34 (PPG 2000) to 46 (PPG 2700). Six of the tested substances (n = 1, 2, 3, 7, 17, and 34) met the OECD-specified criteria for "ready biodegradability," whereas the tetrapropylene glycol (n = 4) and PPG 2700 substances failed to meet these criteria. Biodegradation half-lives for these eight substances ranged from 3.8 d (PPG 2000) to 33.2 d (PPG 2700) in the ready test, and from 13.6 (PG) to 410 d (PPG 2700) in seawater. Biodegradation half-lives in seawater were significantly correlated with half-lives determined in the ready test. However, half-lives in both tests were correlated poorly with molecular weight, water solubility, and log K(ow). It is speculated that the molecular conformation of these substances, perhaps more so than these other physicochemical properties, has an important role in influencing biodegradability of the propylene glycol substances.

Effect of biogenic fermentation impurities on lactic acid hydrogenation to propylene glycol.

PubMed

Zhang, Zhigang; Jackson, James E; Miller, Dennis J

2008-09-01

The effect of residual impurities from glucose fermentation to lactic acid (LA) on subsequent ruthenium-catalyzed hydrogenation of LA to propylene glycol (PG) is examined. Whereas refined LA feed exhibits stable conversion to PG over carbon-supported ruthenium catalyst in a trickle bed reactor, partially refined LA from fermentation shows a steep decline in PG production over short (<40 h) reaction times followed by a further slow decay in performance. Addition of model impurities to refined LA has varying effects: organic acids, sugars, or inorganic salts have little effect on conversion; alanine, a model amino acid, results in a strong but reversible decline in conversion via competitive adsorption between alanine and LA on the Ru surface. The sulfur-containing amino acids cysteine and methionine irreversibly poison the catalyst for LA conversion. Addition of 0.1 wt% albumin as a model protein leads to slow decline in rate, consistent with pore plugging or combined pore plugging and poisoning of the Ru surface. This study points to the need for integrated design and operation of biological processes and chemical processes in the biorefinery in order to make efficient conversion schemes viable.

Solubility and stability of melatonin in propylene glycol and 2-hydroxypropyl-beta-cyclodextrin vehicles.

PubMed

Lee, B J; Choi, H G; Kim, C K; Parrott, K A; Ayres, J W; Sack, R L

1997-12-01

The physicochemical properties of melatonin (MT) in propylene glycol (PG) and 2-hydroxypropyl-beta-cyclodextrin (2-HPbetaCD) vehicles were characterized. MT was endothermally decomposed as determined by differential scanning calorimetry (DSC). Melting point and heat of fusion obtained were 116.9+/-0.24 degrees C and 7249+/-217 cal/mol, respectively. MT as received from a manufacture was very pure, at least 99.9%. The solubility of MT in PG solution increased slowly until reaching 40% PG and then steeply increased. Solubility of MT increased linearly as concentration of 2-HPbetaCD without PG increased (R(2)=0.993). MT solubility in the mixtures of PG and 2-HPbetaCD also increased linearly but was less than the sum of its solubility in 2-HPbetaCD and PG individually. The MT solubility was low in water, simulated gastric or intestinal fluid but the highest in the mixture of PG (40 v/v%) and 2-HPbetaCD (30 w/v%) although efficiency of MT solubilization in 2-HPbetaCD decreased as the concentration of PG increased. MT was degraded in a fashion of the first order kinetics (r(2)>0.90). MT was unstable in strong acidic solution (HCl-NaCl buffer, pH 1.4) but relatively stable in other pH values of 4 approximately 10 at 70 degrees C. In HCl-NaCl buffer, MT in 10% PG was more quickly degraded and then slowed down at a higher concentration. However, the degradation rate constant of MT in 2-HPbetaCD was not changed significantly when compared to the water. The current studies can be applied to the dosage formulations for the purpose of enhancing percutaneous absorption or bioavailability of MT.

Toxicity of the main electronic cigarette components, propylene glycol, glycerin, and nicotine, in Sprague-Dawley rats in a 90-day OECD inhalation study complemented by molecular endpoints.

PubMed

Phillips, Blaine; Titz, Bjoern; Kogel, Ulrike; Sharma, Danilal; Leroy, Patrice; Xiang, Yang; Vuillaume, Grégory; Lebrun, Stefan; Sciuscio, Davide; Ho, Jenny; Nury, Catherine; Guedj, Emmanuel; Elamin, Ashraf; Esposito, Marco; Krishnan, Subash; Schlage, Walter K; Veljkovic, Emilija; Ivanov, Nikolai V; Martin, Florian; Peitsch, Manuel C; Hoeng, Julia; Vanscheeuwijck, Patrick

2017-11-01

While the toxicity of the main constituents of electronic cigarette (ECIG) liquids, nicotine, propylene glycol (PG), and vegetable glycerin (VG), has been assessed individually in separate studies, limited data on the inhalation toxicity of them is available when in mixtures. In this 90-day subchronic inhalation study, Sprague-Dawley rats were nose-only exposed to filtered air, nebulized vehicle (saline), or three concentrations of PG/VG mixtures, with and without nicotine. Standard toxicological endpoints were complemented by molecular analyses using transcriptomics, proteomics, and lipidomics. Compared with vehicle exposure, the PG/VG aerosols showed only very limited biological effects with no signs of toxicity. Addition of nicotine to the PG/VG aerosols resulted in effects in line with nicotine effects observed in previous studies, including up-regulation of xenobiotic enzymes (Cyp1a1/Fmo3) in the lung and metabolic effects, such as reduced serum lipid concentrations and expression changes of hepatic metabolic enzymes. No toxicologically relevant effects of PG/VG aerosols (up to 1.520  mg PG/L + 1.890 mg VG/L) were observed, and no adverse effects for PG/VG/nicotine were observed up to 438/544/6.6 mg/kg/day. This study demonstrates how complementary systems toxicology analyses can reveal, even in the absence of observable adverse effects, subtoxic and adaptive responses to pharmacologically active compounds such as nicotine. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Microwave dielectric relaxation spectroscopy study of propylene glycol/ethanol binary mixtures: Temperature dependence

NASA Astrophysics Data System (ADS)

Vishwam, T.; Shihab, Suriya; Murthy, V. R. K.; Tiong, Ha Sie; Sreehari Sastry, S.

2017-05-01

Complex dielectric permittivity measurements of propylene glycol (PG) in ethanol at various mole fractions were measured by using open-ended coaxial probe technique at different temperatures in the frequency range 0.02 < ν/GHz < 20. The dipole moment (μ), excess dipole moment (Δμ),excess permittivity (εE), excess inverse relaxation time(1/τ)E, Bruggeman parameter (fB), excess Helmholtz energy (ΔFE) are determined using experimental data. From the minimum energy based geometry optimization, dipole moments of individual monomers of propylene glycol and ethanol and their binary system have been evaluated theoretically at gaseous state as well as alcoholic medium by using PCM and IEFPCM solvation models from the Hatree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-311G* and 6-311G** basis sets. The obtained results have been interpreted in terms of the short and long range ordering of the dipoles, Kirkwood correlation factor (geff), thermodynamic parameters, mean molecular polarizability (αM) and interaction in the mixture through hydrogen bonding. Dielectric relaxation study of propylene glycol in ethanol medium Determination of excess dielectric and thermodynamic parameters Comparison of experimental dipole moment with theoretical calculations Interpretation of the molecular interactions in the liquid through H-bonding Correlation between the evaluated dielectric parameters and theoretical results

Acute and chronic in vivo effects of exposure to nicotine and propylene glycol from an E-cigarette on mucociliary clearance in a murine model

PubMed Central

Laube, Beth L.; Afshar-Mohajer, Nima; Koehler, Kirsten; Chen, Gang; Lazarus, Philip; Collaco, Joseph M.; McGrath-Morrow, Sharon A.

2017-01-01

Objective To determine the effect of an acute (1 week) and chronic (3 weeks) exposure to E-cigarette (E-cig) emissions on mucociliary clearance (MCC) in murine lungs. Methods C57BL/6 male mice (age 10.5 ±2.4 weeks) were exposed for 20min/day to E-cigarette aerosol generated by a Joyetech 510-T® E-cig containing either 0% nicotine (N)/propylene glycol (PG) for 1 week (n = 6), or 3 weeks (n = 9), or 2.4% N/PG for one week (n = 6), or 3 weeks (n = 9), followed by measurement of MCC. Control mice (n = 15) were not exposed to PG alone, or N/PG. MCC was assessed by gamma camera following aspiration of 99mtechnetium aerosol and was expressed as the amount of radioactivity removed from both lungs over 6 hours (MCC6hrs). Venous blood was assayed for cotinine levels in control mice and in mice exposed for 3-weeks to PG alone and N/PG. Results MCC6hrs in control mice and in mice acutely exposed to PG alone and N/PG was similar, averaging (±1 standard deviation) 8.6±5.2%, 7.5±2.8% and 11.2±5.9%, respectively. In contrast, chronic exposure to PG alone stimulated MCC6hrs (17.2 ±8.0)% and this stimulation was significantly blunted following chronic exposure to N/PG (8.7 ±4.6)% (p < .05). Serum cotinine levels were <0.5ng/ml in control mice and in mice exposed to PG alone, whereas, N/PG exposed mice averaged 14.6 ± 12.0 ng/ml. Conclusions In this murine model, a chronic, daily, 20 min-exposure to N/PG, but not an acute exposure, slowed MCC, compared to exposure to PG alone and led to systemic absorption of nicotine. PMID:28651446

Thymol nanoemulsified by whey protein-maltodextrin conjugates: the enhanced emulsifying capacity and antilisterial properties in milk by propylene glycol.

PubMed

Xue, Jia; Davidson, P Michael; Zhong, Qixin

2013-12-26

The objective of this research was to enhance the capability of whey protein isolate-maltodextrin conjugates in nanoemulsifying thymol using propylene glycol to improve antilisterial properties in milk. Thymol was predissolved in PG and emulsified in 7% conjugate solution. Transparent dispersions with mean diameters of <30 nm were observed up to 1.5%w/v thymol. In skim and 2% reduced fat milk, Listeria monocytogenes Scott A was reduced from ∼5 log CFU/mL to below the detection limit in 6 h by 0.1% w/v and 0.45% w/v nanoemulsified thymol, respectively, contrasting with gradual reductions to 1.15 and 2.26 log CFU/mL after 48 h by same levels of free thymol. In full fat milk, L. monocytogenes was gradually reduced to be undetectable after 48 h by 0.6% w/v nanoemulsified thymol, contrasting with the insignificant reduction by free thymol. The improved antilisterial activities of nanoemulsified thymol resulted from the increased solubility in milk and synergistic activity with propylene glycol.

Assessment of toxicity and tolerability of a combination vehicle; 5% Pharmasolve, 45% Propylene glycol and 50% Polyethylene glycol 400 in rats following repeated intravenous administration.

PubMed

Pandey, Santosh Kumar; Goyal, Vinod Kumar; Nalge, Prashant; Are, Purnachander; Vincent, Sthevaan; Nirogi, Ramakrishna

2017-12-01

The selection of a suitable vehicle for administration of NCEs in non-clinical studies is always a challenge for poorly soluble compounds. Challenge is increased if the dose formulation is intended for intravenous (i.v.) administration where isotonic, biologically compatible pH and solution form is an absolute requirement. Vehicle toxicity and tolerability data are not readily available for a number of combination vehicles therefore, an i.v. tolerability studies was planned in rats with 5% v/v Pharmasolve (NMP), 45% v/v Propylene glycol (PG) and 50% v/v Polyethylene glycol (PEG) 400 combination, at dose volume of 0.5, 1, 2 and 5 mL/kg body weight for 28 days. The vehicle combination was administered via lateral tail vein and effects on clinical signs, body weights, feed consumption, clinical pathology and histopathology were evaluated. Clinical signs of toxicity like tremors, convulsions and death were noticed at 5 mL/kg during the course of the study. At 2 mL/kg, injection site injury without systemic toxicity was noticed. In conclusion, 1 mL/kg of a combination vehicle of 5% NMP, 45% PG and 55% PEG 400 can be administered intravenously once-a-day up to 28 days without any discomfort or injury to rats. Copyright © 2017 Elsevier Inc. All rights reserved.

Dietary propylene glycol and in vitro embryo production after ovum pick-up in heifers with different anti-Müllerian hormone profiles.

PubMed

Gamarra, G; Ponsart, C; Lacaze, S; Le Guienne, B; Humblot, P; Deloche, M-C; Monniaux, D; Ponter, A A

2015-11-01

Rapid genetic improvement in cattle requires the production of high numbers of embryos of excellent quality. Increasing circulating insulin and/or glucose concentrations improves ovarian follicular growth, which may improve the response to superovulation. The measurement of anti-Müllerian hormone (AMH) can help predict an animal's response to superovulation treatment. The aim of the present study was to investigate whether increasing circulating insulin concentrations, through propylene glycol (PG) drenches, could improve in vitro embryo production in oestrus-synchronised superovulated heifers with different AMH profiles. Holstein heifers were grouped according to pre-experimental AMH concentrations as low (L) or high (H). The PG drench increased circulating insulin and glucose concentrations and reduced β-hydroxybutyrate and urea concentrations compared with the control group. AMH was a good predictor of follicle and oocyte numbers at ovum pick-up (OPU), and of oocyte and embryo quality (AMH H>AMH L). PG in the AMH H group increased the number of follicles and blastocyst quality above that in the control group, but did not improve these parameters in the AMH L group. These results indicate that short-term oral PG supplementation modifies an animal's metabolic milieu and is effective in improving in vitro embryo production, after superovulation-OPU, more markedly in heifers with high rather than low AMH concentrations.

Mucoadhesive Fenretinide Patches for Site-specific Chemoprevention of Oral Cancer: Enhancement of Oral Mucosal Permeation of Fenretinide by Co-incorporation of Propylene Glycol and Menthol

PubMed Central

Wu, Xiao; Desai, Kashappa-Goud H.; Mallery, Susan R.; Holpuch, Andrew S.; Phelps, Maynard P.; Schwendeman, Steven P.

2012-01-01

The objective of this study was to enhance oral mucosal permeation of fenretinide by co-incorporation of propylene glycol (PG) and menthol in fenretinide/Eudragit® RL PO mucoadhesive patches. Fenretinide is an extremely hydrophobic chemopreventive compound with poor tissue permeability. Co-incorporation of 5-10 wt% PG (mean Js = 16-23 μg cm−2 h−1; 158-171 μg fenretinide/g tissue) or 1-10 wt% PG + 5 wt% menthol (mean Js = 18-40 μg cm−2 h−1; 172-241 μg fenretinide/g tissue) in fenretinide/Eudragit® RL PO patches led to significant ex vivo fenretinide permeation enhancement (p < 0.001). Addition of PG above 2.5 wt% in the patch resulted in significant cellular swelling in the buccal mucosal tissues. These alterations were ameliorated by combining both enhancers and reducing PG level. After buccal administration of patches in rabbits, in vivo permeation of fenretinide across the oral mucosa was greater (~43 μg fenretinide/g tissue) from patches that contained optimized permeation enhancer content (2.5 wt% PG + 5 wt% menthol) relative to permeation obtained from enhancer-free patch (~ 17 μg fenretinide/g tissue) (p < 0.001). In vitro and in vivo release of fenretinide from patch was not significantly increased by co-incorporation of permeation enhancers, indicating that mass transfer across the tissue, and not the patch, largely determined the permeation rate control in vivo. As a result of its improved permeation and its lack of deleterious local effects, the mucoadhesive fenretinide patch co-incorporated with 2.5 wt% PG + 5 wt% menthol represents an important step in the further preclinical evaluation of oral site-specific chemoprevention strategies with fenretinide. PMID:22280430

Vertical and horizontal distributions of microbial abundances and enzymatic activities in propylene-glycol-affected soils.

PubMed

Biró, Borbála; Toscano, Giuseppe; Horváth, Nikoletta; Matics, Heléna; Domonkos, Mónika; Scotti, Riccardo; Rao, Maria A; Wejden, Bente; French, Helen K

2014-01-01

The natural microbial activity in the unsaturated soil is vital for protecting groundwater in areas where high loads of biodegradable contaminants are supplied to the surface, which usually is the case for airports using aircraft de-icing fluids (ADF) in the cold season. Horizontal and vertical distributions of microbial abundance were assessed along the western runway of Oslo Airport (Gardermoen, Norway) to monitor the effect of ADF dispersion with special reference to the component with the highest chemical oxygen demand (COD), propylene glycol (PG). Microbial abundance was evaluated by several biondicators: colony-forming units (CFU) of some physiological groups (aerobic and anaerobic heterotrophs and microscopic fungi), most probable numbers (MPN) of PG degraders, selected catabolic enzymatic activities (fluorescein diacetate (FDA) hydrolase, dehydrogenase, and β-glucosidase). High correlations were found between the enzymatic activities and microbial counts in vertical soil profiles. All microbial abundance indicators showed a steep drop in the first meter of soil depth. The vertical distribution of microbial abundance can be correlated by a decreasing exponential function of depth. The horizontal trend of microbial abundance (evaluated as total aerobic CFU, MPN of PG-degraders, and FDA hydrolase activity) assessed in the surface soil at an increasing distance from the runway is correlated negatively with the PG and COD loads, suggesting the relevance of other chemicals in the modulation of microbial growth. The possible role of potassium formate, component of runway de-icers, has been tested in the laboratory by using mixed cultures of Pseudomonas spp., obtained by enrichment with a selective PG medium from soil samples taken at the most contaminated area near the runway. The inhibitory effect of formate on the growth of PG degraders is proven by the reduction of biomass yield on PG in the presence of formate.

Comparison of the Efficacy of Carboxymethylcellulose 0.5%, Hydroxypropyl-guar Containing Polyethylene Glycol 400/Propylene Glycol, and Hydroxypropyl Methyl Cellulose 0.3% Tear Substitutes in Improving Ocular Surface Disease Index in Cases of Dry Eye.

PubMed

Maharana, Prafulla K; Raghuwanshi, Sapna; Chauhan, Ashish K; Rai, Vaishali G; Pattebahadur, Rajesh

2017-01-01

To compare the efficacy of carboxymethylcellulose 0.5% (CMC), hydroxypropyl-guar containing polyethylene glycol 400/propylene glycol (PEG/PG), and hydroxypropyl methylcellulose 0.3% (HPMC) as tear substitutes in patients with dry eye. A retrospective evaluation of cases presenting with symptoms of dry eye from July 2014 to June 2015 was done. Patients with Ocular Surface Disease Index (OSDI) scoring >12 were included in the study. Parameters such as age, gender, Schirmer test (ST), and tear film breakup time (TBUT) were recorded on day 0, week 1, and week 4. For analysis, cases were divided into three groups; Group 1 - CMC, Group 2 - PEG/PG, and Group 3 - HPMC. Overall, 120 patients were included in the study. Demographic data and baseline characteristics were comparable among the groups. Group 2 had significant improvement in percentage change in OSDI (weeks 0-1, 0-4, and 1-4, P = 0.00), TBUT (weeks 0-1, P = 0.01; 0-4, P = 0.006; and 1-4, P = 0.007), and in ST (weeks 0-1, P = 0.02; 0-4, P = 0.002; and 1-4, P = 0.008) compared to Group 1 at all follow-ups. Group 3 had improvements similar to Group 2, but it was not at all follow-ups (improvement in percentage change OSDI [weeks 0-1, 0-4, and 1-4, P = 0.00], TBUT [weeks 0-1, P = 0.10; 0-4, P = 0.03; and 1-4, P = 0.04], and in ST [weeks 0-1, P = 0.007; 0-4, P = 0.03; and 1-4, P = 0.12]). No significant difference was found between Groups 2 and 3. Hydroxypropyl-guar containing PEG/PG and HPMC as tear substitutes are better than CMC. While HPMC was comparable to PEG/PG in subjective improvement, the objective improvement was not consistent.

21 CFR 172.858 - Propylene glycol alginate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Propylene glycol alginate. 172.858 Section 172.858... Propylene glycol alginate. The food additive propylene glycol alginate (CAS Reg. No. 9005-37-2) may be used... the act: (1) The name of the additive, “propylene glycol alginate” or “propylene glycol ester of...

21 CFR 172.858 - Propylene glycol alginate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Propylene glycol alginate. 172.858 Section 172.858... CONSUMPTION Multipurpose Additives § 172.858 Propylene glycol alginate. The food additive propylene glycol... information required by the act: (1) The name of the additive, “propylene glycol alginate” or “propylene...

21 CFR 172.858 - Propylene glycol alginate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Propylene glycol alginate. 172.858 Section 172.858... CONSUMPTION Multipurpose Additives § 172.858 Propylene glycol alginate. The food additive propylene glycol... information required by the act: (1) The name of the additive, “propylene glycol alginate” or “propylene...

Propylene glycol accumulation in critically ill patients receiving continuous intravenous lorazepam infusions.

PubMed

Horinek, Erica L; Kiser, Tyree H; Fish, Douglas N; MacLaren, Robert

2009-12-01

Lorazepam is recommended by the Society of Critical Care Medicine as the preferred agent for sedation of critically ill patients. Intravenous lorazepam contains propylene glycol, which has been associated with toxicity when high doses of lorazepam are administered. To evaluate the accumulation of propylene glycol in critically ill patients receiving lorazepam by continuous infusion and determine factors associated with propylene glycol concentration. A 6-month, retrospective, safety assessment was conducted of adults admitted to the medical intensive care unit who were receiving lorazepam by continuous infusion for 12 hours or more. Propylene glycol serum concentrations were obtained 24-48 hours after continuous-infusion lorazepam was initiated and every 3-5 days thereafter. Propylene glycol accumulation was defined as concentrations of 25 mg/dL or more. Groups with and without propylene glycol accumulation were compared and factors associated with propylene glycol concentration were determined using multivariate correlation regression analyses. Forty-eight propylene glycol serum samples were obtained from 33 patients. Fourteen (42%) patients had propylene glycol accumulation, representing 23 (48%) serum samples. Univariate analyses showed the following factors were related to propylene glycol accumulation: baseline renal dysfunction, presence of alcohol withdrawal, sex, age, Acute Physiology and Chronic Health Evaluation (APACHE II) score, rate of lorazepam continuous infusion, and 24-hour lorazepam dose. Multivariate linear regression modeling demonstrated that propylene glycol concentration was strongly associated with the continuous infusion rate and 24-hour dose (adjusted r(2) > or = 0.77; p < 0.001). Independent correlation analyses showed that these 2 variables were so strongly associated with propylene glycol concentration (r(2) > or = 0.71; p < 0.001) that they alone predicted propylene glycol concentration. Seven (21%) patients developed renal dysfunction after continuous-infusion lorazepam was initiated, but associated causes were indeterminable. Other possible propylene glycol-associated adverse effects were not observed. The continuous infusion rate and cumulative 24-hour lorazepam dose are strongly associated with and independently predict propylene glycol concentrations. Despite the absence of confirmed propylene glycol-associated adverse effects, clinicians should be aware that propylene glycol accumulation may occur with continuous-infusion lorazepam.

Effect of postpartum propylene glycol allocation to over-conditioned Holstein cows on concentrations of milk metabolites.

PubMed

Bjerre-Harpøth, Vibeke; Storm, Adam C; Vestergaard, Mogens; Larsen, Mogens; Larsen, Torben

2016-05-01

The objective of the study was to investigate the effect of propylene glycol (PG) allocation on concentrations of milk metabolites with potential use as indicators of glucogenic status in high yielding postpartum dairy cows. At time of calving, nine ruminally cannulated Holstein cows were randomly assigned to ruminal dosing of 500 g/d tap water (CON, n = 4) or 500 g/d PG (PPG, n = 5). The PG was given with the morning feeding week 1-4 postpartum (treatment period) and cows were further followed during week 5-8 postpartum (follow-up period). All cows were fed the same postpartum diet. Milk samples were obtained at each milking (3 times/d) in the treatment period, and at morning milking during the follow-up period. Weekly blood samples were obtained from -4 to +8 weeks relative to calving and daily blood samples from -7 until +7 d relative to calving. The main effect of PG allocation was an increased glucogenic status, e.g. visualised by a prompt marked increase in blood fructosamine. During the treatment period, milk concentration of free glucose tended to be greater, whereas milk concentrations of isocitrate and BHBA were lower for PPG compared with CON. It is proposed that the ratio between free glucose and isocitrate in milk may be a potential biomarker for glucogenic status in the vulnerable early postpartum period. We will pursue this issue in the future.

Physical and Chemical Properties and Subcutaneous Implantation of Mineral Trioxide Aggregate Mixed with Propylene Glycol.

PubMed

Marciano, Marina Angélica; Guimarães, Bruno Martini; Amoroso-Silva, Pablo; Camilleri, Josette; Hungaro Duarte, Marco Antonio

2016-03-01

The aim of this study was to evaluate the physical, chemical, and biological properties of mineral trioxide aggregate (MTA) mixed with 80% distilled water and 20% propylene glycol (PG) compared with MTA mixed with distilled water only. Flowability, film thickness, and solubility were analyzed according to American National Standards Institute/American Dental Association specification 57/2000. Initial and final setting times were assessed according to American Society for Testing and Materials specification C266/08. Porosity was assessed by using mercury intrusion porosimetry after 1 and 28 days of hydration, and the pH and calcium ion release were assessed after 3, 24, 72, and 168 hours. For the tissue reaction, the cements were implanted in 24 albino rats (2 groups, n = 12). An analysis of the inflammatory infiltrate was performed after 15, 30, and 60 days. MTA + PG exhibited lower film thickness and higher final setting time. No differences were verified for flowability (P > .05). MTA + PG showed high porosity at 1 day of hydration (P < .05). All the test cements demonstrated an alkaline pH. Microscopic analysis of the specimens revealed neoformation of connective tissue in contact with the cements. The introduction of PG as a mixing vehicle alters the physical and chemical properties of MTA and is biologically acceptable. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Acute and chronic in vivo effects of exposure to nicotine and propylene glycol from an E-cigarette on mucociliary clearance in a murine model.

PubMed

Laube, Beth L; Afshar-Mohajer, Nima; Koehler, Kirsten; Chen, Gang; Lazarus, Philip; Collaco, Joseph M; McGrath-Morrow, Sharon A

2017-04-01

To determine the effect of an acute (1 week) and chronic (3 weeks) exposure to E-cigarette (E-cig) emissions on mucociliary clearance (MCC) in murine lungs. C57BL/6 male mice (age 10.5 ± 2.4 weeks) were exposed for 20 min/day to E-cigarette aerosol generated by a Joyetech 510-T ® E-cig containing either 0% nicotine (N)/propylene glycol (PG) for 1 week (n = 6), or 3 weeks (n = 9), or 2.4% N/PG for one week (n = 6), or 3 weeks (n = 9), followed by measurement of MCC. Control mice (n = 15) were not exposed to PG alone, or N/PG. MCC was assessed by gamma camera following aspiration of 99m technetium aerosol and was expressed as the amount of radioactivity removed from both lungs over 6 hours (MCC6hrs). Venous blood was assayed for cotinine levels in control mice and in mice exposed for 3-weeks to PG alone and N/PG. MCC6hrs in control mice and in mice acutely exposed to PG alone and N/PG was similar, averaging (±1 standard deviation) 8.6 ± 5.2%, 7.5 ± 2.8% and 11.2 ± 5.9%, respectively. In contrast, chronic exposure to PG alone stimulated MCC6hrs (17.2 ± 8.0)% and this stimulation was significantly blunted following chronic exposure to N/PG (8.7 ± 4.6)% (p < .05). Serum cotinine levels were <0.5 ng/ml in control mice and in mice exposed to PG alone, whereas, N/PG exposed mice averaged 14.6 ± 12.0 ng/ml. In this murine model, a chronic, daily, 20 min-exposure to N/PG, but not an acute exposure, slowed MCC, compared to exposure to PG alone and led to systemic absorption of nicotine.

Enhanced withdrawal of polychlorinated biphenyls: A comparison of colestipol, mineral oil, propylene glycol, and petroleum jelly with or without restricted feeding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polin, D.; Underwood, M.; Lehning, E.

Meat type chickens were fed a commercial mixture of polychlorinated biphenyl (PCB), Aroclor 1254, at 10 ppm for 14 days, then treated for 21 days to hasten the withdrawal of PCB with either mineral oil (MO), petroleum jelly (PJ), propylene glycol (PG), or colestipol (CO) at 5% of the diet, or at 10% of the diet when restricted to 50% of control intake (50% FR). Whole carcass analyses for PCB revealed that MO + 50% FR reduced PCB to 1.91 mg/bird, or 32% of the body burden (5.96 mg) in nontreated chickens previously fed PCB, whereas those restricted in feedmore » intake by 50% (50% FR) had almost no change (6.44 mg/bird) in body burdens. The PJ, PG, and CO in combination with 50% FR reduced body burdens of PCB to 47, 57, and 77%, respectively, of the control value. When treated with MO, PJ, PG, or CO alone (no 50% FR), chickens had body burdens reduced to only 67 to 90% of control, depending on th compound. Thus, feed restriction was necessary for the MO and PJ to have their greatest effect. Carcass lipid values and body weight gains were markedly reduced by the feed restriction. The CO reduced carcass lipid in nonrestricted chickens by 30%.« less

Poloxamer 188 and propylene glycol-based rectal suppository enhances anticancer effect of 5-fluorouracil in mice.

PubMed

Paek, Seung-Hwan; Xuan, Jing-Ji; Choi, Han-Gon; Park, Byung Chul; Lee, Yoon-Seok; Jeong, Tae-Cheon; Jin, Chun Hua; Oh, Yu-Kyoung; Kim, Jung-Ae

2006-05-01

The tumoricidal and apoptosis-inducing activities of 5-fluorouracil (5-FU) have been demonstrated in experimental and clinical investigations. Clinically, the 5-FU suppository form has been widely adopted for its advantages of less systemic toxicity, higher local tissue concentrations, and reduced first-pass effect. In this study, we investigated the feasibility of rectal administration of 5-FU suppository based on poloxamer 188 (P188) and propylene glycol (PG) and its anticancer effect on the murine experimental cancer models. The rectal suppository was made with 70% P188 and 30% PG, which was a solid phase at room temperature and instantly melted at physiological temperature. The treatment with the 5-FU suppository was more effective than the oral route in decreasing the volume of rectal cancer in mice. In addition, the survival rate of the mice with rectal cancer was higher in the group treated with the 5-FU suppository than in the group treated with 5-FU orally. Furthermore, in mice skin cancers induced by inoculation of murine CT-26 colon carcinoma cells, the anticancer effect of 5-FU was significantly enhanced by the rectal administration of the suppository than by oral treatment. Taken together, the results suggest that a poloxamer gel system with 5-FU/P188/PG is an effective rectal dosage form for the treatment of both rectal and non-rectal cancers.

40 CFR 180.1250 - C8, C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... of glycerol and propylene glycol; exemption from the requirement of a tolerance. 180.1250 Section 180..., C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the requirement of... monocaprylate, glycerol monocaprate, and glycerol monolaurate) and propylene glycol (propylene glycol...

40 CFR 180.1250 - C8, C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... of glycerol and propylene glycol; exemption from the requirement of a tolerance. 180.1250 Section 180..., C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the requirement of... monocaprylate, glycerol monocaprate, and glycerol monolaurate) and propylene glycol (propylene glycol...

40 CFR 180.1250 - C8, C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... of glycerol and propylene glycol; exemption from the requirement of a tolerance. 180.1250 Section 180..., C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the requirement of... monocaprylate, glycerol monocaprate, and glycerol monolaurate) and propylene glycol (propylene glycol...

21 CFR 500.50 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in... determined that this use of propylene glycol is not prior sanctioned. [61 FR 19544, May 2, 1996] ...

21 CFR 500.50 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in... determined that this use of propylene glycol is not prior sanctioned. [61 FR 19544, May 2, 1996] ...

21 CFR 500.50 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in... determined that this use of propylene glycol is not prior sanctioned. [61 FR 19544, May 2, 1996] ...

Efficacy of a fixed combination of 0.09 % xanthan gum/0.1 % chondroitin sulfate preservative free vs polyethylene glycol/propylene glycol in subjects with dry eye disease: a multicenter randomized controlled trial.

PubMed

Pérez-Balbuena, Ana L; Ochoa-Tabares, Juan C; Belalcazar-Rey, Sandra; Urzúa-Salinas, Cristian; Saucedo-Rodríguez, Laura R; Velasco-Ramos, Regina; Suárez-Sánchez, Raúl G; Rodríguez-Carrizalez, Adolfo D; Oregón-Miranda, Aldo A

2016-09-20

Dry eye disease (DED) is multifactorial, affecting 5-34 % of the global adult population and reducing quality of life. The artificial tears or lubricants are the therapy most used for the treatment of DED, due to their low side effect profile, which attempt to modify the properties of the tear film. The aim of the present study was to evaluate the clinical efficacy of a fixed combination of xanthan gum and chondroitin sulfate preservative free on the ocular surface of patients with dry eye disease during 60 days of intervention. A phase III, double-blind, masked, controlled, multicenter, clinical trial of 148 subjects, randomized to either a fixed combination of xanthan gum 0.09 % and chondroitin sulfate 0.1 % (XG/CS) ophthalmic solution (n = 76) or a fixed combination of polyethylene glycol 400 0.4 % and propylene glycol 0.3 % (PEG/PG) (n = 72). Subjects self-dosed four times daily during 60 days. Follow-up was set on days 2, 7, 15, 30 and 60. Assessments of anterior/posterior segment ocular signs were performed. The outcome measures included Schirmer test, tear film break-up time and OSDI score. Security variables included intraocular pressure, lisamine green and fluorescein ocular surface stains. The primary efficacy endpoints were similar between groups at baseline. After intervention time Schirmer test increased in both groups compared to baseline, XG/CS (6.4 ± 2.2 vs 11.0 ± 6.6; p = 0.002) and PEG/PG (6.5 ± 2.5 vs 10.5 ± 5.6; p = 0.019) respectively. Similar results were reported in the tear film break-up time in XG/CS (5.5 ± 2.1 vs 7.4 ± 2.9; p = 0.027) and PEG/PG (5.2 ± 2.0 vs 7.4 ± 2.7; p = 0.046) respectively. The OSDI score decreased to normal values in both groups, XG/CS (19.3 ± 7.4 vs 7.3 ± 5.9; p = 0.001) and PEG/PG (19.3 ± 7.5 vs 7.9 ± 8.2; p = 0.001) respectively. There was no significant difference between treatments for any parameter. Moreover, both groups decreased the presence of burning sensation, tearing, foreign body sensation, conjunctival hyperemia and photophobia. The adverse events were not related to the interventions. Xanthan gum/chondroitin sulfate preservative free showed similar clinical efficacy, evaluated with OSDI score, TBUT and Schirmer test compared to polyethylene glycol/propylene glycol in the treatment of dry eye disease. ClinicalTrials.gov: NCT01657253 . Date of registration May 19, 2014.

Aphids preserved in propylene glycol can be used for reverse transcription-polymerase chain reaction detection of Potato virus Y.

PubMed

Nie, Xianzhou; Pelletier, Yvan; Mason, Nicola; Dilworth, Andrea; Giguère, Marie-Andrée

2011-08-01

The effectiveness of propylene glycol on the retention of RNA target of Potato virus Y (PVY), an aphid stylet-borne virus, in Myzus persicae was investigated in comparison to ethanol and liquid nitrogen/-80°C. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the PVY targets from the propylene glycol/ethanol/liquid nitrogen preserved single aphids after a 5min acquisition period from infected potato plants. In the liquid nitrogen/-80°C and 70% ethanol treatments, 55.6% and 38.8% aphids tested PVY-positive, respectively. In the 0-75% propylene glycol treatments, 12.2-44.7% aphids tested PVY-positive. The lowest detection rate was in the 0% (positive rate, 15.2%) and the 10% propylene glycol (positive rate, 12.2%). As the propylene glycol concentration increased to 25%, 29.8% aphids tested positive. A high PVY-positive rate was also found in 35-75% propylene glycol treatments at 44.7% (35% propylene glycol), 36.7% (50% propylene glycol) and 34.8% (75% propylene glycol), which is comparable to the rate shown in 70% ethanol. No significant difference in the positive detection rate was observed in aphids preserved in 50% propylene glycol at room temperature for 2, 4 and 10 days. These results demonstrate that propylene glycol at 25-75% can retain PVY targets effectively in aphids for an extended time period, and thus can be used in aphid traps to preserve viruliferous aphids for later RT-PCR detection of PVY. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Polyethylene glycol as marker for nitrofurazone allergy: 20 years of experience from Turkey.

PubMed

Özkaya, Esen; Kılıç, Sıla

2018-03-01

Polyethylene glycols (PEGs) and propylene glycol (PG) are used as vehicles in various medicinal and cosmetic products. They are potential contact sensitizers, including low molecular weight PEGs in nitrofurazone preparations that are still widely used in Turkey. To investigate the prevalence of allergic contact dermatitis caused by PEG and PG in a relatively large group of patients in Turkey. In this retrospective, cross-sectional, single-centre study, 836 patients patch tested with PEG and PG between 1996 and 2015 were reviewed. Thirty-five patients (4.2%) showed positive patch test reactions to PEG, and 7 (0.8%) showed positive patch test reactions to PG, partly as late positive reactions with PEG. PEG sensitivity was almost exclusively related to nitrofurazone allergy. Patch test reactions to PG were currently relevant mainly with regard to the use of minoxidil, and antiherpetic or corticosteroid creams. Ten patients (25%) had concomitant contact allergies to various topical drugs containing mainly PEGs. PEG sensitivity seems to be a marker for contact allergy to topical nitrofurazone in Turkey. Nitrofurazone allergy appears to favour concomitant sensitization to PEG. We would suggest the inclusion of PEG in an extended baseline patch test series in Turkey. Late patch test readings are important to diagnose delayed positive reactions to PEG. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Haemoglobinuria caused by propylene glycol in sheep

PubMed Central

Potter, B. J.

1958-01-01

Haemoglobinuria occurred in sheep anaesthetized by an intravenous injection of pentobarbitone sodium containing propylene glycol: an equivalent dose failed to cause haemoglobinuria in rabbits. Intravenous injection of an aqueous solution of 20% propylene glycol caused haemoglobinaemia and haemoglobinuria in sheep. Neither distilled water nor 20% glycerol in water administered under identical conditions produced these effects. Haemoglobinuria occurred on some occasions when an aqueous 20% solution of propylene glycol was administered to sheep after an injection of saline: it never occurred when a solution of 20% propylene glycol prepared with physiological saline was injected. It is suggested that saline may protect against the haemolytic action of propylene glycol in sheep and that propylene glycol should be avoided as a menstruum for pharmaceutical preparations to be used for injection into the blood stream of these animals. PMID:13618540

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torlakoglu, A.; Gueclue, G.

Waste polyethylene terephthalate (PET) flakes were depolymerized by using propylene glycol (PG) in the presence of zinc acetate as catalyst. Glycolysis reaction products of waste PET obtained by using PET/glycol molar ratio 1/2. Two short oil alkyd resins of high acid values (30-40 mgKOH/g) were prepared from phthalic anhydride (PA), glycerin (G), coconut oil fatty acids (COFA) and glycolyzed products of waste PET (PET-based alkyd resins) or glycols (PG) (reference alkyd resins). These alkyd resins were blended with 30%, 40%, and 50% of a commercial urea-formaldehyde, melamine-formaldehyde and urea-formaldehyde/melamine-formaldehyde mixture (1/1 weight ratio) and heated at 140 deg. C. Themore » physical and chemical properties such as drying time, hardness, abrasion resistance, adhesion strength, water resistance, alkaline resistance, acid resistance, gelation time, and thermal oxidative degradation resistance (with thermogravimetric analysis, TGA) of these alkyd-amino resins were investigated. The properties of the waste PET-based resins were found to be compatible with the properties of the reference resins.« less

Use of a Rapid Ethylene Glycol Assay: a 4-Year Retrospective Study at an Academic Medical Center.

PubMed

Rooney, Sydney L; Ehlers, Alexandra; Morris, Cory; Drees, Denny; Davis, Scott R; Kulhavy, Jeff; Krasowski, Matthew D

2016-06-01

Ethylene glycol (EG) is a common cause of toxic ingestions. Gas chromatography (GC)-based laboratory assays are the gold standard for diagnosing EG intoxication. However, GC requires specialized instrumentation and technical expertise that limits feasibility for many clinical laboratories. The objective of this retrospective study was to determine the utility of incorporating a rapid EG assay for management of cases with suspected EG poisoning. The University of Iowa Hospitals and Clinics core clinical laboratory adapted a veterinary EG assay (Catachem, Inc.) for the Roche Diagnostics cobas 8000 c502 analyzer and incorporated this assay in an osmolal gap-based algorithm for potential toxic alcohol/glycol ingestions. The main limitation is that high concentrations of propylene glycol (PG), while readily identifiable by reaction rate kinetics, can interfere with EG measurement. The clinical laboratory had the ability to perform GC for EG and PG, if needed. A total of 222 rapid EG and 24 EG/PG GC analyses were documented in 106 patient encounters. Of ten confirmed EG ingestions, eight cases were managed entirely with the rapid EG assay. PG interference was evident in 25 samples, leading to 8 GC analyses to rule out the presence of EG. Chart review of cases with negative rapid EG assay results showed no evidence of false negatives. The results of this study highlight the use of incorporating a rapid EG assay for the diagnosis and management of suspected EG toxicity by decreasing the reliance on GC. Future improvements would involve rapid EG assays that completely avoid interference by PG.

21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Succistearin (stearoyl propylene glycol hydrogen... Other Specific Usage Additives § 172.765 Succistearin (stearoyl propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol hydrogen succinate) may be safely used in...

21 CFR 582.4666 - Propylene glycol.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol. 582.4666 Section 582.4666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance is generally...

21 CFR 582.4666 - Propylene glycol.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Propylene glycol. 582.4666 Section 582.4666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance is generally...

21 CFR 582.4666 - Propylene glycol.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Propylene glycol. 582.4666 Section 582.4666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance is generally...

21 CFR 582.4666 - Propylene glycol.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Propylene glycol. 582.4666 Section 582.4666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance is generally...

21 CFR 582.4666 - Propylene glycol.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol. 582.4666 Section 582.4666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance is generally...

Processes and systems for the production of propylene glycol from glycerol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frye, John G; Oberg, Aaron A; Zacher, Alan H

2015-01-20

Processes and systems for converting glycerol to propylene glycol are disclosed. The glycerol feed is diluted with propylene glycol as the primary solvent, rather than water which is typically used. The diluted glycerol feed is sent to a reactor where the glycerol is converted to propylene glycol (as well as other byproducts) in the presence of a catalyst. The propylene glycol-containing product from the reactor is recycled as a solvent for the glycerol feed.

A rapid analysis of plasma/serum ethylene and propylene glycol by headspace gas chromatography.

PubMed

Ehlers, Alexandra; Morris, Cory; Krasowski, Matthew D

2013-12-01

A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using 1,3-propanediol as the internal standard. The method employed a single-step derivitization using phenylboronic acid, was linear to 200 mg/dL and had a lower limit of quantitation of 1 mg/dL suitable for clinical analyses. The analytical method described allows for laboratories with HS-GC instrumentation to analyze ethanol, methanol, isopropanol, ethylene glycol, and propylene glycol on a single instrument with rapid switch-over from alcohols to glycols analysis. In addition to the novel HS-GC method, a retrospective analysis of patient specimens containing ethylene glycol and propylene glycol was also described. A total of 36 patients ingested ethylene glycol, including 3 patients who presented with two separate admissions for ethylene glycol toxicity. Laboratory studies on presentation to hospital for these patients showed both osmolal and anion gap in 13 patients, osmolal but not anion gap in 13 patients, anion but not osmolal gap in 8 patients, and 1 patient with neither an osmolal nor anion gap. Acidosis on arterial blood gas was present in 13 cases. Only one fatality was seen; this was a patient with initial serum ethylene glycol concentration of 1282 mg/dL who died on third day of hospitalization. Propylene glycol was common in patients being managed for toxic ingestions, and was often attributed to iatrogenic administration of propylene glycol-containing medications such as activated charcoal and intravenous lorazepam. In six patients, propylene glycol contributed to an abnormally high osmolal gap. The common presence of propylene glycol in hospitalized patients emphasizes the importance of being able to identify both ethylene glycol and propylene glycol by chromatographic methods.

21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Succistearin (stearoyl propylene glycol hydrogen succinate). 172.765 Section 172.765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol hydrogen...

21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Succistearin (stearoyl propylene glycol hydrogen succinate). 172.765 Section 172.765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol hydrogen...

21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Succistearin (stearoyl propylene glycol hydrogen succinate). 172.765 Section 172.765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol hydrogen...

21 CFR 582.1666 - Propylene glycol.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1666 Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance...

21 CFR 582.1666 - Propylene glycol.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1666 Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance...

21 CFR 582.1666 - Propylene glycol.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1666 Propylene glycol. (a) Product. Propylene glycol. (b) Conditions of use. This substance...

Propylene glycol intoxication in a dog.

PubMed

Claus, Melissa A; Jandrey, Karl E; Poppenga, Robert H

2011-12-01

To describe the clinical course, treatment, and outcome of a dog with propylene glycol intoxication. An adult castrated male Australian cattle dog presented to an emergency clinic for an acute onset of ataxia and disorientation after roaming a construction site unsupervised. He tested positive for ethylene glycol using a point-of-care test kit. Treatment for ethylene glycol intoxication included intermittent intravenous boluses of 20% ethanol and hemodialysis. Predialysis and postdialysis blood samples were submitted to the toxicology lab to assess for both ethylene and propylene glycol. The patient tested negative for ethylene glycol and positive for propylene glycol at 1100 mg/dL predialysis and 23 mg/dL postdialysis. The dog made a full recovery. To the authors' knowledge, this is the first report of documented propylene glycol intoxication in a dog, as well as the first report to describe hemodialysis as treatment for propylene glycol intoxication in a dog. © Veterinary Emergency and Critical Care Society 2011.

Propylene Glycol Poisoning From Excess Whiskey Ingestion: A Case of High Osmolal Gap Metabolic Acidosis.

PubMed

Cunningham, Courtney A; Ku, Kevin; Sue, Gloria R

2015-01-01

In this report, we describe a case of high anion gap metabolic acidosis with a significant osmolal gap attributed to the ingestion of liquor containing propylene glycol. Recently, several reports have characterized severe lactic acidosis occurring in the setting of iatrogenic unintentional overdosing of medications that use propylene glycol as a diluent, including lorazepam and diazepam. To date, no studies have explored potential effects of excess propylene glycol in the setting of alcohol intoxication. Our patient endorsed drinking large volumes of cinnamon flavored whiskey, which was likely Fireball Cinnamon Whisky. To our knowledge, this is the first case of propylene glycol toxicity from an intentional ingestion of liquor containing propylene glycol.

Propylene Glycol Poisoning From Excess Whiskey Ingestion

PubMed Central

Ku, Kevin; Sue, Gloria R.

2015-01-01

In this report, we describe a case of high anion gap metabolic acidosis with a significant osmolal gap attributed to the ingestion of liquor containing propylene glycol. Recently, several reports have characterized severe lactic acidosis occurring in the setting of iatrogenic unintentional overdosing of medications that use propylene glycol as a diluent, including lorazepam and diazepam. To date, no studies have explored potential effects of excess propylene glycol in the setting of alcohol intoxication. Our patient endorsed drinking large volumes of cinnamon flavored whiskey, which was likely Fireball Cinnamon Whisky. To our knowledge, this is the first case of propylene glycol toxicity from an intentional ingestion of liquor containing propylene glycol. PMID:26904700

21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

Code of Federal Regulations, 2014 CFR

2014-04-01

... propylene glycol. 172.850 Section 172.850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and propylene glycol may be safely used in...

21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

Code of Federal Regulations, 2012 CFR

2012-04-01

... propylene glycol. 172.850 Section 172.850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and propylene glycol may be safely used in food in accordance with the following prescribed conditions: (a) The...

21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

Code of Federal Regulations, 2013 CFR

2013-04-01

... propylene glycol. 172.850 Section 172.850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and propylene glycol may be safely used in food in accordance with the following prescribed conditions: (a) The...

Anaerobic treatability of wastewater contaminated with propylene glycol.

PubMed

Sezgin, Naim; Tonuk, Gulseven Ubay

2013-09-01

The purpose of this study was to investigate the biodegradability of propylene glycol in anaerobic conditions by using methanogenic culture. A master reactor was set up to develop a culture that would be acclimated to propylene glycol. After reaching steady-state, culture was transferred to serum bottles. Three reactors with same initial conditions were run for consistency. Propylene glycol was completely biodegradable under anaerobic methanogenic conditions. Semi-continuous reactors operated at a temperature of 35°C had consistently achieved a propylene glycol removal of higher than 95 % based on chemical oxygen demand (COD). It was found that in semi-continuous reactors, anaerobic treatment of propylene glycol at concentrations higher than 1,500 mg COD m(-3) day(-1) was not convenient due to instable effluent COD.

Effects of a single glucocorticoid injection on propylene glycol-treated cows with clinical ketosis.

PubMed

van der Drift, Saskia G A; Houweling, Martin; Bouman, Marina; Koets, Ad P; Tielens, Aloysius G M; Nielen, Mirjam; Jorritsma, Ruurd

2015-05-01

This study investigated the metabolic effects of glucocorticoids when administered to propylene glycol-treated cows with clinical ketosis. Clinical ketosis was defined by depressed feed intake and milk production, and a maximal score for acetoacetate in urine. All cows received 250 mL oral propylene glycol twice daily for 3 days and were randomly assigned to a single intramuscular injection with sterile isotonic saline solution (n = 14) or dexamethasone-21-isonicotinate (n = 17). Metabolic blood variables were monitored for 6 days and adipose tissue variables for 3 days. β-Hydroxybutyrate (BHBA) concentrations in blood decreased in all cows during treatment, but were lower in glucocorticoid-treated cows. Cows treated with glucocorticoids had higher plasma glucose and insulin concentrations, whereas concentrations of non-esterified fatty acids, 3-methylhistidine and growth hormone were unaffected. mRNA expression of hormone-sensitive lipase, BHBA receptor and peroxisome proliferator-activated receptor type γ in adipose tissue was not affected. This shows that lipolytic effects do not appear to be important in ketotic cows when glucocorticoids are combined with PG. Plasma 3-methyl histidine concentrations were similar in both groups, suggesting that glucocorticoids did not increase muscle breakdown and that the greater rise in plasma glucose in glucocorticoid-treated cows may not be due to increased supply of glucogenic amino acids from muscle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Composition and hydrophilicity control of Mn-doped ferrite (MnxFe3-xO4) nanoparticles induced by polyol differentiation.

PubMed

Vamvakidis, Kosmas; Katsikini, Maria; Vourlias, George; Angelakeris, Mavroeidis; Paloura, Eleni C; Dendrinou-Samara, Catherine

2015-03-28

Manganese doped ferrite (MnxFe3-xO4) nanoparticles with x = 0.29-0.77 were prepared under solvothermal conditions in the presence solely of a polyol using the trivalent manganese and iron acetylacetonates as precursors. In this facile approach, a variety of polyols such as polyethylene glycol (PEG 8000), tetraethylene glycol (TEG), propylene glycol (PG) and a mixture of TEG and PG (1 : 1) were utilized in a triple role as a solvent, a reducing agent and a surface-functionalizing agent. The composition of the fine cubic-spinel structures was found to be related to the reductive ability of each polyol, while determination of structural characteristics plus the inversion parameter (i = 0.18-0.38) were provided by X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy at both the Fe and Mn K-edges. The saturation magnetization increased up to 80 emu g(-1) when x = 0.35 and i = 0.22. In addition, the as-prepared nanocrystals coated with PEG, PG and PG&TEG showed excellent colloidal stability in water, while the TEG-coated particles were not water dispersible and converted to hydrophilic when were extra PEGylated. Measurements of the (1)H NMR relaxation in water were carried out and the nanoprobes were evaluated as potential contrast agents.

21 CFR 500.50 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409 of...

21 CFR 589.1001 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Propylene glycol in or on cat food. 589.1001... Listing of Specific Substances Prohibited From Use in Animal Food or Feed § 589.1001 Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat...

21 CFR 589.1001 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Propylene glycol in or on cat food. 589.1001... Listing of Specific Substances Prohibited From Use in Animal Food or Feed § 589.1001 Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat...

21 CFR 589.1001 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Propylene glycol in or on cat food. 589.1001... Listing of Specific Substances Prohibited From Use in Animal Food or Feed § 589.1001 Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat...

21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Propylene glycol mono- and diesters of fats and... CONSUMPTION Multipurpose Additives § 172.856 Propylene glycol mono- and diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the...

21 CFR 500.50 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409 of...

Hydrogenolysis Of 5-Carbon Sugars, Sugar Alcohols And Compositions For Reactions Involving Hydrogen

DOEpatents

Werpy, Todd A.; Frye, Jr., John G.; Zacher, Alan H.; Miller, Dennis J.

2004-01-13

Methods and compositions for reactions of hydrogen over a Re-containing catalyst with compositions containing a 5-carbon sugar, sugar alcohol, or lactic acid are described. It has been surprisingly discovered that reaction with hydrogen over a Re-containing multimetallic catalyst resulted in superior conversion and selectivity to desired products such as propylene glycol. A process for the synthesis of PG from lactate or lactic acid is also described.

A positive chemical ionization GC/MS method for the determination of airborne ethylene glycol and propylene glycols in non-occupational environments.

PubMed

Zhu, Jiping; Feng, Yong-Lai; Aikawa, Bio

2004-11-01

An analytical method for ethylene glycol and propylene glycols has been developed for measuring airborne levels of these chemicals in non-occupational environments such as residences and office buildings. The analytes were collected on charcoal tubes, solvent extracted, and analyzed by gas chromatography-mass spectrometry using a positive chemical ionization technique. The method had a method detection limit of 0.07 microg m(-3) for ethylene glycol and 0.03 microg m(-3) for 1,2- and 1,3-propylene glycols, respectively, based on a 1.44 m3 sampling volume. Indoor air samples of several residential homes and other indoor environments have been analyzed. The median concentrations of ethylene glycol and 1,2-propylene glycol in nine residential indoor air samples were 53 microg m(-3) and 13 microg m(-3) respectively with maximum values of 223 microg m(-3) and 25 microg m(-3) detected for ethylene glycol and 1,2-propylene glycol respectively. The concentrations of these two chemicals in one office and two laboratories were at low microg m(-3) levels. The maximum concentration of 1,3-propylene glycol detected in indoor air was 0.1 microg m(-3).

Status Epilepticus due to Intraperitoneal Injection of Vehicle Containing Propylene Glycol in Sprague Dawley Rats

PubMed Central

Meade, Seth M.; Smith, Cara S.; Chen, Keying; Kleinman, Nanette; Capadona, Jeffrey R.

2017-01-01

Published reports of status epilepticus due to intraperitoneal injection containing propylene glycol in rats are sparse. In fact, there are no reports specifying a maximum safe dose of propylene glycol through intraperitoneal administration. We report here a case of unexpected seizures in Sprague Dawley rats after receiving an intraperitoneal injection containing propylene glycol. Nine-week-old, 225–250 gram male rats were reported to experience tremor progressing to seizures within minutes after given injections of resveratrol (30 mg/kg) dissolved in a 40 : 60 propylene glycol/corn oil vehicle solution by direct intraperitoneal (IP) slow bolus injection or via a preplaced intraperitoneal catheter. The World Health Organization suggests a maximum dose of 25 mg/kg/day of propylene glycol taken orally and no more than 25 mg/dL in blood serum, whereas the animals used in our study got a calculated maximum 0.52 g/kg (25 times lower dose). Blood tests from the seizing rat support a diagnosis of hemolysis and lactic acidosis which may have led to the seizures, all of which appeared to be a consequence of the propylene glycol administration. These findings are consistent with oral and intravenous administration of propylene glycol toxicity as previously reported in other species, including humans. To our knowledge, this report represents the first published case of status epilepticus due to an IP injection containing propylene glycol. PMID:28785508

Status Epilepticus due to Intraperitoneal Injection of Vehicle Containing Propylene Glycol in Sprague Dawley Rats.

PubMed

Ereifej, Evon S; Meade, Seth M; Smith, Cara S; Chen, Keying; Kleinman, Nanette; Capadona, Jeffrey R

2017-01-01

Published reports of status epilepticus due to intraperitoneal injection containing propylene glycol in rats are sparse. In fact, there are no reports specifying a maximum safe dose of propylene glycol through intraperitoneal administration. We report here a case of unexpected seizures in Sprague Dawley rats after receiving an intraperitoneal injection containing propylene glycol. Nine-week-old, 225-250 gram male rats were reported to experience tremor progressing to seizures within minutes after given injections of resveratrol (30 mg/kg) dissolved in a 40 : 60 propylene glycol/corn oil vehicle solution by direct intraperitoneal (IP) slow bolus injection or via a preplaced intraperitoneal catheter. The World Health Organization suggests a maximum dose of 25 mg/kg/day of propylene glycol taken orally and no more than 25 mg/dL in blood serum, whereas the animals used in our study got a calculated maximum 0.52 g/kg (25 times lower dose). Blood tests from the seizing rat support a diagnosis of hemolysis and lactic acidosis which may have led to the seizures, all of which appeared to be a consequence of the propylene glycol administration. These findings are consistent with oral and intravenous administration of propylene glycol toxicity as previously reported in other species, including humans. To our knowledge, this report represents the first published case of status epilepticus due to an IP injection containing propylene glycol.

The Discoloration effect of White Mineral Trioxide Aggregate (WMTA), Calcium Enriched Mixture (CEM), and Portland Cement (PC) on Human Teeth.

PubMed

Salem-Milani, Amin; Ghasemi, Saeede; Rahimi, Saeed; Ardalan-Abdollahi, Amir; Asghari-Jafarabadi, Mohammad

2017-12-01

The aim of this study was to evaluate the discoloration induced by CEM cement, Portland cement (PC) and MTA mixed with propylene glycol (MTA-PG) in comparison to White MTA. Ninety extracted premolar and canine teeth were resected 2 mm below the CEJ. The coronal part of crown was prepared with peeso reamer and Gates-Glidden drills, and the specimens were randomly divided into 4 experimental (n=20) and one control (n=10) groups. The tooth crowns in experimental groups 1 to 4 were filled with White MTA, PC, CEM cement and MTA-PG, respectively; and in group 5, the teeth were kept empty. After incubation, digital photographs of teeth were acquired at 4 time points (before, immediately after placing the materials, 3 and 6 months afterwards). Images were transferred to Adobe Photoshop CS4 and CIE L*a*b color space was used for tooth shade assessment. One-Way ANOVA and One-Sample t-test were used to compare discoloration of teeth between groups. Significant statistical discoloration was only observed in the cervical one third of all groups at each time points (except between 3 and 6 months). Tooth discoloration was greatest in PC and lower in MTA and MTA-PG at the end of 6 months. The tooth discoloration between immediately and 3 months after placing the materials had significant difference only between MTA and PC; and also the tooth discoloration between immediately and 6 months after placing the materials was observed only between PC and MTA, and PC and MTA-PG. All of the experimental biomaterials caused tooth discoloration after 6 months, of those, PC had the most and MTA and MTA-PG had the least discoloration effect. Key words: Mineral trioxide aggregate (MTA). Calcium enriched mixture (CEM). Propylene glycol. Portland cement.

Evaluation in vitro and in vivo of dimethicone transdermal therapeutic systems. Influence of propylene glycol on drug release.

PubMed

Ritschel, W A; Nayak, P M

1987-03-01

Coumarin-containing transdermal drug delivery systems were studied in vitro for drug release and in vivo in rats for drug absorption. The matrix of the transdermal delivery system, dimethicone, was a commercially available silicone elastomer. The devices containing 1, 3 and 5% coumarin released in vitro 8.8 (87.4%), 23.4 (74.5%) and 31.6 mg (63.3%) of drug within 24 h. The device containing 5% coumarin was selected for further studies in which 5, 10, 20, 30, 50 and 70% propylene glycol was added. Up to 20% propylene glycol content did not change the amount released. The preparations with 30, 50 and 70% propylene glycol released 69.3, 73.6 and 87.9%, respectively. The 50 and 70% preparations were physically not acceptable. Only the preparations containing 5% coumarin without propylene glycol and 5% coumarin and 30% propylene glycol in the elastomer were evaluated in vivo. The area under the blood level-time curve of the propylene glycol-containing system was twice that of the device without propylene glycol. Blood levels were maintained between about 2 micrograms/ml and 5 micrograms/ml during the time the device was kept on the skin (24 h).

Laboratory-scale evaluation of a combined soil amendment for the enhanced biodegradation of propylene glycol-based aircraft de-icing fluids.

PubMed

Libisch, Balázs; French, Helen K; Hartnik, Thomas; Anton, Attila; Biró, Borbála

2012-01-01

A combined soil amendment was tested in microcosm experiments with an aim to enhance the aerobic biodegradation of propylene glycol (PG)-based aircraft de-icing fluids during and following the infiltration of contaminated snowmelt. A key objective under field conditions is to increase degradation of organic pollutants in the surface soil where higher microbial activity and plant rhizosphere effects may contribute to a more efficient biodegradation of PG, compared to subsoil ground layers, where electron acceptors and nutrients are often depleted. Microcosm experiments were set up in Petri dishes using 50 g of soil mixed with appropriate additives. The samples contained an initial de-icing fluid concentration of 10,000 mg/kg soil. A combined amendment using calcium peroxide, activated carbon and 1 x Hoagland solution resulted in significantly higher degradation rates for PG both at 4 and 22 degrees C. Most probable numbers of bacteria capable of utilizing 10,000 mg/kg de-icing fluid as a sole carbon source were about two orders of magnitude higher in the amended soil samples compared to unamended controls at both temperatures. The elevated numbers of such bacteria in surface soil may be a source of cells transported to the subsoil by snowmelt infiltration. The near-surface application of amendments tested here may enhance the growth of plants and plant roots in the contaminated area, as well as microbes to be found at greater depth, and hence increase the degradation of a contaminant plume present in the ground.

Influence of nanoparticle concentration on thermo-physical properties of CuO-propylene glycol nanofluids.

PubMed

Suganthi, Kuppusamy Swaminathan; Radhakrishnan, Anju K; Anusha, Natarajan; Rajan, Kalpoondi Sekar

2014-06-01

Experiments were performed on the preparation and characterization of CuO-propylene glycol nanofluids. The influence of nanoparticle concentration and temperature on nanofluid viscosity reveals existence of a range of nanoparticle concentration and temperature in which the viscosity of nanofluid is lower than that of propylene glycol, possibly due to interactions between nanoparticles and propylene glycol. A temperature-independent, thermal conductivity enhancement of 38% was obtained for nanoparticle concentration of 1.5 vol% over a temperature range of 10-60 degrees C. We believe that particle clustering contributes to the thermal conductivity enhancement in CuO-propylene glycol nanofluids.

Allergenic Ingredients in Personal Hygiene Wet Wipes.

PubMed

Aschenbeck, Kelly A; Warshaw, Erin M

Wet wipes are a significant allergen source for anogenital allergic contact dermatitis. The aim of the study was to calculate the frequency of potentially allergenic ingredients in personal hygiene wet wipes. Ingredient lists from brand name and generic personal hygiene wet wipes from 4 large retailers were compiled. In the 54 personal hygiene wet wipes evaluated, a total of 132 ingredients were identified (average of 11.9 ingredients per wipe). The most common ingredients were Aloe barbadensis (77.8%), citric acid (77.8%), fragrance (72.2%), sorbic acid derivatives (63.0%), tocopherol derivatives (63.0%), glycerin (59.3%), phenoxyethanol (55.6%), disodium cocoamphodiacetate (53.7%), disodium ethylenediaminetetraacetic acid (EDTA) (42.6%), propylene glycol (42.6%), iodopropynyl butylcarbamate (40.7%), chamomile extracts (38.9%), sodium benzoate (35.2%), bronopol (22.2%), sodium citrate (22.2%), lanolin derivatives (20.4%), parabens (20.4%), polyethylene glycol derivatives (18.5%), disodium phosphate (16.7%), dimethylol dimethyl hydantoin (DMDM) (14.8%), and cocamidopropyl propylene glycol (PG)-dimonium chloride phosphate (11.1%). Of note, methylisothiazolinone (5.6%) was uncommon; methylchloroisothiazolinone was not identified in the personal hygiene wet wipes examined. There are many potential allergens in personal hygiene wet wipes, especially fragrance and preservatives.

Hydrogenolysis of 5-carbon sugars, sugar alcohols, and other methods and compositions for reactions involving hydrogen

DOEpatents

Werpy, Todd A [West Richland, WA; Zacher, Alan H [Kennewick, WA

2002-11-12

Methods and compositions for reactions of hydrogen over a Re-containing catalyst with compositions containing a 5-carbon sugar, sugar alcohol, or lactic acid are described. It has been surprisingly discovered that reaction with hydrogen over a Re-containing multimetallic catalyst resulted in superior conversion and selectivity to desired products such as propylene glycol. A process for the synthesis of PG from lactate or lactic acid is also described.

21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

Code of Federal Regulations, 2010 CFR

2010-04-01

... HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.765 Succistearin (stearoyl propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol hydrogen...

The effect of glycerol, propylene glycol and polyethylene glycol 400 on the partition coefficient of benzophenone-3 (oxybenzone).

PubMed

Mbah, C J

2007-01-01

Sunscreen products are widely used to protect the skin from sun-related deleterious effects. The objective of the study was to investigate the potential effect of glycerol, propylene glycol and polyethylene glycol 400 on dermal absorption of oxybenzone by studying their effects on its partition coefficient. The partition coefficient was evaluated in a chloroform-water system at room temperature. It was found that glycerol and propylene glycol decreased the partition coefficient of oxybenzone, while an increase in partition coefficient was observed with polyethylene glycol 400. The findings suggest that polyethylene glycol 400 in contrast to glycerol and propylene glycol has the potential of increasing the vehicle-skin partition coefficient of oxybenzone when cosmetic products containing such an UV absorber are topically applied to the skin.

Single dose intratympanic mesna application inhibits propylene glycol induced cholesteatoma formation.

PubMed

Ismi, O; Karabulut, Y Y; Bal, K K; Vayisoglu, Y; Unal, M

2017-03-01

Mesna (i.e. sodium 2-mercaptoethanesulfonate; C2H5NaO3S2) has been used in otological surgery such as cholesteatoma dissection and tympanic membrane lateralisation in atelectatic ears. However, this study aimed to investigate its effect on cholesteatoma formation. A total of 20 Wistar rats were divided into two groups of 10 animals. The right and left ears of control animals were treated with saline (saline control group; n = 10 ears) and propylene glycol plus saline (propylene glycol control group; n = 10 ears), respectively. In the mesna group, both ears were treated with propylene glycol plus mesna (n = 20 ears). On days 1, 8 and 15, the saline control group had intratympanic injections of 0.2 ml saline and the propylene glycol control and mesna groups had intratympanic injections of 0.2 ml 100 per cent propylene glycol. On day 22, the propylene glycol control group had a single intratympanic injection of 0.2 ml saline and the mesna group had a single intratympanic injection of 10 per cent mesna. Animals were killed 12 weeks after the last injection and the temporal bones were sent for histopathological evaluation. The cholesteatoma formation rate was 88 per cent in the propylene glycol control group, but was significantly lower in the mesna group (p = 0.01). There were no significant differences in granulation tissue formation (p = 0.498), cyst formation in the bulla (p = 0.381), fibrosis (p = 0.072) and epithelial hyperplasia (p = 0.081) among experimental groups. Intratympanic propylene glycol administration is an effective method of promoting experimental cholesteatoma formation. Administration of a single dose of intratympanic mesna inhibited cholesteatoma formation in an animal model.

Microbial Degradation of Propylene Glycol - Modelling Approach of a Batch Experiment

NASA Astrophysics Data System (ADS)

Dathe, Annette; Fernandez, Perrine; Bakken, Lars; Bloem, Esther; French, Helen

2016-04-01

De-icing chemicals are applied in large amounts at airports during winter conditions to keep the runways and aircrafts ice-free. At Gardermoen airport, Norway, most of the applied chemicals can be captured, but about 10 to 20 % infiltrate into the soil along the runways and during take-off. While the commonly used propylene glycol (PG) is easily degradable by local microbial communities, its biological oxygen demand is high, anoxic zones can develop and soluble Fe+2 and Mn+2 ions eventually can reach the groundwater. The objectives of the presented study are to quantify the mechanisms, which control the order of reduction processes in an unsaturated sandy soil, and to test whether measured redox potentials can help to determine underlying biogeochemical reactions. To investigate the mechanisms of microbial degradation, the water phase of soil samples from Gardermoen Airport was replaced by deionized water with 10 mMol PG or 10 mMol glutamate and the samples were incubated at 10°C for about two weeks. The gas phase was sampled and analyzed automatically every three hours. Microbial degradation of the substrate (PG or glutamate) was modelled following a Monod kinetics using the FME (Flexible Modelling Environment) package of R (Project for Statistical Computing). The model was calibrated against measurements of O2 depletion and CO2 production. The initial concentrations of O2, CO2 and PG or glutamate are known and microbial yields and stoichiometric constants can be calculated from the measurements. Parameter values for the initial microbial population size, maximum microbial growth rate, the half saturation constant, and microbial degradation and respiration rates were fitted using the FME package. The model accounts for carbon from the substrate (PG or glutamate) incorporated into the biomass. Results are promising, but because of the large number of parameters needed to fit a Monod kinetics it is challenging to accurately model a whole redox sequence. The ultimate goal of implementing PG degrading processes into a soil water transport model is still a challenge, and simpler approaches like a first- and second order kinetic are investigated and compared to the behavior of the Monod kinetic.

Measurement of diffusion coefficient of propylene glycol in skin tissue

NASA Astrophysics Data System (ADS)

Genin, Vadim D.; Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.

2015-03-01

Optical clearing of the rat skin under the action of propylene glycol was studied ex vivo. It was found that collimated transmittance of skin samples increased, whereas weight and thickness of the samples decreased during propylene glycol penetration in skin tissue. A mechanism of the optical clearing under the action of propylene glycol is discussed. Diffusion coefficient of propylene glycol in skin tissue ex vivo has been estimated as (1.35±0.95)×10-7 cm2/s with the taking into account of kinetics of both weight and thickness of skin samples. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

The distribution, fate, and effects of propylene glycol substances in the environment.

PubMed

West, Robert; Banton, Marcy; Hu, Jing; Klapacz, Joanna

2014-01-01

The propylene glycol substances comprise a homologous family of synthetic organic molecules that have widespread use and very high production volumes across the globe. The information presented and summarized here is intended to provide an overview of the most current and reliable information available for assessing the potential environmental exposures and impacts of these substances across the manufacture, use, and disposal phases of their product life cycles.The PG substances are characterized as being miscible in water, having very low octanol-water partition coefficients (log Pow) and exhibiting low potential to volatilize from water or soil in both pure and dissolved forms. The combination of these properties dictates that, almost regardless of the mode of their initial emission, they will ultimately associate with surface water, soil, and the related groundwater compartments in the environment. These substances have low affinity for soil and sediment particles, and thus will remain mobile and bio-available within these media.In the atmosphere, the PG substances are demonstrated to have short lifetimes(I. 7-11 h), due to rapid reaction with photochemically-generated hydroxyl radicals.This reactivity, combined with efficient wet deposition of their vapor and aerosol forms, lends to their very low potential for long-range transport via the atmosphere.In the aquatic and terrestrial compartments of the environment, the PG substances are rapidly and ultimately biodegraded under both aerobic and anaerobic conditions by a wide variety of microorganisms, regardless of prior adaptation to the substances.Except for the TePG substance, the propylene glycol substances meet the OECD definition of "readily biodegradable", and according to this definition are not expected to persist in either aquatic or terrestrial environments. The TePG exhibits inherent biodegradability, is not regarded to be persistent, and is expected to ultimately biodegrade in the environment, albeit at a somewhat slower rate. The apparent ease with which microorganisms and higher organisms can metabolize the PG substances, along with their low log Pow and very high water solubility values, portends them to have very low potential for bioaccumulation and/or biomagnification in aquatic and terrestrial organisms. These same properties, along with their neutral structures and lack of biological reactivity, are the reasons for which the PG substances exhibit a base-line, non-polar narcosis mode of toxicity.The PG substances have been shown here to be practically non-toxic to essentially every aquatic and terrestrial animal and plant species tested. Collectively, the available wealth of information relating to persistence, bioaccumulation, and eco-toxicity of these substances allows a definitive conclusion of their categorization as not being PBT (i.e., persistently bioaccumulative/toxic). The PBT screening and categorization of substances on the Canadian Domestic Substances List (DSL) by Environment Canada has formally concluded that each member of this substance family is "not P", "not B", and "not T' according to their associated PBT criteria.Similarly, the preceding evaluations of these high production volume substances within the OECD SIDS program concluded that MPG, DPG, and TPG are low priorities for further examination of potential impacts to humans and the environment.More extensive evaluations of potential risks to human health and the environment were recently completed by industry, as required for their registration under the European Union REACh legislation; each evaluation demonstrated that current uses, associated exposures, and controls thereof, will not result in exposures that exceed predicted no effect concentrations in the environment.

Effect of propylene glycol on adipose tissue mobilization in postpartum over-conditioned Holstein cows.

PubMed

Bjerre-Harpøth, V; Storm, A C; Eslamizad, M; Kuhla, B; Larsen, M

2015-12-01

Our objective was to investigate the quantitative and qualitative effects of propylene glycol (PG) allocation on postpartum adipose tissue mobilization in over-conditioned Holstein cows. Nine ruminally cannulated and arterially catheterized cows were, at parturition, randomly assigned to a ruminal pulse dose of either 500g of tap water (n=4) or 500g of PG (n=5) once a day. The PG was given with the morning feeding for 4 wk postpartum (treatment period), followed by a 4-wk follow-up period. All cows were fed the same prepartum and postpartum diets. At -16 (±3), 4 (±0), 15 (±1) and 29 (±2) days in milk (DIM), body composition was determined using the deuterium oxide dilution technique, liver and subcutaneous adipose tissue biopsies were collected, and mammary gland nutrient uptake was measured. Weekly blood samples were obtained during the experiment and daily blood samples were taken from -7 to 7 DIM. Postpartum feed intake and milk yield was not affected by PG allocation. The body content of lipid was not affected by treatment, but tended to decrease from 4 to 29 DIM with both treatments. Except for the first week postpartum, no difference in plasma nonesterified fatty acids concentration was noted between treatments in the treatment period. Yet, PG allocation resulted in decreased plasma concentrations of β-hydroxybutyrate (BHB) and increased plasma concentrations of glucose. In the follow-up period, plasma concentrations of nonesterified fatty acids, glucose, and BHB did not differ between treatments. Additionally, the change in abundance of proteins in adipose tissue biopsies from prepartum to 4 DIM was not affected by treatment. In conclusion, the different variables to assess body fat mobilization were concurrent and showed that a 4-wk postpartum PG allocation had limited effect on adipose tissue mobilization. The main effect was an enhanced glucogenic status with PG. No carry-over effect of PG allocation was recorded for production or plasma metabolites, and, hence, a new period of metabolic adaption to lactation seemed to occur with PG treatment after ceasing PG allocation. Thus, PG seemed to induce a 2-step adaption to lactation, reducing the immediate postpartum nadir and peak of plasma concentration of glucose and BHB, respectively; which is beneficial for postpartum cows at high risk of lipid-related metabolic diseases. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Carbonyl compounds in electronic cigarette vapors: effects of nicotine solvent and battery output voltage.

PubMed

Kosmider, Leon; Sobczak, Andrzej; Fik, Maciej; Knysak, Jakub; Zaciera, Marzena; Kurek, Jolanta; Goniewicz, Maciej Lukasz

2014-10-01

Glycerin (VG) and propylene glycol (PG) are the most common nicotine solvents used in e-cigarettes (ECs). It has been shown that at high temperatures both VG and PG undergo decomposition to low molecular carbonyl compounds, including the carcinogens formaldehyde and acetaldehyde. The aim of this study was to evaluate how various product characteristics, including nicotine solvent and battery output voltage, affect the levels of carbonyls in EC vapor. Twelve carbonyl compounds were measured in vapors from 10 commercially available nicotine solutions and from 3 control solutions composed of pure glycerin, pure propylene glycol, or a mixture of both solvents (50:50). EC battery output voltage was gradually modified from 3.2 to 4.8V. Carbonyl compounds were determined using the HPLC/DAD method. Formaldehyde and acetaldehyde were found in 8 of 13 samples. The amounts of formaldehyde and acetaldehyde in vapors from lower voltage EC were on average 13- and 807-fold lower than in tobacco smoke, respectively. The highest levels of carbonyls were observed in vapors generated from PG-based solutions. Increasing voltage from 3.2 to 4.8V resulted in a 4 to more than 200 times increase in formaldehyde, acetaldehyde, and acetone levels. The levels of formaldehyde in vapors from high-voltage device were in the range of levels reported in tobacco smoke. Vapors from EC contain toxic and carcinogenic carbonyl compounds. Both solvent and battery output voltage significantly affect levels of carbonyl compounds in EC vapors. High-voltage EC may expose users to high levels of carbonyl compounds. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (generic). 721.10189...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (PMN P-05-186, Chemical...

40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (generic). 721.10189...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (PMN P-05-186, Chemical...

40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (generic). 721.10189...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N..., propylene glycol diamine and aliphatic polyamine, N-(1,3 -dimethylbutylidene) derivs (PMN P-05-186, Chemical...

Influence of propylene glycol on aqueous silica dispersions and particle-stabilized emulsions.

PubMed

Binks, Bernard P; Fletcher, Paul D I; Thompson, Michael A; Elliott, Russell P

2013-05-14

We have studied the influence of adding propylene glycol to both aqueous dispersions of fumed silica nanoparticles and emulsions of paraffin liquid and water stabilized by the same particles. In the absence of oil, aerating mixtures of aqueous propylene glycol and particles yields either stable dispersions, aqueous foams, climbing particle films, or liquid marbles depending on the glycol content and particle hydrophobicity. The presence of glycol in water promotes particles to behave as if they are more hydrophilic. Calculations of their contact angle at the air-aqueous propylene glycol surface are in agreement with these findings. In the presence of oil, particle-stabilized emulsions invert from water-in-oil to oil-in-water upon increasing either the inherent hydrophilicity of the particles or the glycol content in the aqueous phase. Stable multiple emulsions occur around phase inversion in systems of low glycol content, and completely stable, waterless oil-in-propylene glycol emulsions can also be prepared. Accounting for the surface energies at the respective interfaces allows estimation of the contact angle at the oil-polar phase interface; reasonable agreement between measured and calculated phase inversion conditions is found assuming no glycol adsorption on particle surfaces.

Solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, propylene glycol, N-methyl-2-pyrrolidone, and water at 25 degrees C.

PubMed

Jouyban, Abolghasem; Soltanpour, Shahla

2010-09-01

The solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water at 25 degrees C are reported. The generated data are fitted to the Jouyban-Acree model and the mean relative deviations are 2.6%, 1.5%, 5.8%, and 7.4%, respectively for ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water.

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2011 CFR

2011-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2012 CFR

2012-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2014 CFR

2014-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2013 CFR

2013-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced Me esters of reduced polymd. oxidized...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...

Economic value of ionophores and propylene glycol to prevent disease and treat ketosis in Canada

PubMed Central

Gohary, Khaled; Overton, Michael W.; Von Massow, Michael; LeBlanc, Stephen J.; Lissemore, Kerry D.; Duffield, Todd F.

2016-01-01

A partial budget model was developed to evaluate the economic value of Rumensin Controlled Release Capsule (CRC) boluses when administered before calving to reduce disease and increase milk production. After accounting for disease incidences in a herd and the percentage by which Rumensin CRC can reduce them, and the increase in milk production attributable to administration of Rumensin CRC, the return on investment (ROI) per lactation was 4:1. Another partial budget model was developed to estimate the economic value of propylene glycol (PG) to treat ketosis when diagnosed by 3 different cow-side tests or when administered to all cows without using any cow-side testing. After accounting for the sensitivity and specificity of each test, ROI per lactation ranged from 2:1 to 4:1. The ROI was 2:1 when no cow-side testing was used. In conclusion, prevention of diseases that occur in the postpartum period and treatment of ketosis after calving yielded a positive ROI that varies based on disease incidence and method of diagnosis. PMID:27429461

Economic value of ionophores and propylene glycol to prevent disease and treat ketosis in Canada.

PubMed

Gohary, Khaled; Overton, Michael W; Von Massow, Michael; LeBlanc, Stephen J; Lissemore, Kerry D; Duffield, Todd F

2016-07-01

A partial budget model was developed to evaluate the economic value of Rumensin Controlled Release Capsule (CRC) boluses when administered before calving to reduce disease and increase milk production. After accounting for disease incidences in a herd and the percentage by which Rumensin CRC can reduce them, and the increase in milk production attributable to administration of Rumensin CRC, the return on investment (ROI) per lactation was 4:1. Another partial budget model was developed to estimate the economic value of propylene glycol (PG) to treat ketosis when diagnosed by 3 different cow-side tests or when administered to all cows without using any cow-side testing. After accounting for the sensitivity and specificity of each test, ROI per lactation ranged from 2:1 to 4:1. The ROI was 2:1 when no cow-side testing was used. In conclusion, prevention of diseases that occur in the postpartum period and treatment of ketosis after calving yielded a positive ROI that varies based on disease incidence and method of diagnosis.

Evaluation of activated sludge for biodegradation of propylene glycol as an aircraft deicing fluid.

PubMed

Delorit, Justin D; Racz, LeeAnn

2014-04-01

Aircraft deicing fluid used at airport facilities is often collected for treatment or disposal in order to prevent serious ecological threats to nearby surface waters. This study investigated lab scale degradation of propylene glycol, the active ingredient in a common aircraft deicing fluid, by way of a laboratory-scale sequencing batch reactor containing municipal waste water treatment facility activated sludge performing simultaneous organic carbon oxidation and nitrification. The ability of activated sludge to remove propylene glycol was evaluated by studying the biodegradation and sorption characteristics of propylene glycol in an activated sludge medium. The results indicate sorption may play a role in the fate of propylene glycol in AS, and the heterotrophic bacteria readily degrade this compound. Therefore, a field deployable bioreactor may be appropriate for use in flight line applications.

Membrane penetration enhancement of ibuprofen using supersaturation.

PubMed

Iervolino, M; Raghavan, S L; Hadgraft, J

2000-04-05

Permeation enhancement of ibuprofen from supersaturated solutions formed using the cosolvent technique was investigated using silicone as a model membrane. Hydroxpropyl methyl cellulose and hydroxpropyl-beta-cyclodextrin were used to stabilise the supersaturated states. Physical stability studies showed best results for low drug concentrations in a 40:60 propylene glycol/water cosolvent system. Variations in flux across model silicone membranes from saturated solutions were observed as the PG content was increased. The flux of IBU increased with the degree of saturation for solutions prepared in a 40:60 PG/water cosolvent mixture. HPMC and CD were found to be effective in enhancing the stability of supersaturated solutions of IBU. The mechanisms of action are different for the two additives and are discussed.

Ligand-Substitution Reactions of the Tellurium Compound AS-101 in Physiological Aqueous and Alcoholic Solutions.

PubMed

Silberman, Alon; Albeck, Michael; Sredni, Benjamin; Albeck, Amnon

2016-11-07

Since its first crystallization, the aqueous structure of the tellurium-containing experimental drug AS-101 has never been studied. We show that, under the aqueous conditions in which it is administered, AS-101 is subjected to an immediate ligand-substitution reaction with water, yielding a stable hydrolyzed oxide anion product that is identified, for the first time, to be TeOCl 3 - . Studying the structure of AS-101 in propylene glycol (PG), an alcoholic solvent often used for the topical and oral administration of AS-101, revealed the same phenomenon of ligand-substitution reaction between the alcoholic ligands. Upon exposure to water, the PG-substituted product is also hydrolyzed to the same tellurium(IV) oxide form, TeOCl 3 - .

An economic analysis of hyperketonemia testing and propylene glycol treatment strategies in early lactation dairy cattle.

PubMed

McArt, J A A; Nydam, D V; Oetzel, G R; Guard, C L

2014-11-01

The purpose was to develop stochastic economic models which address variation in disease risks and costs in order to evaluate different simulated on-farm testing and propylene glycol (PG) treatment strategies based on herd hyperketonemia (HYK) incidence during the first 30 DIM. Data used in model development concerning the difference in health and production consequences between HYK and non-ketotic cows were based on results from 10 studies representing over 13,000 cows from 833 dairy farms in North America, Canada, and Europe. Inputs for PG associated variables were based on a large field trial using cows from 4 free-stall dairy herds (2 in New York and 2 in Wisconsin). Four simulated on-farm testing and treatment strategies were analyzed at herd HYK incidences ranging from 5% to 80% and included: 1) treating all cows with 5d of PG starting at 5 DIM, 2) testing all cows for HYK 1 day per week (e.g. Mondays) from 3 to 16 DIM and treating all positive cows with 5d of oral PG, 3) testing all cows for HYK 2 days per week (e.g. Mondays and Thursdays) from 3 to 9 DIM and treating all positive cows with 5d of oral PG, and 4) testing all cows for HYK 3 days per week (e.g. Mondays, Wednesdays, and Fridays) from 3 to 16 DIM and treating all positive cows with 5d of oral PG. Cost-benefit analysis included the costs associated with labor to test cows, β-hydroxybutyrate test strips, labor to treat cows, PG, and the associated gain in milk production, decrease in DA and early removal risks of PG treated HYK positive cows compared to non-treated HYK positive cows. Stochastic models were developed to account for variability in the distribution of input variables. Per 100 fresh cows in a herd with an HYK incidence of 40%, the mean economic benefits of the 4 different strategies were $1088, $744, $1166, and $760, respectively. Testing cows 2 days per week from 3 to 9 DIM was the most cost-effective strategy for herds with HYK incidences between 15% and 50%; above 50%, treating all fresh cows with 5d of PG was the most cost-effective strategy. These results show that for herds similar to those used in model, when herd HYK incidences rise above 25%, almost any HYK testing and treatment protocol will be economically beneficial for the farm. Copyright © 2014 Elsevier B.V. All rights reserved.

21 CFR 589.1001 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol in or on cat food. 589.1001... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat... on cat food causes the feed to be adulterated and in violation of the Federal Food, Drug, and...

21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible fats...

21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Propylene glycol mono- and diesters of fats and... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely used in food, subject to the following prescribed conditions: (a) They are produced from edible fats...

21 CFR 589.1001 - Propylene glycol in or on cat food.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol in or on cat food. 589.1001... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat... on cat food causes the feed to be adulterated and in violation of the Federal Food, Drug, and...

Preparation, Optimization, In vitro Evaluation and Ex vivo Permeation Studies of Finasteride loaded gel Formulations Prepared by using Response Surface Methodology.

PubMed

Khan, Muhammad Zia Ullah; Makreski, Petre; Murtaza, Ghulam

2018-05-02

The aim of present explorative study was to prepare and optimize finasteride loaded topical gel formulations by using three factor [propylene glycol (PG), Tween® 80, and sodium lauryl sulphate (SLS)], five level central composite design. Optimized finasteride topical gel formulation (F4), containing PG, Tween® 80, and SLS in a concentration of 0.8 mg, 0.4 mg and 0.2 mg, respectively, showed 6-fold higher values of cumulative drug release, flux, partition coefficient, input rate, lag time, and diffusion coefficient, when compared to control formulation without permeation enhancer. Finally, it can be concluded that finasteride permeation was enhanced by PG, tween® 80 and SLS individually, while in combination only PG along with tween® 80 had synergistic and more pronounced effect on flux, permeability coefficient and input rate while antagonistic effect on lag time and diffusion coefficient was observed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Use of Edible Laminate Layers in Intermediate Moisture Food Rations to Inhibit Moisture Migration

DTIC Science & Technology

2016-04-29

methylcellulose, propylene glycol, citric acid, modified starch , white beeswax Water resistant coating on one side Watson, Inc. Dual-sided HPMC moisture...barrier film Hydroxypropyl methylcellulose, propylene glycol, citric acid, modified starch , white beeswax Water resistant coating on both sides...Moisture Barrier (BWMB) film #1 Pullulan*, beeswax, glycerin, propylene glycol, starch , polysorbate 80 Water soluble Watson, Inc. Pullulan BWMB film

Flavor release and perception in hard candy: influence of flavor compound-flavor solvent interactions.

PubMed

Schober, Amanda L; Peterson, Devin G

2004-05-05

The release kinetics of l-menthol dissolved in propylene glycol (PG), Miglyol, or 1,8-cineole (two common odorless flavor solvents differing in polarity and a hydrophobic flavor compound) were monitored from a model aqueous system via atmospheric pressure chemical ionization mass spectrometry (APCI-MS). Breath analysis was also conducted via APCI-MS to monitor release of l-menthol from hard candy that used PG and Miglyol for l-menthol incorporation. The quantities of l-menthol released when dissolved in PG or Miglyol from the model aqueous system were found to be similar and overall significantly greater in comparison to when dissolved in 1,8-cineole. Analogous results were reported by the breath analysis of hard candy. The release kinetics of l-menthol from PG or Miglyol versus from 1,8-cineole were notably more rapid and higher in quantity. Results from the sensory time-intensity study also indicated that there was no perceived difference in the overall cooling intensity between the two flavor solvent delivery systems (PG and Miglyol).

Mechanisms of propylene glycol and triacetin pyrolysis.

PubMed

Laino, Teodoro; Tuma, Christian; Moor, Philippe; Martin, Elyette; Stolz, Steffen; Curioni, Alessandro

2012-05-10

Propylene glycol and triacetin are chemical compounds, commonly used as food additives. Though the usage of the pure chemicals is not considered harmful when used as dietary supplements, little is known about the nature of their thermal degradation products and the impact they may have on human health. For these reasons, in this manuscript we investigate the thermal decomposition mechanisms of both neutral propylene glycol and triacetin in the gas phase by a novel simulation framework. This is based on a free energy sampling methodology followed by an accurate energy refinement. Structures, Gibbs free energy barriers, and rate constants at 800 K were computed for the different steps involved in the two pyrolytic processes. The thermal decomposition mechanisms found theoretically for propylene glycol and triacetin were validated by a qualitative experimental investigation using gas-phase chromatography-mass spectroscopy, with excellent agreement. The results provide a validation of the novel simulation framework and shed light on the potential hazard to the health that propylene glycol and triacetin may have when exposed to high temperatures.

Severe propylene glycol toxicity secondary to use of anti-epileptics.

PubMed

Pillai, Unnikrishnan; Hothi, Jatinder C; Bhat, Zeenat Y

2014-01-01

Propylene glycol toxicity presenting as high anion gap metabolic acidosis and osmolar gap has been extensively reported in literature, and most of them are secondary to intravenous lorazepam infusion. However, propylene glycol is used as a solvent in a number of medications that are frequently utilized in critical care setting, and hence one should be aware that the toxicity is possible from a variety of medication. Phenobarbital and phenytoin are one of those, and we hereby report a novel case of propylene glycol toxicity secondary to phenobarbital and phenytoin infusion in a patient with refractory status epilepticus. Furthermore, our patient had end-stage renal disease, which we think could have been an important precipitating factor for the toxicity. Because most of the symptoms from propylene glycol toxicity can mimic sepsis-which is very common in critical care unit patients-this life threatening scenario could be easily missed. Regular monitoring of osmolar gap is an easily available intervention in the at risk patients.

Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms

PubMed Central

Nalawade, Triveni Mohan; Bhat, Kishore; Sogi, Suma H. P.

2015-01-01

Aim: The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro. Materials and Methods: Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study. Results: All vehicles exhibited bactericidal activity at 100% concentration. Conclusion: Propylene glycol was effective against three organisms namely S. mutans E. faecalis and E. coli and its bactericidal activity was at 50%, 25% and 50% respectively. PEG 1000 was effective against S. mutans and E. coli at 25%. Hence propylene glycol was effective on more number of organisms of which E. faecalis is a known resistant species. PEG 1000 was bactericidal at a lower concentration but was effective on two organisms only. PMID:25992336

Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms.

PubMed

Nalawade, Triveni Mohan; Bhat, Kishore; Sogi, Suma H P

2015-01-01

The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro. Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study. All vehicles exhibited bactericidal activity at 100% concentration. Propylene glycol was effective against three organisms namely S. mutans E. faecalis and E. coli and its bactericidal activity was at 50%, 25% and 50% respectively. PEG 1000 was effective against S. mutans and E. coli at 25%. Hence propylene glycol was effective on more number of organisms of which E. faecalis is a known resistant species. PEG 1000 was bactericidal at a lower concentration but was effective on two organisms only.

One-pot catalytic conversion of cellulose into polyols with Pt/CNTs catalysts.

PubMed

Yang, Li; Yan, Xiaopei; Wang, Qiwu; Wang, Qiong; Xia, Haian

2015-03-02

A series of Pt nanoparticles supported on carbon nanotubes (CNTs) were synthesized using the incipient-wetness impregnation method. These catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscope (TEM) techniques. The characterization results indicate that the Pt nanoparticles were highly dispersed on the surface of the CNTs, and the mean size was less than 5 nm. These catalysts were utilized to convert cellulose to hexitol, ethylene glycerol (EG), and 1,2-propylene glycol (1,2-PG) under low H2 pressure. The total yields were as high as 71.4% for EG and 1,2-PG using 1Pt/CNTs as the catalyst in the hydrolytic hydrogenation of cellulose under mild reaction conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparation and Thermo-Physical Properties of Fe2O3-Propylene Glycol Nanofluids.

PubMed

Shylaja, A; Manikandan, S; Suganthi, K S; Rajan, K S

2015-02-01

Iron oxide (Fe2O3) nanoparticles were prepared from ferric chloride and ferrous sulphate by precipitation reaction. Fe2O3-propylene glycol nanofluid was prepared by dispersing Fe2O3 nanoparticles in propylene glycol through stirred bead milling, shear homogenization and probe ultrasonication. The nanofluid was characterized through measurement of viscosity, particle size distribution and thermal conductivity. The interactions between Fe2O3 nanoparticles and propylene glycol on the nanoparticle surfaces lead to reduction in viscosity, the magnitude of which increases with nanoparticle concentration (0-2 vol%) at room temperature. The thermal conductivity enhancement for 2 vol% nanofluid was about 21% at room temperature, with liquid layering being the major contributor for thermal conductivity enhancement.

End-group characterisation of poly(propylene glycol)s by means of electrospray ionisation-tandem mass spectrometry (ESI-MS/MS).

PubMed

Jackson, Anthony T; Slade, Susan E; Thalassinos, Konstantinos; Scrivens, James H

2008-10-01

The end-group functionalisation of a series of poly(propylene glycol)s has been characterised by means of electrospray ionisation-tandem mass spectrometry (ESI-MS/MS). A series of peaks with mass-to-charge ratios that are close to that of the precursor ion were used to generate information on the end-group functionalities of the poly(propylene glycol)s. Fragment ions resulting from losses of both of the end groups were noted from some of the samples. An example is presented of how software can be used to significantly reduce the length of time involved in data interpretation (which is typically the most time-consuming part of the analysis).

Detection of diethylene glycol adulteration in propylene glycol--method validation through a multi-instrument collaborative study.

PubMed

Li, Xiang; Arzhantsev, Sergey; Kauffman, John F; Spencer, John A

2011-04-05

Four portable NIR instruments from the same manufacturer that were nominally identical were programmed with a PLS model for the detection of diethylene glycol (DEG) contamination in propylene glycol (PG)-water mixtures. The model was developed on one spectrometer and used on other units after a calibration transfer procedure that used piecewise direct standardization. Although quantitative results were produced, in practice the instrument interface was programmed to report in Pass/Fail mode. The Pass/Fail determinations were made within 10s and were based on a threshold that passed a blank sample with 95% confidence. The detection limit was then established as the concentration at which a sample would fail with 95% confidence. For a 1% DEG threshold one false negative (Type II) and eight false positive (Type I) errors were found in over 500 samples measured. A representative test set produced standard errors of less than 2%. Since the range of diethylene glycol for economically motivated adulteration (EMA) is expected to be above 1%, the sensitivity of field calibrated portable NIR instruments is sufficient to rapidly screen out potentially problematic materials. Following method development, the instruments were shipped to different sites around the country for a collaborative study with a fixed protocol to be carried out by different analysts. NIR spectra of replicate sets of calibration transfer, system suitability and test samples were all processed with the same chemometric model on multiple instruments to determine the overall analytical precision of the method. The combined results collected for all participants were statistically analyzed to determine a limit of detection (2.0% DEG) and limit of quantitation (6.5%) that can be expected for a method distributed to multiple field laboratories. Published by Elsevier B.V.

Confocal Raman microscopy and multivariate statistical analysis for determination of different penetration abilities of caffeine and propylene glycol applied simultaneously in a mixture on porcine skin ex vivo.

PubMed

Mujica Ascencio, Saul; Choe, ChunSik; Meinke, Martina C; Müller, Rainer H; Maksimov, George V; Wigger-Alberti, Walter; Lademann, Juergen; Darvin, Maxim E

2016-07-01

Propylene glycol is one of the known substances added in cosmetic formulations as a penetration enhancer. Recently, nanocrystals have been employed also to increase the skin penetration of active components. Caffeine is a component with many applications and its penetration into the epidermis is controversially discussed in the literature. In the present study, the penetration ability of two components - caffeine nanocrystals and propylene glycol, applied topically on porcine ear skin in the form of a gel, was investigated ex vivo using two confocal Raman microscopes operated at different excitation wavelengths (785nm and 633nm). Several depth profiles were acquired in the fingerprint region and different spectral ranges, i.e., 526-600cm(-1) and 810-880cm(-1) were chosen for independent analysis of caffeine and propylene glycol penetration into the skin, respectively. Multivariate statistical methods such as principal component analysis (PCA) and linear discriminant analysis (LDA) combined with Student's t-test were employed to calculate the maximum penetration depths of each substance (caffeine and propylene glycol). The results show that propylene glycol penetrates significantly deeper than caffeine (20.7-22.0μm versus 12.3-13.0μm) without any penetration enhancement effect on caffeine. The results confirm that different substances, even if applied onto the skin as a mixture, can penetrate differently. The penetration depths of caffeine and propylene glycol obtained using two different confocal Raman microscopes are comparable showing that both types of microscopes are well suited for such investigations and that multivariate statistical PCA-LDA methods combined with Student's t-test are very useful for analyzing the penetration of different substances into the skin. Copyright © 2016 Elsevier B.V. All rights reserved.

Liquid for absorption of solar heat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, T.; Iwamoto, Y.; Kadotani, K.

A liquid for the absorption of solar heat, useful as an heat-absorbing medium in water heaters and heat collectors comprises: a dispersing medium selected from the group consisting of propylene glycol, mixture of propylene glycol with water, mixture of propylene glycol with water and glycerin, and mixture of glycerin with water, a dispersant selected from the group consisting of polyvinylpyrrolidone, caramel, and mixture of polyvinylpyrrolidone with caramel, and a powdered activated carbon as a black coloring material.

Potentiation of Sodium Metabisulfite Toxicity by Propylene Glycol in Both in Vitro and in Vivo Systems.

PubMed

Yoo, Jean; Lim, Yeon-Mi; Kim, Haewon; Kim, Eun-Ji; Lee, Doo-Hee; Lee, Byeongwoo; Kim, Pilje; Yu, Seung Do; Kim, Hyun-Mi; Yoon, Byung-Il; Shim, Ilseob

2018-01-01

Many consumer products used in our daily lives result in inhalation exposure to a variety of chemicals, although the toxicities of the active ingredients are not well known; furthermore, simultaneous exposure to chemical mixtures occurs. Sodium metabisulfite (SM) and propylene glycol (PG) are used in a variety of products. Both the cytotoxicity and the sub-acute inhalation toxicity of each chemical and their mixtures were evaluated. Assays for cell viability, membrane damage, and lysosome damage demonstrated that SM over 100 μg/ml induced significant cytotoxicity; moreover, when PG, which was not cytotoxic, was mixed with SM, the cytotoxicity of the mixture was enhanced. Solutions of 1, 5, and 20% SM, each with 1% PG solution, were prepared, and the whole body of rats was exposed to aerosols of the mixture for 6 h/day, 5 days/week for 2 weeks. The rats were sacrificed 1 (exposure group) or 7 days (recovery group) after termination of the exposure. The actual concentration of SM in the low-, medium-, and high-exposure groups was 3.91 ± 1.26, 35.73 ± 6.01, and 80.98 ± 5.47 mg/m 3 , respectively, and the actual concentration of PG in each group was 6.47 ± 1.25, 8.68 ± 0.6, and 8.84 ± 1.77 mg/m 3 . The repeated exposure to SM and PG caused specific clinical signs including nasal sound, sneeze, and eye irritation which were not found in SM single exposure. In addition, the body weight of treatment group rats decreased compared to that of the control group rats in a time-dependent manner. The total protein concentration and lactate dehydrogenase activity in the bronchoalveolar lavage fluid (BALF) increased. Histopathological analysis of the lungs, liver, and nasal cavity was performed. Adverse effects were observed in the nasal cavity, with squamous cell metaplasia identified in the front of the nasal cavity in all high-exposure groups, which completely recovered 7 days after exposure was terminated. Whereas inhalation of SM for 2 weeks only reduced body weight in the high-dose group, inhalation of SM and PG mixtures for 2 weeks significantly decreased body weight and induced metaplasia of the respiratory epithelium into squamous cells in the medium- and high-dose groups. In conclusion, PG potentiated the toxicity of SM in human lung epithelial cells and the inhalation toxicity in rats.

Antimicrobial Activity of Endodontic Medicaments and Vehicles using Agar Well Diffusion Method on Facultative and Obligate Anaerobes

PubMed Central

Bhat, Kishore G; Sogi, Suma

2016-01-01

Aims The aim of this study was to determine the relative antimicrobial effectiveness of these endodontic medicaments and various vehicles using an agar well diffusion assay. Materials and methods Double Antibiotic Paste(DAP), modified DAP, 2% Chlorhexidine gluconate and their combination with four vehicles namely Polyethylene glycol 400 (PEG), Propylene glycol (PG), combinations of PG with PEG and lastly Glycerine were tested using agar well diffusion assay. The minimum bactericidal concentration was noted against four standard strains of organisms ie Streptococcus mutans ATCC( American Type Culture Collection) 25175, Staphylococcus aureus ATCC 12598, Enterococcus faecalis ATCC 35550 and Eschericia coli ATCC 25922. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Issues of resistance, limited spectrum of activity and lack of antifungal properties, the hunt for the ideal intracanal medicament continues. In this regard, the vehicles used to form the pastes play a supportive role by forming the appropriate consistency for placement and may dramatically influence their chemical characteristics like their solubility and diffusion. Thus, inorder to use safer and equally effective intracanal medicaments, Chlorhexidine gluconate is being unveiled in this study. Results The difference between the four vehicles when combined with the same endodontic medicament studied above is nonsignificant (NS) except against Porphyromonas gingivalis. Propylene glycol is significantly effective than Glycerine when used with DAP ie C+M medicament combination. (p = 0.029) Conclusion 2% chlorhexidine gluconate and modified DAP can definitely replace DAP and triple antibiotic paste as end-odontic medicaments with chlorhexidine having an added advantage of bactericidal action, substantivity, biocompatibility, low toxicity, and lesser chances of developing resistance. How to cite this article Nalawade TM, Bhat KG, Sogi S. Antimicrobial Activity of Endodontic Medicaments and Vehicles using Agar Well Diffusion Method on Facultative and Obligate Anaerobes. Int J Clin Pediatr Dent 2016;9(4):335-341. PMID:28127166

Enzymatic remediated biodegradation of propylene glycol 1,2-dinitrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, M.; Geelhaar, L.; Speedie, M.K.

1995-12-31

Two bacterial species, Enterobacter agglomerans and Bacillus thuringiensis/cereus, which were selected from nitroglycerin (GTN) contaminated soil, have previously been shown to have denitrating ability on nitroglycerin. This abstract presents the investigation of the cell free extracts from both microorganisms for the degradation of another nitrate ester contaminant; propylene glycol 1,2-dinitrate (PGDN). This compound has been previously considered resistant to the biodegradation. In order to probe the pathway, the whole process was monitored by using [1-{sup 14}C]-PGDN as substrate and the intermediates were identified by HPLC and TLC chromatography. Long term biodegradation experiments have shown that the enzymes in the cytoplasmmore » fraction of Bacillus thuringiensis/cereus and the membrane fraction of Enterobacter agglomerans convert PGDN successively into propylene glycol 1-mononitrate (1-PGMN) and propylene glycol 2-mononitrate (2-PGMN), and finally, propylene glycol. The capacity to achieve sequential and complete degradation of PGDN implies that it follows a similar mechanism to that observed in the GTN degradation. Cofactor requirements for PGDN breakdown have been studied, it was found that no dissociable, dialyzable cofactors are required.« less

Benzene formation in electronic cigarettes.

PubMed

Pankow, James F; Kim, Kilsun; McWhirter, Kevin J; Luo, Wentai; Escobedo, Jorge O; Strongin, Robert M; Duell, Anna K; Peyton, David H

2017-01-01

The heating of the fluids used in electronic cigarettes ("e-cigarettes") used to create "vaping" aerosols is capable of causing a wide range of degradation reaction products. We investigated formation of benzene (an important human carcinogen) from e-cigarette fluids containing propylene glycol (PG), glycerol (GL), benzoic acid, the flavor chemical benzaldehyde, and nicotine. Three e-cigarette devices were used: the JUULTM "pod" system (provides no user accessible settings other than flavor cartridge choice), and two refill tank systems that allowed a range of user accessible power settings. Benzene in the e-cigarette aerosols was determined by gas chromatography/mass spectrometry. Benzene formation was ND (not detected) in the JUUL system. In the two tank systems benzene was found to form from propylene glycol (PG) and glycerol (GL), and from the additives benzoic acid and benzaldehyde, especially at high power settings. With 50:50 PG+GL, for tank device 1 at 6W and 13W, the formed benzene concentrations were 1.9 and 750 μg/m3. For tank device 2, at 6W and 25W, the formed concentrations were ND and 1.8 μg/m3. With benzoic acid and benzaldehyde at ~10 mg/mL, for tank device 1, values at 13W were as high as 5000 μg/m3. For tank device 2 at 25W, all values were ≤~100 μg/m3. These values may be compared with what can be expected in a conventional (tobacco) cigarette, namely 200,000 μg/m3. Thus, the risks from benzene will be lower from e-cigarettes than from conventional cigarettes. However, ambient benzene air concentrations in the U.S. have typically been 1 μg/m3, so that benzene has been named the largest single known cancer-risk air toxic in the U.S. For non-smokers, chronically repeated exposure to benzene from e-cigarettes at levels such as 100 or higher μg/m3 will not be of negligible risk.

Glass transition and relaxation dynamics of propylene glycol-water solutions confined in clay

NASA Astrophysics Data System (ADS)

Elamin, Khalid; Björklund, Jimmy; Nyhlén, Fredrik; Yttergren, Madeleine; Mârtensson, Lena; Swenson, Jan

2014-07-01

The molecular dynamics of aqueous solutions of propylene glycol (PG) and propylene glycol methylether (PGME) confined in a two-dimensional layer-structured Na-vermiculite clay has been studied by broadband dielectric spectroscopy and differential scanning calorimetry. As typical for liquids in confined geometries the intensity of the cooperative α-relaxation becomes considerably more suppressed than the more local β-like relaxation processes. In fact, at high water contents the calorimetric glass transition and related structural α-relaxation cannot even be observed, due to the confinement. Thus, the intensity of the viscosity related α-relaxation is dramatically reduced, but its time scale as well as the related glass transition temperature Tg are for both systems only weakly influenced by the confinement. In the case of the PGME-water solutions it is an important finding since in the corresponding bulk system a pronounced non-monotonic concentration dependence of the glass transition related dynamics has been observed due to the growth of hydrogen bonded relaxing entities of water bridging between PGME molecules [J. Sjöström, J. Mattsson, R. Bergman, and J. Swenson, Phys. Chem. B 115, 10013 (2011)]. The present results suggest that the same type of structural entities are formed in the quasi-two-dimensional space between the clay platelets. It is also observed that the main water relaxation cannot be distinguished from the β-relaxation of PG or PGME in the concentration range up to intermediate water contents. This suggests that these two processes are coupled and that the water molecules affect the time scale of the β-relaxation. However, this is most likely true also for the corresponding bulk solutions, which exhibit similar time scales of this combined relaxation process below Tg. Finally, it is found that at higher water contents the water relaxation does not merge with, or follow, the α-relaxation above Tg, but instead crosses the α-relaxation, indicating that the two relaxation processes are independent of each other. This can only occur if the two processes do not occur in the same parts of the confined solutions. Most likely the hydration shell of the interlayer Na+ ions is causing this water relaxation, which does not participate in the α-relaxation at any temperature.

Glass transition and relaxation dynamics of propylene glycol-water solutions confined in clay.

PubMed

Elamin, Khalid; Björklund, Jimmy; Nyhlén, Fredrik; Yttergren, Madeleine; Mårtensson, Lena; Swenson, Jan

2014-07-21

The molecular dynamics of aqueous solutions of propylene glycol (PG) and propylene glycol methylether (PGME) confined in a two-dimensional layer-structured Na-vermiculite clay has been studied by broadband dielectric spectroscopy and differential scanning calorimetry. As typical for liquids in confined geometries the intensity of the cooperative α-relaxation becomes considerably more suppressed than the more local β-like relaxation processes. In fact, at high water contents the calorimetric glass transition and related structural α-relaxation cannot even be observed, due to the confinement. Thus, the intensity of the viscosity related α-relaxation is dramatically reduced, but its time scale as well as the related glass transition temperature Tg are for both systems only weakly influenced by the confinement. In the case of the PGME-water solutions it is an important finding since in the corresponding bulk system a pronounced non-monotonic concentration dependence of the glass transition related dynamics has been observed due to the growth of hydrogen bonded relaxing entities of water bridging between PGME molecules [J. Sjöström, J. Mattsson, R. Bergman, and J. Swenson, Phys. Chem. B 115, 10013 (2011)]. The present results suggest that the same type of structural entities are formed in the quasi-two-dimensional space between the clay platelets. It is also observed that the main water relaxation cannot be distinguished from the β-relaxation of PG or PGME in the concentration range up to intermediate water contents. This suggests that these two processes are coupled and that the water molecules affect the time scale of the β-relaxation. However, this is most likely true also for the corresponding bulk solutions, which exhibit similar time scales of this combined relaxation process below Tg. Finally, it is found that at higher water contents the water relaxation does not merge with, or follow, the α-relaxation above Tg, but instead crosses the α-relaxation, indicating that the two relaxation processes are independent of each other. This can only occur if the two processes do not occur in the same parts of the confined solutions. Most likely the hydration shell of the interlayer Na(+) ions is causing this water relaxation, which does not participate in the α-relaxation at any temperature.

Severe lactic acidosis after an iatrogenic propylene glycol overdose.

PubMed

Zosel, Amy; Egelhoff, Elizabeth; Heard, Kennon

2010-02-01

Propylene glycol is a diluent found in many intravenous and oral drugs, including phenytoin, diazepam, and lorazepam. Propylene glycol is eliminated from the body by oxidation through alcohol dehydrogenase to form lactic acid. Under normal conditions, the body converts lactate to pyruvate and metabolizes pyruvate through the Krebs cycle. Lactic acidosis has occurred in patients, often those with renal dysfunction, who were receiving prolonged infusions of drugs that contain propylene glycol as a diluent. We describe a 50-year-old man who experienced severe lactic acidosis after receiving an accidental overdose of lorazepam, which contains propylene glycol. The patient was acutely intoxicated, with a serum ethanol concentration of 406 mg/dl. He had choked on a large piece of meat and subsequently experienced pulseless electrical activity with ventricular fibrillation cardiac arrest. He was brought to the emergency department; within 2 hours, he was admitted to the intensive care unit for initiation of the hypothermia protocol. The patient began to experience generalized tonic-clonic seizures 12 hours later, which resolved after several boluses of lorazepam. A lorazepam infusion was started; however, it was inadvertently administered at a rate of 2 mg/minute instead of the standard rate of 2 mg/hour. Ten hours later, the administration error was recognized and the infusion stopped. The patient's peak propylene glycol level was 659 mg/dl, pH 6.9, serum bicarbonate level 5 mEq/L, and lactate level 18.6 mmol/L. Fomepizole was started the next day and was continued until hospital day 3. Continuous renal replacement therapy was started and then replaced with continuous venovenous hemofiltration (CVVH) for the remainder of the hospital stay. The patient's acidosis resolved by day 3, when his propylene glycol level had decreased to 45 mg/dl. Fomepizole was discontinued, but the patient's prognosis was poor (anoxic brain injury); thus care was withdrawn and the patient died. Although the patient's outcome was death, his lactic acidosis was treated successfully with fomepizole and CVVH. Clinicians should be aware that an iatrogenic overdose of lorazepam may result in severe propylene glycol toxicity, which may be treated with fomepizole and CVVH.

PNNL Provides Catalyst for Sustainable Propylene Glycol Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madison, Alison L.; Lund, Eric C.

2012-02-28

Submission for annual FLC magazine publication, Technology for Today, featuring technologies transferred by federal labs. Subject: PNNL transfer of Propylene Glycol from Renewable Sources catalytic process to Archer Daniels Midland Company.

A field trial on the effect of propylene glycol on displaced abomasum, removal from herd, and reproduction in fresh cows diagnosed with subclinical ketosis.

PubMed

McArt, J A A; Nydam, D V; Oetzel, G R

2012-05-01

The purpose was to determine the effect of oral propylene glycol (PG) administration in fresh cows diagnosed with subclinical ketosis (SCK). Measured outcomes were development of displaced abomasum (DA) and removal from herd in the first 30 d in milk (DIM), conception to first service, and time to conception within 150 DIM. Cows from 4 freestall dairy herds (2 in New York and 2 in Wisconsin) were each tested 6 times for SCK from 3 to 16 DIM on Mondays, Wednesdays, and Fridays using the Precision Xtra meter (Abbott Laboratories, Abbott Park, IL). Subclinical ketosis was defined as a blood β-hydroxybutyrate concentration of 1.2 to 2.9 mmol/L. Cows with SCK were randomized to treatment group (oral PG) or untreated control group (no PG); treatment cows were orally drenched with 300 mL of PG once daily from the day they tested 1.2 to 2.9 mmol/L until the day they tested <1.2 mmol/L. Mixed effects multivariable Poisson regression was used to assess the effect of PG on DA, removal from herd, and conception to first service; a semiparametric proportional hazards model was used to evaluate the days-to-conception outcome. A total of 741 of 1,717 (43.2%) eligible enrolled cows had at least 1 β-hydroxybutyrate test of 1.2 to 2.9 mmol/L. Of these, 372 were assigned to the PG treatment group and 369 to the control group. Thirty-nine cows (5.3%) developed a DA after testing positive for SCK and 30 cows (4.0%) died or were sold within the first 30 DIM. Based on risk ratios, control cows were 1.6 times more likely [95% confidence interval (CI)=1.3 to 2.0] to develop a DA and 2.1 times more likely (95% CI=1.2 to 3.6) to die or be sold than cows treated with PG. In addition, PG-treated cows were 1.3 times more likely (risk ratio 95% CI=1.1 to 1.5) to conceive at first insemination than control cows in 3 of the herds. No difference was observed in days to conception within 150 DIM between treatment groups (hazard ratio for PG cows=1.1, 95% CI=0.8 to 1.4), with a median time to conception of 100 d (95% CI=93 to 111) and 104 d (95% CI=95 to 114) for PG-treated and control cows, respectively. These results show that intensive detection of SCK, followed by treatment of positive cows with oral PG decreased the risk of developing a DA or leaving the herd within the first 30 DIM and increased the risk of conception to first service. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Hydrogenolysis of Glycerol to Propylene Glycol on Nanosized Cu-Zn-Al Catalysts Prepared Using Microwave Process.

PubMed

Kim, Dong Won; Ha, Sang Ho; Moon, Myung Jun; Lim, Kwon Taek; Ryu, Young Bok; Lee, Sun Do; Lee, Man Sig; Hong, Seong-Soo

2015-01-01

Cu-Zn-Al catalysts were prepared using microwave-assisted process and co-precipitation methods. The prepared catalysts were characterized by XRD, BET, XPS and TPD of ammonia and their catalytic activity for the hydrogenolysis of glycerol to propylene glycol was also examined. The XRD patterns of Cu/Zn/Al mixed catalysts show CuO and ZnO crystalline phase regardless of preparation method. The highest glycerol hydrogenolysis conversion is obtained with the catalyst having a Cu/Zn/Al ratio of 2:2:1. Hydrogen pre-reduction of catalysts significantly enhanced both glycerol conversions and selectivity to propylene glycol. The glycerol conversion increased with an increase of reaction temperature. However, the selectivity to propylene glycol increased with an increase of temperature, and then declined to 30.5% at 523 K.

The effect of additives on release and in vitro skin retention of flavonoids from emulsion and gel semisolid formulations.

PubMed

Dyja, R; Jankowski, A

2017-08-01

To assess the effect of two different additives (propylene glycol (PG) and polyethylene glycol 400 (PEG 400)) on release and in vitro skin retention of quercetin and chrysin from semisolid bases (amphiphilic creams and acidic carbomer gels). For obtaining semisolid formulations, flavonoids were pre-dissolved in the liquid (PG or PEG 400) or directly suspended in the semisolid base. Three chrysin formulations ('cream 0', 'PG-cream' and 'PEG 400-cream') and five quercetin formulations ('cream 0', 'PG cream', 'PEG 400 cream', 'gel 0' and 'PG gel') were prepared. The release studies were carried out in Franz diffusion cells by means of a cellulose membrane. The porcine ear skin was used in in vitro skin retention studies. The dissolution was a prerequisite to increase the release rates of tested flavonoids from obtained semisolid formulations. The cumulative amount of chrysin released after 6 h from 'PEG 400 cream' containing partly dissolved form of that flavonoid was higher than that from 'cream 0' or 'PG cream' containing its suspended form. The formulations containing quercetin dissolved in PG ('PG cream', 'PG gel') or PEG 400 ('PEG 400 cream') exhibited higher release rates of that flavonoid than corresponding semisolid suspensions ('cream 0' or 'gel 0'). The effects of both liquid additives (PG and PEG 400) on the cumulative amount of quercetin released after 6 h were comparable. However, there was no correlation between the release rate and the skin retention. The amounts of the flavonoids found in the skin were strongly affected by the type of the used solvent. While PG increased the skin retention of both flavonoids, PEG 400 had no effect on chrysin skin retention and delayed quercetin skin absorption. The proper choice of the solvent added to the semisolid base is crucial for enhanced skin delivery of the tested flavonoids. PG is more efficient absorption promoter than PEG 400 of both chrysin and quercetin. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Crystallization of toxic glycol solvates of rifampin from glycerin and propylene glycol contaminated with ethylene glycol or diethylene glycol.

PubMed

de Villiers, Melgardt M; Caira, Mino R; Li, Jinjing; Strydom, Schalk J; Bourne, Susan A; Liebenberg, Wilna

2011-06-06

This study was initiated when it was suspected that syringe blockage experienced upon administration of a compounded rifampin suspension was caused by the recrystallization of toxic glycol solvates of the drug. Single crystal X-ray structure analysis, powder X-ray diffraction, thermal analysis and gas chromatography were used to identify the ethylene glycol in the solvate crystals recovered from the suspension. Controlled crystallization and solubility studies were used to determine the ease with which toxic glycol solvates crystallized from glycerin and propylene glycol contaminated with either ethylene or diethylene glycol. The single crystal structures of two distinct ethylene glycol solvates of rifampin were solved while thermal analysis, GC analysis and solubility studies confirmed that diethylene glycol solvates of the drug also crystallized. Controlled crystallization studies showed that crystallization of the rifampin solvates from glycerin and propylene glycol depended on the level of contamination and changes in the solubility of the drug in the contaminated solvents. Although the exact source of the ethylene glycol found in the compounded rifampin suspension is not known, the results of this study show how important it is to ensure that the drug and excipients comply with pharmacopeial or FDA standards.

Dynamics of aqueous binary glass-formers confined in MCM-41.

PubMed

Elamin, Khalid; Jansson, Helén; Swenson, Jan

2015-05-21

Dielectric permittivity measurements were performed on water solutions of propylene glycol (PG) and propylene glycol monomethyl ether (PGME) confined in 21 Å pores of the silica matrix MCM-41 C10 in wide frequency (10(-2)-10(6) Hz) and temperature (130-250 K) ranges. The aim was to elucidate how the formation of large hydrogen bonded structural entities, found in bulk solutions of PGME, was affected by the confined geometry, and to make comparisons with the dynamic behavior of the PG-water system. For all solutions the measurements revealed four almost concentration independent relaxation processes. The intensity of the fastest process is low compared to the other relaxation processes and might be caused by both hydroxyl groups of the pore surfaces and by local motions of water and solute molecules. The second fastest process contains contributions from both the main water relaxation as well as the intrinsic β-relaxation of the solute molecules. The third fastest process is the viscosity related α-relaxation. Its concentration independency is very different compared to the findings for the corresponding bulk systems, particularly for the PGME-water system. The experimental data suggests that the surface interactions induce a micro-phase separation of the two liquids, resulting in a full molecular layer of water molecules coordinating to the hydrophilic hydroxyl groups on the surfaces of the silica pores. This, in turn, increases the geometrical confinement effect for the remaining solution even more and prevents the building up of the same type of larger structural entities in the PGME-water system as in the corresponding bulk solutions. The slowest process is mainly hidden in the high conductivity contribution at low frequencies, but its temperature dependence can be extracted for the PGME-water system. However, its origin is not fully clear, as will be discussed.

Randomized clinical field trial on the effects of butaphosphan-cyanocobalamin and propylene glycol on ketosis resolution and milk production.

PubMed

Gordon, J L; LeBlanc, S J; Kelton, D F; Herdt, T H; Neuder, L; Duffield, T F

2017-05-01

The purpose of this study was to determine the effects of a butaphosphan-cyanocobalamin combination product (B+C) and 2 durations of propylene glycol treatment (PG; 3 versus 5 d) on ketosis resolution and early lactation milk yield. Cows from 9 freestall herds (8 in Ontario and 1 in Michigan) were tested at weekly intervals between 3 and 16 d in milk. Ketosis was defined as blood β-hydroxybutyrate (BHB) ≥1.2 mmol/L. Ketotic cows were randomly assigned to treatment with 25 mL of B+C or 25 mL of saline placebo for 3 d and 3 or 5 d of 300 g of PG orally in a 2 × 2 factorial arrangement. Outcomes evaluated for all farms included ketosis cure (blood BHB <1.2 mmol/L at 1 wk after enrollment), maintenance of ketosis cure (blood BHB <1.2 mmol/L 1 and 2 wk after enrollment), and blood BHB concentrations at 1 and 2 wk after enrollment. Daily milk weights were collected in 3 herds. Poisson regression was used to evaluate cure and maintenance of cure, whereas repeated-measures ANOVA was used to evaluate blood BHB concentrations in the 2 wk after enrollment and average daily milk production in the 30 d after treatment. A total of 594 animals were enrolled in the study with 124 treated with B+C and 5 d of PG, 176 treated with B+C and 3 d of PG, 128 treated with saline and 5 d of PG, and 166 treated with saline and 3 d of PG. Animals with blood BHB >2.4 mmol/L at the time of enrollment were 1.7 times more likely [95% confidence interval (CI): 1.4 to 2.2] to cure and had a decrease of 0.25 ± 0.11 mmol/L blood BHB at 1 wk after enrollment if treated with 5 d of PG compared with 3 d, though this response was not seen in animals with BHB of 1.2 to 2.4 mmol/L at enrollment. Cows with blood glucose concentrations <2.2 mmol/L at enrollment produced 3.1 kg/d (95% CI: 1.3 to 5.0) more milk if treated with B+C and 3.4 kg/d (95% CI: 1.7 to 5.1) more milk if treated with 5 d of PG compared with their respective controls. This response was not seen in animals with blood glucose ≥2.2 mmol/L at enrollment and there was no interaction between treatments. These results indicate that extended PG treatment is beneficial in decreasing blood BHB concentrations in more severely affected animals. Additionally, both B+C treatment and extended PG treatment improved milk yield in animals with low blood glucose at the time of ketosis diagnosis. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Methods of producing compounds from plant material

DOEpatents

Werpy, Todd A.; Schmidt, Andrew J.; Frye, Jr., John G.; Zacher, Alan H.; Franz, James A.; Alnajjar, Mikhail S.; Neuenschwander, Gary G.; Alderson, Eric V.; Orth, Rick J.; Abbas, Charles A.; Beery, Kyle E.; Rammelsberg, Anne M.; Kim, Catherine J.

2006-01-03

The invention includes methods of processing plant material by adding water to form a mixture, heating the mixture, and separating a liquid component from a solid-comprising component. At least one of the liquid component and the solid-comprising component undergoes additional processing. Processing of the solid-comprising component produces oils, and processing of the liquid component produces one or more of glycerol, ethylene glycol, lactic acid and propylene glycol. The invention includes a process of forming glycerol, ethylene glycol, lactic acid and propylene glycol from plant matter by adding water, heating and filtering the plant matter. The filtrate containing starch, starch fragments, hemicellulose and fragments of hemicellulose is treated to form linear poly-alcohols which are then cleaved to produce one or more of glycerol, ethylene glycol, lactic acid and propylene glycol. The invention also includes a method of producing free and/or complexed sterols and stanols from plant material.

Methods of producing compounds from plant materials

DOEpatents

Werpy, Todd A [West Richland, WA; Schmidt, Andrew J [Richland, WA; Frye, Jr., John G.; Zacher, Alan H. , Franz; James A. , Alnajjar; Mikhail S. , Neuenschwander; Gary G. , Alderson; Eric V. , Orth; Rick J. , Abbas; Charles A. , Beery; Kyle E. , Rammelsberg; Anne M. , Kim; Catherine, J [Decatur, IL

2010-01-26

The invention includes methods of processing plant material by adding water to form a mixture, heating the mixture, and separating a liquid component from a solid-comprising component. At least one of the liquid component and the solid-comprising component undergoes additional processing. Processing of the solid-comprising component produces oils, and processing of the liquid component produces one or more of glycerol, ethylene glycol, lactic acid and propylene glycol. The invention includes a process of forming glycerol, ethylene glycol, lactic acid and propylene glycol from plant matter by adding water, heating and filtering the plant matter. The filtrate containing starch, starch fragments, hemicellulose and fragments of hemicellulose is treated to form linear poly-alcohols which are then cleaved to produce one or more of glycerol, ethylene glycol, lactic acid and propylene glycol. The invention also includes a method of producing free and/or complexed sterols and stanols from plant material.

Propylene glycol

Integrated Risk Information System (IRIS)

Propylene glycol ; CASRN 57 - 55 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents.

PubMed

Troutt, William D; DiDonato, Matthew D

2017-11-01

Cannabis use has increased in the United States, particularly the use of vaporized cannabis oil, which is often mixed with thinning agents for use in vaporizing devices. E-cigarette research shows that heated thinning agents produce potentially harmful carbonyls; however, similar studies have not been conducted (1) with agents that are commonly used in the cannabis industry and (2) at temperatures that are appropriate for cannabis oil vaporization. The goal of this study was to determine whether thinning agents used in the cannabis industry produce potentially harmful carbonyls when heated to a temperature that is appropriate for cannabis oil vaporization. Four thinning agents (propylene glycol [PG], vegetable glycerin [VG], polyethylene glycol 400 [PEG 400], and medium chain triglycerides [MCT]) were heated to 230°C and the resulting vapors were tested for acetaldehyde, acrolein, and formaldehyde. Each agent was tested three times. Testing was conducted in a smoking laboratory. Carbonyl levels were measured in micrograms per puff block. Analyses showed that PEG 400 produced significantly higher levels of acetaldehyde and formaldehyde than PG, MCT, and VG. Formaldehyde production was also significantly greater in PG compared with MCT and VG. Acrolein production did not differ significantly across the agents. PG and PEG 400 produced high levels of acetaldehyde and formaldehyde when heated to 230°C. Formaldehyde production from PEG 400 isolate was particularly high, with one inhalation accounting for 1.12% of the daily exposure limit, nearly the same exposure as smoking one cigarette. Because PG and PEG 400 are often mixed with cannabis oil, individuals who vaporize cannabis oil products may risk exposure to harmful formaldehyde levels. Although more research is needed, consumers and policy makers should consider these potential health effects before use and when drafting cannabis-related legislation.

Propylene glycol monomethyl ether (PGME)

Integrated Risk Information System (IRIS)

Propylene glycol monomethyl ether ( PGME ) ; CASRN 107 - 98 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

Propylene glycol monoethyl ether

Integrated Risk Information System (IRIS)

Propylene glycol monoethyl ether ; CASRN 52125 - 53 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments fo

Inert Reassessment Document for Propylene glycol alginate - CAS No. 9005-37-2

EPA Pesticide Factsheets

As an inert pesticide ingredient, propylene glycol alginate is exempt from the requirement for a tolerance when used as a deforming agent in pesticide formulations applies to growing crops, or to raw agricultural commodities after harvest.

Physicochemical properties of valsartan and the effect of ethyl alcohol, propylene glycol and pH on its solubility.

PubMed

Mbah, C J

2005-11-01

The aqueous solubility and partition coefficient of valsartan were determined at room temperature. The effect of ethyl alcohol, propylene glycol and pH on its solubility was also investigated. It was found that both solvents increased the solubility of the drug in water. The solubilizing power of ethyl alcohol was found to be higher than that of propylene glycol. Valsartan solubility was also observed to increase at high pH values and its lipophilicity wasdemonstrated by the high positive value of the logarithm of partition coefficient.

Characterization of Propylene Glycol-Mitigated Freeze/Thaw Agglomeration of a Frozen Liquid nOMV Vaccine Formulation by Static Light Scattering and Micro-Flow Imaging.

PubMed

Mensch, Christopher D; Davis, Harrison B; Blue, Jeffrey T

2015-01-01

The purpose of this work was to investigate the susceptibility of an aluminum adjuvant and an aluminum-adjuvanted native outer membrane vesicle (nOMV) vaccine formulation to freeze/thaw-induced agglomeration using static light scattering and micro-flow Imaging analysis; and to evaluate the use of propylene glycol as a vaccine formulation excipient by which freeze/thaw-induced agglomeration of a nOMV vaccine formulation could be mitigated. Our results indicate that including 7% v/v propylene glycol in an nOMV containing aluminum adjuvanted vaccine formulation, mitigates freeze/thaw-induced agglomeration. We evaluated the effect of freeze-thawing on an aluminum adjuvant and an aluminum adjuvanted native outer membrane vesicle (nOMV) vaccine formulation. Specifically, we characterized the freeze/thaw-induced agglomeration through the use of static light scattering, micro-flow imaging, and cryo-electron microscopy analysis. Further, we evaluated the use of 0-9% v/v propylene glycol as an excipient which could be included in the formulation for the purpose of mitigating the agglomeration induced by freeze/thaw. The results indicate that using 7% v/v propylene glycol as a formulation excipient is effective at mitigating agglomeration of the nOMV vaccine formulation, otherwise induced by freeze-thawing. © PDA, Inc. 2015.

In-vitro permeation of the insect repellent N,N-diethyl-m-toluamide (DEET) and the sunscreen oxybenzone.

PubMed

Gu, Xiaochen; Kasichayanula, Sreeneeranj; Fediuk, Daryl J; Burczynski, Frank J

2004-05-01

The permeation behaviours of the insect repellent N,N-diethyl-m-toluamide (DEET) and the sunscreen oxybenzone were assessed in a series of in-vitro diffusion studies, using piglet skin and poly (dimethylsiloxane) (PDMS) membrane. The transmembrane permeability of DEET and oxybenzone across piglet skin and PDMS membrane was dependent on dissolving vehicles and test concentrations. An enhanced permeation increase across piglet skin was found for DEET and oxybenzone when both compounds were present in the same medium (DEET: 289% in propylene glycol, 243% in ethanol and 112% in poly(ethylene glycol) (PEG-400); oxybenzone: 139% in PEG-400, 120% in propylene glycol and 112% in ethanol). Permeation enhancement was also observed in PDMS membrane (DEET: 207% in ethanol, 124% in PEG-400 and 107% in propylene glycol; oxybenzone: 254% in PEG-400, 154% in ethanol and 105% in propylene glycol). PDMS membrane was found to be a suitable candidate for in-vitro diffusion evaluations. This study shows that the permeations of the insect repellent DEET and the sunscreen oxybenzone were synergistically enhanced when they were applied simultaneously.

Impact of the propylene glycol-water-borax coolant on material recovery operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duerksen, W.K.; Taylor, P.A.

1983-05-01

The reaction of the propylene glycol-water-borax coolant with nitric acid has now been studied in some detail. This document is intended to provide a summary of the results. Findings are summarized under nine headings. Tests have also been conducted to determine if the new coolant would have any adverse effects on the uranium recycle systems. Experiments were scientifically designed after observation of the production operations so that accurate response to the immediate production concerns could be provided. Conclusions from these studies are: formation of glycol nitrates is very improbable; the reaction of concentrated (70%) nitric acid with pure propylene glycolmore » is very violent and hazardous; dilution of the nitric acid-glycol mixture causes a drastic decrease in the rate and intensity of the reaction; the mechanism of the nitric acid propylene glycol reaction is autocatalytic in nitrous acid; no reaction is observed between coolant and 30% nitric acid unless the solution is heated; the coolant reacts fairly vigorously with 55% nitric acid after a concentration-dependent induction time; experiments showed that the dissolution of uranium chips that had been soaked in coolant proceeded at about the same rate as if the chips had not previously contacted glycol; thermodynamic calculations show that the enthalpy change (heat liberated) by the reaction of nitric acid (30%) with propylene glycol is smaller than if the same amount of nitric acid reacted with uranium. Each of these conclusions is briefly discussed. The effect of new coolant on uranium recycle operations is then briefly discussed.« less

Solution stability of Captisol-stabilized melphalan (Evomela) versus Propylene glycol-based melphalan hydrochloride injection.

PubMed

Singh, Ramsharan; Chen, Jin; Miller, Teresa; Bergren, Michael; Mallik, Rangan

2016-12-14

The objective of this study was to compare the stability of recently approved Captisol-stabilized propylene glycol-free melphalan injection (Evomela™) against currently marketed propylene glycol-based melphalan injection. The products were compared as reconstituted solutions in vials as well as admixture solutions prepared from normal saline in infusion bags. Evomela and propylene glycol-based melphalan injection were reconstituted in normal saline and organic custom diluent, respectively, according to their package insert instructions. The reconstituted solutions were diluted in normal saline to obtain drug admixture solutions at specific drug concentrations. Stability of the solutions was studied at room temperature by assay of melphalan and determination of melphalan-related impurities. Results show that based on the increase in total impurities in propylene glycol-based melphalan injection at 0.45 mg/mL, Evomela admixture solutions are about 5, 9, 15 and 29 times more stable at concentrations of 0.45, 1.0, 2.0 and 5.0 mg/mL, respectively. Results confirmed that reconstituted Evomela solution can be stored in the vial for up to 1 h at RT or for up to 24 h at refrigerated temperature (2-8 °C) with no significant degradation. After storage in the vial, it remains stable for an additional 3-29 h after preparation of admixture solution in infusion bags at concentrations of 0.25-5.0 mg/mL, respectively. In addition, Evomela solution in saline, at concentration of 5.0 mg/mL melphalan was bacteriostatic through 72 h storage at 2-8 °C. Formulation of melphalan with Captisol technology significantly improved stability compared to melphalan hydrochloride reconstituted with propylene-glycol based diluents.

A freeze-stable formulation for DTwP and DTaP vaccines.

PubMed

Xue, Honggang; Yang, Bangling; Kristensen, Debra D; Chen, Dexiang

2014-01-01

Inadvertent vaccine freezing often occurs in the cold chain and may cause damage to freeze‑sensitive vaccines. Liquid vaccines that contain aluminum salt adjuvants are particularly vulnerable. Polyol cryoprotective excipients have been shown to prevent freeze damage to hepatitis B vaccine. In this study, we examined the freeze-protective effect of propylene glycol on diphtheria-tetanus-pertussis-whole-cell (DTwP) and acellular (DTaP) vaccines. Pilot lots of DTwP and DTaP formulated with 7.5% propylene glycol underwent 3 freeze-thaw treatments. The addition of propylene glycol had no impact on pH, particle size distribution, or potency of the vaccines prior to freeze-thaw treatment; the only change noted was an increase in osmolality. The potencies and the physical properties of the vaccines containing cryoprotectant were maintained after freeze-thawing and for 3 months in accelerated stability studies. The results from this study indicate that formulating vaccines with propylene glycol can protect diphtheria-tetanus-pertussis vaccines against freeze damages.

Solvent Chemistry in the Electronic Cigarette Reaction Vessel

NASA Astrophysics Data System (ADS)

Jensen, R. Paul; Strongin, Robert M.; Peyton, David H.

2017-02-01

Knowledge of the mechanism of formation, levels and toxicological profiles of the chemical products in the aerosols (i.e., vapor plus particulate phases) of e-cigarettes is needed in order to better inform basic research as well as the general public, regulators, and industry. To date, studies of e-cigarette emissions have mainly focused on chromatographic techniques for quantifying and comparing the levels of selected e-cigarette aerosol components to those found in traditional cigarettes. E-cigarettes heat and aerosolize the solvents propylene glycol (PG) and glycerol (GLY), thereby affording unique product profiles as compared to traditional cigarettes. The chemical literature strongly suggests that there should be more compounds produced by PG and GLY than have been reported in e-cigarette aerosols to date. Herein we report an extensive investigation of the products derived from vaporizing PG and GLY under mild, single puff conditions. This has led to the discovery of several new compounds produced under vaping conditions. Prior reports on e-cigarette toxin production have emphasized temperature as the primary variable in solvent degradation. In the current study, the molecular pathways leading to enhanced PG/GLY reactivity are described, along with the most impactful chemical conditions promoting byproduct production.

Adult Behavior in Male Mice Exposed to E-Cigarette Nicotine Vapors during Late Prenatal and Early Postnatal Life.

PubMed

Smith, Dani; Aherrera, Angela; Lopez, Armando; Neptune, Enid; Winickoff, Jonathan P; Klein, Jonathan D; Chen, Gang; Lazarus, Philip; Collaco, Joseph M; McGrath-Morrow, Sharon A

2015-01-01

Timed-pregnant C57BL/6J mice were exposed to 2.4% nicotine in propylene glycol (PG) or 0% nicotine /PG once a day from gestational day 15 until delivery. After delivery, offspring and mothers were exposed to E-cigarette vapors for an additional 14 days from postnatal day 2 through 16. Following their last exposure serum cotinine levels were measured in female juvenile mice. Male mice underwent behavioral testing at 14 weeks of age to assess sensorimotor, affective, and cognitive functional domains. Adult male mice exposed to 2.4% nicotine/PG E-cigarette vapors had significantly more head dips in the zero maze test and higher levels of rearing activity in the open field test compared to 0% nicotine/PG exposed mice and untreated controls. In the water maze test after reversal training, the 2.4% nicotine/PG mice spent more than 25% of time in the new location whereas the other groups did not. Adult male mice exhibited increased levels of activity in the zero maze and open field tests when exposed to E-cigarette vapor containing nicotine during late prenatal and early postnatal life. These findings indicate that nicotine exposure from E-cigarettes may cause persistent behavioral changes when exposure occurs during a period of rapid brain growth.

21 CFR 184.1666 - Propylene glycol.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propylene glycol. 184.1666 Section 184.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

21 CFR 184.1666 - Propylene glycol.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Propylene glycol. 184.1666 Section 184.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

21 CFR 582.1666 - Propylene glycol.

Code of Federal Regulations, 2010 CFR

2010-04-01

... is generally recognized as safe (except in cat food) when used in accordance with good manufacturing... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

21 CFR 582.1666 - Propylene glycol.

Code of Federal Regulations, 2011 CFR

2011-04-01

... is generally recognized as safe (except in cat food) when used in accordance with good manufacturing... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylated fatty acid esters of glycerol and... DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and...

21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Lactylated fatty acid esters of glycerol and... DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and...

Propylene Glycol-Related Delirium After Esmolol Infusion.

PubMed

Kapitein, Berber S; Biesmans, Renee S C G; van der Sijs, Heleen S I; de Wildt, Saskia S N

2014-07-01

Excipients used in oral or intravenous preparations may cause serious adverse events. We present the case of a 15-year-old boy with hypertrophic cardiomyopathy. In the pediatric intensive care unit, he received high doses of continuous intravenous esmolol (range = 20-400 µg/kg/min) for cardiac rhythm control. After a few days he developed a delirium not responding to high doses of antipsychotics or discontinuation of benzodiazepines. We eventually realized that the IV esmolol formulation contained high doses of propylene glycol and ethanol, which may accumulate after prolonged infusion and cause intoxication. Intoxication with propylene glycolcan cause neuropsychiatric symptoms. The boy's propylene glycol plasma concentration was approximately 4 g/L, whereas clinical symptoms arise at concentrations above 1 to 1.44 g/L. Application of the Naranjo adverse drug reaction probability scale suggested a probable relationship (score 6) between the propylene glycol infusion and the delirium. After discontinuation of esmolol, the delirium disappeared spontaneously. This is the first case describing excipient toxicity of esmolol, with an objective causality assessment revealing a probable relationship for the adverse event-namely, delirium-and esmolol. Although excipient toxicity is a well-known adverse drug reaction, this case stresses the importance for easily available information for and education of physicians. © The Author(s) 2014.

Evaluation of the effect of green tea extract on mouth bacterial activity in the presence of propylene glycol.

PubMed

Moghbel, Abdolhossein; Farjzadeh, Ahmad; Aghel, Nasrin; Agheli, Homaun; Raisi, Nafiseh

2012-01-01

Compounds present in green tea have proved to inhibit the growth and activity of bacteria associated with infections. To assess the effects of green tea leaves extract in presence of propylene glycol on the aerobic mouth bacteria load. Saliva of 25 volunteer girl students aging 20-25 years were selected and evaluated by a mouthwash sample containing 1% tannin, as the most effective antibacterial complex in green tea. Comparative studies were also conducted between green tea mouthwashes containing 1% tannin and a similar sample with 10% propylene glycol added during extraction. This comparison was applied for a chlorhexidine 0.2% sample as a chemical mouthwash brand, too. There was a meaningful difference between the green tea mouthwashes containing 10% propylene glycol and the simple green tea extract (P < 0.05). Significant difference was also seen between the herbal and chemical mouthwashes (P < 0.05). The extract 1% tannin containing 10% propylene glycol reduced the aerobic mouth bacterial load of the student salvia about 64 percent. The pH monotonousness in different days and temperatures approved the stability of tannin in liquid water medium. Using green tea extract as a herbal mouthwash is safe and harmless specially for children and pregnant women. This result led us to suppose that green tea may prevent plaque formation on teeth, coming over halitosis due to mouth infection, too. These effects need to be approved in an in vivo trial as a second study.

Smart poly(oligo(propylene glycol) methacrylate) hydrogel prepared by gamma radiation

NASA Astrophysics Data System (ADS)

Suljovrujic, E.; Micic, M.

2015-01-01

The synthesis of poly(oligo(propylene glycol) methacrylate) (POPGMA) from functionalised oligo(propylene glycol) methacrylate (OPGMA) monomers by gamma radiation-induced radical polymerisation is reported for the first time; POPGMA homopolymeric hydrogel with oligo(propylene glycol) (OPG) pendant chains, as a non-linear PPGMA-analogue, was synthesised from an monomer-solvent (OPGMA375-water/ethanol) mixture at different irradiation doses (5, 10, 25, and 40 kGy). Determination of the gel fraction was conducted after synthesis. The swelling properties of the POPGMA hydrogel were preliminarily investigated over wide pH (2.2-9.0) and temperature (4-70 °C) ranges. Additional characterisation of structure and properties was conducted by UV-vis and Fourier transform infrared (FTIR) spectroscopy as well as by differential scanning calorimetry (DSC). In order to evaluate the potential for biomedical applications, biocompatibility (cytocompatibility and haemolytic activity) studies were performed as well. Sol-gel conversion was relatively high for all irradiation doses, indicating radiation-induced synthesis as a good method for fabricating this hydrogel. Thermoresponsiveness and variations in swelling capacity as a result of thermosensitive OPG pendant chains with a lower critical solution temperature (LCST) were mainly observed below room temperature; thus, the volume phase transition temperature (VPTT) of POPGMA homopolymeric hydrogel is about 15 °C. Furthermore, POPGMA has satisfactory biocompatibility. The results indicate that the hydrogels with propylene glycol pendant chains can be easily prepared by gamma radiation and have potential for different applications as smart and biocompatible polymers.

Comparison of biodegradation of poly(ethylene glycol)s and poly(propylene glycol)s.

PubMed

Zgoła-Grześkowiak, Agnieszka; Grześkowiak, Tomasz; Zembrzuska, Joanna; Łukaszewski, Zenon

2006-07-01

The biodegradation of poly(ethylene glycol)s (PEGs) and poly(propylene glycol)s (PPGs), both being major by-products of non-ionic surfactants biodegradation, was studied under the conditions of the River Water Die-Away Test. PEGs were isolated from a water matrix using solid-phase extraction with graphitized carbon black sorbent, then derivatized with phenyl isocyanate and determined by HPLC with UV detection. PPGs were isolated from a water matrix by liquid-liquid extraction with chloroform, then derivatized with naphthyl isocyanate and determined by HPLC with fluorescence detection. The primary biodegradation of both PEGs and PPGs reached approximately 99% during the test. The tests show different biodegradation pathways of PEG and PPG. During PEG biodegradation, their chains are shortened leading to the formation of ethylene glycol and diethylene glycol. During PPG biodegradation, no short-chained biodegradation products were found.

Effects of propylene glycol drenching before and after luteolysis on blood glucose, ovarian steroids and follicular dynamics in heifers.

PubMed

Umeki, A; Tanaka, T; Kamomae, H

2012-02-01

The effect of propylene glycol drenching on ovarian and hormonal dynamics was studied in heifers. Five cycling heifers were used twice (as control and treatment) with crossover design. After the confirmation of ovulation (day 0), the heifers in the treatment group received propylene glycol on days 6, 7 and 8 as an oral drench (250 ml of 90% propylene glycol). On day 10, prostaglandin F2α (PGF2α), 15 mg per head of dinoprost, was administered intramuscularly to induce luteal regression followed by the follicular phase and then propylene glycol was again administered twice daily (500 ml/day) on days 10, 11 and 12. Palpation per rectum and ovarian ultrasonography were performed every other day from days 0 to 10, and daily after PGF2α administration until the subsequent ovulation (second ovulation) for analysis of follicular and luteal dynamics. Blood samples were also collected every other day from days 0 to 10, and then at 6 h intervals after PGF2α administration until the second ovulation. For the samples taken at 6-h intervals after PGF2α administration, the concentrations of glucose showed clear daily fluctuations in both groups. Changes in the plasma concentration of glucose in the treatment group were significantly (P < 0.05) higher than those of the control groups during the period between 0 and 72 h after PGF2α administration. No significant difference was detected in the growth of dominant follicles, maximum diameter of the ovulatory follicles and the changes in oestradiol and progesterone during the follicular phase between treatment and control groups. This study showed the clear daily fluctuations and stimulatory changes in the blood glucose concentrations at 24-h intervals during the short-term treatment of propylene glycol drenching in heifers. However, no significant changes in ovarian and hormonal dynamics were found under such metabolic conditions.

Antifreeze poisoning

MedlinePlus

The poisonous ingredients in antifreeze are: Ethylene glycol Methanol Propylene glycol ... For ethylene glycol: Death may occur within the first 24 hours. If the patient survives, there may be little ...

A field trial on the effect of propylene glycol on milk yield and resolution of ketosis in fresh cows diagnosed with subclinical ketosis.

PubMed

McArt, J A A; Nydam, D V; Ospina, P A; Oetzel, G R

2011-12-01

The purpose of this study was to determine the effect of oral propylene glycol (PG) administration on ketosis resolution and milk yield in cows diagnosed with subclinical ketosis (SCK). Cows from 4 freestall dairy herds (2 in New York and 2 in Wisconsin) were each tested 6 times for SCK from 3 to 16 d in milk on Mondays, Wednesdays, and Fridays. Subclinical ketosis was defined as a β-hydroxybutyrate (BHBA) concentration of 1.2 to 2.9 mmol/L, [corrected] and clinical ketosis was defined as ≥ 3.0 mmol/L. [corrected]. Cows with SCK were randomized to the treatment group (oral PG) or control group (no PG); treatment cows were drenched with 300 mL of PG once daily from the day they tested 1.2 to 2.9 mmol/L [corrected] until the day they tested <1.2 mmol/L. [corrected]. Outcomes evaluated for all farms included time from SCK until BHBA test <1.2 mmol/L [corrected] or until BHBA test ≥ 3.0 mmol/L. [corrected]. Individual milk weights for the first 30 d of lactation were evaluated for the 3 farms monitoring daily milk. Semiparametric proportional hazards models were used to evaluate time to event outcomes; repeated-measures ANOVA was used to assess milk weights. A total of 741 of 1,717 (43.2%) eligible enrolled cows had at least one BHBA test of 1.2 to 2.9 mmol/L. [corrected]. Of these, 372 were assigned to the treatment group and 369 to the control group. Based on hazard ratios, PG-treated cows were 1.50 times more likely (95% confidence interval=1.26 to 1.79) to resolve their SCK and 0.54 times less likely (95% confidence interval=0.34 to 0.86) to develop clinical ketosis than control cows. Across the 3 herds measuring individual milk weights, treated cows produced 0.23 kg more milk per milking in the first 30 d of lactation than control cows, for a total difference of 0.69 kg/cow per day. After identification of a treatment by herd interaction, stratification by herd showed that treated cows produced more milk per milking on farm A (0.44 kg) and farm B (0.53 kg) in the first 30 d of lactation than control cows, for a total difference of 1.34 and 1.59 kg/d, respectively; milk production did not differ (0.02 kg per milking) between the 2 groups on farm D. These results show the positive effects of oral PG administration in fresh cows with SCK by helping to resolve SCK and preventing clinical ketosis. In addition, oral PG improves milk yield during early lactation in cows diagnosed with SCK. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Kinetics of microbial degradation of deicing chemicals in percolated porous media - the modeling perspective

NASA Astrophysics Data System (ADS)

Wehrer, Markus; Lissner, Heidi; Totsche, Kai

2013-04-01

A quantitative knowledge of the fate of deicing chemicals in the subsurface can be provided by analysis of laboratory and field experiments with numerical simulation models. In the present study, experimental data of microbial degradation of the deicing chemical propylene glycol (PG) under flow conditions in soil columns and field lysimeters were simulated to analyze the process conditions of degradation and to obtain the according parameters. Results from the column experiment were evaluated applying different scenarios of an advection-dispersion model using HYDRUS-1D. To reconstruct the data, different competing degradation models were included, i.e., zero order, first order and inclusion of a growing and decaying biomass. The general breakthrough behavior of propylene glycol in soil columns can be simulated well using a coupled model of solute transport and degradation with growth and decay of biomass. The susceptibility of the model to non-unique solutions was investigated using systematical forward and inverse simulations. We found that the model tends to equifinal solutions under certain conditions. Complex experimental boundary conditions can help to avoid this. Under field conditions, the situation is far more complex than in the laboratory. Studying the fate of PG with undisturbed lysimeters we found that aerobic and anaerobic degradation occurs simultaneously. We attribute this to the physical structure and the aggregated nature of the undisturbed soil material . This results in the presence of spatially disjoint oxidative and reductive regions of microbial activity and requires, but is not fully reflected by a dual porosity model. Currently, the numerical simulation of this system is in progress, considering several flow and transport models. A stochastic global search algorithm (DREAM-ZS) is used in conjuction with HYDRUS-1D to avoid local minima in the inverse simulations. The study shows the current limitations and potentials of modeling degradation in an aggregated and structured system under flow conditions.

Successful sperm cryopreservation of the brown-marbled grouper, Epinephelus fuscoguttatus using propylene glycol as cryoprotectant.

PubMed

Yusoff, Maisarah; Hassan, Badrul Nizam; Ikhwanuddin, Muhd; Sheriff, Shahreza Md; Hashim, Fatimah; Mustafa, Sufian; Koh, Ivan Chong Chu

2018-04-01

This study developed the cryopreservation of brown-marbled grouper spermatozoa for practical application. We examined 32 cryodiluents, developed from four types of cryoprotectants [propylene glycol (PG), dimethyl-sulphoxide (Me 2 SO), dimethyl-acetamide (DMA) and ethylene glycol (EG)] at four concentrations of 5, 10, 15 and 20% in combination with two extenders [Fetal bovine serum (FBS) and artificial seminal plasma (ASP). Cooling rates were examined by adjusting the height of straws (2.5-12.5 cm) from the liquid nitrogen (LN) vapor and cooled for 5 min before immersion into LN. DNA laddering was used to detect DNA damage in cryopreserved sperm. In fertilization trials, 0.5 g of eggs was mixed with cryopreserved sperm stored for 30 days in LN. The best motility of post-thaw sperm was achieved using 15% PG + 85% FBS (76.7 ± 8.8%); 10% PG + 90% FBS was also effective as cryodiluent. Generally, FBS gave better post-thaw motility compared to ASP. The optimum cooling rate was at 17.6 °C min -1 obtained by freezing at the height of 7.5 cm surface of LN. The results obtained showed that cryopreserved sperm of brown-marbled grouper suffered slight DNA fragmentation, which resulted in significantly lower motility. However, the fertilization (90.9 ± 0.5%), hatching (64.5 ± 4.1%) and deformity rates (3.8 ± 0.2%) obtained from cryopreserved sperm showed no significant difference with fresh sperm. These findings show that the developed protocol for cryopreservation of brown-marbled grouper sperm was viable and will be useful for successful breeding and seed production of brown-marbled grouper. Copyright © 2018 Elsevier Inc. All rights reserved.

Optimization of a novel improver gel formulation for Barbari flat bread using response surface methodology.

PubMed

Pourfarzad, Amir; Haddad Khodaparast, Mohammad Hossein; Karimi, Mehdi; Mortazavi, Seyed Ali

2014-10-01

Nowadays, the use of bread improvers has become an essential part of improving the production methods and quality of bakery products. In the present study, the Response Surface Methodology (RSM) was used to determine the optimum improver gel formulation which gave the best quality, shelf life, sensory and image properties for Barbari flat bread. Sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM) and propylene glycol (PG) were constituents of the gel and considered in this study. A second-order polynomial model was fitted to each response and the regression coefficients were determined using least square method. The optimum gel formulation was found to be 0.49 % of SSL, 0.36 % of DATEM and 0.5 % of PG when desirability function method was applied. There was a good agreement between the experimental data and their predicted counterparts. Results showed that the RSM, image processing and texture analysis are useful tools to investigate, approximate and predict a large number of bread properties.

E-cigarette liquids: Constancy of content across batches and accuracy of labeling.

PubMed

Etter, Jean-François; Bugey, Aurélie

2017-10-01

To assess whether bottles of refill liquids for e-cigarettes were filled true to label, whether their content was constant across two production batches, and whether they contained impurities. In 2013, we purchased on the Internet 18 models from 11 brands of e-liquids. We purchased a second sample of the same models 4months later. We analyzed their content in nicotine, anabasine, propylene glycol, glycerol, ethylene glycol and diethylene glycol, and tested their pH. The median difference between the nicotine value on the labels and the nicotine content in the bottles was 0.3mg/mL (range -5.4 to +3.5mg/mL, i.e. -8% to +30%). For 82% of the samples, the actual nicotine content was within 10% of the value on the labels. All models contained glycerol (median 407mg/mL), and all but three models contained propylene glycol (median 650mg/mL). For all samples, levels of anabasine, ethylene glycol and diethylene glycol were below our limits of detection. The pH of all the e-liquids was alkaline (median pH=9.1; range 8.1 to 9.9). The measured content of two batches of the same model varied by a median of 0% across batches for propylene glycol, 1% for glycerol, 0% for pH, and 0.5% for nicotine (range -15% to +21%; 5th and 95th percentiles: -15% and +10%). The nicotine content of these e-liquids matched the labels on the bottles, and was relatively constant across production batches. The content of propylene glycol and glycerol was also stable across batches, as was the pH. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of the Effect of Green Tea Extract on Mouth Bacterial Activity in the Presence of Propylene Glycol

PubMed Central

Moghbel, Abdolhossein; Farjzadeh, Ahmad; Aghel, Nasrin; Agheli, Homaun; Raisi, Nafiseh

2012-01-01

Background Compounds present in green tea have proved to inhibit the growth and activity of bacteria associated with infections. Objectives To assess the effects of green tea leaves extract in presence of propylene glycol on the aerobic mouth bacteria load. Materials and Methods Saliva of 25 volunteer girl students aging 20-25 years were selected and evaluated by a mouthwash sample containing 1% tannin, as the most effective antibacterial complex in green tea. Comparative studies were also conducted between green tea mouthwashes containing 1% tannin and a similar sample with 10% propylene glycol added during extraction. This comparison was applied for a chlorhexidine 0.2% sample as a chemical mouthwash brand, too. Results There was a meaningful difference between the green tea mouthwashes containing 10% propylene glycol and the simple green tea extract (P < 0.05). Significant difference was also seen between the herbal and chemical mouthwashes (P < 0.05). The extract 1% tannin containing 10% propylene glycol reduced the aerobic mouth bacterial load of the student salvia about 64 percent. The pH monotonousness in different days and temperatures approved the stability of tannin in liquid water medium. Conclusions Using green tea extract as a herbal mouthwash is safe and harmless specially for children and pregnant women. This result led us to suppose that green tea may prevent plaque formation on teeth, coming over halitosis due to mouth infection, too. These effects need to be approved in an in vivo trial as a second study. PMID:24624155

Anaerobic biotransformation of explosives in aquifer slurries amended with ethanol and propylene glycol.

PubMed

Adrian, Neal R; Arnett, Clint M

2007-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6-trinitrotoluene (TNT) are explosives that are frequently found as environmental contaminants on military installations. Hydrogen has been shown to support the anaerobic transformation of these explosives. We investigated ethanol and propylene glycol as electron donors for providing syntrophically produced H2 for stimulating the anaerobic biodegradation of explosives in contaminated soil. The study was conducted using anoxic microcosms constructed with slurries of the contaminated soil and groundwater. The addition of 5mM ethanol and propylene glycol enhanced the biodegradation of RDX and HMX relative to the control bottles. Ethanol was depleted within about 20 days, resulting in the transient formation of hydrogen, acetate, and methane. The hydrogen headspace concentration increased from 8 ppm to 1838 ppm before decreasing to background concentrations. Propylene glycol was completely degraded after 15 days, forming hydrogen, propionate, and acetate as end-products. The hydrogen headspace concentrations increased from 56 ppm to 628 ppm before decreasing to background concentrations. No methane formation was observed during the incubation period of 48 days. Our findings indicate the addition of ethanol and propylene to the aquifer slurries increased the hydrogen concentrations and enhanced the biotransformation of RDX and HMX in the explosive-contaminated soil.

21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

Code of Federal Regulations, 2010 CFR

2010-04-01

... fatty acids. 172.856 Section 172.856 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely... and/or fatty acids in compliance with § 172.860 and/or oleic acid derived from tall oil fatty acids in...

21 CFR 172.856 - Propylene glycol mono- and diesters of fats and fatty acids.

Code of Federal Regulations, 2011 CFR

2011-04-01

... fatty acids. 172.856 Section 172.856 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... diesters of fats and fatty acids. Propylene glycol mono- and diesters of fats and fatty acids may be safely... and/or fatty acids in compliance with § 172.860 and/or oleic acid derived from tall oil fatty acids in...

Experimental Investigation of Heat Transfer Characteristics of Automobile Radiator using TiO2-Nanofluid Coolant

NASA Astrophysics Data System (ADS)

Salamon, V.; Senthil kumar, D.; Thirumalini, S.

2017-08-01

The use of nanoparticle dispersed coolants in automobile radiators improves the heat transfer rate and facilitates overall reduction in size of the radiators. In this study, the heat transfer characteristics of water/propylene glycol based TiO2 nanofluid was analyzed experimentally and compared with pure water and water/propylene glycol mixture. Two different concentrations of nanofluids were prepared by adding 0.1 vol. % and 0.3 vol. % of TiO2 nanoparticles into water/propylene glycol mixture (70:30). The experiments were conducted by varying the coolant flow rate between 3 to 6 lit/min for various coolant temperatures (50°C, 60°C, 70°C, and 80°C) to understand the effect of coolant flow rate on heat transfer. The results showed that the Nusselt number of the nanofluid coolant increases with increase in flow rate. At low inlet coolant temperature the water/propylene glycol mixture showed higher heat transfer rate when compared with nanofluid coolant. However at higher operating temperature and higher coolant flow rate, 0.3 vol. % of TiO2 nanofluid enhances the heat transfer rate by 8.5% when compared to base fluids.

Use of amphiphilic triblock copolymers for enhancing removal efficiency of organic pollutant from contaminated media

NASA Astrophysics Data System (ADS)

Lee, Jun Hyup; Lee, Byungsun; Son, Intae; Kim, Jae Hong; Kim, Chunho; Yoo, Ji Yong; Wu, Jong-Pyo; Kim, Younguk

2015-11-01

We have studied amphiphilic triblock copolymers poly(ethylene glycol)- b-poly(propylene glycol)- b-poly(ethylene glycol) (PEG- b-PPG- b-PEG) and poly(propylene glycol)- b-poly(ethylene glycol)- b-poly(propylene glycol) (PPG- b-PEG- b-PPG) as possible substitutes for sodium dodecyl sulfate as anionic surfactants for the removal of hydrophobic contaminants. The triblock copolymers were compared with sodium dodecyl sulfate in terms of their abilities to remove toluene as hydrophobic contaminant in fuel, and the effects of polymer structure, PEG content, and concentration were studied. The PEG- b-PPG- b-PEG copolymer containing two hydrophilic PEG blocks was more effective for the removal of hydrophobic contaminant at extremely high concentration. We also measured the removal capabilities of the triblock copolymers having various PEG contents and confirmed that removal capability was greatest at 10% PEG content regardless of polymer structure. As with sodium dodecyl sulfate, the removal efficiency of a copolymer has a positive correlation with its concentration. Finally, we proposed the amphiphilic triblock copolymer of PPG- b-PEG- b-PPG bearing 10% PEG content that proved to be the most effective substitute for sodium dodecyl sulfate.

Effects of chilled storage and cryopreservation on sperm characteristics, antioxidant enzyme activities, and lipid peroxidation in Pacific cod Gadus microcephalus

NASA Astrophysics Data System (ADS)

Wang, Xueying; Shi, Xuehui; Liu, Yifan; Yu, Daode; Guan, Shuguang; Liu, Qinghua; Li, Jun

2016-07-01

The present study evaluated the effects of chilled storage and cryopreservation on sperm motion characteristics, antioxidant enzyme activities, and lipid peroxidation in the Pacific cod Gadus macrocephalus. Sperm motility and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (Gr), and lipid peroxidation (measured via malondialdehyde (MDA) content) were determined after the milt was stored at 4°C for 12 h, cryopreserved without cryoprotectant in 12% propylene glycol (PG), cryopreserved in 12% PG+0.1 mol/L trehalose, or cryopreserved in 12% PG spermatozoa but centrifuged to decant the supernatant prior to cryopreservation (only sperm cells were cryopreserved). After chilled storage or cryopreservation, the SOD, CAT and GPx activities were reduced in sperm cells and increased in seminal plasma in almost all treatments; sperm motility parameters were also decreased. However, the addition of trehalose into the cryoprotectant could significantly improve the postthaw sperm quality as revealed by the sperm average path velocity. This improvement might be attributed to the function of trehalose in scavenging reactive oxygen species. Chilled storage and cryopreservation had significant effects on sperm motion characteristics, antioxidant enzyme activities, and lipid peroxidation in the Pacific cod.

Delivery of risperidone from gels across porcine skin in vitro and in vivo in rabbits.

PubMed

Ning, Yuming; Chen, Xiaojin; Yu, Zhenwei; Liang, Wenquan; Li, Fanzhu

2018-05-01

The purpose of this study was to develop and evaluate a transdermal delivery system for RIS using hydrogels. First, the effects of different concentrations of hydroxypropyl methylcellulose and Carbomer 934 (CBR) on RIS permeation were investigated in porcine skin. The optimized formulation was chosen as the base gel to screen for penetration enhancers. The pharmacokinetics of the optimized RIS formulation was then studied in vitro in rabbits. A formulation with 0.5% CBR showed the highest RIS permeation and was selected as the base gel. RIS permeation was further increased by incorporation of Azone, lauryl alcohol, or menthol, and the enhancing effects of the three were dose-dependent. When each enhancer combined with propylene glycol (PG) a synergistic effect was found. A combination of 6% menthol and 6% PG exhibited highest RIS in vitro penetration rate and showed a high efficiency in vivo, with a relative bioavailability of 131.53% compared with intragastric administration. These findings showed that 1% RIS in 0.5% CBR, containing a combination of 6% menthol and 6% PG, can deliver doses of RIS that are therapeutically relevant for treating patients with schizophrenia.

Relative toxicities of pure propylene and ethylene glycol and formulated deicers on plant species

DOE Office of Scientific and Technical Information (OSTI.GOV)

DuFresne, D.L.; Pillard, D.A.

1994-12-31

Propylene and ethylene glycol deicers are commonly used at airports in the US and other countries to remove and retard the accumulation of snow and ice on aircraft. Deicers may not only enter water bodies without treatment, due to excessive storm-related flow, but also may expose terrestrial organisms to high concentrations through surface runoff. Most available toxicity data are for aquatic vertebrates and invertebrate species; this study examined effects on terrestrial and aquatic plants. Terrestrial plant species included both a monocot (rye grass, Lolium perenne) and a dicot (lettuce, Lactuca saliva). Aquatic species included a single cell alga (Selenastrum capricomutum),more » and an aquatic macrophyte (duckweed, Lemna minor). Glycol deicers were obtained in the formulated mixtures used on aircraft. Pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Parameters measured included germination, root and shoot length, survival, and growth. Formulated deicers, like those used at airports, were generally more toxic than pure chemicals, based on glycol concentration. This greater toxicity of formulated deicers is consistent with results of tests using animal species.« less

Evaporation of Particle-Stabilized Emulsion Sunscreen Films.

PubMed

Binks, Bernard P; Fletcher, Paul D I; Johnson, Andrew J; Marinopoulos, Ioannis; Crowther, Jonathan M; Thompson, Michael A

2016-08-24

We recently showed (Binks et al., ACS Appl. Mater. Interfaces, 2016, DOI: 10.1021/acsami.6b02696) how evaporation of sunscreen films consisting of solutions of molecular UV filters leads to loss of UV light absorption and derived sun protection factor (SPF). In the present work, we investigate evaporation-induced effects for sunscreen films consisting of particle-stabilized emulsions containing a dissolved UV filter. The emulsions contained either droplets of propylene glycol (PG) in squalane (SQ), droplets of SQ in PG or droplets of decane in PG. In these different emulsion types, the SQ is involatile and shows no evaporation, the PG is volatile and evaporates relatively slowly, whereas the decane is relatively very volatile and evaporates quickly. We have measured the film mass and area, optical micrographs of the film structure, and the UV absorbance spectra during evaporation. For emulsion films containing the involatile SQ, evaporation of the PG causes collapse of the emulsion structure with some loss of specular UV absorbance due to light scattering. However, for these emulsions with droplets much larger than the wavelength of light, the light is scattered only at small forward angles so does not contribute to the diffuse absorbance and the film SPF. The UV filter remains soluble throughout the evaporation and thus the UV absorption by the filter and the SPF remain approximately constant. Both PG-in-SQ and SQ-in-PG films behave similarly and do not show area shrinkage by dewetting. In contrast, the decane-in-PG film shows rapid evaporative loss of the decane, followed by slower loss of the PG resulting in precipitation of the UV filter and film area shrinkage by dewetting which cause the UV absorbance and derived SPF to decrease. Measured UV spectra during evaporation are in reasonable agreement with spectra calculated using models discussed here.

Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations

PubMed Central

Peace, Michelle R.; Baird, Tyson R.; Smith, Nathaniel; Wolf, Carl E.; Poklis, Justin L.; Poklis, Alphonse

2016-01-01

Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography–tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography–mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations. PMID:27165804

Ultra-Violet/Electron Beam Detoxification of Nitroglycerin/Propylene Glycol Dinrate Waste Water, Phase 1

DTIC Science & Technology

1994-03-16

University of Vienna’s Institute for Theoretical and Radiation Chemistry provided assistance in the development of chemical theory. Z. Liu, Associate...Professor of Applied Chemistry at the University of Science and Technology, Hefei, Peoples Republic of China provided support with physical measurements. The...include Glyocollic acid " Inogani Nitates> 90 nitroglycerine, propylene glycol dinitrate Inorganic Nitrates (PGDN), trimethylolethane trinitrate MDL

In vitro-in vivo correlation in skin permeation.

PubMed

Mohammed, D; Matts, P J; Hadgraft, J; Lane, M E

2014-02-01

In vitro skin permeation studies have been used extensively in the development and optimisation of delivery of actives in vivo. However, there are few reported correlations of such in vitro studies with in vivo data. The aim of this study was to investigate the skin permeation of a model active, niacinamide, both in vitro and in vivo. Conventional diffusion cell studies were conducted in human skin to determine niacinamide permeation from a range of vehicles which included dimethyl isosorbide (DMI), propylene glycol (PG), propylene glycol monolaurate (PGML), N-methyl 2-pyrrolidone (NMP), Miglyol 812N® (MG), and mineral oil (MO). Single, binary or ternary systems were examined. The same vehicles were subsequently examined to investigate niacinamide delivery in vivo. For this proof-of-concept study one donor was used for the in vitro studies and one volunteer for the in vivo investigations to minimise biovariability. Analysis of in vitro samples was conducted using HPLC and in vivo uptake of niacinamide was evaluated using Confocal Raman spectroscopy (CRS). The amount of niacinamide permeated through skin in vitro was linearly proportional to the intensity of the niacinamide signal determined in the stratum corneum in vivo. A good correlation was observed between the signal intensities of selected vehicles and niacinamide signal intensity. The findings provide further support for the use of CRS to monitor drug delivery into and across the skin. In addition, the results highlight the critical role of the vehicle and its disposition in skin for effective dermal delivery.

Potential harmful health effects of inhaling nicotine-free shisha-pen vapor: a chemical risk assessment of the main components propylene glycol and glycerol.

PubMed

Kienhuis, Anne S; Soeteman-Hernandez, Lya G; Bos, Peter Mj; Cremers, Hans Wjm; Klerx, Walther N; Talhout, Reinskje

2015-01-01

A shisha-pen is an electronic cigarette variant that is advertised to mimic the taste of a water pipe, or shisha. The aim of this study was to assess the potential harmful health effects caused by inhaling the vapor of a nicotine-free shisha-pen. Gas chromatography analysis was performed to determine the major components in shisha-pen vapor. Risk assessment was performed using puff volumes of e-cigarettes and "normal" cigarettes and a 1-puff scenario (one-time exposure). The concentrations that reached the airways and lungs after using a shisha-pen were calculated and compared to data from published toxicity studies. The main components in shisha-pen vapor are propylene glycol and glycerol (54%/46%). One puff (50 to 70 mL) results in exposure of propylene glycol and glycerol of 430 to 603 mg/m(3) and 348 to 495 mg/m(3), respectively. These exposure concentrations were higher than the points of departure for airway irritation based on a human study (propylene glycol, mean concentration of 309 mg/m(3)) and a rat study (glycerol, no-observed adverse effect level of 165 mg/m(3)). Already after one puff of the shisha-pen, the concentrations of propylene glycol and glycerol are sufficiently high to potentially cause irritation of the airways. New products such as the shisha-pen should be detected and risks should be assessed to inform regulatory actions aimed at limiting potential harm that may be caused to consumers and protecting young people to take up smoking.

Time-resolved emission spectra of 4-dimethylamino-4‧-cyano-stilbene and resveratrol in high viscosity solvents and silica matrices

NASA Astrophysics Data System (ADS)

Borowiak, Małgorzata; Grobelna, Beata; Synak, Anna; Bojarski, Piotr; Kubicki, Aleksander A.

2013-11-01

Time-resolved emission spectra of 4-dimethylamino-4‧-cyano-stilbene (DMACS) and 3,5,4‧-trihydroxy-stilbene (resveratrol, RSV) in propylene glycol and in rigid silica xerogel matrix at 23 °C were studied. For the polar molecule DMACS in propylene glycol, a 66 nm shift of maximum wavelength of emission spectra was observed within 1 ns after excitation, and most of the shift occurred during the first 200 ps. For resveratrol in propylene glycol no such a shift was observed. The rigid silica environment eliminates some deactivation pathways and stabilizes spectroscopic properties of both molecules. Spectral properties of nonpolar and high dipole moment molecules in viscous liquids and rigid environments are compared. Results are explained on the basis of intramolecular processes and solute-solvent relaxation, as well.

Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production.

PubMed

Berlowska, Joanna; Cieciura, Weronika; Borowski, Sebastian; Dudkiewicz, Marta; Binczarski, Michal; Witonska, Izabela; Otlewska, Anna; Kregiel, Dorota

2016-10-17

Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

Clonazepam oral droplets for the treatment of acute epileptic seizures.

PubMed

Sakata, Osamu; Onishi, Hiraku; Machida, Yoshiharu

2008-12-01

Oral droplet formulations of clonazepam (CZ) were developed to examine their potentials as an alternative to i.v. administration for the treatment of acute epileptic seizures. Propylene glycol containing 2.5% (wt/wt) CZ with or without 5.0% (wt/wt) oleic acid (OA) was prepared as a solution by heating at 90 degrees C and subsequently lowering the temperature to 30 degrees C. The droplet (20 microL) was administered to the oral cavity between the lower gum and bottom lip before CZ precipitation started. With a droplet of propylene glycol loaded with 2.5% (wt/wt) CZ and 5.0% (wt/wt) OA, the plasma concentration reached 20 ng/mL (minimal effective concentration) within 10 min and was maintained between 20 and 60 ng/mL, less than a toxic level, for a period of 60 min. For a droplet of propylene glycol loaded only with CZ at 2.5% (wt/wt), it took more than 15 min for the plasma concentration to reach 20 ng/mL. It is suggested that a droplet of CZ/OA/propylene glycol (2.5:5.0:92.5, wt/wt) might be useful as an alternative to i.v. injection of CZ for the treatment of acute epileptic seizures.

Preparation and evaluation of microemulsion-based transdermal delivery of Cistanche tubulosa phenylethanoid glycosides

PubMed Central

Yang, Jianhua; Xu, Huanhuan; Wu, Shanshan; Ju, Bowei; Zhu, Dandan; Yan, Yao; Wang, Mei; Hu, Junping

2017-01-01

The primary aim of the present study was to develop a novel microemulsion (ME) formulation to deliver phenylethanoid glycoside (PG) for use in skin lighteners and sunscreens. The oil phase was selected on the basis of drug solubility, while the surfactant and cosurfactant were screened and selected on the basis of their solubilizing capacity and the efficiency with which they formed MEs. Pseudoternary phase diagrams were constructed to evaluate ME regions and five formulations of oil-in-water MEs were selected as vehicles. In vitro skin permeation experiments were performed to optimize the ME formulation and to evaluate its permeability in comparison to that of saline solution. The physicochemical properties of the optimized ME and the permeating ability of PG delivered by this ME were also investigated. The optimized ME formulation was composed of isopropyl myristate (7%, w/w), Cremorphor EL (21%, w/w), propylene glycol (7%, w/w) and water (65%, w/w). The cumulative amount of PG that permeated through excised mouse skin when carried by ME was ~1.68 times that when PG was carried by saline solution only. The cumulative amount of PG in the microemulsion (4149.650±37.3 µg·cm−2) was significantly greater than that of PG in the saline solution (2288.63±20.9 µg·cm−2). Furthermore, the permeability coefficient indicated that optimized microemulsion was a more efficient carrier for transdermal delivery of PG than the control solution (8.87±0.49 cm/hx10−3 vs. 5.41±0.12 cm/hx10−3). Taken together, the permeating ability of ME-carried PG was significantly increased compared with saline solution. PMID:28138704

Trimethoprim/Sulfamethoxazole-Induced Severe Lactic Acidosis: A Case Report and Review of the Literature.

PubMed

Bulathsinghala, Marie; Keefer, Kimberly; Van de Louw, Andry

2016-04-01

Propylene glycol (PG) is used as a solvent in numerous medications, including trimethoprim/sulfamethoxazole (TMP/SMX) and lorazepam, and is metabolized in the liver to lactic acid. Cases of lactic acidosis related to PG toxicity have been described and always involved large doses of benzodiazepines and PG. We present the first case of severe lactic acidosis after a 3-day course of TMP/SMX alone, involving allegedly safe amounts of PG.A 31-year-old female with neurofibromatosis and pilocytic astrocytoma, receiving temozolomide and steroids, was admitted to the intensive care unit for pneumonia and acute respiratory failure requiring intubation. Her initial hemodynamic and acid-base statuses were normal. She was treated with intravenous TMP/SMX for possible Pneumocystis jirovecii pneumonia and was successfully extubated on day 2. On day 3, she developed tachypnea and arterial blood gas analysis revealed a severe metabolic acidosis (pH 7.2, PCO2 19 mm Hg, bicarbonates 8 mEq/L) with anion gap of 25 mEq/L and lactate of 12.1 mmol/L. TMP/SMX was discontinued and the lactate decreased to 2.9 mmol/L within 24 hours while her plasma bicarbonates normalized, without additional intervention. The patient never developed hypotension or severe hypoxia, and her renal and liver functions were normal. No other cause for lactic acidosis was identified and it resolved after TMP/SMX cessation alone, suggesting PG toxicity.Although PG-related lactic acidosis is well recognized after large doses of lorazepam, clinicians should bear in mind that TMP/SMX contains PG as well and should suspect PG toxicity in patients developing unexplained metabolic acidosis while receiving TMP/SMX.

Concentration of Nicotine and Glycols in 27 Electronic Cigarette Formulations.

PubMed

Peace, Michelle R; Baird, Tyson R; Smith, Nathaniel; Wolf, Carl E; Poklis, Justin L; Poklis, Alphonse

2016-07-01

Personal battery-powered vaporizers or electronic cigarettes were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. Electronic cigarettes and their e-cigarette liquid formulations are virtually unregulated. These formulations are typically composed of propylene glycol and/or glycerin, flavoring components and an active drug, such as nicotine. Twenty-seven e-cigarette liquid formulations that contain nicotine between 6 and 22 mg/L were acquired within the USA and analyzed by various methods to determine their contents. They were screened by Direct Analysis in Real Time™ Mass Spectrometry (DART-MS). Nicotine was confirmed and quantitated by high-performance liquid chromatography-tandem mass spectrometry, and the glycol composition was confirmed and quantitated by gas chromatography-mass spectrometry. The DART-MS screening method was able to consistently identify the exact mass peaks resulting from the protonated molecular ion of nicotine, glycol and a number of flavor additives within 5 mmu. Nicotine concentrations were determined to range from 45 to 131% of the stated label concentration, with 18 of the 27 have >10% variance. Glycol composition was generally accurate to the product description, with only one exception where the propylene glycol to glycerin percentage ratio was stated as 50:50 and the determined concentration of propylene glycol to glycerin was 81:19 (% v/v). No unlabeled glycols were detected in these formulations. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of in vitro percutaneous absorption of lorazepam and clonazepam from hydro-alcoholic gel formulations.

PubMed

Puglia, C; Bonina, F; Trapani, G; Franco, M; Ricci, M

2001-10-09

Clonazepam and lorazepam are two anxiolytics, antidepressant agents, having suitable features for transdermal delivery. The objectives of this study were to evaluate the in vitro percutaneous absorption of these drugs through excised human skin (stratum corneum and epidermis, SCE) and to determine their in vitro permeation behavior from a series of hydro-alcoholic gel formulations containing various enhancing agents. The best permeation profile was obtained for both drugs applying them together with Azone in combination with propylene glycol (PG): these enhancers were able to increase the clonazepam and lorazepam percutaneous fluxes at steady-state about threefold, compared to the free enhancer formulations (Control). To explain the mechanism of the used promoters, the benzodiazepine diffusion and partitioning coefficients from the gel containing the enhancers were calculated. The results indicated that the Azone in combination with PG could act by increasing the benzodiazepine diffusion coefficients, Transcutol increased only the SC/vehicle partition coefficients, limonene in combination with PG appeared to increase both partition and diffusion coefficients moderately, while PG did not increase both the parameters. Furthermore, to evaluate the potential application of tested benzodiazepine formulations containing Azone in combination with PG using the flux values from the in vitro experiments, the corresponding steady-state plasma concentrations (C(SS)) were calculated. The obtained calculated C(SS) values are within the lorazepam therapeutic range and suggest that transdermal delivery of this drug could be regarded as feasible.

Transport phenomena governing nicotine emissions from electronic cigarettes: model formulation and experimental investigation

PubMed Central

Talih, Soha; Balhas, Zainab; Salman, Rola; El-Hage, Rachel; Karaoghlanian, Nareg; El-Hellani, Ahmad; Baassiri, Mohamad; Jaroudi, Ezzat; Eissenberg, Thomas; Saliba, Najat; Shihadeh, Alan

2017-01-01

Electronic cigarettes (ECIGs) electrically heat and aerosolize a liquid containing propylene glycol (PG), vegetable glycerin (VG), flavorants, water, and nicotine. ECIG effects and proposed methods to regulate them are controversial. One regulatory focal point involves nicotine emissions. We describe a mathematical model that predicts ECIG nicotine emissions. The model computes the vaporization rate of individual species by numerically solving the unsteady species and energy conservation equations. To validate model predictions, yields of nicotine, total particulate matter, PG, and VG were measured while manipulating puff topography, electrical power, and liquid composition across 100 conditions. Nicotine flux, the rate at which nicotine is emitted per unit time, was the primary outcome. Across conditions, the measured and computed nicotine flux were highly correlated (r = 0.85, p<.0001). As predicted, device power, nicotine concentration, PG/VG ratio, and puff duration influenced nicotine flux (p<.05), while water content and puff velocity did not. Additional empirical investigation revealed that PG/VG liquids act as ideal solutions, that liquid vaporization accounts for more than 95% of ECIG aerosol mass emissions, and that as device power increases the aerosol composition shifts towards the less volatile components of the parent liquid. To the extent that ECIG regulations focus on nicotine emissions, mathematical models like this one can be used to predict ECIG nicotine emissions and to test the effects of proposed regulation of factors that influence nicotine flux. PMID:28706340

40 CFR 180.1250 - C8, C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false C8, C10, and C12 fatty acid monoesters..., C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the requirement of a tolerance. The C8, C10, and C12 straight-chain fatty acid monoesters of glycerol (glycerol...

Acetylcholinesterase and Acetylcholine Receptor.

DTIC Science & Technology

1986-01-21

Cl3CCH2OH) binds similarly to its carbon analogue, neopentyl alcohol, and chloral binds better than its carbon analogue, pivalaldehyde. In the latter case...III. Since the 3H-DFP was obtained in propylene glycol , the stability of DFP in the hydroxylic solvent and thus its true concentration was investi...solution of unlabeled DFP in propylene glycol was obtained from NEN for use in model experi- ments and found to have no inhibiting activity. We turned

40 CFR 180.1250 - C8, C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false C8, C10, and C12 fatty acid monoesters..., C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the requirement of a tolerance. The C8, C10, and C12 straight-chain fatty acid monoesters of glycerol (glycerol...

Determination of semi-volatile additives in wines using SPME and GC-MS.

PubMed

Sagandykova, Gulyaim N; Alimzhanova, Mereke B; Nurzhanova, Yenglik T; Kenessov, Bulat

2017-04-01

Parameters of headspace solid-phase microextraction, such as fiber coating (85μm CAR/PDMS), extraction time (2min for white and 3min for red wines), temperature (85°C), pre-incubation time (15min) were optimized for identification and quantification of semi-volatile additives (propylene glycol, sorbic and benzoic acids) in wines. To overcome problems in their determination, an evaporation of the wine matrix was performed. Using the optimized method, screening of 25 wine samples was performed, and the presence of propylene glycol, sorbic and benzoic acids was found in 22, 20 and 6 samples, respectively. Analysis of different wines using a standard addition approach showed good linearity in concentration ranges 0-250, 0-125, and 0-250mg/L for propylene glycol, sorbic and benzoic acids, respectively. The proposed method can be recommended for quality control of wine and disclosing adulterated samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antibacterial action of calcium hydroxide vehicles and calcium hydroxide pastes.

PubMed

Pacios, María Gabriela; Silva, Clara; López, María Elena; Cecilia, Marta

2012-11-01

To evaluate the in vitro action of vehicles alone and with calcium hydroxide against different bacterial species. Agar plates were inoculated with the microbial suspensions, and wells were made and filled with the calcium hydroxide pastes and the vehicles used to prepare the pastes. The zones of inhibited bacterial growth were recorded, and the resulting measurements were statistically analyzed. Enterococcus faecalis was the most resistant microorganism to all medicaments. Calcium hydroxide + p-monochlorophenol; calcium hydroxide + p-monochlorophenol-propylene glycol pastes; and p-monochlorophenol, p-monochlorophenol-propylene glycol, and chlorhexidine gluconate gel alone showed the largest zones of inhibition against all the tested microorganisms. The vehicle used to prepare the calcium hydroxide paste might contribute to its antibacterial action. Chlorhexidine gluconate gel used alone, and camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol as vehicles of calcium hydroxide, could be recommended, in an antimicrobial sense. © 2012 Wiley Publishing Asia Pty Ltd.

Organic chemical degradation by remote study of the redox conditions

NASA Astrophysics Data System (ADS)

Fernandez, P. M.; Revil, A.; Binley, A. M.; Bloem, E.; French, H. K.

2014-12-01

Monitoring the natural (and enhanced) degradation of organic contaminants is essential for managing groundwater quality in many parts of the world. Contaminated sites often have limited access, hence non-intrusive methods for studying redox processes, which drive the degradation of organic compounds, are required. One example is the degradation of de-icing chemicals (glycols and organic salts) released to the soil near airport runways during winter. This issue has been broadly studied at Oslo airport, Gardermoen, Norway using intrusive and non-intrusive methods. Here, we report on laboratory experiments that aim to study the potential of using a self-potential, DCresistivity, and time-domain induced polarization for geochemical characterization of the degradation of Propylene Glycol (PG). PG is completely miscible in water, does not adsorb to soil particles and does not contribute to the electrical conductivity of the soil water. When the contaminant is in the unsaturated zone near the water table, the oxygen is quickly consumed and the gas exchange with the surface is insufficient to ensure aerobic degradation, which is faster than anaerobic degradation. Since biodegradation of PG is highly oxygen demanding, anaerobic pockets can exist causing iron and manganese reduction. It is hypothesised that nitrate would boost the degradation rate under such conditions. In our experiment, we study PG degradation in a sand tank. We provide the system with an electron highway to bridge zones with different redox potential. This geo-battery system is characterized by self-potential, resistivity and induced polarization anomalies. An example of preliminary results with self-potential at two different times of the experiment can be seen in the illustration. These will be supplemented with more direct information on the redox chemistry: in-situ water sampling, pH, redox potential and electrical conductivity measurements. In parallel, a series of batch experiments have been performed to study anoxic microbial degradation using gas and resistivity measurements.

FERMENTATION OF ETHYLENE GLYCOL BY CLOSTRIDIUM GLYCOLICUM, SP. N1

PubMed Central

Gaston, Lamont W.; Stadtman, E. R.

1963-01-01

Gaston, Lamont W. (National Heart Institute, National Institutes of Health, Bethesda, Md.) and E. R. Stadtman. Fermentation of ethylene glycol by Clostridium glycolicum, sp. n. J. Bacteriol. 85:356–362. 1963.—An anaerobic organism which utilizes ethylene glycol as a source of energy and carbon has been isolated from mud. It is a long (5 μ), slender, motile, gram-positive, spore-forming rod, with peritrichous flagellae. It grows well from 22 to 37 C at pH 7.4 to 7.6, and ferments glucose, fructose, sorbitol, dulcitol, and cellulose. It does not reduce nitrates, form indole, or cause hemolysis or proteolysis except for a slight attack on coagulated egg albumin. Fifteen amino acids and the vitamins biotin and pantothenate are required for optimal growth on ethylene glycol. Analogues other than propylene glycol do not support growth. Ethylene glycol and propylene glycol are stoichiometrically converted to equal amounts of the respective acid and alcohol. PMID:13946772

Influence of flavor solvent on flavor release and perception in sugar-free chewing gum.

PubMed

Potineni, Rajesh V; Peterson, Devin G

2008-05-14

The influence of flavor solvent [triacetin (TA), propylene glycol (PG), medium chained triglycerides (MCT), or no flavor solvent (NFS)] on the flavor release profile, the textural properties, and the sensory perception of a sugar-free chewing gum was investigated. Time course analysis of the exhaled breath and saliva during chewing gum mastication indicated that flavor solvent addition or type did not influence the aroma release profile; however, the sorbitol release rate was statistically lower for the TA formulated sample in comparison to those with PG, MCT, or NFS. Sensory time-intensity analysis also indicated that the TA formulated sample was statistically lower in perceived sweetness intensity, in comparison with the other chewing gum samples, and also had lower cinnamon-like aroma intensity, presumably due to an interaction between sweetness intensity on aroma perception. Measurement of the chewing gum macroscopic texture by compression analysis during consumption was not correlated to the unique flavor release properties of the TA-chewing gum. However, a relationship between gum base plasticity and retention of sugar alcohol during mastication was proposed to explain the different flavor properties of the TA sample.

21 CFR 349.12 - Ophthalmic demulcents.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Polyethylene glycol 300, 0.2 to 1 percent. (3) Polyethylene glycol 400, 0.2 to 1 percent. (4) Polysorbate 80, 0.2 to 1 percent. (5) Propylene glycol, 0.2 to 1 percent. (e) Polyvinyl alcohol, 0.1 to 4 percent. (f...

21 CFR 349.12 - Ophthalmic demulcents.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Polyethylene glycol 300, 0.2 to 1 percent. (3) Polyethylene glycol 400, 0.2 to 1 percent. (4) Polysorbate 80, 0.2 to 1 percent. (5) Propylene glycol, 0.2 to 1 percent. (e) Polyvinyl alcohol, 0.1 to 4 percent. (f...

21 CFR 349.12 - Ophthalmic demulcents.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Polyethylene glycol 300, 0.2 to 1 percent. (3) Polyethylene glycol 400, 0.2 to 1 percent. (4) Polysorbate 80, 0.2 to 1 percent. (5) Propylene glycol, 0.2 to 1 percent. (e) Polyvinyl alcohol, 0.1 to 4 percent. (f...

Differences in the rheological properties and mixing compatibility with heparinoid cream of brand name and generic steroidal ointments: The effects of their surfactants.

PubMed

Kitagawa, Shuji; Yutani, Reiko; Kodani, Rhu-Ichi; Teraoka, Reiko

2016-01-01

Most steroidal ointments contain propylene glycol (PG) and surfactants, which improve the solubility of corticosteroids in white petrolatum. Surfactants aid the uniform dispersal of PG within white petrolatum. Since the surfactants used in generic ointments are usually different from those used in brand name ointments, we investigated the effects of surfactants on the rheological properties of three brand name ointments and six equivalent generic ointments. We detected marked differences in hardness, adhesiveness, and spreadability among the ointments. Further examinations of model ointments consisting of white petrolatum, PG, and surfactants revealed that the abovementioned properties, especially hardness and adhesiveness, were markedly affected by the surfactants. Since steroidal ointments are often admixed with moisturizing creams prior to use, we investigated the mixing compatibility of the ointments with heparinoid cream and how this was affected by their surfactants. We found that the ointments containing glyceryl monostearate demonstrated good mixing compatibility, whereas those containing non-ionic surfactants with polyoxyethylene chains exhibited phase separation. These results were also consistent with the findings for the model ointments, which indicates that the mixing compatibility of steroidal ointments with heparinoid cream is determined by the emulsifying capacity of the surfactants in their oily bases.

Photochromic Properties of Tungsten Oxide/Methylcellulose Composite Film Containing Dispersing Agents.

PubMed

Yamazaki, Suzuko; Ishida, Hiroki; Shimizu, Dai; Adachi, Kenta

2015-12-02

Tungsten oxide-based photochromic films which changed reversibly in air between colorless- transparent in the dark and dark blue under UV irradiation were prepared by using methylcellulose as a film matrix and polyols such as ethylene glycol (EG), propylene glycol (PG), and glycerin (Gly) as dispersing agents. Influence of the dispersing agents and water in the films on the photochromic behavior was systematically studied. Under UV irradiation, absorption bands around 640 and 980 nm increased and the coloring rate was the following order: Gly > EG > PG. An increase in the amounts of dispersing agents or water accelerated the coloring rate. By increasing the water content of the film, a new absorption peak appeared at ca. 775 nm and the Raman spectra indicated a shift of W-O-W stretching vibration to lower wavenumber which was due to the formation of hydrogen bonding. All absorption spectra were fit by three Lorentz functions, whose bands were ascribed to various packing of WO6 octahedra. After the light was turned off, the formation of W(5+) was stopped and bleaching occurred by the reaction with O2 in air to recover its original transparent state. We anticipate that the biodegradable photochromic films developed in this study can be applied in recyclable display medium and especially in detachable films for glass windows whose light transmission properties are changed by sunlight, i.e., for usage as an alternative of smart windows without applying voltage.

Effects of polyalkylene glycols and fatty acid soaps on properties of synthetic lubricating-cooling fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stulii, A.A.

1983-01-01

The lack of any effect of the polyalkylene glycols on the series of properties of the fatty acid soaps was confirmed by replacing the PEG-35 in the synthetic lubricating-cooling fluid (LCF) by a polyethylene glycol with a molecular weight of 400 or 6000, a propylene oxide oligomer with a molecular weight of 700, or a copolymer of ethylene and propylene oxides (Pluronic 44, Pluriol PE-6400, Hydropol 200). Attempts to select surfactants and optimal concentrations in synthetic LCFs based on polyalkylene glycols. Indicates that of the studied soaps, those of the most interest are the triethanolamine soaps of individual C/sub 6/-C/submore » 10/ fatty acids and commercial mixed C/sub 7/-C/sub 9/ synthetic fatty acids. Finds that the polyalkylene glycols and the indicated soaps supplement each other, imparting the required set of properties to the LCF.« less

Exposure of German residents to ethylene and propylene glycol ethers in general and after cleaning scenarios.

PubMed

Fromme, H; Nitschke, L; Boehmer, S; Kiranoglu, M; Göen, T

2013-03-01

Glycol ethers are a class of semi-volatile substances used as solvents in a variety of consumer products like cleaning agents, paints, cosmetics as well as chemical intermediates. We determined 11 metabolites of ethylene and propylene glycol ethers in 44 urine samples of German residents (background level study) and in urine samples of individuals after exposure to glycol ethers during cleaning activities (exposure study). In the study on the background exposure, methoxyacetic acid and phenoxyacetic acid (PhAA) could be detected in each urine sample with median (95th percentile) values of 0.11 mgL(-1) (0.30 mgL(-1)) and 0.80 mgL(-1) (23.6 mgL(-1)), respectively. The other metabolites were found in a limited number of samples or in none. In the exposure study, 5-8 rooms were cleaned with a cleaner containing ethylene glycol monobutyl ether (EGBE), propylene glycol monobutyl ether (PGBE), or ethylene glycol monopropyl ether (EGPE). During cleaning the mean levels in the indoor air were 7.5 mgm(-3) (EGBE), 3.0 mgm(-3) (PGBE), and 3.3 mgm(-3) (EGPE), respectively. The related metabolite levels analysed in the urine of the residents of the rooms at the day of cleaning were 2.4 mgL(-1) for butoxyacetic acid, 0.06 mgL(-1) for 2-butoxypropionic acid, and 2.3 mgL(-1) for n-propoxyacetic acid. Overall, our study indicates that the exposure of the population to glycol ethers is generally low, with the exception of PhAA. Moreover, the results of the cleaning scenarios demonstrate that the use of indoor cleaning agents containing glycol ethers can lead to a detectable internal exposure of residents. Copyright © 2012 Elsevier Ltd. All rights reserved.

Oxidized starch solutions for environmentally friendly aircraft deicers.

PubMed

Plahuta, Joseph M; Teel, Amy L; Ahmad, Mushtaque; Beutel, Mark W; Rentz, Jeremy A; Watts, Richard J

2011-09-01

Deicers currently used for aircraft deicing, including ethylene glycol and propylene glycol, pose significant threats to surface waters, as a result of high biochemical oxygen demand (BOD) and toxicity to aquatic organisms. Oxidized starch may provide a less toxic deicer with lower BOD. The freezing point depression of starch formulations oxidized using hydrogen peroxide and catalysts (i.e., catalyzed hydrogen peroxide [H2O2] propagations-CHP) was 28 degrees C, and viscosities similar to those of commercial deicers were achieved after post-treatment with granular activated carbon. The most effective oxidized starch formulation exerted a 5-day BOD up to 6 times lower than glycol deicers (103 versus 400 to 800 g O2/L). Toxicity to Ceriodaphnia dubia for this formulation (48-hour lethal concentration, 50% [LC50] of 2.73 g/L) was greater than pure propylene glycol (13.1 g/ L), but lower than propylene glycol deicer formulations (1.02 g/L). Organic acids were identified by gas chromatography/mass spectrometry as the primary constituents in the oxidized starch solution. The proposed deicing system would provide effective deicing while exerting minimal environmental effects (e.g., lower toxicity to aquatic organisms and lower BOD). Furthermore, these deicers could be made from waste starch, promoting sustainability.

Turbulent convective flows in a cubic cavity at high Prandtl number

NASA Astrophysics Data System (ADS)

Vasiliev, A.; Sukhanovskii, A.; Frick, P.

2016-10-01

Characteristics of turbulent convective flows in a cubic cell is studied experimentally for high values of Prandtl number. The first set was carriied out with propylene glycol (Pr = 64 and the second one with 25% water solution of propylene glycol (Pr = 24). It was found that increasing of Pr from 6.1 to 24 leads only to the slight change of intensity of the flow but during the next increasing of Pr from 24 to 64 the flow changes its structure.

Presidential Green Chemistry Challenge: 2006 Academic Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 2006 award winner, Professor Galen J. Suppes, developed a process to convert waste glycerin from biodiesel production into propylene glycol to replace ethylene glycol in antifreeze.

Transesterification of propylene glycol methyl ether in chromatographic reactors using anion exchange resin as a catalyst.

PubMed

Oh, Jungmin; Sreedhar, Balamurali; Donaldson, Megan E; Frank, Timothy C; Schultz, Alfred K; Bommarius, Andreas S; Kawajiri, Yoshiaki

2016-09-30

Reactive chromatography using an anion exchange resin is proposed for a transesterification reaction of propylene glycol methyl ether (DOWANOL™ PM) with ethyl acetate to produce propylene glycol methyl ether acetate (DOWANOL™ PMA). This reaction is studied in batch and chromatographic reactors catalyzed by an anion exchange resin. Several anion exchange resins are tested and compared based on the performance of resin as an adsorbent and a catalyst. A chromatographic column is packed with a selected catalyst, AMBERLITE™ IRA904, and both reaction and chromatographic elution are studied at different temperatures and feed concentrations. The resulting chromatograms are fitted to a mathematical model to obtain adsorption equilibrium and reaction kinetic parameters by the inverse method. Compared to esterification investigated in a previous study, transesterification has advantages such as a higher conversion at lower temperature and easy removal of the byproduct which may lead to higher productivity. Deactivation of anion exchange resins is observed and potential solutions are suggested. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of uranium surfaces machined with aqueous propylene glycol-borax or perchloroethylene-mineral oil coolants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.

1986-12-31

The use of perchloroethylene (perc) as an ingredient in coolants for machining enriched uranium at the Oak Ridge Y-12 Plant has been discontinued because of environmental concerns. A new coolant was substituted in December 1985, which consists of an aqueous solution of propylene glycol with borax (sodium tetraborate) added as a nuclear poison and with a nitrite added as a corrosion inhibitor. Uranium surfaces machined using the two coolants were compared with respects to residual contamination, corrosion or corrosion potential, and with the aqueous propylene glycol-borax coolant was found to be better than that of enriched uranium machined with themore » perc-mineral oil coolant. The boron residues on the final-finished parts machined with the borax-containing coolant were not sufficient to cause problems in further processing. All evidence indicated that the enriched uranium surfaces machined with the borax-containing coolant will be as satisfactory as those machined with the perc coolant.« less

Solid-State Characterization of Novel Propylene Glycol Ester Solvates Isolated from Lipid Formulations.

PubMed

Chakravarty, Paroma; Kothari, Sanjeev; Deese, Alan; Lubach, Joseph W

2015-07-06

The purpose of this study was to identify and characterize precipitates obtained from a liquid formulation of GNE068.HCl, a Genentech developmental compound, and lipophilic excipients, such as propylene glycol monocaprylate, and monolaurate. Precipitates were characterized using powder X-ray diffractometry (PXRD), differential scanning calorimetry, thermogravimetry, microscopy, nuclear magnetic resonance spectroscopy (NMR; solution and solid-state) and water sorption analysis. PXRD and NMR revealed the precipitates to be crystalline solvates of propylene glycol esters. The solvates (capryolate and lauroglycolate) were isomorphic and stable up to 70 °C, beyond which melting of the lattice occurred with subsequent dissolution of the active ingredient in the melt (microscopy and variable temperature PXRD). They were found to be mechanically stable (no change in PXRD pattern upon compression) and were nonhygroscopic up to ∼70% RH (25 °C). Our results highlight the outcome of inadvertent drug-excipient interactions in two separate lipid solution formulations with good solid-state properties and, thus, potential for further development.

Optical clearing of articular cartilage: a comparison of clearing agents

NASA Astrophysics Data System (ADS)

Bykov, Alexander; Hautala, Tapio; Kinnunen, Matti; Popov, Alexey; Karhula, Sakari; Saarakkala, Simo; Nieminen, Miika T.; Tuchin, Valery

2015-07-01

Optical clearing technique was applied to the problem of OCT imaging of articular cartilage and subchondral bone. We show that optical clearing significantly enhances visualization of articular cartilage and cartilage-bone interface. The effect of different clearing agents was analyzed. For the clearing, iohexol solution and propylene glycol (PG) were used. Clearing was performed in vitro at room temperature by immersion method. Cylindrical osteochondral samples (d=4.8mm) were drilled from bovine lateral femur and stored in phosphate-buffered saline at -20°C until clearing. Monitoring of clearing process was performed using high-speed spectral-domain OCT system providing axial resolution of 5.8μm at 930nm. Total duration of experiment was 90-100min to ensure saturation of clearing. We have shown that iohexol solution and PG are capable to optically clear articular cartilage enabling reliable characterization of cartilagebone interface with OCT. Being a low osmolarity agent, iohexol provides minimal changes to the thickness of cartilage sample. Clearing saturation time for the cartilage sample with the thickness of 0.9 mm measured with OCT is of 50 min. However, less than 15 min is enough to reliably detect the rear cartilage boundary. Alternatively, PG significantly (60%) reduces the cartilage thickness enabling better visualization of subchondral bone. It was observed that PG has higher clearing rate. The clearing saturation time is of 30 min, however less than 5 min is enough to detect cartilage-bone interface. We conclude that iohexol solution is superior for OCT imaging of cartilage and cartilage-bone interface, while PG suits better for subhondral bone visualization.

21 CFR 184.1666 - Propylene glycol.

Code of Federal Regulations, 2014 CFR

2014-04-01

... chlorinated water to form the chlorohydrin which is converted to the glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the...

Relative toxicities of formulated glycol aircraft deicers and pure glycol products to duckweed (Lemna minor)

DOE Office of Scientific and Technical Information (OSTI.GOV)

DuFresne, D.L.; Pillard, D.A.

1995-12-31

Ethylene and propylene glycol deicers are commonly used at airports in the US and other countries to both remove snow and ice from aircraft, and to retard the accumulation of those materials. Snow and ice often pile up at airports during the winter and are then flushed into the storm sewer system during warmer temperatures or rainfall. Some of this water containing deicers may enter waterbodies without prior treatment, While previous studies have investigated the effects of deicers on aquatic animals and algae, data are not available on the effects on aquatic macrophytes, Glycol deicers were obtained in the formulatedmore » mixtures used on aircraft; pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Duckweed (Lemna minor) fronds were exposed to various concentrations of pure and formulated glycol mixtures. The number of fronds at test termination and chlorophyll concentration (measured using a spectrophotometer) were the measured endpoints. Based upon glycol concentration, the formulated products were more toxic than the pure material. These results are consistent with results seen in other animal and plant studies.« less

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 2. Toxicity of aircraft and runway deicers.

PubMed

Corsi, S R; Hall, D W; Geis, S W

2001-07-01

Streams receiving runoff from General Mitchell International Airport (GMIA), Milwaukee, Wisconsin, USA, were studied to assess toxic impacts of aircraft and runway deicers. Elevated levels of constituents related to deicing (propylene glycol, ethylene glycol, and ammonia) were observed in stream samples. The LC50s of type I deicer for Ceriodaphnia dubia, Pimephelas promelas, Hyalela azteca, and Chironimus tentans and the EC50 for Microtox were less than 5,000 mg/L of propylene glycol. Concentrations up to 39,000 mg/L were observed at airport outfall sites in samples collected during deicing events. The IC25s of type I deicer for C. dubia and P. promelas were less than 1,500 mg/L of propylene glycol. Concentrations up to 960 mg/L were observed in low-flow samples at an airport outfall site. Measured toxicity of stream water was greatest during winter storms when deicers were applied. Chronic toxicity was observed at airport outfall samples from low-flow periods in the winter and the summer, with the greater toxic impacts from the winter sample. All forms of toxicity in stream-water samples decreased as downstream flows increased.

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 2. Toxicity of aircraft and runway deicer

USGS Publications Warehouse

Corsi, Steven; Hall, David W.; Geis, Steven W.

2001-01-01

Streams receiving runoff from General Mitchell International Airport (GMIA), Milwaukee, Wisconsin, USA, were studied to assess toxic impacts of aircraft and runway deicers. Elevated levels of constituents related to deicing (propylene glycol, ethylene glycol, and ammonia) were observed in stream samples. The LC50s of type I deicer for Ceriodaphnia dubia, Pimephelas promelas, Hyalela azteca, and Chironimus tentans and the EC50 for Microtox® were less than 5,000 mg/L of propylene glycol. Concentrations up to 39,000 mg/L were observed at airport outfall sites in samples collected during deicing events. The IC25s of type I deicer for C. dubia and P. promelas were less than 1,500 mg/L of propylene glycol. Concentrations up to 960 mg/L were observed in low-flow samples at an airport outfall site. Measured toxicity of stream water was greatest during winter storms when deicers were applied. Chronic toxicity was observed at airport outfall samples from low-flow periods in the winter and the summer, with the greater toxic impacts from the winter sample. All forms of toxicity in stream-water samples decreased as downstream flows increased.

In vivo comparison of the optical clearing efficacy of optical clearing agents in human skin by quantifying permeability using optical coherence tomography.

PubMed

Guo, Xiao; Guo, Zhouyi; Wei, Huajiang; Yang, Hongqin; He, Yonghong; Xie, Shusen; Wu, Guoyong; Deng, Xiaoyuan; Zhao, Qingliang; Li, Lanquan

2011-01-01

The objective of this work is to quantify and compare the optical clearing efficacy of glucose, propylene glycol, glycerol solutions through the human skin tissue in vivo by calculating permeability coefficient of three solutions. Currently, the permeability coefficient of agent in tissues was extracted from optical coherence tomography (OCT) amplitude data mainly through the OCT signal slope and the OCT amplitude methods. In this study, we report the OCT attenuation coefficient method which is a relatively novel and rarely reported methodology to measure the permeability coefficient during the optical skin clearing procedure. The permeability coefficients for 40% propylene glycol, glucose and glycerol were (2.74 ± 0.05) × 10(-6) cm s(-1), (1.78 ± 0.04) × 10(-6) cm s(-1) and (1.67 ± 0.04) × 10(-6) cm s(-1), respectively. It could be clearly seen that the permeability coefficient of the 40% propylene glycol solution is higher than that of 40% glucose solution, and the permeability coefficient of the 40% glucose solution is higher than that of the 40% glycerol solution. These indicate 40% propylene glycol solution is more effective than others in the human skin in vivo. We then compare and prove consistency of optical clearing efficacy figured out by three different methods. © 2011 The Authors. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

21 CFR 184.1666 - Propylene glycol.

Code of Federal Regulations, 2013 CFR

2013-04-01

... glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 255...

21 CFR 184.1666 - Propylene glycol.

Code of Federal Regulations, 2012 CFR

2012-04-01

... glycol by treatment with sodium carbonate solution. It is also prepared by heating glyercol with sodium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 255...

Effects of pitfall trap preservative on collections of carabid beetles (Coleoptera: Carabidae)

USGS Publications Warehouse

McCravy, K.W.; Willand, J.E.

2007-01-01

Effects of six pitfall trap preservatives (5% acetic acid solution, distilled water, 70% ethanol, 50% ethylene glycol solution, 50% propylene glycol solution, and 10% saline solution) on collections of carabid beetles (Coleoptera: Carabidae) were studied in a west-central Illinois deciduous forest from May to October 2005. A total of 819 carabids, representing 33 species and 19 genera, were collected. Saline produced significantly fewer captures than did acetic acid, ethanol, ethylene glycol, and propylene glycol, while distilled water produced significantly fewer captures than did acetic acid. Significant associations between numbers of captures and treatment were seen in four species: Amphasia interstitialis (Say), Calathus opaculus LeConte, Chlaenius nemoralis Say, and Cyclotrachelus sodalis (LeConte). Results of this study suggest that type of preservative used can have substantial effects on abundance and species composition of carabids collected in pitfall traps.

Characterisation of mainstream and passive vapours emitted by selected electronic cigarettes.

PubMed

Geiss, Otmar; Bianchi, Ivana; Barahona, Francisco; Barrero-Moreno, Josefa

2015-01-01

Electronic cigarettes have achieved growing popularity since their introduction onto the European market. They are promoted by manufacturers as healthier alternatives to tobacco cigarettes, however debate among scientists and public health experts about their possible impact on health and indoor air quality means further research into the product is required to ensure decisions of policymakers, health care providers and consumers are based on sound science. This study investigated and characterised the impact of 'vaping' (using electronic cigarettes) on indoor environments under controlled conditions using a 30m(3) emission chamber. The study determined the composition of e-cigarette mainstream vapour in terms of propylene glycol, glycerol, carbonyls and nicotine emissions using a smoking machine with adapted smoking parameters. Two different base recipes for refill liquids, with three different amounts of nicotine each, were tested using two models of e-cigarettes. Refill liquids were analysed on their content of propylene glycol, glycerol, nicotine and qualitatively on their principal flavourings. Possible health effects of e-cigarette use are not discussed in this work. Electronic cigarettes tested in this study proved to be sources for propylene glycol, glycerol, nicotine, carbonyls and aerosol particulates. The extent of exposure differs significantly for active and passive 'vapers' (users of electronic cigarettes). Extrapolating from the average amounts of propylene glycol and glycerol condensed on the smoking machine filter pad to the resulting lung-concentration, estimated lung concentrations of 160 and 220mgm(-3) for propylene glycol and glycerol were obtained, respectively. Vaping refill liquids with nicotine concentrations of 9mgmL(-1) led to vapour condensate nicotine amounts comparable to those of low-nicotine regular cigarettes (0.15-0.2mg). In chamber studies, peak concentrations of 2200μgm(-3) for propylene glycol, 136μgm(-3) for glycerol and 0.6μgm(-3) for nicotine were reached. Carbonyls were not detected above the detection limits in chamber studies. Particles in the size range of 20nm to 300nm constantly increased during vaping activity and reached final peak concentrations of 7×10(6)particlesL(-1). Moreover, the tested products showed design flaws such as leakages from the cartridge reservoirs. Possible long term effects of e-cigarettes on health are not yet known. E-cigarettes, the impact of vaping on health and the composition of refill liquids require therefore further research into the product characteristics. The consumers would benefit from harmonised quality and safety improvements of e-cigarettes and refill liquids. Copyright © 2014 The Authors. Published by Elsevier GmbH.. All rights reserved.

Metal reduction at point-of-use filtration

NASA Astrophysics Data System (ADS)

Umeda, Toru; Daikoku, Shusaku; Varanasi, Rao; Tsuzuki, Shuichi

2016-03-01

We explored the metal removal efficiency of Nylon 6,6 and HDPE (High Density Polyethylene) membrane based filters, in solvents of varying degree of polarity such as Cyclohexanone and 70:30 mixture of PGME (Propylene Glycol Monomethyl Ether) and PGMEA (Propylene Glycol Monomethyl Ether), In all the solvents tested, Nylon 6,6 membrane filtration was found to be significantly more effective in removing metals than HDPE membranes, regardless of their respective membrane pore sizes. Hydrophilic interaction chromatography (HILIC) mechanism was invoked to rationalize metal removal efficiency dependence on solvent hydrophobicity.

Synthesis and characterization of biodegradable poly (ethylene glycol) and poly (caprolactone diol) end capped poly (propylene fumarate) cross linked amphiphilic hydrogel as tissue engineering scaffold material.

PubMed

Krishna, Lekshmi; Jayabalan, Muthu

2009-12-01

Biodegradable poly (caprolactone diol-co-propylene fumarate-co-ethylene glycol) amphiphilic polymer with poly (ethylene glycol) and poly (caprolactone diol) chain ends (PCL-PPF-PEG) was prepared. PCL-PPF-PEG undergoes fast setting with acrylamide (aqueous solution) by free radical polymerization and produces a crosslinked hydrogel. The cross linked and freeze-dried amphiphilic material has porous and interconnected network. It undergoes higher degree of swelling and water absorption to form hydrogel with hydrophilic and hydrophobic domains at the surface and appreciable tensile strength. The present hydrogel is compatible with L929 fibroblast cells. PCL-PPF-PEG/acrylamide hydrogel is a candidate scaffold material for tissue engineering applications.

Synthesis and characterization of amphiphilic block polymer poly(ethylene glycol)-poly(propylene carbonate)-poly(ethylene glycol) for drug delivery.

PubMed

Li, Hongchun; Niu, Yongsheng

2018-08-01

A novel amphiphilic block polymer poly(ethylene glycol)-poly(propylene carbonate)-poly(ethylene glycol) (PEG-PPC-PEG) was synthesized via the dicyclohexylcarbodiimide condensation reaction of double PEG-bis-amine and HOOC-PPC-COOH. The obtained copolymer was characterized by NMR to determine its structure. Using the PEG-PPC-PEG as the carrier and using doxorubicin (DOX) as a model drug, DOX-loaded nanoparticles with core shell structure were synthesized by self-assembly in water. The nanoparticles properties such as particle size, drug loading, encapsulation efficiency (EE) and drug release behavior were investigated as a function of the hydrophobic block length of PPC segments and compared with each other. The results showed that the EE was up to 88.8%. Nanoparticles were found to have a certain effect on the controlled release of DOX. Copyright © 2018 Elsevier B.V. All rights reserved.

The Photocatalytic Application of Semiconductor Stibnite Nanostructure Synthesized via a Simple Microwave-Assisted Approach in Propylene Glycol for Degradation of Dye Pollutants and its Optical Property

NASA Astrophysics Data System (ADS)

Saksornchai, Eksuree; Kavinchan, Jutarat; Thongtem, Somchai; Thongtem, Titipun

2017-11-01

Stibnite (Sb2S3) semiconducting material was successfully synthesized by a rapid and facile microwave route using antimony chloride (SbCl3) and sodiumthiosulfate (Na2S2O3) dissolved in propylene glycol (PG) containing different hydroxyethyl cellulose (HEC) masses. The phase identification, morphology, and elemental composition of products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field- emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The results revealed the orthorhombic phase of Sb2S3 single crystal-forming sheaf-like nanostructure, and a possible formation mechanism was proposed and discussed. Its direct band gap calculated from UV-visible absorption is 1.60 eV. In this research, the photocatalytic activities of Sb2S3 nanostructure were investigated through the degradation of methyl orange (MO) and methylene blue (MB) under visible light irradiation. The as-obtained 0.30 g HEC-added solution (0.3 HEC-Sb2S3) photocatalyst exhibited better photocatalytic activity than the other products, which degraded 91% of MO within 300 min and 90% of MB within 240 min under the Xe-lamp irradiation. The first-order plot was fitted with this experiment which the rate constant ( k) of 0.3 HEC-Sb2S3 for MO and MB degradation are 0.0085 and 0.0098 min-1, respectively. Therefore, the new experience with a novel and simple synthetic procedure of Sb2S3 photocatalyst that exhibits the characteristics of a highly effective photocatalyst under visible light irradiation was discovered.

Propylene glycol-embodying deformable liposomes as a novel drug delivery carrier for vaginal fibrauretine delivery applications.

PubMed

Li, Wei-Ze; Hao, Xu-Liang; Zhao, Ning; Han, Wen-Xia; Zhai, Xi-Feng; Zhao, Qian; Wang, Yu-E; Zhou, Yong-Qiang; Cheng, Yu-Chuan; Yue, Yong-Hua; Fu, Li-Na; Zhou, Ji-Lei; Wu, Hong-Yu; Dong, Chun-Jing

2016-03-28

The purpose of this work was to develop and characterize the fibrauretine (FN) loaded propylene glycol-embodying deformable liposomes (FDL), and evaluate the pharmacokinetic behavior and safety of FDL for vaginal drug delivery applications. FDL was characterized for structure, particle size, zeta potential, deformability and encapsulation efficiency; the ability of FDL to deliver FN across vagina tissue in vitro and the distribution behavior of FN in rat by vaginal drug delivery were investigated, the safety of FDL to the vagina of rabbits and rats as well as human vaginal epithelial cells (VK2/E6E7) were also evaluated. Results revealed that: (i) the FDL have a closed spherical shape and lamellar structure with a homogeneous size of 185±19nm, and exhibited a negative charge of -53±2.7mV, FDL also have a good flexibility with a deformability of 92±5.6 (%phospholipids/min); (ii) the dissolving capacity of inner water phase and hydrophilicity of phospholipid bilayers of deformable liposomes were increased by the presence of propylene glycol, this may be elucidated by the fluorescent probes both lipophilic Nile red and hydrophilic calcein that were filled up the entire volume of the FDL uniformly, so the FDL with a high entrapment capacity (were calculated as percentages of total drug) for FN was 78±2.14%; (iii) the permeability of FN through vaginal mucosa was obviously improved by propylene glycol-embodying deformable liposomes, no matter whether the FN loaded in liposomes or not, although FN loaded in liposomes caused the highest permeability and drug reservoir in vagina; (iv) the FN mainly aggregated in the vagina and uterus, then the blood, spleen, liver, kidney, heart and lungs for vaginal drug delivery, this indicating vaginal delivery of FDL have a better 'vaginal local targeting effect'; and (v) the results of safety evaluation illustrate that the FDL is non-irritant and well tolerated in vivo, thereby establishing its vaginal drug delivery potential. These results indicate that the propylene glycol-embodying deformable liposomes may be a promising drug delivery carrier for vaginal delivery of fibrauretine. Copyright © 2016 Elsevier B.V. All rights reserved.

Penetration enhancer containing vesicles as carriers for dermal delivery of tretinoin.

PubMed

Manconi, Maria; Sinico, Chiara; Caddeo, Carla; Vila, Amparo Ofelia; Valenti, Donatella; Fadda, Anna Maria

2011-06-30

The ability of a recently developed novel class of liposomes to promote dermal delivery of tretinoin (TRA) was evaluated. New penetration enhancer-containing vesicles (PEVs) were prepared adding to conventional phosphatidylcholine vesicles (control liposomes) different hydrophilic penetration enhancers: Oramix NS10 (OrNS10), Labrasol (Lab), Transcutol P (Trc), and propylene glycol (PG). Vesicles were characterized by morphology, size distribution, zeta potential, incorporation efficiency, stability, rheological behaviour, and deformability. Small, negatively charged, non-deformable, multilamellar vesicles were obtained. Rheological studies showed that PEVs had fluidity higher than conventional liposomes. The influence of the obtained PEVs on (trans)dermal delivery of tretinoin was studied by ex vivo diffusion experiments through new born pig skin using formulations having the drug both inside and outside the vesicles, having TRA only inside, in comparison with non-incorporated drug dispersions of the same composition used to produce the studied vesicles. Main result of these experiments was an improved cutaneous drug accumulation and a reduced transdermal TRA delivery (except for PG-PEVs). TRA deposition provided by PEVs was higher for dialysed than for non-dialysed vesicles. Further, the accumulation increased in the order: control liposomes

Analysis of glycols, glycol ethers, and other volatile organic compounds present in household water-based hand pump sprays.

PubMed

Kawakami, Tsuyoshi; Isama, Kazuo; Tanaka-Kagawa, Toshiko; Jinnno, Hideto

2017-11-10

The aim of this investigation is to clarify the types and concentrations of VOCs present in various commercial household water-based hand pump spray products used in Japan, and to estimate their average concentrations in indoor air when the spray product is used. We selected glycol and glycol ethers as the main target compounds, as these chemicals were detected at high frequencies and concentrations in a national survey of Japanese indoor air pollution. The extraction of these chemicals using graphite carbon cartridges was examined, with good recoveries and reproducibilities being obtained. Eighteen chemicals were analyzed in 54 commercial products and 8 chemicals were detected. More specifically, dipropylene glycol (DPG) was present in 44 samples (1.1 × 10 1 -1.8 × 10 4 μg/mL); propylene glycol (PG) was present in 22 samples (1.5 × 10 1 -2.9 × 10 4 μg/mL); diethylene glycol monoethyl ether (DGMEE) was found in 15 samples (trace amount-1.9 × 10 3 μg/mL); diethylene glycol (DEG) was present in 9 samples (1.0 × 10 1 -2.4 × 10 3 μg/mL); 1,3-butandiol (13BG) was found in 5 samples (trace amount-7.4 × 10 3 μg/mL); 2-ethyl-1-hexanol (2E1H) was detected in 5 samples (3.2 × 10 -1 -4.4 × 10 1 μg/mL); diethylene glycol monobutyl ether (DGMBE) was present in 4 samples (2.1 × 10 1 -7.1 × 10 1 μg/mL); and 3-methoxy-3-methylbutanol (MMB) was found in 2 samples (2.4 × 10 1 -4.7 × 10 2 μg/mL). In addition, the average concentrations of these chemicals in indoor air were estimated using their maximum concentrations observed in the spray product. The estimated average concentrations of the chemicals in indoor air were determined to range between 1.0 × 10 -2 and 1.0 mg/m 3 , with the exception of 2E1H and DGMBE. Furthermore, the estimated average concentrations of PG, 13BG, and DGMEE in indoor air were comparable to or higher than those reported in a national survey of Japanese indoor air pollution. It therefore appeared that household water-based hand pump sprays may contribute to the presence of these chemicals in indoor air. In contrast, estimated average concentrations of 2E1H in indoor air were low, its concentrations observed in a national survey of Japanese indoor air pollution are likely due to the use of plasticizers and paints.

Enhancement of Loperamide Dissolution Rate by Liquisolid Compact Technique.

PubMed

Venkateswarlu, Kambham; Preethi, Jami Komala; Chandrasekhar, Kothapalli Bonnoth

2016-09-01

Purpose: The aim of present study was to improve the dissolution rate of poorly soluble drug Loperamide (LPM) by liquisolid compact technique. Methods: Liquisolid compacts of LPM were prepared using Propylene glycol (PG) as a solvent, Avicel pH 102 as carrier, Aerosil as coating material and Sodium Starch Glycolate (SSG) as superdisintegrant. Interactions between the drug and excipients were examined by Fourier Transform Infrared (FTIR) spectroscopy. The dissolution studies for LPM liquisolid formulation, marketed product and pure drug were carried out in pH 1.2 HCl buffer as dissolution media. Results: Results confirmed the absence of chemical interactions between the drug and excipients. From the solubility studies, it was observed the LPM was highly soluble in PG thereby it was selected as a solvent. The dissolution efficiency of LPM at 15 min was increased from 9.99 % for pure drug and 54.57% for marketed product to 86.81% for the tablets prepared by liquisolid compact technique. Stability studies showed no significant change in percent cumulative drug release, hardness, disintegration time, friability and drug content for 3 months. Conclusion: Formulation F2 showed significant increase in dissolution rate compared to the marketed product at pH 1.2 where LPM is largely absorbed. Around 90% of the drug was released from F2 in 30 min compared to the marketed product and it might be due to the increased wetting and surface area of the particles. Hence, the liquisolid compact technique appears to be a promising approach for improving the dissolution rate of poorly soluble drug.

Fast determination of ethylene glycol, 1,2-propylene glycol and glycolic acid in blood serum and urine for emergency and clinical toxicology by GC-FID.

PubMed

Hložek, Tomáš; Bursová, Miroslava; Čabalaa, Radomír

2014-12-01

A simple, cost effective, and fast gas chromatography method with flame ionization detection (GC-FID) for simultaneous measurement of ethylene glycol, 1,2-propylene glycol and glycolic acid was developed and validated for clinical toxicology purposes. This new method employs a relatively less used class of derivatization agents - alkyl chloroformates, allowing the efficient and rapid derivatization of carboxylic acids within seconds while glycols are simultaneously derivatized by phenylboronic acid. The entire sample preparation procedure is completed within 10 min. To avoid possible interference from naturally occurring endogenous acids and quantitation errors 3-(4-chlorophenyl) propionic acid was chosen as an internal standard. The significant parameters of the derivatization have been found using chemometric procedures and these parameters were optimized using the face-centered central composite design. The calibration dependence of the method was proved to be quadratic in the range of 50-5000 mg mL(-1), with adequate accuracy (92.4-108.7%) and precision (9.4%). The method was successfully applied to quantify the selected compounds in serum of patients from emergency units. Copyright © 2014 Elsevier B.V. All rights reserved.

Relative uptake of minoxidil into appendages and stratum corneum and permeation through human skin in vitro.

PubMed

Grice, Jeffrey E; Ciotti, Susan; Weiner, Norman; Lockwood, Peter; Cross, Sheree E; Roberts, Michael S

2010-02-01

We examined uptake of the model therapeutic agent, minoxidil, into appendages, stratum corneum (SC), and through human skin, under the influence of different vehicles. Quantitative estimation of therapeutic drug deposition into all three areas has not previously been reported. Finite doses of minoxidil (2%, w/v) in formulations containing varying amounts of ethanol, propylene glycol (PG), and water (60:20:20, 80:20:0, and 0:80:20 by volume, respectively) were used. Minoxidil in SC (by tape stripping), appendages (by cyanoacrylate casting), and receptor fluid was determined by liquid scintillation counting. At early times (30 min, 2 h), ethanol-containing formulations (60:20:20 and 80:20:0) caused significantly greater minoxidil retention in SC and appendages, compared to the formulation lacking ethanol (0:80:20). A significant increase in minoxidil receptor penetration occurred with the PG-rich 0:80:20 formulation after 12 h. We showed that deposition of minoxidil into appendages, SC, and skin penetration into receptor fluid were similar in magnitude. Transport by the appendageal route is likely to be a key determinant of hair growth promotion by minoxidil. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

Evaluation of transcutol as a clonazepam transdermal permeation enhancer from hydrophilic gel formulations.

PubMed

Mura, P; Faucci, M T; Bramanti, G; Corti, P

2000-02-01

The influence of diethyleneglycol monoethyl ether (transcutol), alone or in combination with propylene glycol, on clonazepam permeation through an artificial membrane and excised rabbit ear skin from Carbopol hydrogels was investigated. Drug kinetic permeation parameters were determined for both series of experiments and compared. Rheological characteristics, drug solubility and membrane/vehicle partition coefficient for each gel formulation were also determined, and their role in the formulation performance was investigated. Both series of experiments showed an increase of drug permeation as a function of transcutol content in the formulation. The combination of transcutol and propylene glycol resulted in a synergistic enhancement of clonazepam flux. A different trend was found in experiments with gels containing mixtures of the two enhancers, where an increase (in the case of artificial membrane) or a decrease (in the case of rabbit ear skin) of drug permeation was found by increasing the transcutol/propylene glycol ratio in the mixture. Such a result is explained on the basis of the particular mechanism of action demonstrated for transcutol which associates the increase of drug solubility to the potent effect of a depot in the skin.

Adult Behavior in Male Mice Exposed to E-Cigarette Nicotine Vapors during Late Prenatal and Early Postnatal Life

PubMed Central

Smith, Dani; Aherrera, Angela; Lopez, Armando; Neptune, Enid; Winickoff, Jonathan P.; Klein, Jonathan D.; Chen, Gang; Lazarus, Philip; Collaco, Joseph M.; McGrath-Morrow, Sharon A.

2015-01-01

Nicotine exposure has been associated with an increased likelihood of developing attention deficit hyperactivity disorder (ADHD) in offspring of mothers who smoked during pregnancy. The goal of this study was to determine if exposure to E-cigarette nicotine vapors during late prenatal and early postnatal life altered behavior in adult mice. Methods Timed-pregnant C57BL/6J mice were exposed to 2.4% nicotine in propylene glycol (PG) or 0% nicotine /PG once a day from gestational day 15 until delivery. After delivery, offspring and mothers were exposed to E-cigarette vapors for an additional 14 days from postnatal day 2 through 16. Following their last exposure serum cotinine levels were measured in female juvenile mice. Male mice underwent behavioral testing at 14 weeks of age to assess sensorimotor, affective, and cognitive functional domains. Results Adult male mice exposed to 2.4% nicotine/PG E-cigarette vapors had significantly more head dips in the zero maze test and higher levels of rearing activity in the open field test compared to 0% nicotine/PG exposed mice and untreated controls. In the water maze test after reversal training, the 2.4% nicotine/PG mice spent more than 25% of time in the new location whereas the other groups did not. Conclusion Adult male mice exhibited increased levels of activity in the zero maze and open field tests when exposed to E-cigarette vapor containing nicotine during late prenatal and early postnatal life. These findings indicate that nicotine exposure from E-cigarettes may cause persistent behavioral changes when exposure occurs during a period of rapid brain growth. PMID:26372012

Change of translational-rotational coupling in liquids revealed by field-cycling {sup 1}H NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meier, R.; Schneider, E.; Rössler, E. A.

2015-01-21

Applying the field-cycling nuclear magnetic resonance technique, the frequency dependence of the {sup 1}H spin-lattice relaxation rate, R{sub 1}(ω)=T{sub 1}{sup −1}(ω), is measured for propylene glycol (PG) which is increasingly diluted with deuterated chloroform. A frequency range of 10 kHz–20 MHz and a broad temperature interval from 220 to about 100 K are covered. The results are compared to those of experiments, where glycerol and o-terphenyl are diluted with their deuterated counter-part. Reflecting intra- as well as intermolecular relaxation, the dispersion curves R{sub 1}(ω,x) (x denotes mole fraction PG) allow to extract the rotational time constant τ{sub rot}(T, x) andmore » the self-diffusion coefficient D(T, x) in a single experiment. The Stokes-Einstein-Debye (SED) relation is tested in terms of the quantity D(T, x) τ{sub rot}(T, x) which provides a measure of an effective hydrodynamic radius or equivalently of the spectral separation of the translational and the rotational relaxation contribution. In contrast to o-terphenyl, glycerol and PG show a spectral separation much larger than suggested by the SED relation. In the case of PG/chloroform mixtures, not only an acceleration of the PG dynamics is observed with increasing dilution but also the spectral separation of rotational and translational relaxation contributions continuously decreases. Finally, following a behavior similar to that of o-terphenyl already at about x = 0.6; i.e., while D(T, x) τ{sub rot}(T, x) in the mixture is essentially temperature independent, it strongly increases with x signaling thus a change of translational-rotational coupling. This directly reflects the dissolution of the hydrogen-bond network and thus a change of solution structure.« less

21 CFR 349.12 - Ophthalmic demulcents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... percent. (2) Hydroxyethyl cellulose, 0.2 to 2.5 percent. (3) Hypromellose, 0.2 to 2.5 percent. (4...) Polyethylene glycol 300, 0.2 to 1 percent. (3) Polyethylene glycol 400, 0.2 to 1 percent. (4) Polysorbate 80, 0.2 to 1 percent. (5) Propylene glycol, 0.2 to 1 percent. (e) Polyvinyl alcohol, 0.1 to 4 percent. (f...

21 CFR 349.12 - Ophthalmic demulcents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... percent. (2) Hydroxyethyl cellulose, 0.2 to 2.5 percent. (3) Hypromellose, 0.2 to 2.5 percent. (4...) Polyethylene glycol 300, 0.2 to 1 percent. (3) Polyethylene glycol 400, 0.2 to 1 percent. (4) Polysorbate 80, 0.2 to 1 percent. (5) Propylene glycol, 0.2 to 1 percent. (e) Polyvinyl alcohol, 0.1 to 4 percent. (f...

Investigation of selected potential environmental contaminants: ethylene glycol, propylene glycols and butylene glycols. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, L.M.

1979-05-01

This report reviews aspects of production, use, environmental exposure and biological effects of ethylene glycol, two isomers of propylene glycol (1,2- and 1,3-propanediol) and four isomers of butylene glycol (1,3-, 1,4-, 2,3-, and 1,2- butanediol). Annual production of ethylene glycol is about 3.7 billion pounds for use primarily in antifreeze and polyester fiber. About 0.5 billion pounds of 1,2-propanediol are produced per year for use in polyester resins, food, pharmaceuticals, and cellophane. Annual domestic demand for 1,4-butanediol is about 0.2 billion pounds for use in the production of tetra-hydrofuran and acetylenic chemicals. The other title glycols are of less importancemore » commercially. The major source of environmental contamination by ethylene glycol and 1,2-propanediol is likely from the disposal of spent antifreeze and de-icing fluids. However, limited monitoring data make it difficult to adequately assess environmental exposure to the glycols. The glycols are capable of being degraded by a variety of acclimated and unacclimated soil, water, and sewage microorganisms. In humans, ethylene glycol intoxication, usually as a result of accidental ingestion of antifreeze, may result in nausea, hypertension, tachycardia, cardiopulmonary failure, renal impairment, coma and death. 1,2-Propanediol is a GRAS food additive of low toxicity. 1,3-Butanediol has been studied as a source of dietary energy. Few studies are available on 1,2-, 2,3- and 1,4-butanediol or on 1,3-propanediol.« less

Allergic contact cheilitis from a lipstick misdiagnosed as herpes labialis: Subsequent worsening due to Zovirax contact allergy.

PubMed

Ozkaya, Esen; Topkarci, Zeynep; Ozarmağan, Güzin

2007-08-01

A 29-year-old Turkish woman with allergic contact cheilitis from a lipstick was misdiagnosed as herpes labialis and subsequently worsened with the application of Zovirax cream. Patch tests were positive to Zovirax cream, propylene glycol, the patient's favourite lipstick and propyl gallate. No reaction was seen with Zovirax ophthalmic ointment and Zovirax tablet. The propylene glycol component of the Zovirax cream and the propyl gallate component of the lipstick were regarded as the responsible contact sensitizers. The differential diagnosis was challenging due to concomitant contact sensitization with these agents.

Clinical Outcomes of Fixed Versus As-Needed Use of Artificial Tears in Dry Eye Disease: A 6-Week, Observer-Masked Phase 4 Clinical Trial.

PubMed

Asbell, Penny; Vingrys, Algis J; Tan, Jacqueline; Ogundele, Abayomi; Downie, Laura E; Jerkins, Gary; Shettle, Lee

2018-05-01

To evaluate the clinical effects of using fixed (four times daily [QID]) versus as-needed (PRN) dosing of an artificial tear product (polyethylene glycol/propylene glycol [PEG/PG]; Systane Ultra) in individuals with dry eye disease. In this prospective, multicenter, observer-masked, active-control, parallel-group trial, participants were randomized (1:2 allocation) to receive 1 drop of PEG/PG QID (n = 34) or PRN (n = 63) for 28 days. The primary endpoint was change from baseline in the total ocular surface staining (TOSS) score (according to the Oxford scale) at day 28. At day 28, the change from baseline in least squares mean (LSM) TOSS scores for QID and PRN groups were -1.19 and -0.94, respectively (treatment difference [TD]: -0.26; 95% confidence interval [CI]: -∞ to 0.21; P = 0.184); superiority of QID versus PRN dosing was not established, as the upper limit of one-sided 95% CI for TD was not <0 (prespecified limit). At day 28, for QID and PRN groups, the LSM change from baseline in Impact of Dry Eye on Everyday Life (IDEEL) scores was symptom-bother, -7.0 and -2.94 (TD: -4.06, P = 0.037); treatment effectiveness, 2.43 and 0.16 (TD: 2.28, P = 0.278); and treatment-related inconvenience, -11.56 and -2.77 (TD: -8.8, P = 0.996), respectively. Incidence of adverse events was low (≤3.2%) in both the groups; no serious adverse events were reported. QID dosing of PEG/PG was not superior to PRN dosing in terms of ocular staining. The IDEEL symptom-bother score favored QID dosing, suggesting that regular use of artificial tears may provide better symptomatic relief than PRN use. (ClinicalTrials.gov number, NCT02446015.).

New Linear and Star-Shaped Thermogelling Poly([R]-3-hydroxybutyrate) Copolymers.

PubMed

Barouti, Ghislaine; Liow, Sing Shy; Dou, Qingqing; Ye, Hongye; Orione, Clément; Guillaume, Sophie M; Loh, Xian Jun

2016-07-18

The synthesis of multi-arm poly([R]-3-hydroxybutyrate) (PHB)-based triblock copolymers (poly([R]-3-hydroxybutyrate)-b-poly(N-isopropylacrylamide)-b-[[poly(methyl ether methacrylate)-g-poly(ethylene glycol)]-co-[poly(methacrylate)-g-poly(propylene glycol)

An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures

NASA Technical Reports Server (NTRS)

Lee, Jason S.; Ray, Richard I.; Lowe, Kristine L.; Jones-Meehan, Joanne; Little, Brenda J.

2003-01-01

Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures.

Effects of vehicles and prodrug properties and their interactions on the delivery of 6-mercaptopurine through skin: S6-acyloxymethyl-6-mercaptopurine prodrugs.

PubMed

Waranis, R P; Sloan, K B

1988-03-01

A homologous series of S6-acyloxymethyl-6-mercaptopurine (6-mono-6-MP) and two 9-acyloxymethyl-6-mercaptopurine (9-mono-6-MP) prodrugs have been synthesized and characterized. The ability of the 6-mono-6-MP prodrugs to deliver 6-mercaptopurine (6-MP) through hairless mouse skin from isopropyl myristate (IPM) and propylene glycol (PG) has been evaluated. There was a good correlation between the log experimental permeability coefficients from the diffusion data and calculated solubility parameters of the prodrugs. Although there was no statistical difference between the rates of delivery of 6-MP by the acetyl through valeryl 6-mono-6-MP prodrugs from IPM, the butyryl and valeryl prodrugs were significantly better at delivering 6-MP from PG. For a given solubility parameter value, the 6-mono-6-MP prodrugs were less soluble in water and IPM, and more soluble in PG than the previously studied S6,9-bisacyloxymethyl-6-MP (6,9-bis-6-MP) prodrugs. On the other hand, for a given solubility parameter, the 6,9-bis-6-MP prodrugs were generally more effective at delivering 6-MP from IPM and PG. The single 9-mono-6-MP prodrug that was evaluated was much less effective at delivering 6-MP than either the 6-mono- or 6,9-bis-6-MP prodrugs. Thus, it is much less important to mask the imidazole than the thionamide functional group in 6-MP to enhance the topical delivery of 6-MP using a prodrug approach.

EVALUATION OF SINK EFFECTS ON VOCS FROM A LATEX PAINT

EPA Science Inventory

The sink strength of two common indoor materials, a carpet and a gypsum board, was evaluated by environmental chamber tests with four volatile organic compounds (VOCs): propylene glycol, ethylene glycol, 2-(2-butoxyethoxy)ethanol (BEE), and texanol. These oxygenated compounds rep...

Application of a high-level peracetic acid disinfection protocol to re-process antibiotic disinfected skin allografts.

PubMed

Lomas, R J; Huang, Q; Pegg, D E; Kearney, J N

2004-01-01

Skin allografts, derived from cadaveric donors, are widely used for the treatment of burns and ulcers. Prior to use in clinical situations, these allografts are disinfected using a cocktail of antibiotics and then cryopreserved. Unfortunately, this antibiotic disinfection procedure fails to decontaminate a significant proportion and these contaminated grafts can not be used clinically. We have investigated whether it is possible to apply a second, more potent disinfection procedure to these contaminated grafts and effectively to re-process them for clinical use. Cadaveric skin grafts, treated with antibiotics and cryopreserved, were thawed and a peracetic acid (PAA) disinfection protocol applied. The grafts were then preserved in a high concentration of glycerol or propylene glycol, and properties thought to be essential for successful clinical performance assessed. The cytotoxicity of the grafts was assessed using both extract and contact assays; damage to the skin collagen was assessed using a collagenase susceptibility assay and the capacity of the grafts to elicit an inflammatory response in vitro was assessed by quantifying the production of the pro-inflammatory cytokine TNF-alpha by human peripheral blood mononuclear phagocytes. PAA disinfection, in conjunction with either glycerol or propylene glycol preservation, did not render the grafts cytotoxic, pro-inflammatory, or increase their susceptibility to collagenase digestion. The rates of penetration of glycerol and propylene glycol into the re-processed skin were comparable to those of fresh skin. This study has demonstrated that PAA disinfection combined with immersion in high concentrations of either glycerol or propylene glycol was an effective method for re-processing contaminated skin allografts, and may justify their clinical use.

Effect of compositions in nanostructured lipid carriers (NLC) on skin hydration and occlusion.

PubMed

Loo, Ch; Basri, M; Ismail, R; Lau, Hln; Tejo, Ba; Kanthimathi, Ms; Hassan, Ha; Choo, Ym

2013-01-01

To study the effects of varying lipid concentrations, lipid and oil ratio, and the addition of propylene glycol and lecithin on the long-term physical stability of nanostructured lipid nanocarriers (NLC), skin hydration, and transepidermal water loss. The various NLC formulations (A1-A5) were prepared and their particle size, zeta potential, viscosity, and stability were analyzed. The formulations were applied on the forearms of the 20 female volunteers (one forearm of each volunteer was left untreated as a control). The subjects stayed for 30 minutes in a conditioned room with their forearms uncovered to let the skin adapt to the temperature (22°C ± 2°C) and humidity (50% ± 2%) of the room. Skin hydration and skin occlusion were recorded at day one (before treatment) and day seven (after treatment). Three measurements for skin hydration and skin occlusion were performed in each testing area. NLC formulations with the highest lipid concentration, highest solid lipid concentration, and additional propylene glycol (formulations A1, A2, and A5) showed higher physical stability than other formulations. The addition of propylene glycol into an NLC system helped to reduce the particle size of the NLC and enhanced its long-term physical stability. All the NLC formulations were found to significantly increase skin hydration compared to the untreated controls within 7 days. All NLC formulations exhibited occlusive properties as they reduced the transepidermal water loss within 7 days. This effect was more pronounced with the addition of propylene glycol or lecithin into an NLC formulation, whereby at least 60% reduction in transepidermal water loss was observed. NLCs with high lipid content, solid lipid content, phospholipid, and lecithin are a highly effective cosmetic delivery system for cosmetic topical applications that are designed to boost skin hydration.

Effect of the Association of Nonsteroidal Anti-inflammatory and Antibiotic Drugs on Antibiofilm Activity and pH of Calcium Hydroxide Pastes.

PubMed

de Freitas, Rafaela Pignatti; Greatti, Vanessa Raquel; Alcalde, Murilo Priori; Cavenago, Bruno Cavalini; Vivan, Rodrigo Ricci; Duarte, Marco Antonio Hungaro; Weckwerth, Ana Carolina Villas Bôas; Weckwerth, Paulo Henrique

2017-01-01

The objective of the present study was to evaluate the in vitro antibiofilm activity and pH of calcium hydroxide associated with different nonsteroidal anti-inflammatory drugs (NSAIDs). The groups analyzed were as follows: group 1, calcium hydroxide paste with propylene glycol; group 2, calcium hydroxide paste with propylene glycol + 5% diclofenac sodium; group 3, calcium hydroxide paste with propylene glycol + 5% ibuprofen; group 4, calcium hydroxide paste with propylene glycol + 5% ciprofloxacin; and group 6, positive control (without medication). For analysis of the pH, the pastes were inserted into tubes and immersed in flasks containing ultrapure water. At the time intervals of 3, 24, 72, and 168 hours, the pH was measured with a calibrated pH meter. For microbial analysis, biofilm was induced in 30 bovine dentin blocks for 21 days. Subsequently, the pastes were placed on the blocks with biofilm for 7 days. Afterward, the pastes were removed by irrigation with sterile water, and the specimens were analyzed with a laser scanning confocal microscope with the 50 μL Live/Dead BacLight Bacterial Viability solution L7012 Kit (Molecular Probes, Inc, Eugene, OR). Data were subjected to statistical analysis at a significance level of 5%. The highest pH values were found for calcium hydroxide associated with ciprofloxacin in all periods analyzed. With the exception of pure calcium hydroxide paste, the other groups showed statistically significant differences (P < .05) in comparison with the positive control. The association of NSAIDs or antibiotic did not interfere with the pH of calcium hydroxide paste and increased the antimicrobial action of calcium hydroxide paste against Enterococcus faecalis biofilm formation. Published by Elsevier Inc.

Membrane permeability of the human granulocyte to water, dimethyl sulfoxide, glycerol, propylene glycol and ethylene glycol.

PubMed

Vian, Alex M; Higgins, Adam Z

2014-02-01

Granulocytes are currently transfused as soon as possible after collection because they rapidly deteriorate after being removed from the body. This short shelf life complicates the logistics of granulocyte collection, banking, and safety testing. Cryopreservation has the potential to significantly increase shelf life; however, cryopreservation of granulocytes has proven to be difficult. In this study, we investigate the membrane permeability properties of human granulocytes, with the ultimate goal of using membrane transport modeling to facilitate development of improved cryopreservation methods. We first measured the equilibrium volume of human granulocytes in a range of hypo- and hypertonic solutions and fit the resulting data using a Boyle-van't Hoff model. This yielded an isotonic cell volume of 378 μm(3) and an osmotically inactive volume of 165 μm(3). To determine the permeability of the granulocyte membrane to water and cryoprotectant (CPA), cells were injected into well-mixed CPA solution while collecting volume measurements using a Coulter Counter. These experiments were performed at temperatures ranging from 4 to 37°C for exposure to dimethyl sulfoxide, glycerol, ethylene glycol, and propylene glycol. The best-fit water permeability was similar in the presence of all of the CPAs, with an average value at 21°C of 0.18 μmatm(-1)min(-1). The activation energy for water transport ranged from 41 to 61 kJ/mol. The CPA permeability at 21°C was 6.4, 1.0, 8.4, and 4.0 μm/min for dimethyl sulfoxide, glycerol, ethylene glycol, and propylene glycol, respectively, and the activation energy for CPA transport ranged between 59 and 68 kJ/mol. Copyright © 2013 Elsevier Inc. All rights reserved.

Electronic Cigarettes: Their Constituents and Potential Links to Asthma.

PubMed

Clapp, Phillip W; Jaspers, Ilona

2017-10-05

Vaping is gaining popularity in the USA, particularly among teens and young adults. While e-cigs are commonly represented as safer alternatives to tobacco cigarettes, little is known regarding the health effects of their short- or long-term use, especially in individuals with pre-existing respiratory diseases such as asthma. Flavored e-cig liquids (e-liquids) and e-cig aerosols contain airway irritants and toxicants that have been implicated in the pathogenesis and worsening of lung diseases. In this review, we will summarize existing data on potential health effects of components present in e-cig aerosols, such as propylene glycol, vegetable glycerin, nicotine, and flavorings, and discuss their relevance in the context of asthma. Recent survey data indicate that adolescents with asthma had a higher prevalence of current e-cig use (12.4%) compared to their non-asthmatics peers (10.2%) and conveyed positive beliefs about tobacco products, especially e-cigs. Similarly, a study conducted among high school students from Ontario, Canada, indicated a greater likelihood of e-cig use in asthmatics as compared to their non-asthmatic peers. Availability of different flavorings is often cited as the main reason among youth/adolescents for trying e-cigs or switching from cigarettes to e-cigs. Occupational inhalation of some common food-safe flavoring agents is reported to cause occupational asthma and worsen asthmatic symptoms. Moreover, workplace inhalation exposures to the flavoring agent diacetyl have caused irreversible obstructive airway disease in healthy workers. Additionally, recent studies report that thermal decomposition of propylene glycol (PG) and vegetable glycerin (VG), the base constituents of e-liquids, produces reactive carbonyls, including acrolein, formaldehyde, and acetaldehyde, which have known respiratory toxicities. Furthermore, recent nicotine studies in rodents reveal that prenatal nicotine exposures lead to epigenetic reprogramming in the offspring, abnormal lung development, and multigenerational transmission of asthmatic-like symptoms. Comparisons of the toxicity and health effects of e-cigs and conventional cigarettes often focus on toxicants known to be present in cigarette smoke (CS) (i.e., formaldehyde, nitrosamines, etc.), as well as smoking-associated clinical endpoints, such as cancer, bronchitis, and chronic obstructive pulmonary disease (COPD). However, this approach disregards potential toxicity of components unique to flavored e-cigs, such as PG, VG, and the many different flavoring chemicals, which likely induce respiratory effects not usually observed in cigarette smokers.

Basic poly(propylene glycols) as reference compounds for internal mass calibration in positive-ion matrix-assisted laser desorption/ionization mass spectrometry.

PubMed

Gross, Jürgen H

2017-12-01

Basic poly(propylene glycols), commercially available under the trade name Jeffamine, are evaluated for their potential use as internal mass calibrants in matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry. Due to their basic amino endgroups Jeffamines are expected to deliver [M+H] + ions in higher yields than neutral poly(propylene glycols) or poly(ethylene glycols). Aiming at accurate mass measurements and molecular formula determinations by matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry, four Jeffamines (M-600, M-2005, D-400, D-230) were thus compared. As a result, Jeffamine M-2005 is introduced as a new mass calibrant for positive-ion matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry in the range of m/z 200-1200 and the reference mass list is provided. While Jeffamine M-2005 is compatible with α-cyano-4-hydroxycinnamic acid, 2,5-dihydroxybenzoic acid, and 2-[(2 E)-3-(4- tert-butylphenyl)-2-methylprop-2-enylidene]malonitrile matrix, its use in combination with 2-[(2 E)-3-(4- tert-butylphenyl)-2-methylprop-2-enylidene]malonitrile provides best results due to low laser fluence requirements. Applications to PEG 300, PEG 600, the ionic liquid trihexyl(tetradecyl)-phosphonium tris(pentafluoroethyl)-trifluorophosphate, and [60]fullerene demonstrate mass accuracies of 2-5 ppm.

Effects of lipophilic components on the compatibility of lipid-based formulations with hard gelatin capsules.

PubMed

Chen, Feng-Jing; Etzler, Frank M; Ubben, Johanna; Birch, Amy; Zhong, Li; Schwabe, Robert; Dudhedia, Mayur S

2010-01-01

The present study investigated the effect of lipophilic components on the compatibility of propylene glycol (PG)-containing lipid-based drug delivery system (LBDDS) formulations with hard gelatin capsules. The presence of a lipophilic active pharmaceutical ingredient (API) (log P approximately 6.1) and an additional lipophilic excipient (Capmul MCM) significantly affected the activity of PG in the fills and the equilibrium of PG between capsule shells and fills. These changes in activity and equilibrium of PG were furthermore correlated to the mechanical and thermal properties of the liquid-filled capsules and subsequently linked to the shelf-life of the capsules on stability with respect to capsule deformation. The present study also investigated the mechanism by which lipophilic component(s) might affect the activity of PG in the fill formulations and the equilibrium of PG between capsule shells and fills. The activities of PG in two series of "binary" mixtures with Capmul MCM and with Cremophor EL were measured, respectively. The mixtures of PG containing Capmul MCM were found to be more nearly ideal than those containing Cremophor EL. The observed negative deviation from Rauolt's law indicates that the excess free energies of mixing are less then zero indicating favorable interaction between PG and the other component. It is speculated that enhanced hydrogen bonding opportunities with Cremophor EL are responsible for the decreased excess free energy of mixing. Replacement of Cremophor EL with lipophilic API also reduces the hydrogen bonding opportunities for PG in the mixtures. This hypothesis may further explain the increased activity of PG in the fills and the shifted equilibrium of PG toward the capsule shells. Activity determination utilizing headspace gas chromatography (GC) using short 30 min incubation time seems to be a time-efficient approach for assessing capsule-fill compatibility. Direct measurements of PG migration and other physical properties of the capsules took much longer time (7 weeks) for ranking the predicted capsule deformation at 40 degrees C. Asides from the time savings, activity determination can be considered to be material sparing by offering capsule-fill compatibility assessment even without the need for preparing liquid-filled capsules once appropriate positive and negative references are established. With further optimization, this approach should enable high throughput screening of LBDDS for capsule-fill compatibility in liquid-filled capsule development.

[Ethylene glycol and propylene glycol ethers - Reproductive and developmental toxicity].

PubMed

Starek-Świechowicz, Beata; Starek, Andrzej

2015-01-01

Both ethylene and propylene glycol alkyl ethers (EGAEs and PGAEs, respectively) are widely used, mainly as solvents, in industrial and household products. Some EGAEs demonstrate gonadotoxic, embriotoxic, fetotoxic and teratogenic effects in both humans and experimental animals. Due to the noxious impact of these ethers on reproduction and development of organisms EGAEs are replaced for considerably less toxic PGAEs. The data on the mechanisms of testicular, embriotoxic, fetotoxic and teratogenic effects of EGAEs are presented in this paper. Our particular attention was focused on the metabolism of some EGAEs and their organ-specific toxicities, apoptosis of spermatocytes associated with changes in the expression of various genes that code for oxidative stress factors, protein kinases and nuclear hormone receptors. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Solubility and thermodynamics of apremilast in different mono solvents: Determination, correlation and molecular interactions.

PubMed

Shakeel, Faiyaz; Haq, Nazrul; Alanazi, Fars K; Alsarra, Ibrahim A

2017-05-15

The solubility data of recently launched poorly soluble antipsoriatic drug apremilast (APM) in any mono solvent or cosolvent mixtures with respect to temperature are not available in literature. Hence, in this research work, the solubility of APM in twelve different mono solvents namely "water, methanol, ethanol, isopropanol (IPA), ethylene glycol (EG), propylene glycol (PG), 1-butanol, 2-butanol, ethyl acetate (EA), dimethyl sulfoxide (DMSO), polyethylene glycol-400 (PEG-400) and Transcutol ® " was determined at temperatures "T=298.2K to 318.2K" and pressure "p=0.1 MPa". Eexperimental solubilities of APM in mole fraction were determined by a static equilibrium method using high performance liquid chromatography at 254nm. Experimental solubilities of APM in mole fraction were correlated well with "Van't Hoff and Apelblat models". The solubilities of APM in mole fraction were recorded highest in DMSO (9.91×10 -2 ), followed by EA (2.54×10 -2 ), Transcutol (2.51×10 -2 ), PEG-400 (2.16×10 -2 ),PG (4.01×10 -3 ), EG (1.61×10 -3 ), IPA (4.96×10 -4 ), 1-butanol (4.18×10 -4 ), 2-butanol (3.91×10 -4 ), methanol (2.25×10 -4 ), ethanol (2.20×10 -4 ) and water (1.29×10 -6 ) at "T=318.2K" and similar results were also obtained at each temperature evaluated. The molecular interactions between solute and solvent molecules were evaluated by the determination of activity coefficients. Based on activity coefficients, the higher solute-solvents molecular interactions were recorded in APM-DMSO, APM-EA, APM-Transcutol and APM-PEG-400 in comparison with other combination of solute and solvents. "Apparent standard thermodynamic parameters" of APM indicated an "endothermic and entropy-driven dissolution" of APM in all mono solvents evaluated. Based on these results, APM was proposed as freely soluble in DMSO, EA and Transcutol, sparingly soluble in PEG0-400, slightly soluble in methanol, ethanol, IPA, EG, PG, 1-butanol and 2-butanol and practically insoluble in water. Hence, DMSO, EA and Transcutol were selected as the best solvents and water and ethanol were selected as the anti-solvents for APM. Copyright © 2017 Elsevier B.V. All rights reserved.

Prescription Proportion of Pomegranate Extract Gallic Acid Gel by Orthogonal Design

NASA Astrophysics Data System (ADS)

Fan, Gaofu; Liu, Xiushu; Tang, Jie; Gong, Jumei; Fu, Entao; Cai, Yuhua; Xu, Zhenguo

2018-05-01

The aim of the present work was to optimize the formulation of pomegranate extract gallic acid gel by orthogonal design. Using orthogonal design, propylene glycol, carbomer-940 and gel pH level as influencing factors, the evaluation key index was external apearance malleability, uniformity, and eccentric for gel, and the optimum formula was selected. The present findings suggest that 10% propylene glycol, 1.5% Carbopol-940, and gel pH in the range of 4.5∼5.5, and the indexes of the optimal. The inclusion complexes showed that after the orthogonal design, the preparation process was simple, stable and controllable quality, with production feasibility.

Molecular interactions in the betaine monohydrate-polyol deep eutectic solvents: Experimental and computational studies

NASA Astrophysics Data System (ADS)

Zahrina, Ida; Mulia, Kamarza; Yanuar, Arry; Nasikin, Mohammad

2018-04-01

DES (deep eutectic solvents) are a new class of ionic liquids that have excellent properties. The strength of interaction between molecules in the DES affects their properties and applications. In this work, the strength of molecular interactions between components in the betaine monohydrate salt and polyol (glycerol or/and propylene glycol) eutectic mixtures was studied by experimental and computational studies. The melting point and fusion enthalpy of the mixtures were measured using STA (Simultaneous Thermal Analyzer). The nature and strength of intermolecular interactions were observed by FT-IR and NMR spectroscopy. The molecular dynamics simulation was used to determine the number of H-bonds, percent occupancy, and radial distribution functions in the eutectic mixtures. The interaction between betaine monohydrate and polyol is following order: betaine monohydrate-glycerol-propylene glycol > betaine monohydrate-glycerol > betaine monohydrate-propylene glycol, where the latter is the eutectic mixture with the lowest stability, strength and extent of the hydrogen bonding interactions between component molecules. The presence of intra-molecular hydrogen bonding interactions, the inter-molecular hydrogen bonding interactions between betaine molecule and polyol, and also interactions between polyol and H2O of betaine monohydrate in the eutectic mixtures.

Analysis of symptoms and their potential associations with e-liquids' components: a social media study.

PubMed

Li, Qiudan; Zhan, Yongcheng; Wang, Lei; Leischow, Scott J; Zeng, Daniel Dajun

2016-07-30

The electronic cigarette (e-cigarette) market has grown rapidly in recent years. However, causes of e-cigarette related symptoms among users and their impact on health remain uncertain. This research aims to mine the potential relationships between symptoms and e-liquid components, such as propylene glycol (PG), vegetable glycerine (VG), flavor extracts, and nicotine, using user-generated data collected from Reddit. A total of 3605 e-liquid related posts from January 1st, 2011 to June 30th, 2015 were collected from Reddit. Then the patterns of VG/PG distribution among different flavors were analyzed. Next, the relationship between throat hit, which was a typical symptom of e-cigarette use, and e-liquid components was studied. Finally, other symptoms were examined based on e-liquid components and user sentiment. We discovered 3 main sets of findings: 1) We identified three groups of flavors in terms of VG/PG ratios. Fruits, cream, and nuts flavors were similar. Sweet, menthol, and seasonings flavors were classified into one group. Tobacco and beverages flavors were the third group. 2) Throat hit was analyzed and we found that menthol and tobacco flavors, as well as high ratios of PG and nicotine level, could produce more throat hit. 3) A total of 9 systems of 25 symptoms were identified and analyzed. Components including VG/PG ratio, flavor, and nicotine could be possible reasons for these symptoms. E-liquid components shown to be associated with e-cigarette use symptomology were VG/PG ratios, flavors, and nicotine levels. Future analysis could be conducted based on the structure of e-liquid components categories built in this study. Information revealed in this study could be utilized by e-cigarette users to understand the relationship between e-liquid type and symptoms experienced, by vendors to choose appropriate recipes of e-liquid, and by policy makers to develop new regulations.

Transient high glycaemic intake in the last trimester of pregnancy increases offspring birthweight and postnatal growth rate in sheep: a randomised control trial

PubMed Central

Smith, NA; McAuliffe, FM; Quinn, K; Lonergan, P; Evans, ACO

2009-01-01

Objective Investigate the effect of transient hyperglycemic intake (analogous to snacking on high glycaemic foods) in the third trimester of pregnancy on offspring birthweight and subsequent growth in sheep. Design Randomised trial. Setting University research farm. Sample Third trimester pregnant ewes. Methods Ewes were blocked on weight, age and litter size and were randomly assigned to receive oral administration of 100 ml of propylene glycol (PG; n = 51) or 100 ml of water (control, C; n = 53) twice/day. Twice during treatment, 12 ewes from each group were selected and blood samples collected to determine the glucose and insulin response to treatment. Main outcome measures At birth, blood was collected from the lambs, their body dimensions measured and body weights recorded at 0, 6 and 12 weeks of age after which lambs were slaughtered when they reached 40 kg live weight. Results Administration of PG elevated (P < 0.05) plasma glucose and insulin concentrations for 2 hours post administration compared with control ewes. Lambs (C: n = 80; PG: n = 70) born to ewes fed high glycaemic meals had higher birthweights (C: 5.01 ± 0.18 kg; PG: 5.27 ± 0.22 kg, P = 0.032), plasma glucose concentrations (P = 0.001) and ponderal index (weight/height3, P = 0.043) and reached a similar (P > 0.05) slaughter carcass weight (C: 20.0 ± 0.51 kg; PG: 20.6 ± 0.55 kg) at an earlier age (PG: 166.0 ± 13.2; C: 183.4 ± 13.8 days, P = 0.039) compared with control lambs. Conclusions Transient high glycaemic intakes in the third trimester of pregnancy resulted in heavier offspring at birth that had faster growth rates in early postnatal life. This animal model is relevant for studying the relationship between maternal diet, fetal size and the risk of childhood obesity. PMID:19385960

A study of the osmotic characteristics, water permeability, and cryoprotectant permeability of human vaginal immune cells.

PubMed

Shu, Zhiquan; Hughes, Sean M; Fang, Cifeng; Huang, Jinghua; Fu, Baiwen; Zhao, Gang; Fialkow, Michael; Lentz, Gretchen; Hladik, Florian; Gao, Dayong

2016-04-01

Cryopreservation of specimens taken from the genital tract of women is important for studying mucosal immunity during HIV prevention trials. However, it is unclear whether the current, empirically developed cryopreservation procedures for peripheral blood cells are also ideal for genital specimens. The optimal cryopreservation protocol depends on the cryobiological features of the cells. Thus, we obtained tissue specimens from vaginal repair surgeries, isolated and flow cytometry-purified immune cells, and determined fundamental cryobiological characteristics of vaginal CD3(+) T cells and CD14(+) macrophages using a microfluidic device. The osmotically inactive volumes of the two cell types (Vb) were determined relative to the initial cell volume (V0) by exposing the cells to hypotonic and hypertonic saline solutions, evaluating the equilibrium volume, and applying the Boyle van't Hoff relationship. The cell membrane permeability to water (Lp) and to four different cryoprotective agent (CPA) solutions (Ps) at room temperature were also measured. Results indicated Vb values of 0.516 V0 and 0.457 V0 for mucosal T cells and macrophages, respectively. Lp values at room temperature were 0.196 and 0.295 μm/min/atm for T cells and macrophages, respectively. Both cell types had high Ps values for the three CPAs, dimethyl sulfoxide (DMSO), propylene glycol (PG) and ethylene glycol (EG) (minimum of 0.418 × 10(-3) cm/min), but transport of the fourth CPA, glycerol, occurred 50-150 times more slowly. Thus, DMSO, PG, and EG are better options than glycerol in avoiding severe cell volume excursion and osmotic injury during CPA addition and removal for cryopreservation of human vaginal immune cells. Published by Elsevier Inc.

Stability and characterization of perphenazine aerosols generated using the capillary aerosol generator.

PubMed

Li, Xihao; Blondino, Frank E; Hindle, Michael; Soine, William H; Byron, Peter R

2005-10-13

Perphenazine (a potent antiemetic) was aerosolized using capillary aerosol generator to generate respirable condensation aerosols from drug in propylene glycol (PG) solutions, by pumping the liquids through a heated capillary tube. The study characterized the stability of perphenazine during and following aerosol generation. The stability-indicating HPLC method (C-8 column with a mobile phase of 52% 0.01 M pH 3.0 acetate buffer+48% acetonitrile) also enabled the study of perphenazine stability in solution under acidic, basic, oxidizing and photolysing conditions. An LC-MS (ESI+) method was used to characterize the degradation products. Perphenazine was found to be stable in acidic and basic conditions, while perphenazine sulfoxide was the major product formed in dilute peroxide solutions. Two photo-degradation products were formed in PG that were tentatively identified by LC-MS; one of these was synthesized and confirmed to be 2-[4-(3-phenothiazin-10-yl-propyl)-piperazino]-ethanol. Both photolysis products showed that aromatic dechlorination had occurred and one appeared to also result from interaction with the solvent. Within an aerosolization energy window of 84-95 J, fine particle aerosols were generated from perphenazine PG formulations with no significant degradation. Small amounts of degradation products were produced in all samples during aerosolization at elevated (non-optimal) energies. These were largely consistent with those seen to result from oxidation and photolysis in solution, showing that oxidation and dehalogenation appeared to be the main degradation pathways followed when the CAG system was overheated.

The influence of self-assembling supramolecular structures on the passive membrane transport of ion-paired molecules.

PubMed

Benaouda, F; Brown, M B; Shah, B; Martin, G P; Jones, S A

2012-12-15

Weak ion-ion interactions, such as those associated with ion-pair formation, are difficult to isolate and characterise in the liquid state, but they have the potential to alter significantly the physicochemical behaviour of molecules in solution. The aim of this work was to gain a better understanding of how ion-ion interactions influenced passive membrane transport. The test system was composed of propylene (PG) glycol, water and diclofenac diethylamine (DDEA). Infrared spectroscopy was employed to determine the nature of the DDEA ion-pair interactions and the drug-vehicle association. Passive transport was assessed using homogeneous synthetic membranes. Solution-state analysis demonstrated that the ion-pair was unperturbed by vehicle composition changes, but the solvent-DDEA interactions were modified. DDEA-PG/water hydrogen bonding influenced the ion-pair solubility (X(dev)) and the solvent interactions slowed transport rate in PG-rich vehicles (0.84±0.05 μg cm(-2) h(-1), at ln(X(dev))=0.57). In water-rich co-solvents, the presence of strong water structuring facilitated a significant increase (p<0.05) in transmembrane penetration rate (e.g. 4.33±0.92 μg cm(-2) h(-1), at ln(X(dev))=-0.13). The data demonstrates that weak ion-ion interactions can result in the embedding of polar entities within a stable solvent complex and spontaneous supramolecular assembly should be considered when interpreting transmembrane transport processes of ionic molecules. Copyright © 2012 Elsevier B.V. All rights reserved.

Color stability, radiopacity, and chemical characteristics of white mineral trioxide aggregate associated with 2 different vehicles in contact with blood.

PubMed

Guimarães, Bruno Martini; Tartari, Talita; Marciano, Marina Angélica; Vivan, Rodrigo Ricci; Mondeli, Rafael Francisco Lia; Camilleri, Josette; Duarte, Marco Antonio Hungaro

2015-06-01

Discoloration of mineral trioxide aggregate (MTA) can be exacerbated by the interaction of the cement with body fluids such as blood. This study aimed to analyze the color alteration, chemical characteristics, and radiopacity of MTA manipulated with 2 different vehicles after immersion in blood or distilled water (DW). MTA mixed with 100% DW or 80% DW/20% propylene glycol (PG) as vehicles were placed into rubber rings and incubated at 37°C and 100% relative humidity until set. Color assessment and scanning electron microscopy/energy-dispersive spectroscopy analysis were performed after setting and repeated after 7, 15, and 30 days after immersion in blood and DW. Statistical analysis for color alteration and radiopacity was performed using nonparametric Kruskal-Wallis and Dunn tests (P < .05). When 80% DW/20% PG was used as the vehicle, significantly lower color alterations were observed for all time periods compared with 100% DW when immersed in blood (P < .05). All surfaces displayed morphologic changes after immersion in both media because of loss of bismuth. A decrease in radiopacity was observed over time in all groups, with a statistically significant difference after 30 days for groups DW immersed in blood and 80% DW/20% immersed in both media (P < .05). The ratio of 80% DW/20% PG as a vehicle for MTA results in a lower color alteration when in contact with blood. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Copolymers from photochemical thiol-ene polycondensation of fatty dienes with alkyl dithiols

USDA-ARS?s Scientific Manuscript database

Photochemical thiol-ene polycondensation of unsaturated monomers based on renewable 9-decenoic acid with various alkyl dithiols readily afforded copolymers in high yield. Monomers were prepared by acid-catalyzed condensation of 9-decenoic acid with diols such as ethylene glycol, 1,2-propylene glycol...

Addition of poly (propylene glycol) to multiblock copolymer to optimize siRNA delivery.

PubMed

Dai, Zhi; Arévalo, Maria T; Li, Junwei; Zeng, Mingtao

2014-01-01

Previous studies have examined different strategies for siRNA delivery with varying degrees of success. These include use of viral vectors, cationic liposomes, and polymers. Several copolymers were designed and synthesized based on blocks of poly(ethylene glycol) PEG, poly(propylene glycol) PPG, and poly(l-lysine). These were designated as P1, P2, and P3. We studied the copolymer self-assembly, siRNA binding, particle size, surface potential, architecture of the complexes, and siRNA delivery. Silencing of GFP using copolymer P3 to deliver GFP-specific siRNA to Neuro-2a cells expressing GFP was almost as effective as using Lipofectamine 2000, with minimal cytotoxicity. Thus, we have provided a new copolymer platform for siRNA delivery that we can continue to modify for improved delivery of siRNA in vitro and eventually in vivo.

Cryopreservation of umbilical cord blood-derived mesenchymal stem cells without dimethyl sulfoxide.

PubMed

Wang, Hai-Yan; Lun, Zhao-Rong; Lu, Shu-Shen

2011-01-01

Cryopreservation of umbilical cord blood-derived mesenchymal stem cells (UCB-derived MSCs) is crucial step for its clinical applications in cell transplantation therapy. In the cryopreservation of MSCs, dimethyl sulfoxide has been widely used as a cryoprotectant (CPA). However, it has been proved that DMSO has toxic side effects to human body. In this study, DMSO-free CPA solutions which contained ethylene glycol (EG), 1, 2-propylene glycol (PG) and sucrose as basic CPAs, supplemented with polyvinyl alcohol (PVA) as an additive, were developed for the cryopreservation of UCB-derived MSCs. The cryopreservation of UCB-derived MSCs was achieved by vitrification via plunging into liquid nitrogen and by programmed freezing via an optical-DSC system respectively. The viability of thawed UCB-derived MSCs was tested by trypan blue exclusion assay. Results showed that the viability of thawed UCB-derived MSCs was enhanced from 71.2% to 95.4% in the presence of PVA for vitrification, but only < 10% to 45% of viability was found for programmed freezing. These results indicate that PVA exerts a beneficial effect on the cryopreservation of UCB-derived MSCs and suggest the vitrification in combination with the dimethyl sulfoxide free CPA solutions supplemented with PVA would be an efficient protocol for the cryopreservation of UCB-derived MSCs.

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 1. Biochemical oxygen demand and dissolved oxygen in receiving streams.

PubMed

Corsi, S R; Booth, N L; Hall, D W

2001-07-01

Aircraft and runway deicers are used during cold weather at many of the world's airports to facilitate safe air travel. Propylene glycol-, ethylene glycol-, and urea-based deicers are known to have very high biochemical oxygen demand. At General Mitchell International Airport (GMIA) in Milwaukee, Wisconsin, USA, deicer application, water chemistry, and dissolved oxygen (DO) data were collected for two deicing seasons in order to evaluate and define premanagement water quality parameters prior to the implementation of a glycol management program. Calculations using stream-monitoring data during a controlled release of deicer provided an estimate of 0.8/d for the first-order decay rate constant, substantially higher than published laboratory test results. For eight precipitation events with deicing activities, between 2.4 and 99% of propylene and ethylene glycol applied to aircraft was delivered directly to receiving streams. The percentage of glycol runoff during an event increased with increasing storm-flow volume. Elevated concentrations of glycol and biochemical oxygen demand were measured downstream from the airport. However, the frequency of low DO concentrations in the receiving streams is comparable with that at an upstream reference site. This is possibly due to slowed bacteria metabolism at low water temperatures, short travel times, and dilution from downstream tributaries.

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 1. Biochemical oxygen demand and dissolved oxygen in receiving streams

USGS Publications Warehouse

Corsi, S.R.; Booth, N.L.; Hall, D.W.

2001-01-01

Aircraft and runway deicers are used during cold weather at many of the world's airports to facilitate safe air travel. Propylene glycol-, ethylene glycol-, and urea-based deicers are known to have very high biochemical oxygen demand. At General Mitchell International Airport (GMIA) in Milwaukee, Wisconsin, USA, deicer application, water chemistry, and dissolved oxygen (DO) data were collected for two deicing seasons in order to evaluate and define premanagement water quality parameters prior to the implementation of a glycol management program. Calculations using stream-monitoring data during a controlled release of deicer provided an estimate of 0.8/d for the first-order decay rate constant, substantially higher than published laboratory test results. For eight precipitation events with deicing activities, between 2.4 and 99% of propylene and ethylene glycol applied to aircraft was delivered directly to receiving streams. The percentage of glycol runoff during an event increased with increasing storm-flow volume. Elevated concentrations of glycol and biochemical oxygen demand were measured downstream from the airport. However, the frequency of low DO concentrations in the receiving streams is comparable with that at an upstream reference site. This is possibly due to slowed bacteria metabolism at low water temperatures, short travel times, and dilution from downstream tributaries.

Evaporation of Sunscreen Films: How the UV Protection Properties Change.

PubMed

Binks, Bernard P; Brown, Jonathan; Fletcher, Paul D I; Johnson, Andrew J; Marinopoulos, Ioannis; Crowther, Jonathan M; Thompson, Michael A

2016-06-01

We have investigated the evaporation of thin sunscreen films and how the light absorption and the derived sun protection factor (SPF) change. For films consisting of solutions of common UV filters in propylene glycol (PG) as solvent, we show how evaporation generally causes three effects. First, the film area can decrease by dewetting leading to a transient increase in the average film thickness. Second, the film thins by evaporative loss of the solvent. Third, precipitation of the UV filter occurs when solvent loss causes the solubility limit to be reached. These evaporation-induced changes cause the UV absorbance of the film to decrease with resultant loss of SPF over the time scale of the evaporation. We derive an approximate model which accounts semiquantitatively for the variation of SPF with evaporation. Experimental results for solutions of different UV filters on quartz, different skin mimicking substrates, films with added nanoparticles, films with an added polymer and films with fast-evaporating decane as solvent (instead of slow evaporating PG) are discussed and compared with model calculations. Addition of either nanoparticles or polymer suppress film dewetting. Overall, it is hoped that the understanding gained about the mechanisms whereby film evaporation affects the SPF will provide useful guidance for the formulation of more effective sunscreens.

Formulation study of topically applied lotion: in vitro and in vivo evaluation.

PubMed

Hussain Shah, Syed Nisar; Hussain, Talib; Ullah Khan, Ikram; Asghar, Sajid; Shahzad, Yasser

2013-01-01

This article presents the development and evaluation of a new topical formulation of diclofenac diethylamine (DDA) as a locally applied analgesic lotion. To this end, the lotion formulations were formulated with equal volume of varying concentrations (1%, 2%, 3%, 4%; v/v) of permeation enhancers, namely propylene glycol (PG) and turpentine oil (TO). These lotions were subjected to physical studies (pH, viscosity, spreadability, homogeneity, and accelerated stability), in vitro permeation, in vivo animal studies and sensatory perception testing. In vitro permeation of DDA from lotion formulations was evaluated across polydimethylsiloxane membrane and rabbit skin using Franz cells. It was found that PG and TO content influenced the permeation of DDA across model membranes with the lotion containing 4% v/v PG and TO content showed maximum permeation enhancement of DDA. The flux values for L4 were 1.20±0.02 μg.cm(-2).min(-1) and 0.67 ± 0.02 μg.cm(-2).min(-1) for polydimethylsiloxane and rabbit skin, respectively. Flux values were significantly different (p < 0.05) from that of the control. The flux enhancement ratio of DDA from L4 was 31.6-fold and 4.8-fold for polydimethylsiloxane and rabbit skin, respectively. In the in vivo animal testing, lotion with 4% v/v enhancer content showed maximum anti-inflammatory and analgesic effect without inducing any irritation. Sensatory perception tests involving healthy volunteers rated the formulations between 3 and 4 (values ranging between -4 to +4, indicating a range of very bad to excellent, respectively). It was concluded that the DDA lotion containing 4% v/v PG and TO exhibit the best performance overall and that this specific formulation should be the basis for further clinical investigations.

Formulation Study of Topically Applied Lotion: In Vitro and In Vivo Evaluation

PubMed Central

Hussain Shah, Syed Nisar; Hussain, Talib; Ullah Khan, Ikram; Asghar, Sajid; Shahzad, Yasser

2013-01-01

Introduction This article presents the development and evaluation of a new topical formulation of diclofenac diethylamine (DDA) as a locally applied analgesic lotion. Methods To this end, the lotion formulations were formulated with equal volume of varying concentrations (1%, 2%, 3%, 4%; v/v) of permeation enhancers, namely propylene glycol (PG) and turpentine oil (TO). These lotions were subjected to physical studies (pH, viscosity, spreadability, homogeneity, and accelerated stability), in vitro permeation, in vivo animal studies and sensatory perception testing. In vitro permeation of DDA from lotion formulations was evaluated across polydimethylsiloxane membrane and rabbit skin using Franz cells. Results It was found that PG and TO content influenced the permeation of DDA across model membranes with the lotion containing 4% v/v PG and TO content showed maximum permeation enhancement of DDA. The flux values for L4 were 1.20±0.02 μg.cm-2.min-1 and 0.67 ± 0.02 μg.cm-2.min-1 for polydimethylsiloxane and rabbit skin, respectively. Flux values were significantly different (p < 0.05) from that of the control. The flux enhancement ratio of DDA from L4 was 31.6-fold and 4.8-fold for polydimethylsiloxane and rabbit skin, respectively. In the in vivo animal testing, lotion with 4% v/v enhancer content showed maximum anti-inflammatory and analgesic effect without inducing any irritation. Sensatory perception tests involving healthy volunteers rated the formulations between 3 and 4 (values ranging between -4 to +4, indicating a range of very bad to excellent, respectively). Conclusion It was concluded that the DDA lotion containing 4% v/v PG and TO exhibit the best performance overall and that this specific formulation should be the basis for further clinical investigations. PMID:23678465

The effects of electronic cigarette emissions on systemic cotinine levels, weight and postnatal lung growth in neonatal mice.

PubMed

McGrath-Morrow, Sharon A; Hayashi, Madoka; Aherrera, Angela; Lopez, Armando; Malinina, Alla; Collaco, Joseph M; Neptune, Enid; Klein, Jonathan D; Winickoff, Jonathan P; Breysse, Patrick; Lazarus, Philip; Chen, Gang

2015-01-01

Electronic cigarette (E-cigarettes) emissions present a potentially new hazard to neonates through inhalation, dermal and oral contact. Exposure to nicotine containing E-cigarettes may cause significant systemic absorption in neonates due to the potential for multi-route exposure. Systemic absorption of nicotine and constituents of E-cigarette emissions may adversely impact weight and lung development in the neonate. To address these questions we exposed neonatal mice to E-cigarette emissions and measured systemic cotinine levels and alveolar lung growth. Neonatal mice were exposed to E-cigarettes for the first 10 days of life. E-cigarette cartridges contained either 1.8% nicotine in propylene glycol (PG) or PG vehicle alone. Daily weights, plasma and urine cotinine levels and lung growth using the alveolar mean linear intercept (MLI) method were measured at 10 days of life and compared to room air controls. Mice exposed to 1.8% nicotine/PG had a 13.3% decrease in total body weight compared to room air controls. Plasma cotinine levels were found to be elevated in neonatal mice exposed to 1.8% nicotine/PG E-cigarettes (mean 62.34± 3.3 ng/ml). After adjusting for sex and weight, the nicotine exposed mice were found to have modestly impaired lung growth by MLI compared to room air control mice (p<.054 trial 1; p<.006 trial 2). These studies indicate that exposure to E-cigarette emissions during the neonatal period can adversely impact weight gain. In addition exposure to nicotine containing E-cigarettes can cause detectable levels of systemic cotinine, diminished alveolar cell proliferation and a modest impairment in postnatal lung growth.

The influence of alcohol, propylene glycol and 1,2-pentanediol on the permeability of hydrophilic model drug through excised pig skin.

PubMed

Duracher, Lucie; Blasco, Laurent; Hubaud, Jean-Claude; Vian, Laurence; Marti-Mestres, Gilberte

2009-06-05

Alcohol and glycol including 1,2-pentanediol, a new product in this field, were examined for their transdermal penetration enhancing in vitro properties using pig skin and caffeine as a model drug. In order to investigate a possible influence of these compounds, we followed diffusion from an aqueous solution with caffeine followed by a series of different vehicles, their compositions were: (1) in water as a control; (2) in propylene glycol/ethanol/water (25:25:48; v/v/v); (3) in 1,2-pentanediol/water (2.5:95.5, v/v); (4) in 1,2-pentanediol/water (5:93, v/v); in propylene glycol/water (5:93; v/v); and in ethanol/water (5:93; v/v). The stratum corneum/vehicle partition coefficients (K(m)), maximum flux (J), enhancement factor (EF), 24-h receptor concentration (Q(24h)) were determined and compared to control values (caffeine in water). Permeation was also expressed in percentage of the applied dose absorbed in the different compartments. In all test models, caffeine was released and penetrated into pig skin. The 1,2-pentanediol was presented as the most effective enhancer; with a low proportion of this compound (only 5%), caffeine penetrated the skin quicker and in a greater extent. While this compound showed promise as penetration enhancer, further study was required to determine its effectiveness with others drugs and its irritation potential.

Experimental Investigation of the Thermophysical Properties of TiO2/Propylene Glycol-Water Nanofluids for Heat-Transfer Applications

NASA Astrophysics Data System (ADS)

Leena, M.; Srinivasan, S.

2018-05-01

Nanofluids have been prepared by dispersing TiO2 nanoparticles in 70:30% (by weight) water-propylene glycol mixture. The thermal conductivity and viscosity were found experimentally at various temperatures with the volume concentrations 0.1-0.8%. The results indicate that the thermal conductivity of the nanofluids increases with the volume concentration and temperature. Similarly, the viscosity of the nanofluids increases with the volume concentration but decreases with increase in the temperature. Correlations have been proposed for estimating the thermal conductivity and viscosity of the nanofluids. The potential heat transfer benefits of their use in laminar and turbulent flow conditions has been explained.

One-pot Catalyst-free Synthesis of β- and γ-Hydroxy Sulfides Using Diaryliodonium Salts and Microwaves

EPA Science Inventory

A facile one-pot high-yield protocol is described for the preparation of β- and γ-hydroxy sulfides directly from diaryliodonium salts, potassium thiocyanate, and ethane-1,2-diol (ethylene glycol)/propane-1,3-diol (β-propylene glycol) without the need for any addit...

One-Pot Catalyst-Free Synthesis of β- and γ-Hydroxy Sulfides using Diaryliodonium Salts and Microwave Irradiation

EPA Science Inventory

A facile one-pot high-yield protocol is described for the preparation of β- and γ-hydroxy sulfides directly from diaryliodonium salts, potassium thiocyanate, and ethane-1,2-diol (ethylene glycol)/propane-1,3-diol (β-propylene glycol) without the need for any additional catalyst o...

A randomized controlled trial of dexamethasone as an adjunctive therapy to propylene glycol for treatment of hyperketonemia in postpartum dairy cattle.

PubMed

Tatone, Elise H; Duffield, Todd F; Capel, Michael B; DeVries, Trevor J; LeBlanc, Stephen J; Gordon, Jessica L

2016-11-01

Treatment of hyperketonemia with oral propylene glycol has proven efficacy but the cure rate remains moderate. Dexamethasone has long been suggested as a treatment for hyperketonemia, even though evidence of its efficacy is contradictory. The objective of this randomized controlled trial was to evaluate the effect of adding a single intramuscular injection of 20mg of dexamethasone to oral propylene glycol therapy for hyperketonemia [blood β-hydroxybutyrate (BHB) ≥1.2mmol/L]. All cows between 3 and 16d in milk on 4 dairy farms in New York State were tested once weekly for hyperketonemia using a handheld ketone meter. All enrolled animals received 312g (300mL) of propylene glycol orally once daily for 4d and either a single injection of dexamethasone or an equivalent volume of sterile saline. A total of 509 animals were enrolled, with 254 and 255 in the placebo and dexamethasone groups, respectively. Treatment with dexamethasone decreased the odds of being hyperketonemic in the second week posttreatment; however, the odds of hyperketonemia in the first week posttreatment only decreased in those animals that were treated at a BHB blood concentration between 1.2 and 1.5mmol/L. For the 8% of cows with blood BHB >3.2mmol/L at enrollment, receiving dexamethasone increased the odds of being hyperketonemic the following week. We detected no difference between treatment groups in the odds of postpartum disease or in milk production. For cows with initial BHB of 1.2 to 1.5mmol/L, treatment with dexamethasone tended to reduce the odds of pregnancy at first insemination. Based on the small and conditional benefits of dexamethasone and a lack of difference in milk yield or disease incidence, we do not recommend the use of dexamethasone to treat hyperketonemia. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of compositions in nanostructured lipid carriers (NLC) on skin hydration and occlusion

PubMed Central

Loo, CH; Basri, M; Ismail, R; Lau, HLN; Tejo, BA; Kanthimathi, MS; Hassan, HA; Choo, YM

2013-01-01

Purpose To study the effects of varying lipid concentrations, lipid and oil ratio, and the addition of propylene glycol and lecithin on the long-term physical stability of nanostructured lipid nanocarriers (NLC), skin hydration, and transepidermal water loss. Methods The various NLC formulations (A1–A5) were prepared and their particle size, zeta potential, viscosity, and stability were analyzed. The formulations were applied on the forearms of the 20 female volunteers (one forearm of each volunteer was left untreated as a control). The subjects stayed for 30 minutes in a conditioned room with their forearms uncovered to let the skin adapt to the temperature (22°C ± 2°C) and humidity (50% ± 2%) of the room. Skin hydration and skin occlusion were recorded at day one (before treatment) and day seven (after treatment). Three measurements for skin hydration and skin occlusion were performed in each testing area. Results NLC formulations with the highest lipid concentration, highest solid lipid concentration, and additional propylene glycol (formulations A1, A2, and A5) showed higher physical stability than other formulations. The addition of propylene glycol into an NLC system helped to reduce the particle size of the NLC and enhanced its long-term physical stability. All the NLC formulations were found to significantly increase skin hydration compared to the untreated controls within 7 days. All NLC formulations exhibited occlusive properties as they reduced the transepidermal water loss within 7 days. This effect was more pronounced with the addition of propylene glycol or lecithin into an NLC formulation, whereby at least 60% reduction in transepidermal water loss was observed. Conclusion NLCs with high lipid content, solid lipid content, phospholipid, and lecithin are a highly effective cosmetic delivery system for cosmetic topical applications that are designed to boost skin hydration. PMID:23293516

DEVELOPMENT OF A PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR PROPYLENE GLYCOL MONOMETHYL ETHER AND ITS ACETATE IN RATS AND HUMANS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corley, Rick A.; Gies, Richard A.; Wu, Hong

2005-03-05

Propylene glycol monomethyl ether (PM), along with its acetate, is the most widely used of the propylene glycol ether family of solvents. The most common toxic effects of PM observed in animal studies include sedation, very slight alpha2u globulin-mediated nephropathy (male rats only) and hepatomegally at high exposures (typically >1000 ppm). Sedation in animal studies usually resolves within a few exposures to 3000 ppm (the highest concentration used in subchronic and chronic inhalation studies) due to the induction of metabolizing enzymes. Data from a variety of pharmacokinetic and mechanistic studies have been incorporated into a PBPK model for PM andmore » its acetate in rats and mice. Published controlled exposure and workplace biomonitoring studies have also been included for comparisons of the internal dosimetry of PM and its acetate between laboratory animals and humans. PM acetate is rapidly hydrolyzed to PM, which is further metabolized to either glucuronide or sulphate conjugates (minor pathways) or propylene glycol (major pathway). In vitro half-lives for PM acetate range from 14-36 min depending upon the tissue and species. In vivo half-lives are considerably faster, reflecting the total contributions of esterases in the blood and tissues of the body, and are on the order of just a few minutes. Thus, very little PM acetate is found in vivo and, other than potential portal of entry irritation, the toxicity of PM acetate is related to PM. Regardless of the source for PM (either PM or its acetate), rats were predicted to have a higher Cmax and AUC for PM in blood than humans, especially at concentrations greater than the current ACGIH TLV of 100 ppm. This would indicate that the major systemic effects of PM would be expected to be less severe in humans than rats at comparable inhalation exposures.« less

Venting of a Water/Inhibited Propylene Glycol Mixture in a Vacuum Environment-Characterization and Representative Test Results

NASA Technical Reports Server (NTRS)

Ungar, Eugene K.; Erickson, Lisa R.

2011-01-01

A planned use of the Orion space vehicle involves its residence at the International Space Station for six months at a time. One concept of operations involves temporarily venting portions of the idle Orion active thermal control system (ATCS) during the docked phase, preventing freezing. The venting would have to be reasonably complete with few, if any, completely filled pockets of frozen liquid. Even if pockets of frozen liquid did not damage the hardware during the freezing process, they could prevent the system from filling completely prior to its reactivation. The venting of single component systems in a space environment has been performed numerous times and is well understood. Local nucleation occurs at warm, relatively massive parts of the system, which creates vapor and forces the bulk liquid out of the system. The remnants of the liquid will freeze, then evaporate over time through local heating. Because the Orion ATCS working fluid is a 50/50 mixture of water and inhibited propylene glycol, its boiling behavior was expected to differ from that of a pure fluid. It was thought that the relatively high vapor pressure water might evaporate preferentially, leaving behind a mixture enriched with the low vapor pressure propylene glycol, which would be vaporization ]resistant. Owing to this concern, a test was developed to compare the evaporation behavior of pure water, a 50/50 mixture of water and inhibited propylene glycol, and inhibited propylene glycol. The test was performed using room temperature fluids in an instrumented thin walled stainless steel vertical tube. The 1 in x 0.035 in wall tube was instrumented with surface thermocouples and encased in closed cell polyurethane foam. Reticulated polyurethane foam was placed inside the tube to reduce the convection currents. A vacuum system connected to the top of the tube set the pressure boundary condition. Tests were run for the three fluids at back pressures ranging from 1 to 18 torr. During each test, the mass of the test article was measured as it changed over time, as was its temperature and backpressure. The tests were successful. Somewhat surprisingly, the results showed that the evaporation behavior of the three fluids had more similarities than differences. The 50/50 mixture evaporated similarly to the pure water - albeit at a slower rate. The test results indicate that our extensive space - based experience with venting of single component fluids can be applied to the problem of Orion ATCS venting as long as the appropriate puts, takes, and caveats are applied.

[Testing of the composition of e-cigarette liquids - Manufacturer-declared vs. true contents in a selected series of products].

PubMed

Kucharska, Małgorzata; Wesołowski, Wiktor; Czerczak, Sławomir; Soćko, Renata

Electronic cigarettes are currently in common use. However, in Poland there is no specific legislation governing the sale of these products. At the same time, no information has been made public about the hazards e-cigarettes pose to the users and bystanders - passive smokers. The aim of the study was to determine the qualitative composition of the analyzed liquid, which is an essential element of regulating the distribution of such cigarettes. Under this study the method for determining the composition of e-cigarette liquids was developed. This method employs gas chromatography with mass spectrometry (GC-MS). Levels of nicotine and flavoring components were determined in 50 e-liquid samples. The results were compared with the information provided by the manufacturer on the packaging. The applied method of qualitative determination helped to identify the main ingredients, such as nicotine and propylene glycol (PG). Propylene glycol was found to be present in all liquids, because it was used as the solvent for nicotine and flavors. There was a good agreement between the declared and the determined content of nicotine in the analyzed samples. The agreement was considerably poorer for the remaining e-liquid ingredients, mainly flavors. There was no agreement between the flavor substances specified by the manufacturer and aroma identified in the e-cigarette liquid, which may pose a risk to users of e-cigarettes, particularly those susceptible to allergies. Several unsaturated aliphatic alcohols and aldehydes found to be present in the liquids, unstable at elevated temperatures, may be more harmful to the smoker than the original compounds. Therefore, it is essential to implement in Poland the legal provisions regarding e-cigarettes. Med Pr 2016;67(2):239-253. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Effects of Solvent and Temperature on Free Radical Formation in Electronic Cigarette Aerosols.

PubMed

Bitzer, Zachary T; Goel, Reema; Reilly, Samantha M; Foulds, Jonathan; Muscat, Joshua; Elias, Ryan J; Richie, John P

2018-01-16

The ever-evolving market of electronic cigarettes (e-cigarettes) presents a challenge for analyzing and characterizing the harmful products they can produce. Earlier we reported that e-cigarette aerosols can deliver high levels of reactive free radicals; however, there are few data characterizing the production of these potentially harmful oxidants. Thus, we have performed a detailed analysis of the different parameters affecting the production of free radical by e-cigarettes. Using a temperature-controlled e-cigarette device and a novel mechanism for reliably simulating e-cigarette usage conditions, including coil activation and puff flow, we analyzed the effects of temperature, wattage, and e-liquid solvent composition of propylene glycol (PG) and glycerol (GLY) on radical production. Free radicals in e-cigarette aerosols were spin-trapped and analyzed using electron paramagnetic resonance. Free radical production increased in a temperature-dependent manner, showing a nearly 2-fold increase between 100 and 300 °C under constant-temperature conditions. Free radical production under constant wattage showed an even greater increase when going from 10 to 50 W due, in part, to higher coil temperatures compared to constant-temperature conditions. The e-liquid PG content also heavily influenced free radical production, showing a nearly 3-fold increase upon comparison of ratios of 0:100 (PG:GLY) and 100:0 (PG:GLY). Increases in PG content were also associated with increases in aerosol-induced oxidation of biologically relevant lipids. These results demonstrate that the production of reactive free radicals in e-cigarette aerosols is highly solvent dependent and increases with an increase in temperature. Radical production was somewhat dependent on aerosol production at higher temperatures; however, disproportionately high levels of free radicals were observed at ≥100 °C despite limited aerosol production. Overall, these findings suggest that e-cigarettes can be designed to minimize exposure to these potentially harmful products.

Change of translational-rotational coupling in liquids revealed by field-cycling 1H NMR

NASA Astrophysics Data System (ADS)

Meier, R.; Schneider, E.; Rössler, E. A.

2015-01-01

Applying the field-cycling nuclear magnetic resonance technique, the frequency dependence of the 1H spin-lattice relaxation rate, R 1 ω = T1 - 1 ω , is measured for propylene glycol (PG) which is increasingly diluted with deuterated chloroform. A frequency range of 10 kHz-20 MHz and a broad temperature interval from 220 to about 100 K are covered. The results are compared to those of experiments, where glycerol and o-terphenyl are diluted with their deuterated counter-part. Reflecting intra- as well as intermolecular relaxation, the dispersion curves R 1 ω , x (x denotes mole fraction PG) allow to extract the rotational time constant τrot(T, x) and the self-diffusion coefficient D(T, x) in a single experiment. The Stokes-Einstein-Debye (SED) relation is tested in terms of the quantity D(T, x) τrot(T, x) which provides a measure of an effective hydrodynamic radius or equivalently of the spectral separation of the translational and the rotational relaxation contribution. In contrast to o-terphenyl, glycerol and PG show a spectral separation much larger than suggested by the SED relation. In the case of PG/chloroform mixtures, not only an acceleration of the PG dynamics is observed with increasing dilution but also the spectral separation of rotational and translational relaxation contributions continuously decreases. Finally, following a behavior similar to that of o-terphenyl already at about x = 0.6; i.e., while D(T, x) τrot(T, x) in the mixture is essentially temperature independent, it strongly increases with x signaling thus a change of translational-rotational coupling. This directly reflects the dissolution of the hydrogen-bond network and thus a change of solution structure.

Solubility determination of raloxifene hydrochloride in ten pure solvents at various temperatures: Thermodynamics-based analysis and solute-solvent interactions.

PubMed

Ahad, Abdul; Shakeel, Faiyaz; Alfaifi, Omar Ali; Raish, Mohammad; Ahmad, Ajaz; Al-Jenoobi, Fahad I; Al-Mohizea, Abdullah M

2018-06-10

The purpose of the present study was to determine the solubility of raloxifene hydrochloride (RHCl) in ten solvents: water, ethanol, isopropyl alcohol (IPA), ethylene glycol (EG), propylene glycol (PG), polyethylene glycol-400 (PEG-400), Transcutol, 1-butanol, dimethyl sulfoxide (DMSO), and ethyl acetate (EA) at temperatures of 298.2-323.2 K and a pressure of 0.1 MPa. The solubility data obtained was fitted upon "Apelblat and Van't Hoff" equations. The maximum mole fraction solubility of RHCl was obtained in DMSO (5.02 × 10 -2 at 323.2 K), followed by PEG-400 (5.92 × 10 -3 at 323.2 K), EA (3.11 × 10 -3 at 323.2 K), Transcutol (1.22 × 10 -3 at 323.2 K), PG (2.19 × 10 -4 at 323.2 K), 1-butanol (1.96 × 10 -4 at 323.2 K), IPA (1.47 × 10 -4 at 323.2 K), ethanol (7.90 × 10 -5 at 323.2 K), EG (6.65 × 10 -5 at 323.2 K), and water (3.60 × 10 -5 at 323.2 K). Similar fashions were noticed at each studied temperature. The higher solubility of RHCl in DMSO, PEG-400, EA, and Transcutol was possibly referable to their lower polarity in comparison with water. The molecular interactions between the solute and solvent molecules were estimated by calculating parameters like activity coefficients, and more prominent solute-solvent molecular interactions were noted for RHCl-DMSO, RHCl-EA, and RHCl-PEG-400 in comparison with the other solute-solvent combinations. The outcomes of the "apparent thermodynamic analysis" showed that the dissolution of RHCl was "endothermic, spontaneous and entropy-driven" in all investigated solvents. The obtained solubility data of RHCl in commonly used solvents could be useful in the purification, recrystallization, and dosage form design of the drug. Copyright © 2018 Elsevier B.V. All rights reserved.

Compensated Arrhenius formalism applied to a conductivity study in poly(propylene glycol) diacrylate monomers.

PubMed

Dubois, F; Derouiche, Y; Leblond, J M; Maschke, U; Douali, R

2015-09-01

The temperature dependence of the ionic conductivity is studied in a series of poly(propylene glycol) diacrylate monomers. The experimental data are analyzed by means of the approach recently proposed by Petrowsky et al. [J. Phys. Chem. B. 113, 5996 (2009)10.1021/jp810095g]. This so-called compensated Arrhenius formalism (CAF) approach takes into account the influence of the dielectric permittivity on the exponential prefactor in the classical Arrhenius equation. The experimental data presented in this paper show a good agreement with the CAF; this means that the exponential prefactor is principally dielectric permittivity dependent. The compensated data revealed two conduction processes with different activation energies; they correspond to low and high temperature ranges, respectively.

Compensated Arrhenius formalism applied to a conductivity study in poly(propylene glycol) diacrylate monomers

NASA Astrophysics Data System (ADS)

Dubois, F.; Derouiche, Y.; Leblond, J. M.; Maschke, U.; Douali, R.

2015-09-01

The temperature dependence of the ionic conductivity is studied in a series of poly(propylene glycol) diacrylate monomers. The experimental data are analyzed by means of the approach recently proposed by Petrowsky et al. [J. Phys. Chem. B. 113, 5996 (2009), 10.1021/jp810095g]. This so-called compensated Arrhenius formalism (CAF) approach takes into account the influence of the dielectric permittivity on the exponential prefactor in the classical Arrhenius equation. The experimental data presented in this paper show a good agreement with the CAF; this means that the exponential prefactor is principally dielectric permittivity dependent. The compensated data revealed two conduction processes with different activation energies; they correspond to low and high temperature ranges, respectively.

A toxicological review of the propylene glycols.

PubMed

Fowles, Jeff R; Banton, Marcy I; Pottenger, Lynn H

2013-04-01

The toxicological profiles of monopropylene glycol (MPG), dipropylene glycol (DPG), tripropylene glycol (TPG) and polypropylene glycols (PPG; including tetra-rich oligomers) are collectively reviewed, and assessed considering regulatory toxicology endpoints. The review confirms a rich data set for these compounds, covering all of the major toxicological endpoints of interest. The metabolism of these compounds share common pathways, and a consistent profile of toxicity is observed. The common metabolism provides scientific justification for adopting a read-across approach to describing expected hazard potential from data gaps that may exist for specific oligomers. None of the glycols reviewed presented evidence of carcinogenic, mutagenic or reproductive/developmental toxicity potential to humans. The pathologies reported in some animal studies either occurred at doses that exceeded experimental guidelines, or involved mechanisms that are likely irrelevant to human physiology and therefore are not pertinent to the exposures experienced by consumers or workers. At very high chronic doses, MPG causes a transient, slight decrease in hemoglobin in dogs and at somewhat lower doses causes Heinz bodies to form in cats in the absence of any clinical signs of anemia. Some evidence for rare, idiosyncratic skin reactions exists for MPG. However, the larger data set indicates that these compounds have low sensitization potential in animal studies, and therefore are unlikely to represent human allergens. The existing safety evaluations of the FDA, USEPA, NTP and ATSDR for these compounds are consistent and point to the conclusion that the propylene glycols present a very low risk to human health.

Effects of oral administration of a commercial activated charcoal suspension on serum osmolality and lactate concentration in the dog.

PubMed

Burkitt, Jamie M; Haskins, Steve C; Aldrich, Janet; Jandrey, Karl E; Rezende, Marlis L; Boyle, Jennifer E

2005-01-01

The purpose of this investigation was to determine the effects of an activated charcoal (AC) suspension containing propylene glycol and glycerol on serum osmolality, osmolal gap, and lactate concentration in dogs. Six healthy adult dogs were administered 4 g/kg AC in a commercially available suspension that contained propylene glycol and glycerol as vehicles. Blood samples were taken before and 1, 4, 6, 8, 12, and 24 hours after the administration of the test suspension. Samples were analyzed for osmolality, blood gases, and concentrations of lactate, sodium, potassium, serum urea nitrogen, and glucose. Osmolal gaps were calculated for each time point. Mean serum osmolality, osmolal gap, and lactate concentration were significantly increased after suspension administration compared to baseline. Serum osmolality increased from 311 mOsm/kg at baseline to 353 mOsm/kg, osmolal gap increased from 5 to 52 mOsm/kg, and lactate concentration increased from 1.9 to 4.5 mmol/L after suspension administration (all P < .01). Three of the 6 dogs vomited between 1 and 3 hours after the administration of the test suspension, and 4 of 6 dogs were lethargic. All dogs drank frequently after AC administration. Commercial AC suspension administered at a clinically relevant dose increases serum osmolality, osmolal gap, and lactate concentration in dogs. These laboratory measures and the clinical signs of vomiting, lethargy, and increased frequency of drinking might complicate the diagnosis or monitoring of some intoxications (such as ethylene glycol) in dogs that have previously received AC suspension containing propylene glycol, glycerol, or both as vehicles.

Evaluation of e-liquid toxicity using an open-source high-throughput screening assay

PubMed Central

Keating, James E.; Zorn, Bryan T.; Kochar, Tavleen K.; Wolfgang, Matthew C.; Glish, Gary L.; Tarran, Robert

2018-01-01

The e-liquids used in electronic cigarettes (E-cigs) consist of propylene glycol (PG), vegetable glycerin (VG), nicotine, and chemical additives for flavoring. There are currently over 7,700 e-liquid flavors available, and while some have been tested for toxicity in the laboratory, most have not. Here, we developed a 3-phase, 384-well, plate-based, high-throughput screening (HTS) assay to rapidly triage and validate the toxicity of multiple e-liquids. Our data demonstrated that the PG/VG vehicle adversely affected cell viability and that a large number of e-liquids were more toxic than PG/VG. We also performed gas chromatography–mass spectrometry (GC-MS) analysis on all tested e-liquids. Subsequent nonmetric multidimensional scaling (NMDS) analysis revealed that e-liquids are an extremely heterogeneous group. Furthermore, these data indicated that (i) the more chemicals contained in an e-liquid, the more toxic it was likely to be and (ii) the presence of vanillin was associated with higher toxicity values. Further analysis of common constituents by electron ionization revealed that the concentration of cinnamaldehyde and vanillin, but not triacetin, correlated with toxicity. We have also developed a publicly available searchable website (www.eliquidinfo.org). Given the large numbers of available e-liquids, this website will serve as a resource to facilitate dissemination of this information. Our data suggest that an HTS approach to evaluate the toxicity of multiple e-liquids is feasible. Such an approach may serve as a roadmap to enable bodies such as the Food and Drug Administration (FDA) to better regulate e-liquid composition. PMID:29584716

A novel transdermal nanoethosomal gel of betahistine dihydrochloride for weight gain control: in-vitro and in-vivo characterization

PubMed Central

El-Menshawe, Shahira F; Ali, Adel Ahmed; Halawa, Abdelkhalk Ali; Srag El-Din, Ahmed SG

2017-01-01

Background Betahistine dihydrochloride (BDH) is a histamine analog used to control weight gain, with short elimination half-life and gastric irritation as side effects. Objective The aim of the current investigation is to formulate and optimize a topical BDH ethosomal gel for weight gain control. Materials and methods Box–Behnken design was applied to study the effect of independent variables: phosphatidylcholine (PC), propylene glycol (PG), and ethanol on vesicle size; entrapment efficiency; % drug release; and flux. The morphology and zeta potential of the optimized formulation were evaluated. The % drug release, flux, and pharmacodynamics of the optimized formulation gel were studied. Results The size and entrapment efficiency percent had a direct positive relationship with the concentration of PC and negative relationship with ethanol and PG. The % drug release and flux decreased with increasing PC and PG, while ethanol enhanced both responses. Regression modeling indicated a good correlation between dependent and independent variables, where F16 was chosen as the optimized formulation. F16 showed well-defined spherical vesicles and zeta potential of −24 mV, and % release from the gel exceeded 99.5% over 16 h with the flux of 0.28 mg/cm2/h. Food intake and weight gain of rats were significantly decreased after transdermal application of the BDH ethosomal gel when compared with control, placebo, and BDH gel. The histopathological findings proved the absence of inflammation and decrease in adipose tissue. Conclusion Results obtained showed a significant, sustained transdermal absorption of BDH ethosomal gel and, consequently, a decrease in food intake and weight gain. PMID:29238164

Use of a human skin in vitro model to investigate the influence of 'every-day' clothing and skin surface decontamination on the percutaneous penetration of organophosphates.

PubMed

Moore, C A; Wilkinson, S C; Blain, P G; Dunn, M; Aust, G A; Williams, F M

2014-08-17

Organophosphates (OPs) are widely used in agriculture. Many studies have investigated the capability of personal protective equipment (PPE) to reduce chemical exposure; however, investigations into the protective effect of 'every-day' clothing are rare. The purpose of this study was to investigate the protective effect of 'every-day' clothing against dermal exposure and to measure early decontamination of skin following exposure to chlorpyrifos and dichlorvos. Using human skin in vitro, absorption of (14)C-labelled chlorpyrifos (500 ng/cm(2)), was shown to be significantly reduced when applied to clothed skin (cotton shirt), regardless of application vehicle (isopropanol (IPA) or propylene glycol (PG)). The majority of applied dose was retained within the clothing after 4 h exposure. Significant reduction in absorption of chlorpyrifos (in PG) was seen through clothed skin when supplemented with skin decontamination at 4 h, compared with clothed skin decontaminated after 24 h, however, this was not observed with IPA. Absorption of dichlorvos (5 μg/cm(2)) was greater through unclothed skin than chlorpyrifos for all vehicles (IPA, isopropyl myristate (IPM) and PG). Significant reduction in absorption was observed when decontaminating clothed skin at 30 min, compared with decontamination at 24 h (post-exposure) for all vehicles. indicate that 'every-day' clothing is effective at reducing exposure to chemicals in contact with skin. Washing the skin surface immediately following removal of exposed clothing can further reduce exposure, depending on the properties of the chemical and vehicle applied. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The comparison of in vivo antigenotoxic and antioxidative capacity of two propylene glycol extracts of Calendula officinalis (marigold) and vitamin E in young growing pigs.

PubMed

Frankic, T; Salobir, K; Salobir, J

2009-12-01

The objective of the study was to evaluate the protective effect of Calendula officinalis propylene glycol extracts against oxidative DNA damage and lipid peroxidation induced by high polyunsaturated fatty acid (PUFA) intake in young growing pigs. Forty young growing pigs were assigned to five treatment groups: control; oil (linseed oil supplementation); C. officinalis 1 and 2 groups (linseed oil plus 3 ml/day of C. officinalis propylene glycol extracts); and vitamin E group (linseed oil plus 100 mg/kg of vitamin E). Lymphocyte DNA fragmentation and 24-h urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion were measured to determine DNA damage. Lipid peroxidation was studied by analysing plasma and urine malondialdehyde (MDA), and urine isoprostane concentrations (iPF2α-VI), total antioxidant status of plasma and glutathione peroxidase (GPx) assays. C. officinalis 1 (extract from petals) effectively protected DNA from oxidative damage. It indicated a numerical trend towards the reduction of plasma MDA and urinary iPF2α-VI excretion. Its effect was comparable with that of vitamin E. C. officinalis 2 (extract from flower tops) showed less antioxidant potential than the extract from petals. We can conclude that the amount of C. officinalis extracts proposed for internal use by traditional medicine protects the organism against DNA damage induced by high PUFA intake.

Acrylate-endcapped polymer precursors: effect of chemical composition on the healing efficiency of active concrete cracks

NASA Astrophysics Data System (ADS)

Araújo, Maria; Van Tittelboom, Kim; Dubruel, Peter; Van Vlierberghe, Sandra; De Belie, Nele

2017-05-01

The repair of cracks in concrete is an unavoidable practice since these cracks endanger the durability of the structure. Inspired by nature, the self-healing concept has been widely investigated in concrete as a promising solution to solve the limitations of manual repair. This self-healing functionality may be realized by the incorporation of encapsulated healing agents in concrete. Depending on the nature of the cracks, different healing agents can be used. For structures subjected to repeated loads, elastic materials should be considered to cope with the crack opening and closing movement. In this study, various acrylate-endcapped polymer precursors were investigated for their suitability to heal active cracks. The strain capacity of the polymers was assessed by means of visual observation together with water flow tests after widening of the healed cracks in a stepwise manner. A strain of at least 50% could be sustained by epoxy- and siloxane-based healing agents. For polyester- and urethane/poly(propylene glycol)-based precursors, failure occurred at 50% elongation due to detachment of the polymer from the crack walls. However, for urethane/poly(propylene glycol)-based healing agent, debonding was limited to some local spots. The resistance of the polymerized healing agents against degradation in the strong alkaline environment characteristic for concrete has also been evaluated, with the urethane/poly(propylene glycol)-based precursor showing the best performance to withstand degradation.

In vivo proton MRS to quantify anesthetic effects of pentobarbital on cerebral metabolism and brain activity in rat.

PubMed

Du, Fei; Zhang, Yi; Iltis, Isabelle; Marjanska, Malgorzata; Zhu, Xiao-Hong; Henry, Pierre-Gilles; Chen, Wei

2009-12-01

To quantitatively investigate the effects of pentobarbital anesthesia on brain activity, brain metabolite concentrations and cerebral metabolic rate of glucose, in vivo proton MR spectra, and electroencephalography were measured in the rat brain with various doses of pentobarbital. The results show that (1) the resonances attributed to propylene glycol, a solvent in pentobarbital injection solution, can be robustly detected and quantified in the brain; (2) the concentration of most brain metabolites remained constant under the isoelectric state (silent electroencephalography) with a high dose of pentobarbital compared to mild isoflurane anesthesia condition, except for a reduction of 61% in the brain glucose level, which was associated with a 37% decrease in cerebral metabolic rate of glucose, suggesting a significant amount of "housekeeping" energy for maintaining brain cellular integrity under the isoelectric state; and (3) electroencephalography and cerebral metabolic activities were tightly coupled to the pentobarbital anesthesia depth and they can be indirectly quantified by the propylene glycol resonance signal at 1.13 ppm. This study indicates that in vivo proton MR spectroscopy can be used to measure changes in cerebral metabolite concentrations and cerebral metabolic rate of glucose under varied pentobarbital anesthesia states; moreover, the propylene glycol signal provides a sensitive biomarker for quantitatively monitoring these changes and anesthesia depth noninvasively. (c) 2009 Wiley-Liss, Inc.

In vitro evaluation of the antibacterial activity of Arctium lappa as a phytotherapeutic agent used in intracanal dressings.

PubMed

Gentil, Marcelo; Pereira, Juliana Vianna; Sousa, Yara T Corrêa Silva; Pietro, Rosimeire; Neto, Manoel D Sousa; Vansan, Luiz Pascoal; de Castro França, Suzelei

2006-03-01

The discovery of natural biocomponents from plants with antibacterial activity on endodontic microbiota may lead to new therapies. This study evaluated the antibacterial activity of a phytotherapeutic agent prepared from an ethyl acetate fraction (AcOEt) extracted from Arctium lappa. This agent was compared with calcium hydroxide as an intracanal dressing. Twenty-seven maxillary canines were instrumented, sterilized and inoculated with a mixed bacterial suspension of Pseudomonas aeruginosa, Escherichia coli, Lactobacillus acidophilus, Streptococcus mutans and Candida albicans. The teeth were divided into three groups and their canals filled with: group 1, calcium hydroxide and propylene glycol; group 2, a paste containing AcOEt fraction of A. lappa and propylene glycol; group 3, propylene glycol (control). At 7, 14 and 30 days, three teeth from each group were opened and a paper point was placed in the root canal for 5 min. The paper points were transferred to Petri dishes with Brain Heart Infusion (BHI). The bacterial growth was classified. Mild bacterial growth was found in group 1 at all time intervals; in group 2 there was severe growth at 7 days, but no growth at 14 and 30 days. The phytotherapeutic agent extracted from an AcOEt fraction of A. lappa inhibited the growth of all the microorganisms in this study. Copyright 2006 John Wiley & Sons, Ltd.

New formaldehyde base disinfectants.

NASA Technical Reports Server (NTRS)

Trujillo, R.; Lindell, K. F.

1973-01-01

Preparations of formaldehyde in various organic liquids - ethylene glycol, glycerol, and propylene glycol - serve as effective disinfectants towards microbial vegetative cells and spores. This disinfection is a temperature-dependent process and is manifest when these formaldehyde base disinfectants are dissolved in water. The irritating vapors associated with formaldehyde disinfection are not present in either of these new formaldehyde base disinfectants or in aqueous solutions of them.

Time-weighted average sampling of airborne propylene glycol ethers by a solid-phase microextraction device.

PubMed

Shih, H C; Tsai, S W; Kuo, C H

2012-01-01

A solid-phase microextraction (SPME) device was used as a diffusive sampler for airborne propylene glycol ethers (PGEs), including propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and dipropylene glycol monomethyl ether (DPGME). Carboxen-polydimethylsiloxane (CAR/PDMS) SPME fiber was selected for this study. A polytetrafluoroethylene (PTFE) tubing was used as the holder, and the SPME fiber assembly was inserted into the tubing as a diffusive sampler. The diffusion path length and area of the sampler were 0.3 cm and 0.00086 cm(2), respectively. The theoretical sampling constants at 30°C and 1 atm for PGME, PGMEA, and DPGME were 1.50 × 10(-2), 1.23 × 10(-2) and 1.14 × 10(-2) cm(3) min(-1), respectively. For evaluations, known concentrations of PGEs around the threshold limit values/time-weighted average with specific relative humidities (10% and 80%) were generated both by the air bag method and the dynamic generation system, while 15, 30, 60, 120, and 240 min were selected as the time periods for vapor exposures. Comparisons of the SPME diffusive sampling method to Occupational Safety and Health Administration (OSHA) organic Method 99 were performed side-by-side in an exposure chamber at 30°C for PGME. A gas chromatography/flame ionization detector (GC/FID) was used for sample analysis. The experimental sampling constants of the sampler at 30°C were (6.93 ± 0.12) × 10(-1), (4.72 ± 0.03) × 10(-1), and (3.29 ± 0.20) × 10(-1) cm(3) min(-1) for PGME, PGMEA, and DPGME, respectively. The adsorption of chemicals on the stainless steel needle of the SPME fiber was suspected to be one of the reasons why significant differences between theoretical and experimental sampling rates were observed. Correlations between the results for PGME from both SPME device and OSHA organic Method 99 were linear (r = 0.9984) and consistent (slope = 0.97 ± 0.03). Face velocity (0-0.18 m/s) also proved to have no effects on the sampler. However, the effects of temperature and humidity have been observed. Therefore, adjustments of experimental sampling constants at different environmental conditions will be necessary.

Common Allergens Identified Based on Patch Test Results in Patients with Suspected Contact Dermatitis of the Scalp

PubMed Central

Aleid, Nouf M.; Fertig, Raymond; Maddy, Austin; Tosti, Antonella

2017-01-01

Background Contact dermatitis of the scalp is common and might be caused by many chemicals including metals, ingredients of shampoos and conditioners, dyes, or other hair treatments. Eliciting a careful history and patch tests are necessary to identify the responsible allergen and prevent relapses. Objectives To identify allergens that may cause contact dermatitis of the scalp by reviewing patch test results. Methods We reviewed the records of 1,015 patients referred for patch testing at the Dermatology Department of the University of Miami. A total of 226 patients (205 females and 21 males) with suspected scalp contact dermatitis were identified, and the patch test results and clinical data for those patients were analyzed. Most patients were referred for patch testing from a specialized hair clinic at our institution. Results The most common allergens in our study population were nickel (23.8%), cobalt (21.0%), balsam of Peru (18.2%), fragrance mix (14.4%), carba mix (11.6%), and propylene glycol (PG) (8.8%). The majority of patients were females aged 40–59 years, and scalp itching or burning were reported as the most common symptom. Conclusion Frequent sources of allergens for metals include hair clasps, pins, and brushes, while frequent sources of allergens for preservatives, fragrance mix, and balsam of Peru include shampoos, conditioners, and hair gels. Frequent sources of allergens for PG include topical medications. PMID:28611994

Optimising intratumoral treatment of head and neck squamous cell carcinoma models with the diterpene ester Tigilanol tiglate.

PubMed

Barnett, Catherine M E; Broit, Natasa; Yap, Pei-Yi; Cullen, Jason K; Parsons, Peter G; Panizza, Benedict J; Boyle, Glen M

2018-04-18

The five-year survival rate for patients with head and neck squamous cell carcinoma (HNSCC) has remained at ~50% for the past 30 years despite advances in treatment. Tigilanol tiglate (TT, also known as EBC-46) is a novel diterpene ester that induces cell death in HNSCC in vitro and in mouse models, and has recently completed Phase I human clinical trials. The aim of this study was to optimise efficacy of TT treatment by altering different administration parameters. The tongue SCC cell line (SCC-15) was identified as the line with the lowest efficacy to treatment. Subcutaneous xenografts of SCC-15 cells were grown in BALB/c Foxn1 nu and NOD/SCID mice and treated with intratumoral injection of 30 μg TT or a vehicle only control (40% propylene glycol (PG)). Greater efficacy of TT treatment was found in the BALB/c Foxn1 nu mice compared to NOD/SCID mice. Immunohistochemical analysis indicated a potential role of the host's innate immune system in this difference, specifically neutrophil infiltration. Neither fractionated doses of TT nor the use of a different excipiant led to significantly increased efficacy. This study confirmed that TT in 40% PG given intratumorally as a single bolus dose was the most efficacious treatment for a tongue SCC mouse model.

Determination of Selected Chemical Levels in Room Air and on Surfaces after the Use of Cartridge- and Tank-Based E-Vapor Products or Conventional Cigarettes.

PubMed

Liu, Jianmin; Liang, Qiwei; Oldham, Michael J; Rostami, Ali A; Wagner, Karl A; Gillman, I Gene; Patel, Piyush; Savioz, Rebecca; Sarkar, Mohamadi

2017-08-28

There is an ongoing debate regarding the potential of secondhand exposure of non-users to various chemicals from use of e-vapor products (EVPs). Room air levels of 34 chemicals (nicotine, propylene glycol (PG), glycerol, 15 carbonyl chemicals, 12 volatile organic chemicals (VOCs), and four selected trace elements) were measured where EVPs and cigarettes were used by n = 37 healthy adult tobacco users in an exposure chamber. The products used were MarkTen ® 2.5% Classic (Group I), a Prototype GreenSmoke ® 2.4% (Group II), Ego-T ® Tank with subjects' own e-liquids (Group III) and subjects' own conventional cigarettes (Group IV). Products were used under controlled conditions and 4-h ad libitum use. Background (without subjects) and baseline levels (with subjects) were measured. Cumulative 4-h. levels of nicotine, PG and glycerol measured were several-fold below the time-weighted average limits used in workplace exposure evaluation. Most the other chemicals (>75%) were at or below the limit of quantification during EVP use. Significant levels of chemicals (17 out of 34) were observed in Group IV. Overall, our results indicate that under the study conditions with the products tested, cumulative room air levels of the selected chemicals measured over 4-h were relatively small and were several-fold below the current occupational regulatory and consensus limits.

Phagocytosis and Inflammation: Exploring the effects of the components of E-cigarette vapor on macrophages.

PubMed

Ween, Miranda P; Whittall, Jonathan J; Hamon, Rhys; Reynolds, Paul N; Hodge, Sandra J

2017-08-01

E-cigarettes are perceived as harmless; however, evidence of their safety is lacking. New data suggests E-cigarettes discharge a range of compounds capable of physiological damage to users. We previously established that cigarette smoke caused defective alveolar macrophage phagocytosis. The present study compared the effect E-cigarette of components; E-liquid flavors, nicotine, vegetable glycerine, and propylene glycol on phagocytosis, proinflammatory cytokine secretion, and phagocytic recognition molecule expression using differentiated THP-1 macrophages. Similar to CSE, phagocytosis of NTHi bacteria was significantly decreased by E-liquid flavoring (11.65-15.75%) versus control (27.01%). Nicotine also decreased phagocytosis (15.26%). E-liquid, nicotine, and E-liquid+ nicotine reduced phagocytic recognition molecules; SR-A1 and TLR-2. IL-8 secretion increased with flavor and nicotine, while TNF α , IL-1 β , IL-6, MIP-1 α , MIP-1 β , and MCP-1 decreased after exposure to most flavors and nicotine. PG, VG, or PG:VG mix also induced a decrease in MIP-1 α and MIP-1 β We conclude that E-cigarettes can cause macrophage phagocytic dysfunction, expression of phagocytic recognition receptors and cytokine secretion pathways. As such, E-cigarettes should be treated with caution by users, especially those who are nonsmokers. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Roles of Poly(propylene Glycol) During Solvent-Based Lamination of Ceramic Green Tapes

NASA Technical Reports Server (NTRS)

Suppakarn, Nitinat; Ishida, Hatsuo; Cawley, James D.; Levine, Stanley R. (Technical Monitor)

2000-01-01

Solvent lamination for alumina green tapes is readily accomplished using a mixture of ethanol, toluene and poly(propylene glycol). After lamination, the PPG is clearly present as a discrete film at the interface between the laminated tapes. This condition, however, does not generate delamination during firing. Systematic sets of experiments are undertaken to determine the role of PPG in the lamination process and, specifically, the mechanism by which it is redistributed during subsequent processing. PPG slowly diffuses through the organic binder film at room temperature. The PPG diffusion rapidly increases as temperature is increased to 80 C. The key to the efficiency of adhesives during green-tape lamination is mutual solubility of the nonvolatile component of the glue and the base polymeric binder.

A C. elegans model of electronic cigarette use: Physiological effects of e-liquids in nematodes.

PubMed

Panitz, Daniel; Swamy, Harsha; Nehrke, Keith

2015-12-04

Electronic cigarettes (e-cigs) have recently become very popular particularly among the younger generation. These nicotine delivery devices are viewed as a preferable alternative to more conventional forms of tobacco use and are thought to reduce the risk of chronic obstructive pulmonary disease, the third leading cause of death worldwide. However, there is very little data available on the consequences of e-cig use, though recently nicotine-independent inflammatory responses have been reported. The genetic model organism Caenorhabditis elegans is a soil nematode whose cell biology is remarkably well conserved with mammals. Here, we used C. elegans to test the physiologic effects of e-liquids used to refill e-cigs. Larval worms were exposed from hatching onwards to low concentrations (0.2 %) of e-liquids, distilled e-liquid vapor, propylene glycol (PG), or M9 buffer as a negative control. E-liquids tested included grape, menthol, and V2 Red "classic tobacco" flavors. Nicotine (48 ppm) was tested as a second level variable. Stereotypical physiological outputs were then measured, including developmental rate, fecundity, locomotion, lifespan, and the induction of canonical stress signaling pathways. A small but significant impairment of developmental rate and brood size was observed for PG and V2 Red treated worms compared to the negative control. Worms treated with e-liquids containing nicotine fared significantly worse than those that did not, but vaporization did not increase toxicity. Finally, both PG and V2 Red e-liquid induced an oxidative stress response in the absence of nicotine. PG exposure is sufficient to induce an oxidative stress response in nematodes, while nicotine is not. Both PG and nicotine independently influence physiologic measures of health and viability. The e-liquid flavorings did not significantly impact outcomes and there was no evidence for vaporization altering toxicity. These data suggest that the major physiologically significant component of e-liquids besides nicotine is likely the common solvent PG. We conclude that C. elegans are an appropriate model to rapidly assess parameters that may contribute to the basic cell biological effects of e-cigs.

A Phase IIb, Multicenter, Open-Label, Safety, and Efficacy Study of High-Dose, Propylene Glycol-Free Melphalan Hydrochloride for Injection (EVOMELA) for Myeloablative Conditioning in Multiple Myeloma Patients Undergoing Autologous Transplantation.

PubMed

Hari, Parameswaran; Aljitawi, Omar S; Arce-Lara, Carlos; Nath, Rajneesh; Callander, Natalie; Bhat, Gajanan; Allen, Lee F; Stockerl-Goldstein, Keith

2015-12-01

Autologous stem cell transplantation (ASCT) after high-dose melphalan conditioning is considered a standard of care procedure for patients with multiple myeloma (MM). Current formulations of melphalan (eg, Alkeran for Injection [melphalan hydrochloride]; GlaxoSmithKline, Research Triangle Park, NC, USA) have marginal solubility and limited chemical stability upon reconstitution. Alkeran requires the use of propylene glycol as a co-solvent, which itself has been reported to cause such complications as metabolic/renal dysfunction and arrhythmias. EVOMELA (propylene glycol-free melphalan HCl; Spectrum Pharmaceuticals, Inc., Irvine, CA, USA) is a new i.v. melphalan formulation that incorporates Captisol (Ligand Pharmaceuticals, Inc., La Jolla, CA, USA), a specially modified cyclodextrin that improves the solubility and stability of melphalan and eliminates the need for propylene glycol. This new formulation has been shown to be bioequivalent to Alkeran. EVOMELA (200 mg/m(2)) was administered as 2 doses of 100 mg/m(2) each in a phase IIb, open-label, multicenter study to confirm its safety and efficacy as a high-dose conditioning regimen for patients with MM undergoing ASCT. At 5 centers, 61 patients (26 women) with a median age of 62 years (range, 32-73) were enrolled. All patients achieved myeloablation with a median time of 5 days post-ASCT, and all successfully achieved neutrophil and platelet engraftment with median times of 12 days post-ASCT and 13 days post-ASCT, respectively; treatment-related mortality on day 100 was 0%. Overall response rate (according to independent, blinded review) was high (100%), with an overall complete response rate of 21% (13% stringent complete response; 8% complete response) and overall partial response rate of 79% (61% very good partial response; 18% partial response). The incidence of grade 3 mucositis and stomatitis was low (10% and 5%, respectively) with no grade 4 mucositis or stomatitis reported (graded according to National Cancer Institute Common Terminology Criteria for Adverse Events). Based on investigators' assessment of mucositis using the World Health Organization (WHO) oral toxicity scale, 75% of patients had a shift in mucositis score from WHO grade 0 at baseline to a higher grade on study, of which 13% of patients reported WHO grade 3 as the worst post-treatment mucositis over the course of the study; there were no reports of WHO grade 4 mucositis during the study. This study confirms the efficacy and acceptable safety profile of EVOMELA, a new propylene glycol-free melphalan formulation, as a high-dose conditioning regimen for ASCT in patients with MM. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Diagnosis of toxic alcohols: limitations of present methods.

PubMed

Kraut, Jeffrey A

2015-01-01

Methanol, ethylene glycol, diethylene glycol, and propylene glycol intoxications are associated with cellular dysfunction and an increased risk of death. Adverse effects can develop quickly; thus, there is a need for methods for rapidly detecting their presence. To examine the value and limitations of present methods to diagnose patients with possible toxic alcohol exposure. I searched MEDLINE for articles published between 1969 and 2014 using the terms: toxic alcohols, serum osmolality, serum osmol gap, serum anion gap, metabolic acidosis, methanol, ethylene glycol, diethylene glycol, propylene glycol, and fomepizole. Each article was reviewed for additional references. The diagnosis of toxic alcohol exposure is often made on the basis of this history and physical findings along with an increase in the serum osmol and anion gaps. However, an increase in the osmol and/or anion gaps is not always present. Definitive detection in blood requires gas or liquid chromatography, laborious and expensive procedures which are not always available. Newer methods including a qualitative colorimetric test for detection of all alcohols or enzymatic tests for a specific alcohol might allow for more rapid diagnosis. Exposure to toxic alcohols is associated with cellular dysfunction and increased risk of death. Treatment, if initiated early, can markedly improve outcome, but present methods of diagnosis including changes in serum osmol and anion gap, and use of gas or liquid chromatography have important limitations. Development of more rapid and effective tests for detection of these intoxications is essential for optimal care of patients.

Hyperosmolar metabolic acidosis in burn patients exposed to glycol based topical antimicrobials-A systematic review.

PubMed

Leibson, Tom; Davies, Paige; Nickel, Cheri; Koren, Gideon

2018-06-01

The well documented susceptibility of burn patients to acquired infections via damaged skin mandates application of antimicrobial agents. These agents are dissolved in various vehicles that augment skin absorption thus allowing greater efficacy. Polyethylene glycol (PEG) and Propylene glycol (PropG) are among the most commonly used vehicles, and both have been used in numerous medications and cosmetic products over the past few decades. Rarely, burn patients treated with agents containing these glycols present with a life threatening systemic toxidrome of hyperosmolar metabolic acidosis. We present a systematic review of outcomes in burn patients treated with similar agents. Relevant studies were identified through systematic searches conducted in MEDLINE (Ovid), Embase (Ovid), CENTRAL (Ovid), and Web of Science (Thomson Reuters), from database inception to August 4th, 2016. All publications of clinical burn patient studies included at least one arm receiving a glycol based topical therapy. A total of 61 studies involving 10,282 patients and 4 different antimicrobial medications fulfilled the inclusion criteria. Nine burn patients (0.09%) were documented to present with hyperosmolar metabolic acidosis during topical silver sulfadiazine treatment. Propylene glycol isolated from their blood accounted for the high osmole gap. This first systematic review found very few cases of documented hyperosmolar metabolic acidosis, all within one study that had set to specifically explore this toxidrome. High index of suspicion with frequent osmolar gap monitoring may help identify future toxicities in a timely manner. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

21 CFR 172.870 - Hydroxypropyl cellulose.

Code of Federal Regulations, 2014 CFR

2014-04-01

... by weight aqueous solution at 25 degrees C. (2) A cellulose ether containing propylene glycol groups... disintegrator in tablets or wafers containing dietary supplements of vitamins and/or minerals. The additive is...

Aqueous solubility of diclofenac diethylamine in the presence of pharmaceutical additives: a comparative study with diclofenac sodium.

PubMed

Khalil, E; Najjar, S; Sallam, A

2000-04-01

Aqueous solubility of diclofenac diethylamine (DDEA), a nonsteroidal anti-inflammatory drug currently formulated as a topical emulgel, was studied in the presence of pharmaceutical additives and compared with diclofenac sodium (DS). Electrolytes at low concentrations exhibited a salting-in effect on DDEA with peak solubility that was attributed to the association of DDEA into micelles, followed by a salting-out effect at higher concentrations, by which structure formation by DDEA molecules increased and precipitation occurred. For DS, which is not capable of forming micelles, the salting-out effect was dominant due to the common ion effect. Cosolvents displayed significant enhancement in solubility of both salts except glycerol, which showed a slight increase in solubility of DDEA and a decrease in solubility of DS due to transformation into the less soluble hydrate form. Ethanol and polyethylene glycol (PEG) 400 cosolvent systems at all concentrations showed positive deviations from the log-linear solubility equation. In the case of propylene glycol (PG) cosolvent systems, negative deviations were observed at low volume fractions of cosolvent, while positive deviations were observed at high volume fractions of cosolvent for DS and DDEA. The parent drug, being less ionizable and highly nonpolar, showed negative deviations up to 90% PG content. Thus, the positive deviations for DS and DDEA could be attributed to the more ionizable carboxylic group and its higher ability for hydrogen bonding at higher fractions of cosolvent. Polyvinylpyrrolidone (PVP) and PEG4000 or PEG6000 enhanced the solubility of DS and DDEA, with PVP exerting higher solubilizing efficiency and DS showing better solubility than DDEA. Solubilities of DS in Tween 80 (T80) and Pluronic F-127 (PF127) aqueous solutions were almost similar, while the solubility of DDEA in the presence of T80 was higher than the solubility in the presence of PF127. DS appeared to be located more in the polyoxyethylene mantle of the micelles, while DDEA was located more in the core of the micelles.

Nanofluids and a method of making nanofluids for ground source heat pumps and other applications

DOEpatents

Olson, John Melvin

2013-11-12

This invention covers nanofluids. Nanofluids are a combination of particles between 1 and 100 nanometers, a surfactant and the base fluid. The nanoparticles for this invention are either pyrogenic nanoparticles or carbon nanotubes. These nanofluids improve the heat transfer of the base fluids. The base fluid can be ethylene glycol, or propylene glycol, or an aliphatic-hydrocarbon based heat transfer fluid. This invention also includes a method of making nanofluids. No surfactant is used to suspend the pyrogenic nanoparticles in glycols.

[Electronic cigarette : state of the science about toxicological aspects].

PubMed

Deville, M; Charlier, C

2017-01-01

Electronic cigarettes (e-cigarettes) are presented as a healthier alternative to tobacco smoking. They are designed to contain a solution which is heated to produce an aerosol inhaled by the user. The liquid is mainly composed of propylene glycol, glycerol, flavours and, in some cases, nicotine. Except for nicotine, which can be fatal when ingested at high dose, these components are generally considered as safe. However, the potential effect of long term exposure to inhaled propylene glycol is unknown at this time. As an advantage, toxic compounds responsible for the noxiousness of tobacco smoking (nitrosamines, metals, formaldehyde, carbon monoxide …) are either absent, or present in the smoke of e-cigarette at levels far less compared to conventional cigarette smoke. Finally, efficacy of e-cigarette as a tool for smoking cessation stays to be proven.

A replacement for methoxyflurane (Metofane) in open-circuit anaesthesia.

PubMed

Itah, Refael; Gitelman, Inna; Davis, Claytus

2004-07-01

Methoxyflurane (Metofane) has been widely used as an open-circuit anaesthetic in small laboratory animals for several decades. Its low vapour pressure and high blood solubility have permitted its use in convenient and simple drop-chamber/nose-cone setups. Recently, following the decision by the primary manufacturer to discontinue production, it has become increasingly difficult to obtain methoxyflurane. We describe here a simple and effective adaptation of isoflurane, an excellent inhalation anaesthetic, to open-circuit drop-chamber/nose-cone anaesthesia. It was found that the vapour concentration of isoflurane could be continuously varied by dissolving the anaesthetic in propylene glycol and that a 20% solution produced effective anaesthesia such that in adult mice, 2 ml of 20% isoflurane in propylene glycol induced anaesthesia within 2 min in a one-litre drop chamber. Furthermore, anaesthesia maintenance with 20% isoflurane was tested in two sets of mice. In one set, surgical plane anaesthesia was maintained for 10 min in a head chamber. After removal of the chamber, the animals awoke within one minute and recovered without any indication of post-anaesthetic distress. The second set contained pregnant mice; here anaesthesia was maintained for between 10 and 12 min, during which laparotomy, exposure of one uterine horn, intrauterine injection and wound closure were completed. The recovery from anaesthesia was also within a minute and with no signs of distress. Healthy litters were delivered after a normal gestation. This isoflurane/propylene glycol procedure is simple, effective and humane, and is a good substitute for methoxyflurane.

Calcium hydroxide associated with a new vehicle: Psidium cattleianum leaf extracts. Tissue response evaluation.

PubMed

Valentim, Diego; Bueno, Carlos Roberto Emerenciano; Marques, Vanessa Abreu Sanches; Vasques, Ana Maria Veiga; Cury, Marina Tolomei Sandoval; Cintra, Luciano Tavares Angelo; Dezan, Eloi

2017-07-03

The aim of this study was to evaluate edemogenic activity and subcutaneous inflammatory reaction induced by Psidium cattleianum leaf extracts associated with Ca(OH)2. Thirty male Wistar rats, split equally into three groups [aqueous extract + Ca(OH)2; ethanolic extract + Ca(OH)2; and propylene glycol + Ca(OH)2], were assessed every 3 h or 6 h (five animals in each period). Under general anesthesia, 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein and each combination to be evaluated was subcutaneously injected into the dorsal region 30 min thereafter. Edemogenic activity was analyzed by spectrophotometry (λ=630 nm). For inflammatory reaction analysis, 50 rats received four polyethylene tubes (three experimental groups) and an empty tube (control group). The assessments were made at 7, 15, 30, 60, and 90 days, followed by hematoxylin-eosin staining and by the assignment of scores for evaluation of tissue response intensity. Ethanolic extract + Ca(OH)2 yielded the largest edemogenic activity at 3 h. Intergroup differences at 6 h were not significant. The histological analysis showed progressive repair over time (p<0.05) and aqueous and ethanolic extracts produced similar responses to those of the control and Ca(OH)2 + propylene glycol groups. Psidium cattleianum leaf extracts used as Ca(OH)2 vehicles evoked similar tissue response when compared to Ca(OH)2 associated with propylene glycol.

Synthesis, Multinuclear NMR Characterization and Dynamic Property of Organic–Inorganic Hybrid Electrolyte Membrane Based on Alkoxysilane and Poly(oxyalkylene) Diamine

PubMed Central

Saikia, Diganta; Pan, Yu-Chi; Kao, Hsien-Ming

2012-01-01

Organic–inorganic hybrid electrolyte membranes based on poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) complexed with LiClO4 via the co-condensation of tetraethoxysilane (TEOS) and 3-(triethoxysilyl)propyl isocyanate have been prepared and characterized. A variety of techniques such as differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, alternating current (AC) impedance and solid-state nuclear magnetic resonance (NMR) spectroscopy are performed to elucidate the relationship between the structural and dynamic properties of the hybrid electrolyte and the ion mobility. A VTF (Vogel-Tamman-Fulcher)-like temperature dependence of ionic conductivity is observed for all the compositions studied, implying that the diffusion of charge carriers is assisted by the segmental motions of the polymer chains. A maximum ionic conductivity value of 5.3 × 10−5 Scm−1 is obtained at 30 °C. Solid-state NMR results provide a microscopic view of the effects of salt concentrations on the dynamic behavior of the polymer chains. PMID:24958176

Transdermal delivery of lercanidipine hydrochloride: effect of chemical enhancers and ultrasound.

PubMed

Shetty, Pallavi K; Suthar, Neelam A; Menon, Jyothsna; Deshpande, Praful B; Avadhani, Kiran; Kulkarni, Raghavendra V; Mutalik, Srinivas

2013-08-01

The effects of permeation enhancers and sonophoresis on the transdermal permeation of lercanidipine hydrochloride (LRDP) across mouse skin were investigated. Parameters including drug solubility, partition coefficient, drug degradation and drug permeation in skin were determined. Tween-20, dimethyl formamide, propylene glycol, poly ethylene glycol (5% v/v) and different concentration of ethanol were used for permeation enhancement. Low frequency ultrasound was also applied in the presence and absence of permeation enhancers to assess its effect on augmenting the permeation of drug. All the permeation enhancers, except propylene glycol, increased the transdermal permeation of LRDP. Sonophoresis significantly increased the cumulative amount of LRDP permeating through the skin in comparison to passive diffusion. A synergistic effect was noted when sonophoresis was applied in presence of permeation enhancers. The results suggest that the formulation of LRDP with an appropriate penetration enhancer may be useful in the development of a therapeutic system to deliver LRDP across the skin for a prolonged period (i.e., 24 h). The application of ultrasound in association with permeation enhancers could further serve as non-oral and non-invasive drug delivery modality for the immediate therapeutic effect.

Pharmacokinetic characteristics of formulated alendronate transdermal delivery systems in rats and humans.

PubMed

Choi, Ahyoung; Gang, Hyesil; Whang, Jiae; Gwak, Hyesun

2010-05-01

The objective of this study was to examine the absorption of alendronate from formulated transdermal delivery systems in rats and humans. When alendronate was applied to rats by transdermal delivery systems (7.2 mg) and oral administration (30 mg/kg), a statistically significant difference was found in the amount remaining to be excreted at time t (Ae(t)) and the amount remaining to be excreted at time 0 (Ae(infinity)) (p < 0.01). The highest Ae(infinity) (1267.7+/-65.2 ng) was found in the formulation containing 6% caprylic acid in propylene glycol (PG), which was 5.4- and 2.0-times higher than the PG only formulation and oral administration, respectively. Compared to oral administration, significantly delayed half-life values were obtained from all the formulated transdermal delivery systems. There was a linear relationship (r(2) = 0.9854) between the drug loading dose and Ae(infinity). The Ae(infinity) values from the transdermal delivery system containing 6% caprylic acid (53.8 mg as alendronate) and an oral product (Fosamax), 70 mg as alendronate) in humans were 127.0 +/- 34.2 microg and 237.2 +/- 56.3 microg, respectively. The dose-adjusted relative Ae(infinity) ratio of the transdermal delivery system to oral product was calculated to be 69.7%. The long half-life of alendronate in the transdermal delivery system (50.6 +/- 6.4 h), compared to that of the oral product (3.5 +/- 1.1 h) could allow less-frequent dosing. In conclusion, this study showed that a transdermal delivery system containing 6% caprylic acid in PG could be a favorable alternative for alendronate administration.

Nicotine delivery, retention, and pharmacokinetics from various electronic cigarettes

PubMed Central

St. Helen, Gideon; Havel, Christopher; Dempsey, Delia; Jacob, Peyton; Benowitz, Neal L.

2015-01-01

Aims To measure the systemic retention of nicotine, propylene glycol (PG), and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. Design E-cigarette users recruited over the Internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several time after use. Setting San Francisco, California, USA. Participants Thirteen healthy, experienced adult e-cigarette users (6 females and 7 males). Measurements Plasma nicotine was analyzed by GC-MS/MS, and nicotine, VG, and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. Findings E-cigarettes delivered an average of 1.3 (0.9–1.8) mg (mean and 95% CI) of nicotine and 94% of the inhaled dose, 1.2 (0.8–1.7), was systemically retained. Average maximum plasma nicotine concentration (Cmax) was 8.4 (5.4–11.5) ng/mL and time of maximal concentration (Tmax) was 2 to 5 minutes; one participant had Tmax of 30 minutes. 89% and 92% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 bpm after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. Conclusions E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarettes users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. PMID:26430813

An in vivo confocal Raman study of the delivery of trans retinol to the skin.

PubMed

Pudney, Paul D A; Mélot, Mickaël; Caspers, Peter J; Van Der Pol, Andre; Puppels, Gerwin J

2007-08-01

The purpose of this study is to monitor in vivo the delivery of trans-retinol into human skin. Delivery to real systems, such as skin, can be extremely difficult to execute and is problematic to confirm and measure. So far, methods for studying the delivery of compounds through the skin are mostly ex vivo and so inherently influence the skin and may not translate directly to the in vivo situation. Raman spectroscopy is uniquely placed to be able to measure biological processes in vivo, and this paper shows that the trans-retinol penetration into the skin can successfully be measured in vivo using this technique. This study measured the volar forearm of volunteers treated with 0.3% trans-retinol in propylene glycol (PG)/ethanol and 0.3% trans-retinol in caprylic/capric acid triglyceride (MYRITOL318), an oil found in skin creams. Solutions were applied and then confocal Raman depth profiles were obtained of the stratum corneum (SC) and into the viable epidermis (VE) up to 10 hours after treatment. Remarkable differences between a penetrating and a nonpenetrating solution can clearly be observed. Treating with trans-retinol in PG/ethanol results in trans-retinol penetrating through the SC and into the VE. Its penetration was also observed to be highly correlated with the depth of penetration of the PG, which is well known as an efficient penetration enhancer. In contrast, while treating with trans-retinol in MYRITOL318, trans-retinol hardly penetrates at all. For the first time, the penetration of trans-retinol has been monitored directly after application of solutions, in vivo without skin excision. Here, the effect of two different solutions on the delivery of trans-retinol into the skin was measured very effectively in vivo by Raman spectroscopy.

Toxicity of Tolyltriazole to Bacillus Microorganisms.

DTIC Science & Technology

2000-03-01

been done on the chemical additives [Jank et al, 1974; Kaplan et al, 1982; Raja et al, 1991; Strong-Gunderson et al, 1995; Bausmith and Neufeld, 1996...ADAF is over 3,000 times the COD of typical untreated domestic wastewater [ Bausmith and Neufeld 460]. Chain length and molecular weights of glycols...mtox.htm Bausmith , David S. and Ronald D. Neufeld. "Soil Biodegradation of Propylene Glycol Based Aircraft Deicing Fluids," Water Environment

Evaluation of cytotoxicity of surfactants used in self-micro emulsifying drug delivery systems and their effects on paracellular transport in Caco-2 cell monolayer.

PubMed

Ujhelyi, Zoltán; Fenyvesi, Ferenc; Váradi, Judit; Fehér, Pálma; Kiss, Tímea; Veszelka, Szilvia; Deli, Mária; Vecsernyés, Miklós; Bácskay, Ildikó

2012-10-09

The objective of this study was to examine the cellular effects of the members of two non-ionic amphiphilic tenside groups and their mixtures on human Caco-2 cell monolayers as dependent upon their chemical structures and physicochemical properties. The first group of polyethylene glycol esters is represented by Polysorbates and Labrasol alone and in blends, while the members of the second group. Capryol 90, Capryol PGMC, Lauroglycol 90 and Lauroglycol FCC were used as propylene glycol esters. They are increasingly used in SMEDDS as recent tensides or co-tensides to increase hydrophobic bioavailability of a drug. Critical micelle concentration was measured by determination of surface tension. CMC refers to the ability of solubilization of surfactants. Cytotoxicity tests were performed on Caco-2 cell monolayers by MTT and LDH methods. Paracellular permeability as a marker of the integrity of cell monolayers, was examined with Lucifer yellow assays combined with TransEpithelial Electrical Resistance (TEER) measurements. The effect of these surfactants on tight junctions as evidence for paracellular pathway was also characterized. The results of cytotoxicity assays were in agreement, and showed significant differences among the cytotoxic properties of surfactants in a concentration-dependent manner. Polysorbates 20, 60, 80 are the most toxic compounds. In the case of Labrasol, the degree of esterification and lack of sorbit component decreased cytotoxicity. If the hydrophyl head was changed from polyethylene glycol to propylene glycol the main determined factor of cytotoxicity was the monoester content and the length of carbon chain. In our CMC experiments, we found that only Labrasol showed expressed cytotoxicity above the CMC. It refers to good ability of micelle solubilization of Labrasol. In our paracellular transport experiments each of polyethylene glycol surfactants (Polysorbates and Labrasol) altered TEER values, but propylene glycol esters did not modify the monolayer integrity. Polyethylene glycol esters alone and in blends (0.05% Labrasol--0.001% Polysorbates 20, 60, 80) were able to increase Lucifer yellow permeability significantly below the IC₅₀ concentration. On the other hand Labrasol and Polysorbates 20 have expressed effect on tight junctions of Caco-2 monolayer. It could be concluded that polyethylene glycol ester-type tensides were able to enhance the paracellular permeability by the redistribution of junctional proteins. Our results might ensure useful data for selection of suitable tensides, co-tensides and tenside mixtures for SMEDDS formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

Unveiling the Dependence of Glass Transitions on Mixing Thermodynamics in Miscible Systems

NASA Astrophysics Data System (ADS)

Tu, Wenkang; Wang, Yunxi; Li, Xin; Zhang, Peng; Tian, Yongjun; Jin, Shaohua; Wang, Li-Min

2015-02-01

The dependence of the glass transition in mixtures on mixing thermodynamics is examined by focusing on enthalpy of mixing, ΔHmix with the change in sign (positive vs. negative) and magnitude (small vs. large). The effects of positive and negative ΔHmix are demonstrated based on two isomeric systems of o- vs. m- methoxymethylbenzene (MMB) and o- vs. m- dibromobenzene (DBB) with comparably small absolute ΔHmix. Two opposite composition dependences of the glass transition temperature, Tg, are observed with the MMB mixtures showing a distinct negative deviation from the ideal mixing rule and the DBB mixtures having a marginally positive deviation. The system of 1, 2- propanediamine (12PDA) vs. propylene glycol (PG) with large and negative ΔHmix is compared with the systems of small ΔHmix, and a considerably positive Tg shift is seen. Models involving the properties of pure components such as Tg, glass transition heat capacity increment, ΔCp, and density, ρ, do not interpret the observed Tg shifts in the systems. In contrast, a linear correlation is revealed between ΔHmix and maximum Tg shifts.

Compression and compaction properties of plasticised high molecular weight hydroxypropylmethylcellulose (HPMC) as a hydrophilic matrix carrier.

PubMed

Hardy, I J; Cook, W G; Melia, C D

2006-03-27

The compression and compaction properties of plasticised high molecular weight USP2208 HPMC were investigated with the aim of improving tablet formation in HPMC matrices. Experiments were conducted on binary polymer-plasticiser mixtures containing 17 wt.% plasticiser, and on a model hydrophilic matrix formulation. A selection of common plasticisers, propylene glycol (PG) glycerol (GLY), dibutyl sebacate (DBS) and triacetin (TRI), were chosen to provide a range of plasticisation efficiencies. T(g) values of binary mixtures determined by Dynamic Mechanical Thermal Analysis (DMTA) were in rank order PG>GLY>DBS>TRI>unplasticised HPMC. Mean yield pressure, strain rate sensitivity (SRS) and plastic compaction energy were measured during the compression process, and matrix properties were monitored by tensile strength and axial expansion post-compression. Compression of HPMC:PG binary mixtures resulted in a marked reduction in mean yield pressure and a significant increase in SRS, suggesting a classical plasticisation of HPMC analogous to that produced by water. The effect of PG was also reflected in matrix properties. At compression pressures below 70 MPa, compacts had greater tensile strength than those from native polymer, and over the range 35 and 70 MPa, lower plastic compaction values showed that less energy was required to produce the compacts. Axial expansion was also reduced. Above 70 MPa tensile strength was limited to 3 MPa. These results suggest a useful improvement of HPMC compaction and matrix properties by PG plasticisation, with lowering of T(g) resulting in improved deformation and internal bonding. These effects were also detectable in the model formulation containing a minimal polymer content for an HPMC matrix. Other plasticisers were largely ineffective, matrix strength was poor and axial expansion high. The hydrophobic plasticisers (DBS, TRI) reduced yield pressure substantially, but were poor plasticisers and showed compaction mechanisms that could be attributed to phase separation. The effect of different plasticisers suggests that the deformation characteristics of this HPMC in the solid state is dominated by hydroxyl mediated bonding, rather than by hydrophobic interactions between methoxyl-rich regions.

40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the surfactants (a) polyoxypropylene-polyoxyethylene glycol nomionic block polymers (minimum average... molecular weight of 748 and in which the nonyl group is a propylene trimer isomer, is exempted from the...

40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the surfactants (a) polyoxypropylene-polyoxyethylene glycol nomionic block polymers (minimum average... molecular weight of 748 and in which the nonyl group is a propylene trimer isomer, is exempted from the...

40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the surfactants (a) polyoxypropylene-polyoxyethylene glycol nomionic block polymers (minimum average... molecular weight of 748 and in which the nonyl group is a propylene trimer isomer, is exempted from the...

Ice recrystallization inhibition in ice cream by propylene glycol monostearate.

PubMed

Aleong, J M; Frochot, S; Goff, H D

2008-11-01

The effectiveness of propylene glycol monostearate (PGMS) to inhibit ice recrystallization was evaluated in ice cream and frozen sucrose solutions. PGMS (0.3%) dramatically reduced ice crystal sizes in ice cream and in sucrose solutions frozen in a scraped-surface freezer before and after heat shock, but had no effect in quiescently frozen solutions. PGMS showed limited emulsifier properties by promoting smaller fat globule size distributions and enhanced partial coalescence in the mix and ice cream, respectively, but at a much lower level compared to conventional ice cream emulsifier. Low temperature scanning electron microscopy revealed highly irregular crystal morphology in both ice cream and sucrose solutions frozen in a scraped-surface freezer. There was strong evidence to suggest that PGMS directly interacts with ice crystals and interferes with normal surface propagation. Shear during freezing may be required for its distribution around the ice and sufficient surface coverage.

Control of ethanol withdrawal symptoms in mice by phenytoin.

PubMed

Sprague, G L; Craigmill, A L

1976-12-01

Mice were made physically dependent upon ethanol using either of two methods which involved ethanol vapor inhalation. Following the cessation of exposure to ethanol, the severity of handling-induced convulsions and changes in the response to an electric foot shock (startle reflex) were recorded. Animals given isotonic saline or propylene glycol:ethanol vehicle during withdrawal exhibited handling-induced convulsions, and ethanol (2.0-4.0 g/kg) or phenytoin (5-20 mg/kg) administration during withdrawal resulted in a reduction in the severity of these convulsions. A reduced startle reflex threshold was also evident during withdrawal in mice given isotonic saline or propylene glycol:ethanol vehicle. Ethanol (0.5-4.0 g/kg) or phenytoin (10-20 mg/kg) administration during withdrawal resulted in a significant elevation of the startle reflex threshold compared to control animals. The results are discussed as they relate to others obtained in experimental and clinical studies.

Energetics of the molecular interactions of L-cysteine, L-serine, and L-asparagine in aqueous propylene glycol solutions at 298.15 K

NASA Astrophysics Data System (ADS)

Mezhevoi, I. N.; Badelin, V. G.

2015-03-01

Integral enthalpies of dissolution Δsol H m of L-cysteine, L-serine, and L-asparagine in aqueous solutions of 1,3-propylene glycol at organic solvent concentrations of up to 0.26 mole fraction are measured via the thermochemistry of dissolution. Standard enthalpies of dissolution (Δsol H ○) and transfer (Δtr H ○) of amino acids from water to a mixed solvent are calculated. It is found that the calculated enthalpy coefficients of pair interactions of the amino acids with polyhydric alcohol molecules have positive values. The effect the arrangement of the hydroxyl group in the structure of polyhydric alcohols has on the enthalpy of interaction of amino acids in aqueous solutions is revealed. The effect of different types of interactions in solutions and the structural features of biomolecules and cosolvents on the enthalpy of dissolution of amino acids is analyzed.

Effects of external applications of No. 2 fuel oil on common eider eggs

USGS Publications Warehouse

Szaro, Robert C.; Albers, P.H.; Wolfe, Douglas A.

1977-01-01

Because eggs of marine birds may be exposed to oil adhering to the feathers of adult birds, a study was undertaken to determine the effects of oil contamination. Two hundred common eider eggs were divided into four experimental sets of 50 each. Two sets were treated with No. 2 fuel oil in amounts of 5 microliters to 20 microliters; a third with 20 microliters of propylene glycol, a neutral blocking agent. The fourth set served as a control. Hatching success was 96 percent for the eggs treated with 20 microliters propylene glycol, 96 percent for the controls and 92 percent for the eggs treated with 5 microliters oil hatched. Only 69 percent of the eggs treated with 20 microliters of oil survived - a significant reduction in hatchability (P 0.05). Mean Hatching weights for all sets were statistically equal. Thus, oil pollution may significantly increase embryonic mortality in marine birds.

Rheological properties and thermal conductivity of AlN-poly(propylene glycol) suspensions

NASA Astrophysics Data System (ADS)

Wozniak, Maciej; Rutkowski, Pawel; Kata, Dariusz

2016-01-01

Nanofluids have recently attracted researches' attention as a new generation of heat-transferring fluids used in heat exchangers and for energy storage. Also aluminium nitride is commonly known for its considerable heat conductivity, as high as 320 W/(m K). Because of that, the compound might be a preferable dispersed phase of heat-transferring fluids. This presented studies are focused on nano-AlN-poly(propylene glycol) dispersions which can be applied as potential cooling fluids. The rheological response of the suspensions on shearing and their thermal conductivity in the function of solids concentration and temperature were measured and discussed. The most desired result of the studies is to produce dispersions with Newtonian-like flow at increased temperature and at higher shear rate. All the aforementioned parameters conjugated with significant thermal conductivity of such nanofluids could predispose them to be used as effective cooling media.

Solubility of (+/-)-ibuprofen and S (+)-ibuprofen in the presence of cosolvents and cyclodextrins.

PubMed

Nerurkar, Jayanti; Beach, J W; Park, M O; Jun, H W

2005-01-01

Aqueous solubility is an important parameter for the development of liquid formulations and in the determination of bioavailability of oral dosage forms. Ibuprofen (IB), a nonsteroidal anti-inflammatory drug, is a chiral molecule and is currently used clinically as a racemate (racIB). However, the S form of ibuprofen or S(+)-ibuprofen (SIB) is the biologically active isomer and is primarily responsible for the antiinflammatory activity. Phase solubility studies were carried out to compare the saturation solubilities of racIB and SIB in the presence of common pharmaceutical solvents such as glycerol, sorbitol solution, propylene glycol (PG), and polyethylene glycol (PEG 300) over the range of 20% to 80% v/v in aqueous based systems. The solubilities of the two compounds were also compared in the presence of cyclodextrins such as beta cyclodextrin (CD), hydroxypropyl beta cyclodextrin (HPCD), and beta cyclodextrin sulfobutyl ether sodium salt (CDSB) over the range of 5% to 25% w/v. Solubility determinations were carried at 25 degrees C and 37 degrees C. Cosolvents exponentially increased the solubility of both SIB and racIB, especially in the presence of PG and PEG 300. Glycerol was not very effective in increasing the aqueous solubilities of both compounds, whereas sorbitol solution had a minimal effect on their solubility. PG and PEG 300 increased the solubility of SIB by 400-fold and 1500-fold, respectively, whereas the rise in solubility for racIB was 193-fold and 700-fold, respectively, at 25 degrees C for the highest concentration of the cosolvents used (80% v/v). Of the two compounds studied, higher equilibrium solubilities were observed for SIB as compared with racIB. The derivatized cyclodextrins increased the aqueous solubility of racIB and SIB in a concentration-dependent manner giving AL type of phase diagrams. The phase solubility diagrams indicated the formation of soluble inclusion complexes between the drugs and HPCD and CDSB, which was of 1:1 stoichiometry. The addition of underivatized CD reduced the solubility of racIB and SIB via the formation of an insoluble complex. The S form formed more stable complexes with HPCD and CDSB as compared with raclB. The solubilization process is discussed in terms of solvent polarity and differential solid-state structure of raclB and SIB. The thermodynamic parameters for the solubilization process are presented.

Are glass fiber particles released during the use of electronic cigarettes? Development of a semi-quantitative approach to detect glass particle emission due to vaping.

PubMed

Shin, Jae-Won; Jo, Sang-Hee; Kim, Ki-Hyun; Song, Hee-Nam; Kang, Chang-Hee; Bolan, Nanthi; Hong, Jongki

2018-05-04

This study investigated the emission characteristics of glass particles resulting from smoking electronic cigarettes (ECs). First, the most suitable filter for the collection of glass particles was explored by examining the performance (reliability) of various types of filters. A polycarbonate filter was determined as the optimum choice to collect glass particles in EC aerosol. A cartomizer was filled with EC refill solution composed of an equal volume of propylene glycol (PG) and vegetable glycol (VG). To simulate the potential conditions for glass particle emission, EC vaped aerosols were collected at three distinctive puffing intervals: (1) 0-10 puffs, (2) 101-110 puffs, and (3) 201-210 puffs (flow rate of 1 L min -1 , 2 s per puff, and 10 puffs per sample). Glass particles were observed as early as after 100 times puffing from certain products, while after 200 from others. Thus, glass particles were generated by increasing the number of puffs and usage of the EC cartomizer. The analysis of glass particles collected onto polycarbonate filters by scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) confirmed the presence of glass particles in samples collected after puffing 100-200 times. The study demonstrated that the possibility of glass particle emissions from the EC device increased considerably with the increasing number of total puffs. Copyright © 2018 Elsevier Inc. All rights reserved.

Propylene glycol-linked amino acid/dipeptide diester prodrugs of oleanolic acid for PepT1-mediated transport: synthesis, intestinal permeability, and pharmacokinetics.

PubMed

Cao, Feng; Gao, Yahan; Wang, Meng; Fang, Lei; Ping, Qineng

2013-04-01

In our previous studies, ethylene glycol-linked amino acid diester prodrugs of oleanolic acid (OA), a Biopharmaceutics Classification System (BCS) class IV drug, designed to target peptide transporter 1 (PepT1) have been synthesized and evaluated. Unlike ethylene glycol, propylene glycol is of very low toxicity in vivo. In this study, propylene glycol was used as a linker to further compare the effect of the type of linker on the stability, permeability, affinity, and bioavailability of the prodrugs of OA. Seven diester prodrugs with amino acid/dipeptide promoieties containing L-Val ester (7a), L-Phe ester (7b), L-Ile ester (7c), D-Val-L-Val ester (9a), L-Val-L-Val ester (9b), L-Ala-L-Val ester (9c), and L-Ala-L-Ile ester (9d) were designed and successfully synthesized. In situ rat single-pass intestinal perfusion (SPIP) model was performed to screen the effective permeability (P(eff)) of the prodrugs. P(eff) of 7a, 7b, 7c, 9a, 9b, 9c, and 9d (6.7-fold, 2.4-fold, 1.24-fold, 1.22-fold, 4.15-fold, 2.2-fold, and 1.4-fold, respectively) in 2-(N-morpholino)ethanesulfonic acid buffer (MES) with pH 6.0 showed significant increase compared to that of OA (p < 0.01). In hydroxyethyl piperazine ethanesulfonic acid buffer (HEPES) of pH 7.4, except for 7c, 9a, and 9d, P(eff) of the other prodrugs containing 7a (5.2-fold), 7b (2.0-fold), 9b (3.1-fold), and 9c (1.7-fold) exhibited significantly higher values than that of OA (p < 0.01). In inhibition studies with glycyl-sarcosine (Gly-Sar, a typical substrate of PepT1), P(eff) of 7a (5.2-fold), 7b (2.0-fold), 9b (3.1-fold), and 9c (2.3-fold) had significantly reduced values (p < 0.01). Compared to the apparent permeability coefficient (P(app)) of OA with Caco-2 cell monolayer, significant enhancement of the P(app) of 7a (5.27-fold), 9b (3.31-fold), 9a (2.26-fold), 7b (2.10-fold), 7c (2.03-fold), 9c (1.87-fold), and 9d (1.39-fold) was also observed (p < 0.01). Inhibition studies with Gly-Sar (1 mM) showed that P(app) of 7a, 9b, and 9c significantly reduced by 1.3-fold, 1.6-fold, and 1.4-fold (p < 0.01), respectively. These results may be attributed to PepT1-mediated transport and their differential affinity toward PepT1. According to the permeability and affinity, 7a and 9b were selected in the pharmacokinetic studies in rats. Compared with group OA, C(max) for group 7a and 9b was enhanced to 3.04-fold (p < 0.01) and 2.62-fold (p < 0.01), respectively. AUC(0→24) was improved to 3.55-fold (p < 0.01) and 3.39-fold (p < 0.01), respectively. Compared to the ethylene glycol-linked amino acid diester prodrugs of OA in our previous work, results from this study revealed that part of the propylene glycol-linked amino acid/dipeptide diester prodrugs showed better stability, permeability, affinity, and bioavailability. In conclusion, propylene glycol-linked amino acid/dipeptide diester prodrugs of OA may be suitable for PepT1-targeted prodrugs of OA to improve the oral bioavailability of OA.

Combination of grape extract-silver nanoparticles and liposomes: A totally green approach.

PubMed

Castangia, Ines; Marongiu, Francesca; Manca, Maria Letizia; Pompei, Raffaello; Angius, Fabrizio; Ardu, Andrea; Fadda, Anna Maria; Manconi, Maria; Ennas, Guido

2017-01-15

In the present work, silver nanoparticles were prepared using a totally green procedure combining silver nitrate and an extract of grape pomace as a green source. Additionally, nanoparticles were stabilized using phospholipid and water and/or a mixture of water and propylene glycol (PG). To the best of our knowledge, grape-silver nanoparticle stabilized liposomes or PG-liposomes were formulated, for the first time, combining the residual products of wine-made industry, silver nitrate and phospholipids, avoiding the addition of hazardous substances to human health and the environment, in an easy, scalable and reproducible method. The structure and morphology of grape-silver nanoparticle stabilized vesicles were evaluated by transmission electron microscopy (TEM), UV-vis spectroscopy and photon correlation spectroscopy. Samples were designed as possible carrier for skin protection because of their double function: the grape extract acts as antioxidant and the colloidal silver as antimicrobial agent, which might be helpful in eliminating dangerous free radicals and many pathogenic microorganisms. Obtained nanoparticles were small in size and their combination with phospholipids did not hamper the vesicle formation, which were multilamellar and sized ~100nm. TEM images shows a heterogeneous distribution of nanoparticles, which were located both in the intervesicular medium and in the vesicular structure. Further, grape-silver nanoparticles, when stabilized by liposomes, were able to inhibit the proliferation of both Staphylococcus aureus and Pseudomonas aeruginosa and provided a great protection of keratinocytes and fibroblasts against oxidative stress avoiding their damage and death. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of Two Commercially Available Cannabidiol Formulations for Use in Electronic Cigarettes.

PubMed

Peace, Michelle R; Butler, Karen E; Wolf, Carl E; Poklis, Justin L; Poklis, Alphonse

2016-01-01

Since 24 states and the District of Columbia have legalized marijuana in some form, suppliers of legal marijuana have developed Cannabis sativa products for use in electronic cigarettes (e-cigarettes). Personal battery powered vaporizers, or e-cigarettes, were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. The liquid formulations used in these devices are comprised of an active ingredient such as nicotine mixed with vegetable glycerin (VG) and/or propylene glycol (PG) and flavorings. A significant active ingredient of C. sativa, cannabidiol (CBD), has been purported to have anti-convulsant, anti-nociceptive, and anti-psychotic properties. These properties have potential medical therapies such as intervention of addictive behaviors, treatments for epilepsy, management of pain for cancer patients, and treatments for schizophrenia. However, CBD extracted from C. sativa remains a DEA Schedule I drug since it has not been approved by the FDA for medical purposes. Two commercially available e-cigarette liquid formulations reported to contain 3.3 mg/mL of CBD as the active ingredient were evaluated. These products are not regulated by the FDA in manufacturing or in labeling of the products and were found to contain 6.5 and 7.6 mg/mL of CBD in VG and PG with a variety of flavoring agents. Presently, while labeled as to content, the quality control of manufacturers and the relative safety of these products is uncertain.

A technique to depress desflurane vapor pressure.

PubMed

Brosnan, Robert J; Pypendop, Bruno H

2006-09-01

To determine whether the vapor pressure of desflurane could be decreased by using a solvent to reduce the anesthetic molar fraction in a solution (Raoult's Law). We hypothesized that such an anesthetic mixture could produce anesthesia using a nonprecision vaporizer instead of an agent-specific, electronically controlled, temperature and pressure compensated vaporizer currently required for desflurane administration. One healthy adult female dog. Propylene glycol was used as a solvent for desflurane, and the physical characteristics of this mixture were evaluated at various molar concentrations and temperatures. Using a circle system with a breathing bag attached at the patient end and a mechanical ventilator to simulate respiration, an in-circuit, nonprecision vaporizer containing 40% desflurane and 60% propylene glycol achieved an 11.5% +/- 1.0% circuit desflurane concentration with a 5.2 +/- 0.4 (0 = off, 10 = maximum) vaporizer setting. This experiment was repeated with a dog attached to the breathing circuit under spontaneous ventilation with a fresh gas flow of 0.5 L minute(-1). Anesthesia was maintained for over 2 hours at a mean vaporizer setting of 6.2 +/- 0.4, yielding mean inspired and end-tidal desflurane concentrations of 8.7% +/- 0.5% and 7.9% +/- 0.7%, respectively. Rather than alter physical properties of vaporizers to suit a particular anesthetic agent, this study demonstrates that it is also possible to alter physical properties of anesthetic agents to suit a particular vaporizer. However, propylene glycol may not prove an ideal solvent for desflurane because of its instability in solution and substantial-positive deviation from Raoult's Law.

Dilatant effect enhancers for silica dispersions in poly(propylene glycols).

PubMed

Orawiec, Marcin; Kaczorowski, Marcin; Rokicki, Gabriel

2018-05-29

Shear thickening fluids have found many applications in energy damping materials such as sports guards and liquid body armors. Therefore, an additive which could tailor the dilatant properties of such fluids without significantly affecting other properties, especially zero shear viscosity, could significantly increase the versatility of protective materials based on shear thickening fluids. In this paper, poly(propylene glycols) (PPGs) diacetates are investigated as dilatant effect enhancers for nano-silica dispersions in poly(propylene glycols). The influence of the modifiers on rheological properties of the dispersion is studied and discussed. Additionally, FTIR and rheological properties measurements are conducted in order to determine relative interactions strength between hydroxyl groups of PPGs and silica and carbonyl groups of PPG diacetates. Our findings suggest that the relative attractive interaction strength in studied systems can be arranged in the following order: COCO < COOH < OHOH. Therefore, the addition of PPG diacetate hinders the attractive interactions between liquid and solid. We report that the addition of diacetates can lead both to enhancement and deterioration of dilatant effect depending on the concentration of the modifier and its chain length. Based on conducted measurements and literature data, mechanism explaining that phenomenon is suggested. As a result, we propose an easy to make and cheap dilatant effect enhancer for widely used shear thickening fluids which, when used in small amounts (1-2.5%), raises the viscosity jump drastically. Additionally, the presence of the modifier does not significantly affect the zero shear viscosity of the shear thickening fluid. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis of Poly(Propylene Fumarate)

PubMed Central

Kasper, F. Kurtis; Tanahashi, Kazuhiro; Fisher, John P.; Mikos, Antonios G.

2010-01-01

This protocol describes the synthesis of 500 – 4000 Da poly(propylene fumarate) by a two-step reaction of diethyl fumarate and propylene glycol through a bis(hydroxypropyl) fumarate diester intermediate. Purified PPF can be covalently crosslinked to form degradable polymer networks, which have been widely explored for biomedical applications. The properties of crosslinked PPF networks depend upon the molecular properties of the constituent polymer, such as the molecular weight. The purity of the reactants and the exclusion of water from the reaction system are of utmost importance in the generation of high-molecular-weight PPF products. Additionally, the reaction time and temperature influence the molecular weight of the PPF product. The expected time required to complete this protocol is 3 d. PMID:19325548

Impact of polyethylene glycol 400/propylene glycol/hydroxypropyl-guar and 0.1% sodium hyaluronate on postoperative discomfort following cataract extraction surgery: a comparative study.

PubMed

Labiris, Georgios; Ntonti, Panagiota; Sideroudi, Haris; Kozobolis, Vassilios

2017-01-01

Universal postoperative guidelines for cataract extraction surgery are yet to be introduced. Artificial tears are gaining popularity as an additional integral component of the postoperative regime. The primary objective of this study was to explore the impact of two prevalent artificial tear preparations on postoperative discomfort following cataract extraction surgery. A total of 180 patients that underwent cataract extraction surgery were randomly divided into three groups according to their postoperative regime: a) Study group 1 (SG1) received a fixed combination of tobramycin and dexamethasone (FCTD) quid for 3 weeks and, additionally polyethylene glycol 400/propylene glycol/hydroxypropyl-guar quid, for 6 weeks, b) Study group 2 (SG2) received FCTD quid for 3 weeks and, additionally 0.1% sodium hyaluronate provided in the COMOD® device quid, for 6 weeks, and, c) Control Group (CG) received only FCTD quid for 3 weeks. The following indexes were evaluated at three postoperative checkpoints: 1) Subjective discomfort index (SDI) derived from four direct 10-scale Likert-type questions that were addressed to the patient and pertained to: a) foreign body sensation (FBS), b) blinking discomfort (BD), c) stinging sensation (SS), d) tearing sensation (TS), 2) Tear break-up time (TBUT), 3) Central corneal thickness (CCT) and, 4) Central Corneal Sensitivity (CCS). Both groups showed increased CCT values at the first examination point and reduced CCS values at all examination points. Furthermore, both SGs had better TBUT times at all examination points compared to CG (CG: 8.86 ± 1.08, SG1: 9.59 ± 1.45, CG2: 9.45 ± 1.33, p  < 0.05). BD was significantly better in both SGs only at the 1 st week of examination, while SDI values were better until the 3 rd week and only borderline better at 6 th week. Lastly, no significant differences were detected between SGs, regarding all parameters, at all examination points. Polyethylene glycol 400/propylene glycol/hydroxypropyl-guar and 0.1% sodium hyaluronate provided in the COMOD® device seem to be equally efficient in alleviating OSD symptoms following cataract extraction surgery and any of them should be routinely added to the postoperative regime. ClinicalTrials.gov Identifier: https://clinicaltrials.gov/ct2/show/NCT02558218NCT02558218.

21 CFR 172.858 - Propylene glycol alginate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... do not preclude such use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices, and..., stabilizer, or thickener in fats and oils at a level not to exceed 1.1 percent by weight of the finished...

21 CFR 172.858 - Propylene glycol alginate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... do not preclude such use: (1) As a stabilizer in frozen dairy desserts, in fruit and water ices, and..., stabilizer, or thickener in fats and oils at a level not to exceed 1.1 percent by weight of the finished...

A 10-A spectroscopic ruler applied to short polyprolines.

PubMed

Sahoo, Harekrushna; Roccatano, Danilo; Hennig, Andreas; Nau, Werner M

2007-08-08

Fluorescence resonance energy transfer (FRET) from the amino acid tryptophan (Trp) as donor and a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) as acceptor in peptides of the general structure Trp-(Pro)n-Dbo-NH2 (n = 1-6) was investigated by steady-state and time-resolved fluorescence, CD, and NMR spectroscopy as well as by molecular dynamics (MD) simulations (GROMOS96 force field). The Trp/Dbo FRET pair is characterized by a very short Förster radius (R0 ca. 9 A), which allowed distance determinations in such short peptides. Water and propylene glycol were investigated as solvents. The peptides were designed to show an early nucleation of the poly(Pro)II (PPII) secondary helix structure for n > or = 2, which was confirmed by their CD spectra. The shortest peptide (n = 1) adopts preferentially the trans conformation about the Trp-Pro bond, as confirmed by NMR spectra. The FRET efficiencies ranged 2-72% and were found to depend sensitively on the peptide length, i.e., the number of intervening proline residues. The analysis of the FRET data at different levels of theory (assuming either a fixed distance or distance distributions according to a wormlike chain or Gaussian model) afforded donor-acceptor distances between ca. 8 A (n = 1) and ca. 16 A (n = 6) in water, which were found to be similar or slightly higher in propylene glycol. The distances afforded by the Trp/Dbo FRET pair were found to be reasonable in comparison to literature data, expectations from the PPII helix structure, and the results from MD simulations. The persistence lengths for the longer peptides were found to lie at 30-70 A in water and 220 +/- 40 A in propylene glycol, suggesting a more rigid PPII helical structure in propylene glycol. A detailed comparison with literature data on FRET in polyprolines demonstrates that the donor-acceptor distances extracted by FRET are correlated with the Förster radii of the employed FRET pairs. This demonstrates the limitations of using FRET as a spectroscopic ruler for short polyprolines, which is presumably due to the breakdown of the point dipole approximation in Förster theory, when the size of the chromophores becomes comparable or larger than the distances under investigation.

Phase behavior, morphology, and polymorphism of surfactant systems

NASA Astrophysics Data System (ADS)

Liang, Jingmei

Surfactants are amphiphilic molecules. They spontaneously form various microstructures in water to accommodate the hydrophilic-hydrophobic interactions. Soaps are the oldest kind of man-made surfactants that are commonly used as washing and cleaning agents. In spite of the long history of soap research, many aspects of soaps in nonaqueous solvents remain unclear. Unlike the aqueous soap systems, which have been studied extensively, investigations of nonaqueous, polar soap systems are rather limited. Motivated by the applications of nonaqueous, polar solvents in soap products, we investigated sodium stearate (NaSt)/water/propylene glycol (PG) systems. The effects of gradual substitution of PG for H 2O on the phase behavior, morphology and crystalline structure of NaSt systems were studied by a combination of characterization techniques. The techniques include direct visual observation, differential scanning calorimetry, wide-angle and small angle x-ray scattering, light and cryo-electron microscopy, and solid-state nuclear magnetic resonance. Anhydrous NaSt forms layered crystalline structures at 25°C. With increasing temperature, a distorted hexagonal phase and a hexagonal liquid crystalline phase form. Compared with aqueous soap systems, the regions of liquid crystalline phases in the phase diagrams are reduced as PG replaces or gradually substitutes for H2O. Fibrous and plate-like NaSt crystallites were investigated in the NaSt/PG/H 2O system containing 1-5 wt% NaSt. Despite of the morphological difference, NaSt fibers and platelets share the same layered crystalline structure at the molecular level. NaSt fibers consist of stacked thin ribbons of NaSt bilayers. NaSt platelets exhibit large basal planes {001} surrounded by other faster-growing lateral planes. Two lamellar crystalline structures, alpha-NaSt and beta-NaSt, which formed in the NaSt/PG/H2O system with 10 wt% NaSt, were characterized on the atomic, molecular and microscopic levels. In a PG concentration range of 60-95 wt% in mixtures of H2O and PG, beta-NaSt transforms to alpha-NaSt upon aging. Compared with beta-NaSt, the hydrocarbon chains in alpha-NaSt consist of a higher percentage of trans conformation, which is characteristically more orderly packed and more rigid. alpha-NaSt exhibits a larger bilayer thickness, and dissolves at a lower temperature in the PG/H 2O mixture. The fibrous crystallites of alpha-NaSt are more bundled and oriented compared to those of beta-NaSt.

Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants

USGS Publications Warehouse

Corsi, Steven R.; Mericas, Dean; Bowman, George

2012-01-01

Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

An optimization study of PtSn/C catalysts applied to direct ethanol fuel cell: Effect of the preparation method on the electrocatalytic activity of the catalysts

NASA Astrophysics Data System (ADS)

Almeida, T. S.; Palma, L. M.; Leonello, P. H.; Morais, C.; Kokoh, K. B.; De Andrade, A. R.

2012-10-01

The aim of this work was to perform a systematic study of the parameters that can influence the composition, morphology, and catalytic activity of PtSn/C nanoparticles and compare two different methods of nanocatalyst preparation, namely microwave-assisted heating (MW) and thermal decomposition of polymeric precursors (DPP). An investigation of the effects of the reducing and stabilizing agents on the catalytic activity and morphology of Pt75Sn25/C catalysts prepared by microwave-assisted heating was undertaken for optimization purposes. The effect of short-chain alcohols such as ethanol, ethylene glycol, and propylene glycol as reducing agents was evaluated, and the use of sodium acetate and citric acid as stabilizing agents for the MW procedure was examined. Catalysts obtained from propylene glycol displayed higher catalytic activity compared with catalysts prepared in ethylene glycol. Introduction of sodium acetate enhanced the catalytic activity, but this beneficial effect was observed until a critical acetate concentration was reached. Optimization of the MW synthesis allowed for the preparation of highly dispersed catalysts with average sizes lying between 2.0 and 5.0 nm. Comparison of the best catalyst prepared by MW with a catalyst of similar composition prepared by the polymeric precursors method showed that the catalytic activity of the material can be improved when a proper condition for catalyst preparation is achieved.

Characterization of semi-solid Self-Emulsifying Drug Delivery Systems (SEDDS) of atorvastatin calcium by Raman image spectroscopy and chemometrics.

PubMed

Breitkreitz, Márcia C; Sabin, Guilherme P; Polla, Griselda; Poppi, Ronei J

2013-01-25

A methodology based on Raman image spectroscopy and chemometrics for homogeneity evaluation of formulations containing atorvastatin calcium in Gelucire(®) 44/14 is presented. In the first part of the work, formulations with high amounts of Gelucire(®) 44/14 (80%) and solvents of different polarities (diethylene glycol monoethyl ether, propyleneglycol, propylene glycol monocaprylate and glyceryl mono/dicaprylate/caprate) were prepared for miscibility screening evaluation by classical least squares (CLS). It was observed that Gelucire(®) 44/14 presented higher affinity for the lipophilic solvents glyceryl mono/dicaprylate/caprate and propylene glycol monocaprylate, whose samples were observed to be homogeneous, and lower affinity for the hydrophilic solvents diethylene glycol monoethyl ether and propyleneglycol, whose samples were heterogeneous. In the second part of the work, the ratio of glyceryl mono/dicaprylate/caprate and Gelucire(®) 44/14 was determined based on studies in water and allowed the selection of the proportions of these two excipients in the preconcentrate that provided supersaturation of atorvastatin upon dilution. The preconcentrate was then evaluated for homogeneity by partial least squares (PLS) and an excellent miscibility was observed in this proportion as well. Therefore, it was possible to select a formulation that presented simultaneously homogeneous preconcentrate and solubility enhancement in water by Raman image spectroscopy and chemometrics. Copyright © 2012 Elsevier B.V. All rights reserved.

Allergenic Ingredients in Facial Wet Wipes.

PubMed

Aschenbeck, Kelly A; Warshaw, Erin M

Allergic contact dermatitis commonly occurs on the face. Facial cleansing wipes may be an underrecognized source of allergens. The aim of this study was to determine the frequency of potentially allergenic ingredients in facial wet wipes. Ingredient lists from name brand and generic facial wipes from 4 large retailers were analyzed. In the 178 facial wipes examined, a total of 485 ingredients were identified (average, 16.7 ingredients per wipe). Excluding botanicals, the top 15 potentially allergenic ingredients were glycerin (64.0%), fragrance (63.5%), phenoxyethanol (53.9%), citric acid (51.1%), disodium EDTA (44.4%), sorbic acid derivatives (39.3%), tocopherol derivatives (38.8%), polyethylene glycol derivatives (32.6%), glyceryl stearate (31.5%), sodium citrate (29.8%), glucosides (27.5%), cetearyl alcohol (25.8%), propylene glycol (25.3%), sodium benzoate (24.2%), and ceteareth-20 (23.6%)/parabens (23.6%). Of note, methylisothiazolinone (2.2%) and methylchloroisothiazolinone (1.1%) were uncommon. The top potential allergens of botanical origin included Aloe barbadensis (41.0%), chamomile extracts (27.0%), tea extracts (21.3%), Cucumis sativus (20.2%), and Hamamelis virginiana (10.7%). Many potential allergens are present in facial wet wipes, including fragrances, preservatives, botanicals, glucosides, and propylene glycol.

Measurement of heating coil temperature for e-cigarettes with a "top-coil" clearomizer.

PubMed

Chen, Wenhao; Wang, Ping; Ito, Kazuhide; Fowles, Jeff; Shusterman, Dennis; Jaques, Peter A; Kumagai, Kazukiyo

2018-01-01

To determine the effect of applied power settings, coil wetness conditions, and e-liquid compositions on the coil heating temperature for e-cigarettes with a "top-coil" clearomizer, and to make associations of coil conditions with emission of toxic carbonyl compounds by combining results herein with the literature. The coil temperature of a second generation e-cigarette was measured at various applied power levels, coil conditions, and e-liquid compositions, including (1) measurements by thermocouple at three e-liquid fill levels (dry, wet-through-wick, and full-wet), three coil resistances (low, standard, and high), and four voltage settings (3-6 V) for multiple coils using propylene glycol (PG) as a test liquid; (2) measurements by thermocouple at additional degrees of coil wetness for a high resistance coil using PG; and (3) measurements by both thermocouple and infrared (IR) camera for high resistance coils using PG alone and a 1:1 (wt/wt) mixture of PG and glycerol (PG/GL). For single point thermocouple measurements with PG, coil temperatures ranged from 322 ‒ 1008°C, 145 ‒ 334°C, and 110 ‒ 185°C under dry, wet-through-wick, and full-wet conditions, respectively, for the total of 13 replaceable coil heads. For conditions measured with both a thermocouple and an IR camera, all thermocouple measurements were between the minimum and maximum across-coil IR camera measurements and equal to 74% ‒ 115% of the across-coil mean, depending on test conditions. The IR camera showed details of the non-uniform temperature distribution across heating coils. The large temperature variations under wet-through-wick conditions may explain the large variations in formaldehyde formation rate reported in the literature for such "top-coil" clearomizers. This study established a simple and straight-forward protocol to systematically measure e-cigarette coil heating temperature under dry, wet-through-wick, and full-wet conditions. In addition to applied power, the composition of e-liquid, and the devices' ability to efficiently deliver e-liquid to the heating coil are important product design factors effecting coil operating temperature. Precautionary temperature checks on e-cigarettes under manufacturer-recommended normal use conditions may help to reduce the health risks from exposure to toxic carbonyl emissions associated with coil overheating.

The environmental impact of 4(5)-methylbenzotriazole from aircraft deicing operations

NASA Astrophysics Data System (ADS)

Cornell, Jeffrey Scott

2002-01-01

Hundreds of millions of gallons of aircraft deicer fluid (ADF) are applied to aircraft and runway surfaces annually. Recently public and regulatory attention has forced the air transport industry and military aviation community to examine the environmental impacts of aircraft deicing operations (ADOs), and to seek a balance between flight safety and environmental impact. Little data exists which is useful to evaluate the impact of ADF additives. 4(5)-methylbenzotriazole (MeBT) is used in a variety of industrial and commercial fluids to inhibit metal corrosion; it is a standard additive to most common ADF (approx. 0.5%). This MeBT component is actually a mixture of two isomers: 4-methylbenzotriazole (4-MeBT) and 5-methylbenzotriazole (5-MeBT). A significant amount of MeBT enters the natural environment through aircraft deicing operations. Research was conducted to address important data gaps impacting the ability to assess the environmental impact of MeBT and ADOs. Matrixed toxicity studies were conducted to determine the effect of different additives on ADF ecotoxicity. Aerobic liquid batch-fed microcosms were employed to investigate how MeBT affects the toxicity of wastewater containing ADF, describe how MeBT affects the aerobic biodegradation of propylene glycol (PG), and determine the biodegradability of MeBT. Field samples from contaminated areas were collected and analyzed for comparison. Cell energy production and electron transport assays were conducted to determine if MeBT was capable of disrupting oxidative phosphorylation via uncoupling, as its chemical structure would suggest. MicrotoxRTM studies indicated MeBT was toxic to test bacteria below 10 mg/L. C. dubia and P. promelas , however, were less sensitive to MeBT than bacteria but more sensitive to other ADF additives. The effect of MeBT on PG biodegradation was complex and concentration-dependent. Cell yield and PG biodegradation rates generally decreased with increasing reactor MeBT concentration. ATP:INT assay data in bioreactors containing 10 mg McBT/L suggested ATP production uncoupled from electron transport. Oxygen consumption and aerobic PG biodegradation was completely inhibited between above 2,000 mg MeBT/L. MeBT was not degraded when PG was present above 0.5 mg/L in well-mixed aerobic conditions. 5-MeBT was biodegradable under a variety of aerobic laboratory conditions (when PG was not present) while 4-MeBT was recalcitrant.

Measurement of heating coil temperature for e-cigarettes with a “top-coil” clearomizer

PubMed Central

Wang, Ping; Ito, Kazuhide; Fowles, Jeff; Shusterman, Dennis; Jaques, Peter A.; Kumagai, Kazukiyo

2018-01-01

Objectives To determine the effect of applied power settings, coil wetness conditions, and e-liquid compositions on the coil heating temperature for e-cigarettes with a “top-coil” clearomizer, and to make associations of coil conditions with emission of toxic carbonyl compounds by combining results herein with the literature. Methods The coil temperature of a second generation e-cigarette was measured at various applied power levels, coil conditions, and e-liquid compositions, including (1) measurements by thermocouple at three e-liquid fill levels (dry, wet-through-wick, and full-wet), three coil resistances (low, standard, and high), and four voltage settings (3–6 V) for multiple coils using propylene glycol (PG) as a test liquid; (2) measurements by thermocouple at additional degrees of coil wetness for a high resistance coil using PG; and (3) measurements by both thermocouple and infrared (IR) camera for high resistance coils using PG alone and a 1:1 (wt/wt) mixture of PG and glycerol (PG/GL). Results For single point thermocouple measurements with PG, coil temperatures ranged from 322 ‒ 1008°C, 145 ‒ 334°C, and 110 ‒ 185°C under dry, wet-through-wick, and full-wet conditions, respectively, for the total of 13 replaceable coil heads. For conditions measured with both a thermocouple and an IR camera, all thermocouple measurements were between the minimum and maximum across-coil IR camera measurements and equal to 74% ‒ 115% of the across-coil mean, depending on test conditions. The IR camera showed details of the non-uniform temperature distribution across heating coils. The large temperature variations under wet-through-wick conditions may explain the large variations in formaldehyde formation rate reported in the literature for such “top-coil” clearomizers. Conclusions This study established a simple and straight-forward protocol to systematically measure e-cigarette coil heating temperature under dry, wet-through-wick, and full-wet conditions. In addition to applied power, the composition of e-liquid, and the devices’ ability to efficiently deliver e-liquid to the heating coil are important product design factors effecting coil operating temperature. Precautionary temperature checks on e-cigarettes under manufacturer-recommended normal use conditions may help to reduce the health risks from exposure to toxic carbonyl emissions associated with coil overheating. PMID:29672571

Alteration of skin hydration and its barrier function by vehicle and permeation enhancers: a study using TGA, FTIR, TEWL and drug permeation as markers.

PubMed

Shah, D K; Khandavilli, S; Panchagnula, R

2008-09-01

Vehicles and permeation enhancers (PEs) used in transdermal drug delivery (TDD) of a drug can affect skin hydration, integrity and permeation of the solute administered. This investigation was designed to study the effect of the most commonly used vehicles and PEs on rat skin hydration, barrier function and permeation of an amphiphilic drug, imipramine hydrochloride (IMH). An array of well-established techniques were used to confirm the findings of the study. Thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy were used to determine changes in skin hydration. Alteration of the stratum corneum (SC) structure was investigated using FTIR studies. To monitor the barrier function alteration, transepidermal water loss (TEWL) measurement and permeation studies were performed. Our findings indicate that with hydration, there was an increase in the bound water content of the skin, and pseudoequilibrium of hydration (a drastic decrease in hydration rate) was achieved at around 12 h. Hydration increased the ratio between amide-I and amide-II peaks in FTIR and reduced the C-H stretching peak area. Both propylene glycol (PG) and ethanol (EtOH) dehydrated skin, with the latter showing a predominant effect. Furthermore, it was confirmed that PG and EtOH decreased the bound water content due to alteration in the protein domains and extraction of SC lipids, respectively. The effect of hydration on the SC was found to be similar to that reported for temperature. Permeation studies revealed that the dehydration caused by vehicles decreased IMH flux, whereas the flux was enhanced by PEs. The role of partition was predominant for the permeation of IMH through dehydrated skin. A synergistic effect was observed for PG and menthol in the enhancement of IMH. Further findings provided strong evidence that PG affects protein domains and EtOH extracts lipids from the bilayer. Both PG and EtOH, with or without PEs, increased TEWL. Initial TEWL was well correlated with the flux of IMH through the same skin. It was found that both PG and EtOH affect the permeation of solute and TEWL by dehydration. The experiments also proved that the initial TEWL value has a strong potential as a predictive tool for the permeation of the solute. Copyright 2008 Prous Science, S.A.U. or its licensors. All rights reserved.

Gel bead composition for metal adsorption

DOEpatents

Scott, Charles D.; Woodward, Charlene A.; Byers, Charles H.

1991-01-01

The invention is a gel bead comprising propylene glycol alginate and bone gelatin and is capable of removing metals such as Sr and Cs from solution without adding other adsorbents. The invention could have application to the nuclear industry's waste removal activities.

Gel bead composition for metal adsorption

DOEpatents

Scott, Charles D.; Woodward, Charlene A.; Byers, Charles H.

1990-01-01

The invention is a gel bead comprising propylene glycol alginate and bone gelatin and is capable of removing metals such as Sr and Cs from solution without adding other adsorbents. The invention could have application to the nuclear industry's waste removal activities.

[Study of the effect of surface-active agents on living cells, used as component parts in microemulsions, based on their chemical structures and critical micelle-formative concentration (CMC)].

PubMed

Ujhelyi, Zoltán; Vecsernyés, Miklós; Bácskay, Ildikó

2013-01-01

The aim of this study was to examine the cellular effects of two nonionic amphiphilic tenside groups and their mixtures on human Caco-2 cell monolayers as dependent upon their chemical structures and physicochemical properties. The first group of polyethylene glycol esters is represented by Polysorbates and Labrasol alone and in blends, while the members of the second group:Capryol 90, Capryol PGMC, Lauroglycol 90 and Lauroglycol FCC were used as propylene glycol esters. They are increasingly used in SMEDDS as recent tensides or co-tensides to increase the solubility of hydrophobic drug. Critical micelle concentration was measured by determination of surface tension. CMC refers to the ability of solubilization of surfactants. Cytotoxicity tests were performed on Caco-2 cell monolayers by MTT and LDH methods. Caco-2 cell monolayers are convenient and reliable in vitro models of the gastrointestinal tract. Paracellular permeability was examined with Lucifer yellow assays. The integrity of cell monolayers was observed by TransEpithelial Electrical Resistance (TEER) measurements. Tight junction alterations effected by the surfactants were also characterized as evidence for paracellular pathway. Changes in sub cellular localization of the tight junction proteins: ZO-1, Claudin-land beta-cathenin, were examined by confocal laser scanning microscopy.The results of cytotoxicity assays were in agreement and showed significant differences among the cytotoxic properties of surfactants in a concentration-dependent manner. Polysorbates 20, 60, 80 are the most toxic compounds. In the case of Labrasol, the degree of esterification and lack of sorbit component decreased cytotoxicity. If the hydrophyl head was changed from polyethylene glycol to propylene glycol, the main determined factor of cytotoxicity was the monoester content and the length of carbon chain. In our CMC experiments, we found that only Labrasol showed expressed cytotoxicity above the CMC. It refers to good ability of micelle solubilization of Labrasol. In our paracellular transport experiments each of polyethylene glycol surfactants (Polysorbates and Labrasol) altered TEER values but propylene glycol esters did not modify the monolayer integrity. Polyethylene glycol esters alone and in blends (0.05% Labrasol--0.001% Polysorbates 20, 60, 80) were able to increase Lucifer yellow permeability significantly below the IC50 concentration. On the other hand Labrasol and Polysorbates 20 have expressed effect on tight junctions of Caco-2 monolayer. It could be concluded that polyethylene glycol ester-type tensides were able to enhance the paracellular permeability by the redistribution of junctional proteins. Our results might ensure useful data for selection of suitable tensides, co-tensides and tenside mixtures for SMEDDS formulations.

Ethylene glycol (antifreeze) poisoning in a free-ranging polar bear

USGS Publications Warehouse

Amstrup, Steven C.; Gardner, Craig L.; Myers, Kevin C.; Oehme, Frederick W.

1989-01-01

The bright, fluorescent pink-colored remains of a polar bear were found on an Alaskan island with the gravel and snow adjacent to the bear colored bright purple. Traces of fox urine and feces found nearby were also pink. The punk and purple colors were due to rhodamine B, and ethylene glycol (EG) was present in the soil under the carcass. Evidence is given to suggest the bear consumed a mixture of rhodamine B and EG commonly used to mark roads and runways during snow and ice periods. Such wildlife losses could be prevented by substituting propylene glycol for the EG in such mixtures.

Controlled-Release Personal Use Arthropod Repellent Formulation. Phase 3

DTIC Science & Technology

1987-08-26

Polyethylene Glycol (200) Glyceryl Monotallowate (Varonic L1420) 54.2 lbs. Glyceryl Stearate/ Sodium Lauryl Sulfate (Lexemul AS) 129.3 lbs. Propylene... Sulfate 6-0 Xr ________ (Le.ernul AS) - 0.65__ * 13W00 Cetyl Palmitate (W,xenol 816) 2,600 Xg. Ci Zq! 167 2.2___ 10026 Poyproplen Gycol (15) Stenryl...1 Stearate7Sodium lAu 1l Sulfate T- 4fIa- TW _ - ________ Lex emul AS)__________ ____ _______ 2.41 11315 /Prop lene Glycol D1 cap" lateDf~caerate

Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: II—Mathematical prediction and experimental validation of optimal cryopreservation protocols☆

PubMed Central

Kashuba, Corinna M.; Benson, James D.; Critser, John K.

2014-01-01

In Part I, we documented differences in cryopreservation success measured by membrane integrity in four mouse embryonic stem cell (mESC) lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1), and we demonstrated a potential biophysical basis for these differences through a comparative study characterizing the membrane permeability characteristics and osmotic tolerance limits of each cell line. Here we use these values to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures. We subsequently verified these predictions experimentally for their effects on post-thaw recovery. From this study, we determined that a cryopreservation protocol utilizing 1 M propylene glycol, a cooling rate of 1 °C/minute, and plunging into liquid nitrogen at −41 °C, combined with subsequent warming in a 22 °C water bath with agitation, significantly improved post-thaw recovery for three of the four mESC lines, and did not diminish post-thaw recovery for our single exception. It is proposed that this protocol can be successfully applied to most mESC lines beyond those included within this study once the effect of propylene glycol on mESC gene expression, growth characteristics, and germ-line transmission has been determined. Mouse ESC lines with poor survival using current standard cryopreservation protocols or our proposed protocol can be optimized on a case-by-case basis using the method we have outlined over two papers. For our single exception, the CBA cell line, a cooling rate of 5 °C/minute in the presence of 1.0 M dimethyl sulfoxide or 1.0 M propylene glycol, combined with plunge temperature of −80 °C was optimal. PMID:24560712

The effect of in-service aerospace contaminants on X-band dielectric properties of a bismaleimide/quartz composite

NASA Astrophysics Data System (ADS)

Rodriguez, Luis A.; García, Carla; Grace, Landon R.

2015-05-01

The impact of three common aerospace in-service liquid contaminants on the X-band dielectric properties of a polymer composite radar protecting structure (radome) is investigated and quantified. The dielectric properties of the composite laminate are critical to radar transparency, and thus performance, of the radome structure. Further, polymer composites are highly susceptible to absorption of liquids. As such, the effect of common aerospace contaminants on the dielectric properties of composite laminates is crucial. Measurement of relative permittivity and loss tangent via a split-post dielectric resonant technique at 10 GHz is used to determine the effect of water, deicing fluid, and propylene glycol absorption in a three-ply quartz-reinforced bismaleimide laminate. Additionally, fluid uptake kinetics are investigated as a function of liquid type. An approximately linear relationship between fluid content and relative permittivity is observed for all three contaminant types. A 1% increase in contaminant content by weight results in a 7.8%, 4.5%, and 2.5% increase in relative permittivity of the material due to water, deicing fluid, and propylene glycol, respectively. A more significant impact is seen in material loss tangent, where a 1% increase in contaminant content by weight is responsible for a 378.5%, 593.0%, and 441.5% increase in loss tangent due to the aforementioned fluids, respectively. A fluid uptake weight content of 1.31%, 3.41%, and 4.28% is achieved for water, deicing fluid, and propylene glycol respectively, at approximately 1300 hours exposure. Based on the reported observations, the dielectric property degradation of composite laminates due to these commonly used fluids is of significant concern for in-service aircraft radar systems routinely exposed to these contaminants.

Neurotoxic effects of methylcyclopentadienyl manganese tricarbonyl (MMT) in the mouse: basis of MMT-induced seizure activity.

PubMed

Fishman, B E; McGinley, P A; Gianutsos, G

1987-08-01

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese-containing compound which is used as an additive in unleaded gasoline. One neurotoxic effect of MMT in mice is seizure activity. In this study, seizures were observed in mice treated with MMT in propylene glycol or corn oil. The LD50 associated with seizure activity was lower in mice receiving MMT in propylene glycol (152 mg/kg) than in those receiving MMT in corn oil (999 mg/kg). Manganese concentrations in the brains of mice which showed seizure activity due to MMT were higher than in those that did not (2.45 micrograms/g vs. 1.14 micrograms/g for MMT treated in propylene glycol and 3.25 micrograms/g vs. 1.63 micrograms/g for MMT in corn oil). Mice treated with manganese chloride (MnCl2) showed increases in brain manganese comparable to those of the mice showing seizure activity due to MMT, but exhibited no sign of seizure activity. MMT in non-lethal seizure-inducing doses had no effect on the accumulation of 4-aminobutyric acid (GABA) in mouse brain. However, MMT inhibited the binding of t-[3H]t-butylbicycloorthobenzoate [3H]-TBOB (a ligand for the GABA-A-receptor linked chloride channel) in mouse brain membranes with an IC50 value of 22.8 microM. The data suggest that MMT (organic manganese) or a closely related metabolite and not elemental manganese itself is responsible for the seizure activity observed. The seizure activity may be the result of an inhibitory effect of MMT at the GABA-A receptor linked chloride channel.

BIODEGRADATION OF PROPYLENE GLYCOL AND ASSOCIATED HYDRODYNAMIC EFFECTS IN SAND. (R825549C063)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

78 FR 48618 - Propylene Glycol; Exemption From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

... by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available in... that are not active ingredients as defined [[Page 48619

[Plasma metabonomics of Guifu Dihuang Wan in the treatment of yang deficiency].

PubMed

Xiao, Ya; Jing, Yuan; Chen, Jie-Yu; Li, Fei; Cheng, Jing-Ru; Bi, Jian-Lu; Luo, Ren; Zhao, Xiao-Shan

2016-11-20

To assess the effect of Guifu Dihuang Wan (GFDHW) in the treatment of yang deficiency and explore the underlying molecular mechanism. Sixty-two participants without diseases were randomized into control group (n=31) and experimental group (n=31) and were given lifestyle intervention additional GFDHW treatment for a month. NMR technology was used for metabonomics analysis. Intervention with GFDHW resulted in significantly decreased conversion scores of yang deficiency in the experimental group compared with the control group (P<0.005). The concentrations of lactate, valine, proline, arginine and 3-hydroxybutyrate were increased in the plasma of yang-deficient subjects after lifestyle intervention. GFDHW treatment with lifestyle intervention significantly increased the concentrations of lactate, valine, proline, arginine and 3-hydroxybutyrate and also the levels of alanine, glutamine, alpha glucose, isoleucine, betaine and propylene glycol. GFDHW treatment improves yang deficiency possibly by increasing the concentrations of alanine, glutamine, alpha glucose, isoleucine, betaine and propylene glycol and promoting energy metabolism of the body.

Effect of Alcohols on the Phase Behavior and Emulsification of a Sucrose Fatty Acid Ester/Water/Edible Oil System.

PubMed

Matsuura, Tsutashi; Ogawa, Akihiro; Ohara, Yukari; Nishina, Shogo; Nakanishi, Maho; Gohtani, Shoichi

2018-02-01

The effect of alcohols (ethanol, 1-propanol, propylene glycol, glycerin, sucrose) on the phase behavior and emulsification of sucrose stearic acid ester (SSE)/water/edible vegetable oil (EVO) systems was investigated. Adding sucrose, propylene glycol, and glycerin narrowed the oil-separated two-phase region in the phase diagram of the SSE/water/EVO systems, whereas adding ethanol and 1-propanol expanded the oil-separated two-phase region. Changing the course of emulsification in the phase diagram showed that the size of the oil-droplet particle typically decreased in a system with a narrowed oil-separated region. The emulsification properties of the systems varied with respect to changes in the phase diagram. The microstructure of the systems was examined using small-angle X-ray scattering, and the ability to retain the oil in the lamellar structure of the SSEs was suggested as an important role in emulsification, because the mechanism of the systems was the same as that for the liquid crystal emulsification method.

Preparation and evaluation of quercetin-loaded lecithin-chitosan nanoparticles for topical delivery.

PubMed

Tan, Qi; Liu, Weidong; Guo, Chenyu; Zhai, Guangxi

2011-01-01

The purpose of this study was to investigate lecithin-chitosan nanoparticles as a topical delivery system for quercetin. Tocopheryl propylene glycol succinate was chosen to be the surfactant for the nanosystem. The mean particle size of the nanoparticles was 95.3 nm, and the entrapment efficiency and drug loading for quercetin were 48.5% and 2.45%, respectively. Topical delivery in vitro and in vivo of the quercetin-loaded nanoparticles was evaluated using quercetin propylene glycol solution as the control. Compared with quercetin solution, the quercetin-loaded nanoparticles showed higher permeation ability, and significantly increased accumulation of quercetin in the skin, especially in the epidermis. Microstructure observation of the skin surface after administration indicated that the interaction between ingredients of the nanoparticles and the skin surface markedly changed the morphology of the stratum corneum and disrupted the corneocyte layers, thus facilitating the permeation and accumulation of quercetin in skin. Lecithin-chitosan nanoparticles are a promising carrier for topical delivery of quercetin.

Preparation and evaluation of quercetin-loaded lecithin-chitosan nanoparticles for topical delivery

PubMed Central

Tan, Qi; Liu, Weidong; Guo, Chenyu; Zhai, Guangxi

2011-01-01

Background The purpose of this study was to investigate lecithin-chitosan nanoparticles as a topical delivery system for quercetin. Methods Tocopheryl propylene glycol succinate was chosen to be the surfactant for the nanosystem. The mean particle size of the nanoparticles was 95.3 nm, and the entrapment efficiency and drug loading for quercetin were 48.5% and 2.45%, respectively. Topical delivery in vitro and in vivo of the quercetin-loaded nanoparticles was evaluated using quercetin propylene glycol solution as the control. Results Compared with quercetin solution, the quercetin-loaded nanoparticles showed higher permeation ability, and significantly increased accumulation of quercetin in the skin, especially in the epidermis. Microstructure observation of the skin surface after administration indicated that the interaction between ingredients of the nanoparticles and the skin surface markedly changed the morphology of the stratum corneum and disrupted the corneocyte layers, thus facilitating the permeation and accumulation of quercetin in skin. Conclusion Lecithin-chitosan nanoparticles are a promising carrier for topical delivery of quercetin. PMID:21904452

The effect of solvent interactions on alpha-, beta-, and gamma-cyclodextrin/flavor molecular inclusion complexes.

PubMed

Reineccius, Teresa A; Reineccius, Gary A; Peppard, Terry L

2005-01-26

Three commonly used flavor industry solvents (propylene glycol, triacetin, and triethyl citrate) were tested for their capacity to interfere with the ability of alpha-, beta-, and gamma-cyclodextrin to form molecular inclusion complexes with flavors. Six flavor compounds (ethyl butyrate, ethyl heptanoate, l-menthol, methyl anthranilate, neral, and geranial) were measured by headspace gas chromatography above 2:1 water/ethanol containing appropriate additions of cyclodextrin and flavor solvent. The smallest and most polar solvent molecule represented by propylene glycol had the least effect on cyclodextrin/flavorant complex formation. In contrast, triacetin, intermediate in size among the three flavor diluents studied, had the greatest effect, even though, based on at least some computed molecular parameters, it appears to be more polar than triethyl citrate. The explanation for this apparent anomaly may lie in differences in the extent to which triacetin and triethyl citrate are able to interact with cyclodextrins by means of partial interaction with the hydrophobic cavities of the latter.

Preparation, characterization and pharmacokinetics of fluorescence labeled propylene glycol alginate sodium sulfate

NASA Astrophysics Data System (ADS)

Li, Pengli; Li, Chunxia; Xue, Yiting; Zhang, Yang; Liu, Hongbing; Zhao, Xia; Yu, Guangli; Guan, Huashi

2014-08-01

A rapid and sensitive fluorescence labeling method was developed and validated for the microanalysis of a sulfated polysaccharide drug,namely propylene glycol alginate sodium sulfate (PSS), in rat plasma. Fluorescein isothiocyanate (FITC) was selected to label PSS, and 1, 6-diaminohexane was used to link PSS and FITC in order to prepare FITC-labeled PSS (F-PSS) through a reductive amination reaction. F-PSS was identified by UV-Vis, FT-IR and 1H-NMR spectrum. The cell stability and cytotoxicity of F-PSS were tested in Madin-Darby canine kidney (MDCK) cells. The results indicated that the labeling efficiency of F-PSS was 0.522% ± 0.0248% and the absolute bioavailability was 8.39%. F-PSS was stable in MDCK cells without obvious cytotoxicity. The method was sensitive and reliable; it showed a good linearity, precision, recovery and stability. The FITC labeling method can be applied to investigating the absorption and metabolism of PSS and other polysaccharides in biological samples.

Novel vaginal drug delivery system: deformable propylene glycol liposomes-in-hydrogel.

PubMed

Vanić, Željka; Hurler, Julia; Ferderber, Kristina; Golja Gašparović, Petra; Škalko-Basnet, Nataša; Filipović-Grčić, Jelena

2014-03-01

Deformable propylene glycol-containing liposomes (DPGLs) incorporating metronidazole or clotrimazole were prepared and evaluated as an efficient drug delivery system to improve the treatment of vaginal microbial infections. The liposome formulations were optimized based on sufficient trapping efficiencies for both drugs and membrane elasticity as a prerequisite for successful permeability and therapy. An appropriate viscosity for vaginal administration was achieved by incorporating the liposomes into Carbopol hydrogel. DPGLs were able to penetrate through the hydrogel network more rapidly than conventional liposomes. In vitro studies of drug release from the liposomal hydrogel under conditions simulating human treatment confirmed sustained and diffusion-based drug release. Characterization of the rheological and textural properties of the DPGL-containing liposomal hydrogels demonstrated that the incorporation of DPGLs alone had no significant influence on mechanical properties of hydrogels compared to controls. These results support the great potential of DPGL-in-hydrogel as an efficient delivery system for the controlled and sustained release of antimicrobial drugs in the vagina.

Confocal Raman microscopic investigation of the effectiveness of penetration enhancers for procaine delivery to the skin

NASA Astrophysics Data System (ADS)

Lunter, Dominique; Daniels, Rolf

2014-12-01

A methodology that employs confocal Raman microscopy (CRM) on ex vivo skin samples is proposed for the investigation of drug content and distribution in the skin. To this end, the influence of the penetration enhancers propylene glycol and polyoxyethylene-23-lauryl ether on the penetration and permeation of procaine as a model substance was investigated. The drug content of skin samples that had been incubated with semisolid formulations containing one of these enhancers was examined after skin segmentation. The experiments showed that propylene glycol did not affect the procaine content that was delivered to the skin, whereas polyoxyethylene-23-lauryl ether led to higher procaine contents and deeper penetration. Neither substance was found to influence the permeation rate of procaine. It is thereby shown that CRM can provide additional information on drug penetration and permeation. Furthermore, the method was found to enhance the depth from which Raman spectra can be collected and to improve the depth resolution compared to previously proposed methods.

Poly(ester urea)-Based Adhesives: Improved Deployment and Adhesion by Incorporation of Poly(propylene glycol) Segments.

PubMed

Zhou, Jinjun; Bhagat, Vrushali; Becker, Matthew L

2016-12-14

The adhesive nature of mussels arises from the catechol moiety in the 3,4-dihydroxyphenylalanine (DOPA) amino acid, one of the many proteins that contribute to the unique adhesion properties of mussels. Inspired by these properties, many biomimetic adhesives have been developed over the past few years in an attempt to replace adhesives such as fibrin, cyanoacrylate, and epoxy glues. In the present work, we synthesized ethanol soluble but water insoluble catechol functionalized poly(ester urea) random copolymers that help facilitate delivery and adhesion in wet environments. Poly(propylene glycol) units incorporated into the polymer backbone impart ethanol solubility to these polymers, making them clinically relevant. A catechol to cross-linker ratio of 10:1 with a curing time of 4 h exceeded the performance of commercial fibrin glue (4.8 ± 1.4 kPa) with adhesion strength of 10.6 ± 2.1 kPa. These adhesion strengths are significant with the consideration that the adhesion studies were performed under wet conditions.

In vitro penetration through the skin layers of topically applied glucocorticoids.

PubMed

Carrer, Victor; Alonso, Cristina; Oliver, Marc Adrià; Coderch, Luisa

2018-05-22

Corticoids are actives widely used in the treatment of skin diseases. This work aims to study the penetration of three corticoids (betamethasone, clobetasol and flurandrenolide), their relationship with their Log D values and the effects of the vehicles. The three compounds were applied on a Franz-type diffusion cell in propylene glycol solution and their respective commercial creams and ointments. The active amounts found in the stratum corneum, epidermal and dermal layers of the skin were investigated. Their diffusions were greatly affected by the formulation, moreover higher amounts of substance in the epidermis and dermis were detected in ointments than in creams. The enhancement effect of propylene glycol was also observed. Moreover, the differences between the three substances could be related to their lipophilicity, molecular structure and molecular weight. The more hydrophobic compounds (clobetasol and betamethasone) are present in higher amounts in the epidermis and dermis, while the hydrophilic compound (flurandrenolide) is mostly present in the receptor fluid. This article is protected by copyright. All rights reserved.

Sources of Propylene Glycol and Glycol Ethers in Air at Home

PubMed Central

Choi, Hyunok; Schmidbauer, Norbert; Spengler, John; Bornehag, Carl-Gustaf

2010-01-01

Propylene glycol and glycol ether (PGE) in indoor air have recently been associated with asthma and allergies as well as sensitization in children. In this follow-up report, sources of the PGEs in indoor air were investigated in 390 homes of pre-school age children in Sweden. Professional building inspectors examined each home for water damages, mold odour, building’s structural characteristics, indoor temperature, absolute humidity and air exchange rate. They also collected air and dust samples. The samples were analyzed for four groups of volatile organic compounds (VOCs) and semi-VOCs (SVOCs), including summed concentrations of 16 PGEs, 8 terpene hydrocarbons, 2 Texanols, and the phthalates n-butyl benzyl phthalate (BBzP), and di(2-ethylhexyl)phthalate (DEHP). Home cleaning with water and mop ≥ once/month, repainting ≥ one room prior to or following the child’s birth, and “newest” surface material in the child’s bedroom explained largest portion of total variability in PGE concentrations. High excess indoor humidity (g/m3) additionally contributed to a sustained PGE levels in indoor air far beyond several months following the paint application. No behavioral or building structural factors, except for water-based cleaning, predicted an elevated terpene level in air. No significant predictor of Texanols emerged from our analysis. Overall disparate sources and low correlations among the PGEs, terpenes, Texanols, and the phthalates further confirm the lack of confounding in the analysis reporting the associations of the PGE and the diagnoses of asthma, rhinitis, and eczema, respectively. PMID:21318004

Sources of propylene glycol and glycol ethers in air at home.

PubMed

Choi, Hyunok; Schmidbauer, Norbert; Spengler, John; Bornehag, Carl-Gustaf

2010-12-01

Propylene glycol and glycol ether (PGE) in indoor air have recently been associated with asthma and allergies as well as sensitization in children. In this follow-up report, sources of the PGEs in indoor air were investigated in 390 homes of pre-school age children in Sweden. Professional building inspectors examined each home for water damages, mold odour, building's structural characteristics, indoor temperature, absolute humidity and air exchange rate. They also collected air and dust samples. The samples were analyzed for four groups of volatile organic compounds (VOCs) and semi-VOCs (SVOCs), including summed concentrations of 16 PGEs, 8 terpene hydrocarbons, 2 Texanols, and the phthalates n-butyl benzyl phthalate (BBzP), and di(2-ethylhexyl)phthalate (DEHP). Home cleaning with water and mop ≥ once/month, repainting ≥ one room prior to or following the child's birth, and "newest" surface material in the child's bedroom explained largest portion of total variability in PGE concentrations. High excess indoor humidity (g/m³) additionally contributed to a sustained PGE levels in indoor air far beyond several months following the paint application. No behavioral or building structural factors, except for water-based cleaning, predicted an elevated terpene level in air. No significant predictor of Texanols emerged from our analysis. Overall disparate sources and low correlations among the PGEs, terpenes, Texanols, and the phthalates further confirm the lack of confounding in the analysis reporting the associations of the PGE and the diagnoses of asthma, rhinitis, and eczema, respectively.

Detection of poly(ethylene glycol) residues from nonionic surfactants in surface water by1h and13c nuclear magnetic resonance spectrometry

USGS Publications Warehouse

Leenheer, J.A.; Wershaw, R. L.; Brown, P.A.; Noyes, T.I.

1991-01-01

??? Poly(ethylene glycol) (PEG) residues were detected in organic solute isolates from surface water by 1H nuclear magnetic resonance spectrometry (NMR), 13C NMR spectrometry, and colorimetric assay. PEG residues were separated from natural organic solutes in Clear Creek, CO, by a combination of methylation and chromatographic procedures. The isolated PEG residues, characterized by NMR spectrometry, were found to consist of neutral and acidic residues that also contained poly(propylene glycol) moieties. The 1H NMR and the colorimetric assays for poly(ethylene glycol) residues were done on samples collected in the lower Mississippi River and tributaries between St. Louis, MO, and New Orleans, LA, in July-August and November-December 1987. Aqueous concentrations for poly(ethylene glycol) residues based on colorimetric assay ranged from undetectable to ???28 ??g/L. Concentrations based on 1H NMR spectrometry ranged from undetectable to 145 ??g/L.

Cryopreservation of sperm in Grey mullet Mugil cephalus (Linnaeus, 1758).

PubMed

Balamurugan, Ramachandran; Munuswamy, Natesan

2017-10-01

The aim of this study was to document the effects of cryopreservation on sperm motility and viability in Grey mullet Mugil cephalus. Cryopreservation of sperm was attempted by using two extenders ringer solution for marine fish (RSMF) and V2 extender (V2E) and cryoprotectants dimethylacetamide (DMA), dimethylsulfoxide (DMSO), ethylene glycol (EG), glycerol (GLY), propylene glycol (PG) and methanol (MeOH). Cryoprotectants were assessed at different concentrations individually as well as in combination with varying equilibration times (10 and 30min). For optimization of freezing rate, four freezing protocols (-5, -10, -20 and -30°C/min) were evaluated. After achieving final temperature, samples were plunged in liquid nitrogen (-196°C) and stored for a week. Samples were subsequently thawed in a water bath at 30°C for assessment of sperm motility and viability. Results indicated that cryomedium constituting of V2E extender+10% glycerol with a dilution ratio of 1:1 (sperm: cryomedium) at an equilibration time of 5 to- 10min and freezing rate of -20°C/min was more desirable compared with other factors that were assessed. Use of this protocol resulted in retaining the greatest sperm motility grade 3.0±0.0 (50%-80% sperm movement, fast swimming) and 48.19±3.12% of sperm viability. The results of the present study, therefore, provide base-line data for establishing a protocol for sperm cryopreservation in M.cephalus. Further studies are, however, required for optimization of most suitable sperm cryopreservation protocol. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of clinical dosage forms for a poorly water-soluble drug II: formulation and characterization of a novel solid microemulsion preconcentrate system for oral delivery of a poorly water-soluble drug.

PubMed

Li, Ping; Hynes, Sara R; Haefele, Thomas F; Pudipeddi, Madhu; Royce, Alan E; Serajuddin, Abu T M

2009-05-01

The solution of a poorly water-soluble drug in a liquid lipid-surfactant mixture, which served as a microemulsion preconcentrate, was converted into a solid form by incorporating it in a solid polyethylene glycol (PEG) matrix. The solid microemulsion preconcentrates thus formed consisted of Capmul PG8 (propylene glycol monocaprylate) as oil, Cremophor EL (polyoxyl 35 castor oil) as surfactant, and hydrophilic polymer PEG 3350 as solid matrix. The drug (aqueous solubility: 0.17 microg/mL at pH 1-8 and 25 degrees C) was dissolved in a melt of the mixture at 65-70 degrees C and then the hot solution was filled into hard gelatin capsules; the liquid gradually solidified upon cooling below 55 degrees C. The solid system was characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), confocal Raman microscopy (CRM), and the dispersion testing in water. It was confirmed that a solid microemulsion preconcentrate is a two-phase system, where clusters of crystalline PEG 3350 formed the solid structure (m.p. 55-60 degrees C) and the liquid microemulsion preconcentrate dispersed in between PEG 3350 crystals as a separate phase. The drug remained dissolved in the liquid phase. In vitro release testing showed that the preconcentrate dispersed readily in water forming a microemulsion with the drug dissolved in the oil particles (<150 nm) and the presence of PEG 3350 did not interfere with the process of self-microemulsification.

Microemulsions for oral delivery of insulin: design, development and evaluation in streptozotocin induced diabetic rats.

PubMed

Sharma, G; Wilson, K; van der Walle, C F; Sattar, N; Petrie, J R; Ravi Kumar, M N V

2010-10-01

Insulin loaded microemulsions were developed adopting a low shear reverse micellar approach using didoceyldimethylammonium bromide (DMAB) as the surfactant, propylene glycol (PG) as the co-surfactant, triacetin (TA) as the oil phase and insulin solution as the aqueous phase. A ternary phase diagram was constructed based on multiple cloud point titration to highlight the reverse micellar region. The droplet sizes of the microemulsions were 161.7±24.7nm with PDI of 0.447±0.076 and insulin entrapment of ∼85%. Transmission electron microscopy (TEM) revealed the spherical nature and size homogeneity of the microemulsion droplets. The conformational stability of the entrapped insulin within microemulsions was confirmed by fluorescence spectroscopy and circular dichroism. The microemulsions displayed a 10-fold enhancement in bioavailability compared with plain insulin solution administered per oral in healthy rats. The short-term in vivo efficacy in STZ induced diabetic rats provided the proof of concept by a modest glucose reduction at a dose of 20IU/kg. Together this preliminary data indicate the promise of microemulsions for oral delivery of insulin. Copyright © 2010 Elsevier B.V. All rights reserved.

Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

NASA Astrophysics Data System (ADS)

Acarali, Nil Baran; Bardakci, Melek; Tugrul, Nurcan; Derun, Emek Moroydor; Piskin, Sabriye

2013-06-01

The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120°C), cooling temperature (10-80°C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (1wt%-6wt%), and oleic acid (OA, 1wt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.

Preliminary investigation tests of novel antifungal topical aerosol

PubMed Central

Kapadia, Monali M.; Solanki, S. T.; Parmar, V.; Thosar, M. M.; Pancholi, S. S.

2012-01-01

Spray formulation can minimize pain and irritation experience during the application of conventional dosage forms. Econazole Nitrate is an active ingredient of the aerosol concentrate to be used for twice-daily application because of its long durability in the superficial layers of the fungal infected skin. The aim of this study is preliminary investigation of Econazole Nitrate spray by varying the concentrations of different constituents of the spray. The ratios of Propylene glycol (PG) and isopropyl myristate (IPM) were selected as independent variables in 22 full factorial designs, keeping the concentration of solvent, co-solvent and propellant LPG constant. Aerosol also contained Ethanol as solvent and Isopropyl alcohol as co-solvent. All ingredients of the aerosol were packaged in an aluminum container fitted with continuous-spray valves. Physical properties evaluated for the Econazole Nitrate spray included delivery rate, delivery amount, pressure, minimum fill, leakage, flammability, spray patterns, particle image and plume angle. Glass containers were used to study incompatibility between concentrate and propellant due to the ease of visible inspection. Isopropyl myristate at lower concentrate showed turbidity, while at high concentration it met the requirements for aerosol and produced Econazole Nitrate spray with expected characteristics. PMID:23066214

Phospholipids-embedded fully dilutable liquid nanostructures. Part 2: The role of sodium diclofenac.

PubMed

Amsalem, Orit; Aserin, Abraham; Garti, Nissim

2010-12-01

Complex pseudo-ternary phase diagrams based on sucrose monolaurate (SE), propylene glycol (PG), and phosphatidylcholine (PC) as the "surfactant phase"; triacetin (TA) and decaglycerol ester (10G1CC) as the "oil phase"; and water as the aqueous phase were constructed, into which we solubilized the water-insoluble drug (sodium diclofenac, Na-DFC). In our previous study we demonstrated that the solubilization of Na-DFC in the oil+surfactant phases (prior to diluting it with water), was 90-fold greater than its dissolution in water, and that the system was pH-dependent. The greatest Na-DFC solubilization capacity was obtained at pH 7.2. In this study we examined the effect of the solubilization of Na-DFC in a phosphatidylcholine system using DLS, viscosity, electrical conductivity, SAXS, SD-NMR, and cryo-TEM measurements. It was found that: (1) the system remains micellar after aqueous dilution but with greater polydispersity and greater variety of shapes. We concluded that the structures in the absence of water (but in the presence of PG) were of direct spherical micelles (∼4 nm) mixed with elongated cylindrical micelles (12-140 nm); (2) the aqueous dilution causes fragmentation of the cylinders into smaller spherical micelles; (3) solubilization of Na-DFC behaving like a kosmotropic agent or "structure maker" yields mostly spherical swollen micelles and more ordered systems than in its absence; and (4) Na-DFC is solubilized at the interface of the micelles without swelling the droplets. Copyright © 2010 Elsevier B.V. All rights reserved.

Development and optimization of a new processing approach for manufacturing topical liposomes-in-hydrogel drug formulations by dual asymmetric centrifugation.

PubMed

Ingebrigtsen, Sveinung G; Škalko-Basnet, Nataša; Holsæter, Ann Mari

2016-09-01

The objective of the present study was to utilize dual asymmetric centrifugation (DAC) as a novel processing approach for the production of liposomes-in-hydrogel formulations. Lipid films of phosphatidylcholine, with and without chloramphenicol (CAM), were hydrated and homogenized by DAC to produce liposomes in the form of vesicular phospholipid gels with a diameter in the size range of 200-300 nm suitable for drug delivery to the skin. Different homogenization processing parameters were investigated along with the effect of adding propylene glycol (PG) to the formulations prior to homogenization. The produced liposomes were incorporated into a hydrogel made of 2.5% (v/v) soluble β-1,3/1,6-glucan (SBG) and mixed by DAC to achieve a homogenous liposomes-in-hydrogel-formulation suitable for topical application. CAM-containing liposomes with a vesicle diameter of 282 ± 30 nm and polydispersity index (PI) of 0.13 ± 0.02 were successfully produced by DAC after 50 min centrifugation at 3500 rpm, and homogenously (< 4% content variation) incorporated into the SBG hydrogel. Addition of PG decreased the necessary centrifugation time to 2 min and 55 s, producing liposomes of 230 ± 51 nm and PI of 0.25 ± 0.04. All formulations had an entrapment efficiency of approximately 50%. We managed to develop a relatively fast and reproducible new method for the production of liposomes-in-hydrogel formulations by DAC.

In vitro human epidermal permeation of nicotine from electronic cigarette refill liquids and implications for dermal exposure assessment.

PubMed

Frasch, H Frederick; Barbero, Ana M

2017-11-01

Nicotine plus flavorings in a propylene glycol (PG) vehicle are the components of electronic cigarette liquids (e-liquids), which are vaporized and inhaled by the user. Dermal exposure to nicotine and e-liquids may occur among workers in mixing and filling of e-cigarettes in the manufacturing process. Inadvertent skin contact among consumers is also a concern. In vitro nicotine permeation studies using heat-separated human epidermis were performed with surrogate and two commercial e-liquids, neat and aqueous nicotine donor formulations. Steady-state fluxes (J ss ), and lag times (t lag ) were measured for each formulation. In addition, transient (4 h) exposure and finite dose (1-10 μl/cm 2 ) experiments were undertaken using one commercial e-liquid. Average J ss (μg/cm 2 /h) from formulations were: nicotine in PG (24 mg/ml): 3.97; commercial e-liquid containing menthol (25 mg/ml nicotine): 10.2; commercial e-liquid containing limonene (25 mg/ml nicotine): 23.7; neat nicotine: 175. E-liquid lag times ranged from 5 to 10 h. Absorbed fraction of nicotine from finite doses was ≈0.3 at 48 h. The data were applied to transient exposure and finite dose dermal exposure assessment models and to a simple pharmacokinetic model. Three illustrative exposure scenarios demonstrate use of the data to predict systemic uptake and plasma concentrations from dermal exposure. The data demonstrate the potential for significant nicotine absorption through skin contact with e-cigarette refill solutions and the neat nicotine used to mix them.

Do electronic cigarettes impart a lower potential disease burden than conventional tobacco cigarettes? Review on E-cigarette vapor versus tobacco smoke.

PubMed

Oh, Anne Y; Kacker, Ashutosh

2014-12-01

Development and utilization of electronic cigarettes (ECs) resulted from the search for healthier alternatives to conventional tobacco cigarettes (TCs) and the search for alternative methods for quitting TCs. This review compares the potential disease burden presented by TC smoke to that of EC vapor. Potential disease burden of EC vapor versus TC smoke was assessed by reviewing clinical studies that measured inhaled components. Chemicals and carcinogens produced by vapor versus smoke were compared. Studies show that EC vapors contain far less carcinogenic particles than TC smoke. Whereas ECs have the ability to reach peak serum cotinine/nicotine levels comparable to that of TCs, ECs do not cause an increase in total white blood cell count; thus, ECs have the potential to lower the risk of atherosclerosis and systemic inflammation. Use of ECs has been shown to improve indoor air quality in a home exposed to TC smoke. This reduces secondhand smoke exposure, thus having the potential to decrease respiratory illness/asthma, middle-ear disease, sudden infant death syndrome, and more. However, some studies claim that propylene glycol (PG) vapor can induce respiratory irritation and increase chances for asthma. To minimize risks, EC manufacturers are replacing PG with distilled water and glycerin for vapor production. Based on the comparison of the chemical analysis of EC and TC carcinogenic profiles and association with health-indicating parameters, ECs impart a lower potential disease burden than conventional TCs. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

21 CFR 177.1680 - Polyurethane resins.

Code of Federal Regulations, 2012 CFR

2012-04-01

...′,α″-1,2,3-Propanetriyltris [omega-hydroxypoly (oxypropylene) (15-18 moles)], average molecular weight 3,000. Propylene glycol. α,α′,α″-[Propylidynetris (methylene)] tris [omega-hydroxypoly (oxypropylene) (minimum 1.5 moles)], minimum molecular weight 400. α-[ρ(1,1,3,3-Tetramethylbutyl) - phenyl]-omega...

21 CFR 177.1680 - Polyurethane resins.

Code of Federal Regulations, 2011 CFR

2011-04-01

...′,α″-1,2,3-Propanetriyltris [omega-hydroxypoly (oxypropylene) (15-18 moles)], average molecular weight 3,000. Propylene glycol. α,α′,α″-[Propylidynetris (methylene)] tris [omega-hydroxypoly (oxypropylene) (minimum 1.5 moles)], minimum molecular weight 400. α-[ρ(1,1,3,3-Tetramethylbutyl) - phenyl]-omega...

21 CFR 177.1680 - Polyurethane resins.

Code of Federal Regulations, 2010 CFR

2010-04-01

...′,α″-1,2,3-Propanetriyltris [omega-hydroxypoly (oxypropylene) (15-18 moles)], average molecular weight 3,000. Propylene glycol. α,α′,α″-[Propylidynetris (methylene)] tris [omega-hydroxypoly (oxypropylene) (minimum 1.5 moles)], minimum molecular weight 400. α-[ρ(1,1,3,3-Tetramethylbutyl) - phenyl]-omega...

21 CFR 177.1680 - Polyurethane resins.

Code of Federal Regulations, 2013 CFR

2013-04-01

...′,α″-1,2,3-Propanetriyltris [omega-hydroxypoly (oxypropylene) (15-18 moles)], average molecular weight 3,000. Propylene glycol. α,α′,α″-[Propylidynetris (methylene)] tris [omega-hydroxypoly (oxypropylene) (minimum 1.5 moles)], minimum molecular weight 400. α-[ρ(1,1,3,3-Tetramethylbutyl) - phenyl]-omega...

21 CFR 522.234 - Butamisole hydrochloride.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Butamisole hydrochloride. 522.234 Section 522.234 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... a solution consisting of 70 percent propylene glycol, 4 percent benzyl alcohol and distilled water...

Toxicologic evaluation of humectants added to cigarette tobacco: 13-week smoke inhalation study of glycerin and propylene glycol in Fischer 344 rats.

PubMed

Heck, J Daniel; Gaworski, Charles L; Rajendran, Narayanan; Morrissey, Robert L

2002-11-01

Glycerin (CAS no. 56-81-5) and propylene glycol (CAS no. 57-55-6) are commonly used as humectant ingredients in manufactured cigarettes to control and maintain the moisture content of the cut tobacco filler. The potential of these added humectants to affect the toxicity of cigarette smoke was investigated in a subchronic nose-only smoke inhalation study in rats. Filtered test cigarettes were prepared from an American-style tobacco blend containing either glycerin added at 5.1% w/w tobacco, propylene glycol at 2.2% w/w tobacco, or combinations of these humectants totaling 2.3%, 3.9%, and 7.2% w/w tobacco. Other groups of animals were exposed similarly to the smoke of reference cigarettes without added humectants, or to filtered air (sham control). Smoke exposures were conducted for 1 h/day, 5 days/wk for 13 wk, at target smoke particulate concentrations of 350 mg/m(3). All smoke-exposed groups had equivalent increases in blood carboxyhemoglobin, serum nicotine, and serum cotinine relative to the air controls. Smoke-associated reductions in body weights and occasional increases in heart and lung weights were generally similar among the various exposure conditions at necropsy. Increases in serum alkaline phosphatase and decreases in serum glucose and cholesterol were observed among smoke-exposed females relative to air controls. However, no significant differences in these parameters were evident between the humectant-containing and reference cigarette smoke exposure groups. Assessments of respiration conducted after 3, 6, 9, and 12 wk of smoke exposure indicated an initial smoke-related but not humectant-related decrease in respiratory rate, tidal volume, and minute volume during the first 20 min of each smoke exposure. Respiratory-tract histopathology was consistent across sexes and smoke groups, comprising (1) diffuse and focal alveolar pigmented macrophages and chronic interstitial inflammation in the lung, (2) laryngeal epithelial hyperplasia, squamous metaplasia, and scab formation, and (3) epithelial hyperplasia in the anterior nose. Smoke-related histopathology resolved substantially during a 6-wk postexposure recovery period. Addition of the tested humectants to cigarettes, singly or in combination, had no meaningful effect on the site, occurrence, or severity of respiratory-tract changes or on the measured indices of pulmonary function. It was concluded that the addition of glycerin and propylene glycol to cigarettes does not significantly affect the biological activity of inhaled cigarette smoke in this rat model.

Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes.

PubMed

St Helen, Gideon; Havel, Christopher; Dempsey, Delia A; Jacob, Peyton; Benowitz, Neal L

2016-03-01

To measure the systemic retention of nicotine, propylene glycol (PG) and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. E-cigarette users recruited over the internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several times after use. San Francisco, California, USA. Thirteen healthy, experienced adult e-cigarette users (six females and seven males). Plasma nicotine was analyzed by gas chromatography-mass spectrometry (GC-MS/MS) and nicotine, VG and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. E-cigarettes delivered an average of 1.33 (0.87-1.79) mg [mean and 95% confidence interval (CI)] of nicotine, and 93.8% of the inhaled dose, 1.22 (0.80-1.66) was systemically retained. Average maximum plasma nicotine concentration (Cmax ) was 8.4 (5.4-11.5) ng/ml and time of maximal concentration (Tmax ) was 2-5 minutes. One participant had Tmax of 30 minutes. 84.4% and 91.7% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 beats per minute after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarette users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. © 2015 Society for the Study of Addiction.

Determination of Chemical Compounds Generated from Second-generation E-cigarettes Using a Sorbent Cartridge Followed by a Two-step Elution Method.

PubMed

Uchiyama, Shigehisa; Senoo, Yui; Hayashida, Hideki; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

2016-01-01

We developed an analytical method for analyzing electronic cigarette (E-cigarette) smoke, and measured the carbonyl compounds and volatile organic compounds generated by 10 brands of second-generation E-cigarettes. A glass filter (Cambridge filter pad) for particulate matter and a solid sorbent tube packed with Carboxen-572 for gaseous compounds were used to collect E-cigarette smoke. These were then analyzed using a two-step elution method with carbon disulfide and methanol, followed by high-performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC/MS). Formaldehyde (FA), acetaldehyde (AA), acetone (AC), acrolein (ACR), propanal (PA), acetol (AT), glyoxal (GO), and methyl glyoxal (MGO) were detected by HPLC in some E-cigarettes. Propylene glycol (PG), glycerol (GLY), and some esters were detected by GC/MS. GO and MGO exist mainly as particulate matter. AA, AC, ACR, PA, and AT exist mainly as gaseous compounds. FA exists as both particulate matter and gaseous compounds. These carbonyl compounds have carbon numbers C1 - C3. The main components of E-liquid are PG (C3) and GLY (C3). Therefore, the oxidation of liquids, such as PG and GLY in E-cigarettes upon incidental contact with the heating element in E-cigarette, is suggested as being a possible cause for carbonyl generation. When the puff number exceeds a critical point, carbonyl generation rapidly increases and then remains constant. The results of this study are now being used to determine the following E-cigarette smoking protocol: puff volume, 55 mL; puff duration, 2 s; and puff number, 30. E-cigarette analysis revealed very large variation in carbonyl concentration among not only different brands, but also different samples of the same product. Typical distributions of carbonyl concentration were not observed in any of the E-cigarettes tested, and the mean values greatly differed from median values.

Poly(ethylene oxide monomethyl ether)- block-poly(propylene succinate) Nanoparticles: Synthesis and Characterization, Enzymatic and Cellular Degradation, Micellar Solubilization of Paclitaxel, and in Vitro and in Vivo Evaluation.

PubMed

Jäger, Alessandro; Jäger, Eliézer; Syrová, Zdeňka; Mazel, Tomas; Kováčik, Lubomír; Raška, Ivan; Höcherl, Anita; Kučka, Jan; Konefal, Rafal; Humajova, Jana; Poučková, Pavla; Štěpánek, Petr; Hrubý, Martin

2018-04-11

Polyester-based nanostructures are widely studied as drug-delivery systems due to their biocompatibility and biodegradability. They are already used in the clinic. In this work, we describe a new and simple biodegradable and biocompatible system as the Food and Drug Administration approved polyesters (poly-ε-caprolactone, polylactic acid, and poly(lactic- co-glycolic acid)) for the delivery of the anticancer drug paclitaxel (PTX) as a model drug. A hydrophobic polyester, poly(propylene succinate) (PPS), was prepared from a nontoxic alcohol (propylene glycol) and monomer from the Krebs's cycle (succinic acid) in two steps via esterification and melt polycondensation. Furthermore, their amphiphilic block copolyester, poly(ethylene oxide monomethyl ether)- block-poly(propylene succinate) (mPEO- b-PPS), was prepared by three steps via esterification followed by melt polycondensation and the addition of mPEO to the PPS macromolecules. Analysis of the in vitro cellular behavior of the prepared nanoparticle carriers (NPs) (enzymatic degradation, uptake, localization, and fluorescence resonance energy-transfer pair degradation studies) was performed by fluorescence studies. PTX was loaded to the NPs of variable sizes (30, 70, and 150 nm), and their in vitro release was evaluated in different cell models and compared with commercial PTX formulations. The mPEO- b-PPS copolymer analysis displays glass transition temperature < body temperature < melting temperature, lower toxicity (including the toxicity of their degradation products), drug solubilization efficacy, stability against spontaneous hydrolysis during transport in bloodstream, and simultaneous enzymatic degradability after uptake into the cells. The detailed cytotoxicity in vitro and in vivo tumor efficacy studies have shown the superior efficacy of the NPs compared with PTX and PTX commercial formulations.

Determination of ethylene oxide, ethylene chlorohydrin, and ethylene glycol in aqueous solutions and ethylene oxide residues in associated plastics.

PubMed

Ball, N A

1984-09-01

A gas chromatographic (GC) method was developed for the determination of ethylene oxide and its two reaction products, ethylene chlorohydrin and ethylene glycol, in aqueous ophthalmic solutions. Propylene oxide was used as an internal standard. All three components were determined in one isothermal chromatographic analysis in less than 15 min. An extraction method for the determination of ethylene oxide residues in plastic components was also developed, and certain plastics with different ethylene oxide retention characteristics were identified.

21 CFR 177.1680 - Polyurethane resins.

Code of Federal Regulations, 2014 CFR

2014-04-01

...′-(Isopropylidenedi-p-phenylene)bis[omega-hydroxypoly (oxy-pro-pylene)(3-4 moles)], average molecular weight 675... propylene oxide). Polypropylene glycol. α,α′,α″-1,2,3-Propanetriyltris [omega-hydroxypoly (oxypropylene) (15...)] tris [omega-hydroxypoly (oxypropylene) (minimum 1.5 moles)], minimum molecular weight 400. α-[ρ(1,1,3,3...

BIODEGRADATION OF PROPYLENE GLYCOL AND ASSOCIATED HYDRODYNAMIC EFFECTS IN SAND: 1. CONTINUOUS LOADING. (R825549C063)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Effect of two treatment protocols for ketosis on the resolution, postpartum health, milk yield, and reproductive outcomes of dairy cows.

PubMed

Jeong, Jae-Kwan; Choi, In-Soo; Moon, Sung-Ho; Lee, Soo-Chan; Kang, Hyun-Gu; Jung, Young-Hun; Park, Soo-Bong; Kim, Ill-Hwa

2018-01-15

We determined the effect of ketosis treatment with propylene glycol (PG) or PG plus l-carnitine and methionine (Metabolase ® , Fatro, Bologna, Italy) on the resolution, postpartum health, milk yield, and reproductive performances of dairy cows. Blood from 475 Holstein cows was collected weekly until 4 weeks after calving to measure blood β-hydroxybutyrate (BHBA) concentrations. Cows with blood BHBA concentration ≥1.2 mmol/L were diagnosed with ketosis and were enrolled. One hundred and fifty cows diagnosed with ketosis were randomly assigned to three treatment groups (Day 0): (1) PG (300 g, PO) for 3 days (PG group, n = 50), (2) PG (300 g, PO) plus l-carnitine (1.25 g) plus methionine (5 g, IV) for 3 days (PG + CM group, n = 50), and (3) no treatment (control group, n = 50). On Day 3, blood was collected to evaluate whether the ketosis had resolved. Cows in the PG and PG + CM groups with blood BHBA ≥1.2 mmol/L were retreated for an additional 2 days, and then blood BHBA concentration was evaluated on Days 5 and 10. Blood glucose and haptoglobin concentrations, rumen fill score (RFS), and body condition score (BCS) were measured on Days 0, 3, 5, and 10. Postpartum complications, milk yield during the first 2 months, and reproductive outcomes were evaluated. The probability of resolution from ketosis was higher (P < 0.05) in the PG + CM group than in the control group on Days 3, 5, and 10 (odds ratio: 2.6-6.3). Blood BHBA in the PG + CM group was lower (P < 0.05) than that of the control group on Days 3 and 5, whereas blood glucose in the PG + CM group was higher (P < 0.05) than that of the control group on Days 3 and 5. RFS in the PG and PG + CM groups was higher than that of the control group on Day 10 (P < 0.01), while BCS loss from Day 0-10 in the control group was higher than those of the PG and PG + CM groups (P < 0.05). Milk yields on the 30th and 60th days postpartum were higher in the PG + CM group than the control and PG groups (P < 0.05). Postpartum complications and intervals between calving and first postpartum insemination or pregnancy did not differ among the groups (P > 0.05). In conclusion, treatment of dairy cows with PG plus l-carnitine and methionine improved the chances of resolution of ketosis and increased milk yield, while affecting neither the incidence of postpartum complications nor reproductive performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Biodegradation of Ethylene Glycol by a Salt-Requiring Bacterium1

PubMed Central

Gonzalez, Carlos F.; Taber, Willard A.; Zeitoun, M. A.

1972-01-01

A gram-negative nonmotile rod which was capable of using 1,2-14C-ethylene glycol as a sole carbon source for growth was isolated from a brine pond, Great Salt Lake, Utah. The bacterium (ATCC 27042) required at least 0.85% NaCl for growth and, although the chloride ion was replaceable by sulfate ion, the sodium ion was not replaceable by potassium ion. The maximal concentration of salt tolerated for growth was approximately 12%. The bacterium was oxidase-negative when N,N-dimethyl-p-phenylenediamine was used and weakly positive when N,N,N′,N′-tetramethyl-p-phenylenediamine was used. It grows on many sugars but does not ferment them, it does not have an exogenous vitamin requirement, and it possesses a guanine plus cytosine ratio of 64.3%. Incorporation of ethylene glycol carbon into cell and respired CO2 was quantitated by use of radioactive ethylene glycol and a force-aerated fermentor. Glucose suppressed ethylene glycol metabolism. Cells grown on ethylene and propylene glycol respired ethylene glycol in a Warburg respirometer more rapidly than cells grown on glucose. Spectrophotometric evidence was obtained for oxidation of glycolate to glyoxylate by a dialyzed cell extract. PMID:4568254

Determination of glycols in air: development of sampling and analytical methodology and application to theatrical smokes.

PubMed

Pendergrass, S M

1999-01-01

Glycol-based fluids are used in the production of theatrical smokes in theaters, concerts, and other stage productions. The fluids are heated and dispersed in aerosol form to create the effect of a smoke, mist, or fog. There have been reports of adverse health effects such as respiratory irritation, chest tightness, shortness of breath, asthma, and skin rashes. Previous attempts to collect and quantify the aerosolized glycols used in fogging agents have been plagued by inconsistent results, both in the efficiency of collection and in the chromatographic analysis of the glycol components. The development of improved sampling and analytical methodology for aerosolized glycols was required to assess workplace exposures more effectively. An Occupational Safety and Health Administration versatile sampler tube was selected for the collection of ethylene glycol, propylene glycol, 1,3-butylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol aerosols. Analytical methodology for the separation, identification, and quantitation of the six glycols using gas chromatography/flame ionization detection is described. Limits of detection of the glycol analytes ranged from 7 to 16 micrograms/sample. Desorption efficiencies for all glycol compounds were determined over the range of study and averaged greater than 90%. Storage stability results were acceptable after 28 days for all analytes except ethylene glycol, which was stable at ambient temperature for 14 days. Based on the results of this study, the new glycol method was published in the NIOSH Manual of Analytical Methods.

40 CFR 721.10185 - 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3...

Code of Federal Regulations, 2010 CFR

2010-07-01

...)-, polymers with 5-isocyanato-1- (isocyanatomethyl)-1,3,3-trimethylcyclohexane, propylene glycol and reduced...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10185 1,2-Propanediol, 3-(diethylamino)-, polymers with 5-isocyanato-1...

Chemical additive to maximize antimicrobial effect of chlorine during pilot scale immersion chilling of broiler carcasses

USDA-ARS?s Scientific Manuscript database

A prior laboratory scale study demonstrated the potential for T-128, a proprietary blend including propylene glycol and phosphoric acid, to enhance the antimicrobial efficacy of chlorine during immersion chilling of broiler parts. The objective of the current study was to test the addition of T-128...

Interaction and formation mechanism of binary complex between zein and propylene glycol alginate.

PubMed

Sun, Cuixia; Dai, Lei; Gao, Yanxiang

2017-02-10

The anti-solvent co-precipitation method was used to fabricate the zein-propylene glycol alginate (PGA) binary complex with different mass ratios of zein to PGA (20:1, 10:1, 5:1, 2:1 and 1:1) at pH 4.0. Results showed that attractive electrostatic interaction between zein and PGA occurred and negatively charged binary complex with large size and high turbidity was formed due to the charge neutralization. Hydrogen bonding and hydrophobic effects were involved in the interactions between zein and PGA, leading to the changed secondary structure and improved thermal stability of zein. Aggregates in the irregular shape with large size were obviously observed in the AFM images. PGA alone exhibited a fine filamentous network structure, while zein-PGA binary complex showed a rough branch-like pattern and the surface of "branch" was closely adsorbed by lots of spherical zein particles. Q in zein-PGA binary complex dispersions presented the improved photochemical and thermal stability. The potential mechanism of a two-step process was proposed to explain the formation of zein-PGA binary complexes. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of materials selection on metals reduction in propylene glycol methyl ether acetate, PGMEA

NASA Astrophysics Data System (ADS)

Entezarian, Majid; Geiger, Bob

2016-03-01

The trend in microelectronics fabrication is to produce nano-features measuring down to 10 nm and finer. The PPT levels of organic and inorganic contaminants in the photoresist, solvent and cleaning solutions are becoming a major processing variable affecting the process capability and defectivity. The photoresist usually contains gels, metals, and particulates that could interfere with the lithography process and cause microbridging defects. Nano filters of 5 nm polypropylene, 5 nm polyethylene, and 10 nm natural nylon were used to filter propylene glycol methyl ether acetate PGMEA containing 50 ppb of Na, Mg, Al, Ca, Cr, Mn, Fe, Cu, Zn, and Pb. All filters were effective in removing trivalent Al, Cr, and Fe metals indicating the mechanism for their removal as mechanical sieving. However, the nylon was also very effective in removing the divalent metals showing adsorptive properties. Furthermore, the metal removal of the nylon membrane was studied as a function of surface chemistry. Natural and charged 40 nm nylon membranes were tested and found that charged nylon is more effective for metal removal.

An investigation of bubble coalescence and post-rupture oscillation in non-ionic surfactant solutions using high-speed cinematography.

PubMed

Bournival, G; Ata, S; Karakashev, S I; Jameson, G J

2014-01-15

Most processes involving bubbling in a liquid require small bubbles to maximise mass/energy transfer. A common method to prevent bubbles from coalescing is by the addition of surfactants. In order to get an insight into the coalescence process, capillary bubbles were observed using a high speed cinematography. Experiments were performed in solutions of 1-pentanol, 4-methyl-2-pentanol, tri(propylene glycol) methyl ether, and poly(propylene glycol) for which information such as the coalescence time and the deformation of the resultant bubble upon coalescence was extracted. It is shown in this study that the coalescence time increases with surfactant concentration until the appearance of a plateau. The increase in coalescence time with surfactant concentration could not be attributed only to surface elasticity. The oscillation of the resultant bubble was characterised by the damping of the oscillation. The results suggested that a minimum elasticity is required to achieve an increased damping and considerable diffusion has a detrimental effect on the dynamic response of the bubble, thereby reducing the damping. Copyright © 2013 Elsevier Inc. All rights reserved.

Dynamics and acoustics of a cavitating Venturi flow using a homogeneous air-propylene glycol mixture

NASA Astrophysics Data System (ADS)

Navarrete, M.; Naude, J.; Mendez, F.; Godínez, F. A.

2015-12-01

Dynamics and acoustics generated in a cavitating Venturi tube are followed up as a function of the input power of a centrifugal pump. The pump of 5 hp with a modified impeller to produce uniform bubbly flow, pumps 70 liters of propylene glycol in a closed loop (with a water cooling system), in which the Venturi is arranged. The goal was to obtain correlations among acoustical emission, dynamics of the shock waves and the light emission from cavitation bubbles. The instrumentation includes: two piezoelectric transducers, a digital camera, a high-speed video camera, and photomultipliers. As results, we show the cavitation patterns as function of the pump power, and a graphical template of the distribution of the Venturi conditions as a function of the cavitation parameter. Our observations show for the first time the sudden formation of bubble clouds in the straight portion of the pipe after the diverging section of the Venturi. We assume that this is due to pre-existing of nuclei-cloud structures which suddenly grow up by the tensile tails of propagating shock waves (producing a sudden drop in pressure).

Enhancement of committed hematopoietic stem cell colony formation by nandrolone decanoate after sublethal whole body irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallicchio, V.S.; Chen, M.G.; Watts, T.D.

1984-11-01

The ability of an anabolic steroid, nandrolone decanoate, to increase committed topoietic stem cell (CFU-gm, CFU-e, and BFU-e) colony formation after sublethal irradiation was evaluated. Immediately after receiving whole body irradiation and on the next two days, each mouse was injected intraperitoneally with nandrolone decanoate (1.25 mg) in propylene glycol. Irradiated control mice received only propylene glycol. Compared to controls, drug-treated mice showed marked peripheral blood leukocytosis and more stable packed red cell volume. Drug-treated mice also demonstrated increased erythropoiesis, as CFU-e/BFU-e concentrations from both marrow (9% to 581%) and spleen (15% to 797%) were elevated. Granulopoiesis was increased similarly,more » as CFU-gm concentrations from marrow (38% to 685%) and spleen (9% to 373%) were elevated. These results demonstrate that nandrolone decanoate enhances hematopoietic stem cell recovery after sublethal whole body irradiation. This suggests that following hematopoietic suppression, nandrolone decanoate may stimulate the recovery of hematopoiesis at the stem cell level and in peripheral blood.« less

Reducing surface tension in endodontic chelator solutions has no effect on their ability to remove calcium from instrumented root canals.

PubMed

Zehnder, Matthias; Schicht, Olivier; Sener, Beatrice; Schmidlin, Patrick

2005-08-01

The aim of this study was to evaluate the effect of reducing surface tension in endodontic chelator solutions on their ability to remove calcium from instrumented root canals. Aqueous solutions containing 15.5% EDTA, 10% citric acid, or 18% 1- hydroxyethylidene-1, 1-bisphosphonate (HEBP) were prepared with and without 1% (wt/wt) polysorbate (Tween) 80 and 9% propylene glycol. Surface tension in these solutions was measured using the Wilhelmy method. Sixty-four extracted, single-rooted human teeth of similar length were instrumented and irrigated with a 1% sodium hypochlorite solution and then randomly assigned (n = 8 per group) to receive a final one-minute rinse with 5 ml of test solutions, water, or the pure aqueous Tween/propylene glycol solution. Calcium concentration in eluates was measured using atomic absorption spectrometry. Incorporation of wetting agents resulted in a reduction of surface tension values by approximately 50% in all tested solutions. However, none of the solutions with reduced surface tension chelated more calcium from canals than their pure counterparts (p > 0.05).

Direct estimation of the permeation of topical excipients through artificial membranes and human skin with non-invasive Terahertz time-domain techniques.

PubMed

Lopez-Dominguez, Victor; Boix-Montañes, Antoni; Redo-Sanchez, Albert; Tejada-Palacios, Javier

2016-07-01

Drug permeation through skin, or a synthetic membrane, from locally acting pharmaceutical products can be influenced by the permeation behaviour of pharmaceutical excipients. Terahertz time-domain technology is investigated as a non-invasive method for a direct and accurate measurement of excipients permeation through synthetic membranes or human skin. A series of in-vitro release and skin permeation experiments of liquid excipients (e.g. propylene glycol and polyethylene glycol 400) has been conducted with vertical diffusion cells. The permeation profiles of excipients through different synthetic membranes or skin were obtained using Terahertz pulses providing a direct measurement. Corresponding permeation flux and permeability coefficient values were calculated based on temporal changes of the terahertz pulses. The influence of different experimental conditions, such as the polarity of the membrane and the viscosity of the permeant, was assessed in release experiments. Specific transmembrane flux values of those excipients were directly calculated with statistical differences between cases. Finally, an attempt to estimate the skin permeation of propylene glycol with this technique was also achieved. All these permeation results were likely comparable to those obtained by other authors with usual analytical techniques. Terahertz time-domain technology is shown to be a suitable technique for an accurate and non-destructive measurement of the permeation of liquid substances through different synthetic membranes or even human skin. © 2016 Royal Pharmaceutical Society.

In vitro terahertz monitoring of muscle tissue dehydration under the action of hyperosmotic agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolesnikov, A S; Kolesnikova, E A; Popov, A P

2014-07-31

Dehydration of muscle tissue in vitro under the action of biologically compatible hyperosmotic agents is studied using a laser terahertz spectrometer in the frequency range from 0.25 to 2.5 THz. Broadband terahertz absorption and reflection spectra of the bovine skeletal muscle tissue were obtained under the action of glycerol, polyethylene glycol with the molecular weight 600 (PEG-600), and propylene glycol. The presented results are proposed for application in developing the methods of image contrast enhancement and increasing the depth of biological tissue probing with terahertz radiation. (laser biophotonics)

ESR lineshape and {sup 1}H spin-lattice relaxation dispersion in propylene glycol solutions of nitroxide radicals – Joint analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruk, D., E-mail: danuta.kruk@matman.uwm.edu.pl; Hoffmann, S. K.; Goslar, J.

2013-12-28

Electron Spin Resonance (ESR) spectroscopy and Nuclear Magnetic Relaxation Dispersion (NMRD) experiments are reported for propylene glycol solutions of the nitroxide radical: 4-oxo-TEMPO-d{sub 16} containing {sup 15}N and {sup 14}N isotopes. The NMRD experiments refer to {sup 1}H spin-lattice relaxation measurements in a broad frequency range (10 kHz–20 MHz). A joint analysis of the ESR and NMRD data is performed. The ESR lineshapes give access to the nitrogen hyperfine tensor components and the rotational correlation time of the paramagnetic molecule. The NMRD data are interpreted in terms of the theory of paramagnetic relaxation enhancement in solutions of nitroxide radicals, recentlymore » presented by Kruk et al. [J. Chem. Phys. 138, 124506 (2013)]. The theory includes the effect of the electron spin relaxation on the {sup 1}H relaxation of the solvent. The {sup 1}H relaxation is caused by dipole-dipole interactions between the electron spin of the radical and the proton spins of the solvent molecules. These interactions are modulated by three dynamic processes: relative translational dynamics of the involved molecules, molecular rotation, and electron spin relaxation. The sensitivity to rotation originates from the non-central positions of the interacting spin in the molecules. The electronic relaxation is assumed to stem from the electron spin–nitrogen spin hyperfine coupling, modulated by rotation of the radical molecule. For the interpretation of the NMRD data, we use the nitrogen hyperfine coupling tensor obtained from ESR and fit the other relevant parameters. The consistency of the unified analysis of ESR and NMRD, evaluated by the agreement between the rotational correlation times obtained from ESR and NMRD, respectively, and the agreement of the translation diffusion coefficients with literature values obtained for pure propylene glycol, is demonstrated to be satisfactory.« less

Improvement of post-thaw sperm survivals using liquid nitrogen vapor in a spermcasting oyster Ostrea angasi.

PubMed

Hassan, Md Mahbubul; Li, Xiaoxu; Qin, Jian G

2017-10-01

Low survival of cryopreserved sperm impedes the application of cryopreservation technique in spermcasting oyster species. This study developed a simple method of liquid nitrogen vapor freezing to improve post-thaw sperm survival in the spermcasting oyster Ostrea angasi. The results indicate that the permeable cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG) and propylene glycol (PG) were non-toxic to sperm up to 20% concentration and 90 min exposure whereas methanol at 10% or higher was toxic to sperm for any exposure over 30 min. Among the treatments with permeable cryoprotectants, 15% EG produced the highest post-thaw sperm motility. Sperm motility was further improved by the addition of non-permeable cryoprotectants (trehalose and glucose), with 15% EG + 0.2 M trehalose resulting in the highest post-thaw sperm motility among all the combinations evaluated. The durations of 20, 30 and 60 min equilibrations produced a higher post-thaw sperm motility and plasma membrane integrity (PMI) than 10 min. Higher post-thaw motility and PMI were achieved by freezing sperm at the 8 cm height from the liquid nitrogen surface than at the 2, 4, 6, 10 or 12 cm height. Holding sperm for 10 min in liquid nitrogen vapor produced higher post-thaw motility and PMI than for 2, 5 or 20 min. The cryopreservation protocol developed in this study improved both post-thaw motility and PMI of O. angasi sperm at least 15% higher than those cryopreserved using programmable freezing method. Liquid nitrogen vapor freezing might have greater applicability in improving post-thaw sperm quality of spermcasting oyster species. Copyright © 2017 Elsevier Inc. All rights reserved.

Screening and Identification of Cryopreservative Agents for Human Cellular Biotechnology Experiments in Microgravity

NASA Technical Reports Server (NTRS)

Love,J.; Elliott, T.; Das, G. C.; Hammond, D. K.; Schwarzkopf, R. J.; Jones, L. B.; Baker, T. L.

2006-01-01

Dimethyl sulfoxide (DMSO) has been used as a standard cryopreservative agent for mammalian cell culture; however, prolonged exposure of thawed cells to DMSO can alter cell growth. While DMSO is easily eliminated in ground-based experiments, removal of DMSO in flight-based experiments is more difficult due to various on-orbit constraints. Failure of cryopreservation is due to a number of factors, including intracellular ice formation, solute effect, and apoptotic cell death following thawing. One objective of this study is to identify and characterize an alternative cryopreservative that could be used on the International Space Station (ISS). We systematically screened for potential permeating and non-permeating agents using a human colorectal carcinoma cell line, MIP-101. Cells were suspended in cryopreservation solution and frozen either following a two-step procedure involving initial cooling at -1 C/min overnight followed by storage in liquid nitrogen (LN2) vapor, or by freezing cells directly in the LN2 vapor phase at -10 C/min. Ability to preserve cellular function after one cycle of freeze-thawing was assessed by the recovery of viable cells in short and long-term cell culture experiments. Results showed that permeating preservatives glycerol (G) and ethylene glycol (EG) had an efficacy (80-110%) comparable to, if not better than, 7.5% DMSO; but, propylene glycol (PG) had a somewhat lesser efficacy. Among the non-permeating preservatives, trehalose, raffinose, and dextran exhibited significant protective effect (50-80%) relative to that offered by 7.5% DMSO, but at -10 C and not at -1 C/min cooling rate. Preliminary data thus suggest that a combination of permeating and non-permeating agents may have improved efficacy as a cryoprotectant and serve as an alternate to DMSO for experimentation on ISS.

Evaluation of Propylene Glycol-Based Fluids for Constellation Habitats and Vehicles

NASA Technical Reports Server (NTRS)

Lee, Steve

2009-01-01

Two fluid life tests have been conducted to evaluate propylene glycol-based fluids for use in Constellation habitats and vehicles. The first test was conducted from November 2008 to January 2009 to help determine the compatibility of the propylene glycol-based fluid selected for Orion at the time. When the first test uncovered problems with the fluid selection, an investigation and selection of a new fluid were conducted. A second test was started in March 2010 to evaluate the new selection. For the first test, the fluid was subjected to a thermal fluid loop that had flight-like properties, as compared to Orion. The fluid loop had similar wetted materials, temperatures, flow rates, and aluminum wetted surface area to fluid volume ratio. The test was designed to last for 10 years, the life expectancy of the lunar habitat. However, the test lasted less than two months. System filters became clogged with precipitate, rendering the fluid system inoperable. Upon examination of the precipitate, it was determined that the precipitate composition contained aluminum, which could have only come from materials in the test stand, as aluminum is not part of the original fluid composition. Also, the fluid pH was determined to have increased from 10.1, at the first test sample, to 12.2, at the completion of the test. This high of a pH is corrosive to aluminum and was certainly a contributing factor to the development of precipitate. Due to the problems encountered during this test, the fluid was rejected as a coolant candidate for Orion. A new propylene glycol-based fluid was selected by the Orion project for use in the Orion vehicle. The Orion project has conducted a series of screening tests to help verify that there will be no problems with the new fluid selection. To compliment testing performed by the Orion project team, a new life test was developed to test the new fluid. The new test bed was similar to the original test bed, but with some improvements based on experience gained from the earlier test bed. The surface area of both aluminum and nickel in the test bed were designed to be similar to that of the Orion fluid loop, since the Orion fluid loop was expected to have high concentrations of both metals in the system. Also, additional sample materials were added to the test bed to match recent updates to materials selections for Orion. At the time of this paper publication, approximately five months of testing will have been completed. This paper gives a status of the testing completed to date.

Effects of Δ9-THC and cannabidiol vapor inhalation in male and female rats.

PubMed

Javadi-Paydar, Mehrak; Nguyen, Jacques D; Kerr, Tony M; Grant, Yanabel; Vandewater, Sophia A; Cole, Maury; Taffe, Michael A

2018-06-16

Previous studies report sex differences in some, but not all, responses to cannabinoids in rats. The majority of studies use parenteral injection; however, most human use is via smoke inhalation and, increasingly, vapor inhalation. To compare thermoregulatory and locomotor responses to inhaled ∆ 9 -tetrahydrocannabinol (THC), cannabidiol (CBD), and their combination using an e-cigarette-based model in male and female rats METHODS: Male and female Wistar rats were implanted with radiotelemetry devices for the assessment of body temperature and locomotor activity. Animals were then exposed to THC or CBD vapor using a propylene glycol (PG) vehicle. THC dose was adjusted via the concentration in the vehicle (12.5-200 mg/mL) and the CBD (100, 400 mg/mL) dose was also adjusted by varying the inhalation duration (10-40 min). Anti-nociception was evaluated using a tail-withdrawal assay following vapor inhalation. Plasma samples obtained following inhalation in different groups of rats were compared for THC content. THC inhalation reduced body temperature and increased tail-withdrawal latency in both sexes equivalently and in a concentration-dependent manner. Female temperature, activity, and tail-withdrawal responses to THC did not differ between estrus and diestrus. CBD inhalation alone induced modest hypothermia and suppressed locomotor activity in both males and females. Co-administration of THC with CBD, in a 1:4 ratio, significantly decreased temperature and activity in an approximately additive manner and to similar extent in each sex. Plasma THC varied with the concentration in the PG vehicle but did not differ across rat sex. In summary, the inhalation of THC or CBD, alone and in combination, produces approximately equivalent effects in male and female rats. This confirms the efficacy of the e-cigarette-based method of THC delivery in female rats.

Studying the effectiveness of penetration enhancers to deliver retinol through the stratum cornum by in vivo confocal Raman spectroscopy.

PubMed

Mélot, Mickaël; Pudney, Paul D A; Williamson, Ann-Marie; Caspers, Peter J; Van Der Pol, Andre; Puppels, Gerwin J

2009-08-19

The purpose of this study is to monitor in vivo the effect of chemical penetration enhancers on the delivery of trans-retinol into human skin. Chemical penetration enhancers reversibly alter barrier properties of the SC by disruption of the membrane structures or maximising drug solubility with the skin. So far, most of permeation or penetration experiments are performed in vitro. Raman spectroscopy is uniquely placed to be able to measure biological processes in vivo and this paper shows for the first time that the effect of penetration enhancer on the delivery of trans-retinol can successfully be measured in vivo using this technique. Here, the volar forearm of volunteers was treated with four formulations. One formulation is a highly effective model delivery system identified from ex vivo experiments: trans-retinol in Propylene Glycol (PG)/ethanol, with PG being a well-known and efficient penetration enhancer. The other three formulations are based on 0.3% trans-retinol in Caprylic/Capric Acid Triglyceride (MYRITOL 318), an oil commonly used in skin creams but in two of them a specific penetration enhancer is added. One contains a lipid extractor, Triton X 100, whereas another formulation contains a lipid fluidiser, Oleic Acid. Solutions were applied once and measurements were performed up to 6 h after treatment. Remarkable differences in the delivery of trans-retinol between formulation with or without penetration enhancer can clearly be seen. Moreover, the type of penetration enhancer is also shown to influence the delivery. While using the Oleic Acid, which is a lipid fluidiser, a better delivery of trans-retinol in the skin can be detected. For the first time, the effect of penetration enhancer on the delivery of trans-retinol has been monitored, non invasively in vivo, with time.

Effects of cryoprotectant agents and freezing protocol on motility of black-lip pearl oyster (Pinctada margaritifera L.) spermatozoa.

PubMed

Acosta-Salmón, Héctor; Jerry, Dean R; Southgate, Paul C

2007-02-01

Gamete cryopreservation techniques have been applied to several bivalve mollusc species. However, research activity in this area has primarily focused on cryopreserving gametes from edible oysters (Ostreiidae). Few studies have examined the effect of cryoprotectants and freezing protocols in the preservation of spermatozoa from cultured pearl oysters (Pteriidae). Pearl oyster producers are increasingly looking towards the development of improved family lines and, as a consequence, the ability to cryopreserve gametes would bring about significant benefits to the cultured pearl industry. In response to this need, we evaluated the effect of three cryoprotectant additives (CPA) on motility of spermatozoa from the black-lip pearl oyster, Pinctada margaritifera. These additives have previously been used to cryopreserve gametes of other bivalve species. The following CPA mixtures were evaluated: (1) 0.45M trehalose and 0, 0.64, 1.02 and 1.53 M dimethyl sulfoxide (Me(2)SO); (2) 0.2M glucose and 2M Me(2)SO and (3) 1.31 M propylene glycol (PG). The effects of four different freezing protocols on motility of P. margaritifera spermatozoa were also evaluated (slow, medium, medium-rapid and rapid cooling). This study showed that total motility was best retained when spermatozoa were cryopreserved in 0.45 M trehalose and 0, 0.64, 1.02 or 1.53 M Me(2)SO and frozen using slow to medium-rapid cooling rates (2.1-5.2 degrees Cmin(-1)). Rapid freezing through direct plunging of spermatozoa into liquid nitrogen resulted in the lowest overall retention of motility regardless of the CPA additive; however, CPA mixture also influenced retention of motility, with 0.2M glucose in 2M Me(2)SO and 1.31 M PG retaining the lowest levels of motility for the CPAs evaluated.

Non-Chromate Aluminum Pretreatments

DTIC Science & Technology

2012-03-01

2) Potassium permanganate, seal: polyacrylic acid, poly propylene glycol, fatty acid esters Two solution (coating and seal), elevated temp...OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for...reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of

Ex vivo study of transdermal permeation of four diclofenac salts from different vehicles.

PubMed

Minghetti, Paola; Cilurzo, Francesco; Casiraghi, Antonella; Montanari, Luisa; Fini, Adamo

2007-04-01

The ex vivo permeation of diclofenac was studied using four different salts (sodium, potassium, diethylamine, and epolamine) dissolved in four different solvents (water, propylene glycol (PG), Transcutol, and oleic acid (OA)) as donor phases through a human skin membrane. The four salts show different solubility values and different behavior in the four solvents, which are also permeation enhancers and this fact further is connected to the permeation results. The same order of magnitude of fluxes through the membrane as those previously reported for acidic diclofenac released from buffer solutions of pH >7 were found, taking into account differences originated by different membranes and other parameters tested in the experiments. Saturation concentration for the four salts in different solvents, necessary to calculate permeation coefficients, was critically evaluated; a short discussion made it possible to explain that corrections in the solubility values must be considered, related to the complex behavior in solution of these salts. Statistical processing of the experimental data suggests that differences between the four salts in promoting absorption of the drug is unproven; while differences are evident between the solvents, water is the most effective enhancing vehicle. Aqueous formulations containing diclofenac salt with an organic base appear to be the best combination to promote permeation in topical applications. (c) 2007 Wiley-Liss, Inc.

Preparation and evaluation of miconazole nitrate-loaded solid lipid nanoparticles for topical delivery.

PubMed

Bhalekar, Mangesh R; Pokharkar, Varsha; Madgulkar, Ashwini; Patil, Nilam; Patil, Nilkanth

2009-01-01

The purpose of this study was to prepare miconazole nitrate (MN) loaded solid lipid nanoparticles (MN-SLN) effective for topical delivery of miconazole nitrate. Compritol 888 ATO as lipid, propylene glycol (PG) to increase drug solubility in lipid, tween 80, and glyceryl monostearate were used as the surfactants to stabilize SLN dispersion in the SLN preparation using hot homogenization method. SLN dispersions exhibited average size between 244 and 766 nm. All the dispersions had high entrapment efficiency ranging from 80% to 100%. The MN-SLN dispersion which showed good stability for a period of 1 month was selected. This MN-SLN was characterized for particle size, entrapment efficiency, and X-ray diffraction. The penetration of miconazole nitrate from the gel formulated using selected MN-SLN dispersion as into cadaver skins was evaluated ex-vivo using franz diffusion cell. The results of differential scanning calorimetry (DSC) showed that MN was dispersed in SLN in an amorphous state. The MN-SLN formulations could significantly increase the accumulative uptake of MN in skin over the marketed gel and showed a significantly enhanced skin targeting effect. These results indicate that the studied MN-SLN formulation with skin targeting may be a promising carrier for topical delivery of miconazole nitrate.

Phosphatidylcholine embedded micellar systems: enhanced permeability through rat skin.

PubMed

Spernath, Aviram; Aserin, Abraham; Sintov, Amnon C; Garti, Nissim

2008-02-15

Micellar and microemulsion systems are excellent potential vehicles for delivery of drugs because of their high solubilization capacity and improved transmembrane bioavailability. Mixtures of propylene glycol (PG) and nonionic surfactants with sodium diclofenac (DFC) were prepared in the presence of phosphatidylcholine (PC) as transmembrane transport enhancers. Fully dilutable systems with maximum DFC solubilization capacity (SC) at pH 7 are presented. It was demonstrated that the concentrates underwent phase transitions from reverse micelles to swollen reverse micelles and, via the bicontinuous transitional mesophase, into inverted O/W microstructures. The SC decreases as a function of dilution. DFC transdermal penetration using rat skin in vitro correlated with SC, water content, effect of phospholipid content, presence of an oil phase, and ethanol. Skin penetration from the inverted bicontinuous mesophase and the skin penetration from the O/W-like microstructure were higher than that measured from the W/O-like droplets, especially when the micellar system containing the nonionic surfactant, sugar ester L-1695, and hexaglycerol laurate. PC embedded within the micelle interface significantly increased the penetration flux across the skin compared to micellar systems without the embedded PC at their interface. Moreover, the combination of PC with HECO40 improved the permeation rate (P) and shortened the lag-time (T(L)).

Nicotine delivery from the refill liquid to the aerosol via high-power e-cigarette device.

PubMed

Prévôt, Nathalie; de Oliveira, Fabien; Perinel-Ragey, Sophie; Basset, Thierry; Vergnon, Jean-Michel; Pourchez, Jérémie

2017-06-01

To offer an enhanced and well-controlled nicotine delivery from the refill liquid to the aerosol is a key point to adequately satisfy nicotine cravings using electronic nicotine delivery systems (ENDS). A recent high-power ENDS, exhibiting higher aerosol nicotine delivery than older technologies, was used. The particle size distribution was measured using a cascade impactor. The effects of the refill liquid composition on the nicotine content of each size-fraction in the submicron range were investigated. Nicotine was quantified by liquid chromatography coupled with tandem mass spectrometry. Particle size distribution of the airborne refill liquid and the aerosol nicotine demonstrated that the nicotine is equally distributed in droplets regardless of their size. Results also proved that the nicotine concentration in aerosol was significantly lower compared to un-puffed refill liquid. A part of the nicotine may be left in the ENDS upon depletion, and consequently a portion of the nicotine may not be transferred to the user. Thus, new generation high-power ENDS associated with propylene glycol/vegetable glycerin (PG/VG) based solvent were very efficient to generate carrier-droplets containing nicotine molecules with a constant concentration. Findings highlighted that a portion of the nicotine in the refill liquid may not be transferred to the user.

Organic-inorganic hybrid polymer electrolytes based on polyether diamine, alkoxysilane, and trichlorotriazine: Synthesis, characterization, and electrochemical applications

NASA Astrophysics Data System (ADS)

Saikia, Diganta; Wu, Cheng-Gang; Fang, Jason; Tsai, Li-Duan; Kao, Hsien-Ming

2014-12-01

A new type of highly conductive organic-inorganic hybrid polymer electrolytes has been synthesized by the reaction of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 2,4,6-trichloro-1,3,5-triazine and alkoxysilane precursor 3-(glycidyloxypropyl)trimethoxysilane, followed by doping of LiClO4. The 13C and 29Si solid-sate NMR results confirm the successful synthesis of the organic-inorganic hybrid structure. The solid hybrid electrolyte thus obtained exhibits a maximum ionic conductivity of 1.6 × 10-4 S cm-1 at 30 °C, which is the highest among the organic-inorganic hybrid electrolytes. The hybrid electrolytes are electrochemically stable up to 4.2 V. The prototype electrochromic device with such a solid hybrid electrolyte demonstrates a good coloration efficiency value of 183 cm2 C-1 with a cycle life over 200 cycles. For the lithium-ion battery test, the salt free solid hybrid membrane is swelled with a LiPF6-containing electrolyte solution to reach an acceptable ionic conductivity value of 6.5 × 10-3 S cm-1 at 30 °C. The battery cell carries an initial discharge capacity of 100 mAh g-1 at 0.2C-rate and a coulombic efficiency of about 95% up to 30 cycles without the sign of cell failure. The present organic-inorganic hybrid electrolytes hold promise for applications in electrochromic devices and lithium ion batteries.

Progress in the chemistry of chromium(V) doping agents used in polarized target materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krumpolc, M.; Hill, D.; Struhrmann, H.B.

1990-01-01

We wish to report progress in two areas of the chromium (V)-based doping agents: Two commonly used chromium (V) complexes, I and II, have been synthesized in perdeuterated form (i.e., all hydrogens replaced by deuterium). They are sodium bis(2-ethyl-2-deuteroxy-butyrato)oxochromate(V)monodeuterate, IV, (acronym EDBA-Cr(V)), and sodium bis(2-deuteroxy-2-methylpropionato)oxochromate(V), III, (acronym DMPA-Cr(V)). A synthetic route leading to the preparation of stable, chromium(III)-free solutions of chromium(V) in diols (1,2-ethanediol/ethylene glycol/and 1,2-propanediol/propylene glycol/) has been outlined.

Laser-Induced Thermophoresis of Individual Particles in a Viscous Liquid

DTIC Science & Technology

2011-05-23

of liquid Ap 6.5x10 20 J Hamaker constant of particle [33] Al 5.6x10 20 J Hamaker constant of liquid [34] εR 29.3 Relative permittivity of liquid... Hamaker constants for the particle and liquid are denoted as Ap and Al. Table 2 lists the relevant quantities for propylene glycol and silica, as

Raman and Brillouin scattering of LiClO4 complexed in poly(propylene-glycol)

NASA Astrophysics Data System (ADS)

Schantz, S.; Torell, L. M.; Stevens, J. R.

1988-08-01

Raman spectra of LiClO4 complexed in poly(propylene-glycol) (PPG) have been obtained for concentrations of the monomer to salt ratio (ether oxygen):Li in the range 30:1-5:1. Splitting of the symmetric stretching mode of the ClO4- anion was observed with an intensity profile that varied with salt concentration. This phenomenon indicates a changing environment about the anion. A two-component band analysis leads to the identification of dissociated ions on one hand and solvent-separated ion pairs on the other. The concentration of ion pairs is relatively low compared to that of the dissociated ions, which are predominant for all concentrations. Despite the observed increase in the absolute number of dissociated ions at higher salt concentration, the electrical conductivity is reported to decrease in the same range. This indicates that the number of ``free'' charge carriers is of less importance for the conductivity than the mobility, which is damped in this concentration range. Frequency shifts of the disordered longitudinal-acoustic mode and increased hypersonic velocities, measured with Raman and Brillouin scattering techniques, respectively, indicate increased stiffness of the polymer matrix for increasing salt concentration, which probably results in decreased ion mobility.

New ethanol and propylene glycol free gel formulations containing a minoxidil-methyl-β-cyclodextrin complex as promising tools for alopecia treatment.

PubMed

Lopedota, Angela; Cutrignelli, Annalisa; Denora, Nunzio; Laquintana, Valentino; Lopalco, Antonio; Selva, Stefano; Ragni, Lorella; Tongiani, Serena; Franco, Massimo

2015-05-01

New topical totally aqueous formulations that improve the low water solubility of minoxidil and realize an adequate permeability of drug in the skin are proposed. These formulations are lacking in propylene glycol and alcohol that are the principal irritant ingredients present in minoxidil commercial solutions. In order to enhance poor water solubility of minoxidil randomly methyl-β-cyclodextrin was used, and four hydrogels such as, calcium alginate, sodium alginate, carbopol 934 and hydroxyethylcellulose were utilized to ensure a prolonged time of contact with the scalp. The inclusion complex minoxidil/methyl-β-cyclodextrin with a molar ratio 1:1 was obtained by freeze drying and evaluated by NMR, FT-IR and DSC analysis. An apparent stability constant of formed inclusion complex was calculated by phase solubility diagram and its value was 400 M(-1). The solid inclusion complex was used to prepare gel formulations with similar dose to minoxidil commercial solution. The gels were evaluated for various technological parameters including rheological behavior, in vitro drug release and ex vivo permeation through pig skin. The best performance was observed for the calcium alginate formulation.

Can green solvents be alternatives for thermal stabilization of collagen?

PubMed

Mehta, Ami; Rao, J Raghava; Fathima, Nishter Nishad

2014-08-01

"Go Green" campaign is gaining light for various industrial applications where water consumption needs to be reduced. To resolve this, industries have adopted usage of green, organic solvents, as an alternative to water. For leather making, tanning industry consumes gallons of water. Therefore, for adopting green solvents in leather making, it is necessary to evaluate its influence on type I collagen, the major protein present in the skin matrix. The thermal stability of collagen from rat tail tendon fiber (RTT) treated with seven green solvents namely, ethanol, ethyl lactate, ethyl acetate, propylene carbonate, propylene glycol, polyethylene glycol-200 and heptane was determined using differential scanning calorimetry (DSC). Crosslinking efficiency of basic chromium sulfate and wattle on RTT in green solvents was determined. DSC thermograms show increase in thermal stability of RTT collagen against heat with green solvents (>78°C) compared to water (63°C). In the presence of crosslinkers, RTT demonstrated thermal stability >100°C in some green solvents, resulting in increased intermolecular forces between collagen, solvent and crosslinkers. The significant improvement in thermal stability of collagen potentiates the capability of green solvents as an alternative for water. Copyright © 2014 Elsevier B.V. All rights reserved.

Utility of inline milk fat and protein ratio to diagnose subclinical ketosis and to assign propylene glycol treatment in lactating dairy cows.

PubMed

Jenkins, Nicholas T; Peña, Gustavo; Risco, Carlos; Barbosa, Carolina C; Vieira-Neto, Achilles; Galvão, Klibs N

2015-08-01

The objective was to identify a fat-to-protein ratio (FPR) cut-off to diagnose subclinical ketosis (SCK) and to evaluate the effect of propylene glycol (PPG) treatment of cows with high FPR. The optimized cut-off was > 1.42; sensitivity (Se) = 92%; specificity (Sp) = 65%. A cut-off > 1.5 was selected for the PPG trial for balanced Se-Sp. Fat-to-protein ratio cut-offs > 1.25, 1.35, 1.50, 1.60, and 1.70 resulted in Se-Sp of 100% to 49%, 96% to 59%, 75% to 78%, 33% to 90%, and 8% to 96%, respectively. The proportions of cows with FPR > 1.25, 1.35, 1.42, 1.50, 1.60, and 1.70 were 60%, 50%, 44%, 30%, 14%, and 6%, respectively. Incidences of clinical ketosis and milk yield were similar between cows that received 400 mL of PPG (n = 34) and control cows (n = 38). Prevalence of SCK at enrollment was 29.2%; therefore, FPR > 1.5 is not indicated for treatment. Lower cut-offs should be used for screening.

Utility of inline milk fat and protein ratio to diagnose subclinical ketosis and to assign propylene glycol treatment in lactating dairy cows

PubMed Central

Jenkins, Nicholas T.; Peña, Gustavo; Risco, Carlos; Barbosa, Carolina C.; Vieira-Neto, Achilles; Galvão, Klibs N.

2015-01-01

The objective was to identify a fat-to-protein ratio (FPR) cut-off to diagnose subclinical ketosis (SCK) and to evaluate the effect of propylene glycol (PPG) treatment of cows with high FPR. The optimized cut-off was > 1.42; sensitivity (Se) = 92%; specificity (Sp) = 65%. A cut-off > 1.5 was selected for the PPG trial for balanced Se-Sp. Fat-to-protein ratio cut-offs > 1.25, 1.35, 1.50, 1.60, and 1.70 resulted in Se-Sp of 100% to 49%, 96% to 59%, 75% to 78%, 33% to 90%, and 8% to 96%, respectively. The proportions of cows with FPR > 1.25, 1.35, 1.42, 1.50, 1.60, and 1.70 were 60%, 50%, 44%, 30%, 14%, and 6%, respectively. Incidences of clinical ketosis and milk yield were similar between cows that received 400 mL of PPG (n = 34) and control cows (n = 38). Prevalence of SCK at enrollment was 29.2%; therefore, FPR > 1.5 is not indicated for treatment. Lower cut-offs should be used for screening. PMID:26246632

Quercetagetin-Loaded Zein-Propylene Glycol Alginate Ternary Composite Particles Induced by Calcium Ions: Structure Characterization and Formation Mechanism.

PubMed

Sun, Cuixia; Wei, Yang; Li, Ruirui; Dai, Lei; Gao, Yanxiang

2017-05-17

The complexation of zein and propylene glycol alginate (PGA) was confirmed to improve the entrapment efficiency and loading capacity of quercetagetin (Q) in our previous study. The present work focused on the influence and induction mechanism of calcium ions on structures of Q-loaded zein-PGA ternary composite particles. The incorporation of Ca 2+ resulted in the formation of aggregates with a large dimension between zein particles, led to obvious conformational, secondary, and tertiary structural changes of zein, and caused the disappearance of crystalline structure of zein. PGA exhibited a fine filamentous network structure and became much thicker and stronger in the presence of Ca 2+ . The presence of Q promoted the affinity and binding capacity of Ca 2+ to zein and PGA. An interwoven network structure with enhanced firmness and density was observed in Q-loaded zein-PGA composite particles, leading to improved thermal stability. Three potential mechanisms were proposed to explain the structural characteristics induced by Ca 2+ , including particle-particle collision for zein particles, chain-chain association for PGA molecules, and simultaneous cross-linking coupled with aggregating for Q-loaded zein-PGA composite particles.

Heat transfer nanofluid based on curly ultra-long multi-wall carbon nanotubes

NASA Astrophysics Data System (ADS)

Boncel, Sławomir; Zniszczoł, Aurelia; Pawlyta, Mirosława; Labisz, Krzysztof; Dzido, Grzegorz

2018-02-01

The main challenge in the use of multi-wall carbon nanotube (MWCNT) as key components of nanofluids is to transfer excellent thermal properties from individual nanotubes into the bulk systems. We present studies on the performance of heat transfer nanofluids based on ultra-long ( 2 mm), curly MWCNTs - in the background of various other nanoC-sp2, i.e. oxidized MWCNTs, commercially available Nanocyl™ MWCNTs and spherical carbon nanoparticles (SCNs). The nanofluids prepared via ultrasonication from water and propylene glycol were studied in terms of heat conductivity and heat transfer in a scaled up thermal circuit containing a copper helical heat exchanger. Ultra-long curly MWCNT (1 wt.%) nanofluids (stabilized with Gum Arabic in water) emerged as the most thermally conducting ones with a 23-30%- and 39%-enhancement as compared to the base-fluids for water and propylene glycol, respectively. For turbulent flows ( Re = 8000-11,000), the increase of heat transfer coefficient for the over-months stable 1 wt.% ultra-long MWCNT nanofluid was found as high as >100%. The findings allow to confirm that longer MWCNTs are promising solid components in nanofluids and hence to predict their broader application in heat transfer media.

Method of preparing a high heating value fuel product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somerville, R.; Fan, L.T.

1989-10-24

This patent describes a method of preparing a high heating value fuel product. The method comprising the steps of: blending a high heating value waste material with a cellulosic material; mixing an organic reagent to the blended mixture of the waste material and the cellulosic material, the organic reagent being a mixture having a 4-15 weight percent of a chemical selected from the group consisting of: triethylene, glycol, diethylene glycol, and glycerin propylene glycol; introducing a pozzolanic agent to the blended mixture for controlling the rate of solidification; and forming the blended mixture into a form suitable for handling. Alsomore » described is the same method with the mixture of the organic reagent further comprising: a 20-32 weight percent calcium chloride solution. Another method of preparing a fuel product is also described.« less

Simultaneous heat and mass transfer inside a vertical channel in evaporating a heated falling glycols liquid film

NASA Astrophysics Data System (ADS)

Nait Alla, Abderrahman; Feddaoui, M'barek; Meftah, Hicham

2015-12-01

The interactive effects of heat and mass transfer in the evaporation of ethylene and propylene glycol flowing as falling films on vertical channel was investigated. The liquid film falls along a left plate which is externally subjected to a uniform heat flux while the right plate is the dry wall and is kept thermally insulated. The model solves the coupled governing equations in both phases together with the boundary and interfacial conditions. The systems of equations obtained by using an implicit finite difference method are solved by Tridiagonal Matrix Algorithm. The influence of the inlet liquid flow, Reynolds number in the gas flow and the wall heat flux on the intensity of heat and mass transfers are examined. A comparison between the results obtained for studied glycols and water in the same conditions is made. The results indicate that water evaporates in more intense way in comparison to glycols and the increase of gas flow rate tends to improve slightly the evaporation.

Advantage of using CBA/N strain mice in a non-radioisotopic modification of the local lymph node assay.

PubMed

Takeyoshi, Masahiro; Noda, Shuji; Yamasaki, Kanji; Kimber, Ian

2006-01-01

The murine local lymph node assay (LLNA) is currently recognized as a stand-alone test method for determining the skin sensitizing potential of chemicals. It has been incorporated into the official test guidelines published by some authorities, including the OECD. To avoid the use of radioisotopes, efforts have been made recently to develop non-radioisotopic modifications of the LLNA. A non-radioisotopic modification of the LLNA was developed previously using 5-bromo-2'-deoxyuridine (BrdU) incorporation (non-RI LLNA). However, the non-RI LLNA was found to be somewhat less sensitive than the standard assay. This study reports the advantage of using mice of the CBA/N strain in the non-RI LLNA to improve the sensitivity of this method. The non-RI LLNA was performed using CBA/JN and CBA/N mice exposed to one of four confirmed skin sensitizers, 2,4-dinitrochlorobenzene (DNCB), eugenol (EG), isoeugenol (IEG) or alpha-hexylcinnamic aldehyde (HCA), and to one non-sensitizer, propylene glycol (PG). The EC3 values for DNCB, IEG, EG, HCA and PG were calculated to be 0.1%, 9.6%, 40.6%, 45.5% and >50% in CBA/JN mice and 0.08%, 1.9%, 10.7%, 20.3% and >50% in CBA/N mice, respectively. The EC3 values for DNCB, IEG, EG, HCA and PG in the standard LLNA using CBA/Ca mice and radioisotopes were reported elsewhere as being 0.08%, 1.3%, 13.0%, 8.0% and >50%, respectively. The EC3 values derived from the CBA/N mice in the non-RI LLNA were nearly equivalent to the EC3 values obtained using the standard radioisotopic LLNA with CBA/Ca mice. These data suggest that the use of CBA/N mice may provide a realistic opportunity to develop a version of the LLNA that does not have a requirement for the use of radioisotopes, but which nevertheless has sensitivity approaching, or comparable to, the standard method. 2005 John Wiley & Sons, Ltd.

Alternative Fuels Compatibility with Army Equipment Testing - Alternative Fuels Material Compatibility Analysis

DTIC Science & Technology

2012-02-21

Testing and Materials °C Celsius DiEGME Diethylene Glycol Monomethyl Ether EPDM Ethylene Propylene Diene Monomer FARE Forward Area Refueling...urethane class AU, polyether urethane class EU, EPDM , Viton®, fluorosilicone class FQ, polytetrafluoroethylene (PTFE), polyolefin and polyester...sleeve Material not provided AAFARS 4720-00-540-1368 Hose, nonmetallic Material not provided AAFARS 4720-01-218-6958 Hose, preformed Rubber

A Review of the Environmental Degradation, Ecotoxicity, and Bioaccumulation Potential of the Low Molecular Weight Polyether Polyol Substances.

PubMed

Schupp, Thomas; Austin, Tom; Eadsforth, Charles V; Bossuyt, Bart; Shen, Summer M; West, Robert J

"Polyalkylene glycol" is the name given to a broad class of synthetic organic chemicals which are produced by polymerization of one or more alkylene oxide (epoxide) monomers, such as ethylene oxide (EO) and propylene oxide (PO), with various initiator substances which possess amine or alcohol groups. A generalization of this polymerization reaction is illustrated in Fig. 1.

Facile synthesis and photocatalytic activity of bi-phase dispersible Cu-ZnO hybrid nanoparticles

NASA Astrophysics Data System (ADS)

Liu, Xiao; Liu, HongLing; Zhang, WenXing; Li, XueMei; Fang, Ning; Wang, XianHong; Wu, JunHua

2015-04-01

Bi-phase dispersible Cu-ZnO hybrid nanoparticles were synthesized by one-pot non-aqueous nanoemulsion with the use of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) show high crystallinity of the Cu-ZnO hybrid nanoparticles and an average particle size of ~19.4 nm. The ultraviolet-visible light absorbance spectrometry (UV-vis) and photoluminescence spectrophotometry (PL) demonstrate well dispersibility and excellent optical performance of Cu-ZnO hybrid nanoparticles both in organic and aqueous solvent. The X-ray photoelectron spectroscopy (XPS) confirms Cu1+ and Cu2+ in ZnO. The observation using Sudan red (III) as probe molecule reveals that the Cu-ZnO hybrid nanoparticles possess enhanced photocatalytic activity and stability which are promising for potential applications in photocatalysis.

Influence of pressurized carbon dioxide on ketoprofen-incorporated hot-melt extruded low molecular weight hydroxypropylcellulose.

PubMed

A Ashour, Eman; Kulkarni, Vijay; Almutairy, Bjad; Park, Jun-Bom; Shah, Sejal P; Majumdar, Soumyajit; Lian, Zhuoyang; Pinto, Elanor; Bi, Vivian; Durig, Thomas; Martin, Scott T; Repka, Michael A

2016-01-01

The aim of the current research project was to investigate the effect of pressurized carbon dioxide (P-CO 2 ) on the physico-mechanical properties of ketoprofen (KTP)-incorporated hydroxypropylcellulose (HPC) (Klucel™ ELF, EF, and LF) produced using hot-melt extrusion (HME) techniques and to assess the plasticization effect of P-CO 2 on the various polymers tested. The physico-mechanical properties of extrudates with and without injection of P-CO 2 were examined and compared with extrudates with the addition of 5% liquid plasticizer of propylene glycol (PG). The extrudates were milled and compressed into tablets. Tablet characteristics of the extrudates with and without injection of P-CO 2 were evaluated. P-CO 2 acted as a plasticizer for tested polymers, which allowed for the reduction in extrusion processing temperature. The microscopic morphology of the extrudates was changed to a foam-like structure due to the expansion of the CO 2 at the extrusion die. The foamy extrudates demonstrated enhanced KTP release compared with the extrudates processed without P-CO 2 due to the increase of porosity and surface area of those extrudates. Furthermore, the hardness of the tablets prepared by foamy extrudates was increased and the percent friability was decreased. Thus, the good binding properties and compressibility of the extrudates were positively influenced by utilizing P-CO 2 processing.

Influence of Pressurized Carbon Dioxide on Ketoprofen-Incorporated Hot-Melt Extruded Low Molecular Weight Hydroxypropylcellulose

PubMed Central

Ashour, Eman A.; Kulkarni, Vijay; Almutairy, Bjad; Park, Jun-Bom; Shah, Sejal; Majumdar, Soumyajit; Lian, Zhuoyang; Pinto, Elanor; Bi, Yunxia; Durig, Thomas; Martin, Scott T.; Repka, Michael A.

2017-01-01

Objectives The aim of the current research project was to investigate the effect of pressurized carbon dioxide (P-CO2) on the physico-mechanical properties of Ketoprofen (KTP)-incorporated hydroxypropylcellulose (HPC) (Klucel™ ELF, EF and LF) produced using hot melt extrusion (HME) techniques and to assess the plasticization effect of P-CO2 on the various polymers tested. Methods The physico-mechanical properties of extrudates with and without injection of P-CO2 were examined and compared to extrudates with the addition of 5% liquid plasticizer of propylene glycol (PG). The extrudates were milled and compressed into tablets. Tablet characteristics of the extrudates with and without injection of P-CO2 were evaluated. Results & conclusion P-CO2 acted as a plasticizer for tested polymers, which allowed for the reduction in extrusion processing temperature. The microscopic morphology of the extrudates were changed to a foam-like structure due to expansion of the CO2 at the extrusion die. The foamy extrudates demonstrated enhanced KTP release compared to the extrudates processed without P-CO2 due to the increase of porosity and surface area of those extrudates. Furthermore, the hardness of the tablets prepared by foamy extrudates was increased and the percent friability was decreased. Thus, the good binding properties and compressibility of the extrudates were positively influenced by utilizing P-CO2 processing. PMID:25997363

Transdermal Nitroglycerin Delivery Using Acrylic Matrices: Design, Formulation, and In Vitro Characterization

PubMed Central

Ramazani Saadat Abadi, Ahmad

2014-01-01

Nitroglycerin (TNG) transdermal drug delivery systems (TDDSs) with different acrylic pressure-sensitive adhesives (PSAs) and chemical permeation enhancers (CPEs) were prepared. The effects of PSAs and CPEs types and concentrations on skin permeation and in vitro drug release from devices were evaluated using the dissolution method as well as the modified-jacketed Franz diffusion cells fitted with excised rat abdominal skin. It was demonstrated that the permeation rate or steady state flux (J ss) of the drug through the excised rat skin was dependent on the viscosity and type of acrylic PSA as well as the type of CPE. Among different acrylic PSAs, Duro-Tak 2516 and Duro-Tak 2054 showed the highest and Duro-Tak 2051 showed the lowest J ss. Among the various CPEs, propylene glycol and cetyl alcohol showed the highest and the lowest enhancement of the skin permeation of TNG, respectively. The adhesion properties of devices such as 180° peel strength and probe tack values were obtained. It was shown that increasing the concentration of CPE led to reduction in the adhesion property of PSA. Moreover, after optimization of the formulation, it was found that the use of 10% PG as a CPE and 25% nitroglycerin loading in Duro-Tak 2054 is an effective monolithic DIAP for the development of a transdermal therapeutic system for nitroglycerin. PMID:24511396

Pluronic lecithin organogel (PLO) of diltiazem hydrochloride: effect of solvents/penetration enhancers on ex vivo permeation.

PubMed

Parhi, Rabinarayan; Suresh, Podilam; Pattnaik, Subasini

2016-06-01

In the present study, pluronic lecithin organogel (PLO) of diltiazem hydrochloride (DZH) was developed by taking different ratios of organic phase to aqueous phase (1:3, 1:4, and 1:5) with varying concentration of soya lecithin (20, 30, and 40 % w/w) in organic phase (isopropyl myristate, IPM) and pluronic (20, 25, and 30 % w/w) in aqueous phase, respectively, and characterized for in vitro parameters and ex vivo permeation study. The results of in vitro parameters were found to be within permissible limit and all the PLOs were physically stable at refrigeration and ambient temperature. The influence of phase ratio and different concentrations of soya lecithin on DZH release from the PLOs was found to be significant (p < 0.05), whereas the influences of different concentrations of pluronic were insignificant. The effect of different solvents/penetration enhancers viz. IPM, propylene glycol (PG), dimethyl sulphoxide (DMSO), and D-limonene, in combination and alone, on the permeation of DZH across the dorsal skin of rat was studied. Among all, formulation containing IPM (PLO6) exhibited highest flux of 147.317 μg/cm(2)/h. Furthermore, histopathology section of treated skin sample illustrated that lipid bilayer disruption was the mechanism for the DZH permeation. The above results indicated that PLO6 may serve as a promising alternative delivery system for DZH in the effective treatment of hypertension.

Assessment of skin sensitization under REACH: A case report on vehicle choice in the LLNA and its crucial role preventing false positive results.

PubMed

Watzek, Nico; Berger, Franz; Kolle, Susanne Noreen; Kaufmann, Tanja; Becker, Matthias; van Ravenzwaay, Bennard

2017-04-01

In the EU, chemicals with a production or import volume in quantities of one metric ton per year or more have to be tested for skin sensitizing properties under the REACH regulation. The murine Local Lymph Node Assay (LLNA) and its modifications are widely used to fulfil the data requirement, as it is currently considered the first-choice method for in vivo testing to cover this endpoint. This manuscript describes a case study highlighting the importance of understanding the chemistry of the test material during testing for 'skin sensitization' of MCDA (mixture of 2,4- and 2,6-diamino-methylcyclohexane) with particular focus on the vehicle used. While the BrdU-ELISA modification of the LLNA using acetone/olive oil (AOO) as vehicle revealed expectable positive results. However, the concentration control analysis unexpectedly revealed an instability of MCDA in the vehicle AOO. Further studies on the reactivity showed MCDA to rapidly react with AOO under formation of various imine structures, which might have caused the positive LLNA result. The repetition of the LLNA using propylene glycol (PG) as vehicle did not confirm the positive results of the LLNA using AOO. Finally, a classification of MCDA as skin sensitizer according to the Globally Harmonized System (GHS) was not justified. Copyright © 2017 Elsevier Inc. All rights reserved.

Enhancement of the Oral Bioavailability of Fexofenadine Hydrochloride via Cremophor® El-Based Liquisolid Tablets

PubMed Central

Yehia, Soad Ali; El-Ridi, Mohamed Shafik; Tadros, Mina Ibrahim; El-Sherif, Nolwa Gamal

2015-01-01

Purpose: The current work aimed to develop promising Fexofenadine hydrochloride (FXD) liquisolid tablets able to increase its oral bioavailability and shorten time to reach maximum plasma concentrations (Tmax). Methods: Eighteen liquisolid powders were developed based on 3 variables; (i) vehicle type [Propylene glycol (PG) or Cremophor® EL (CR)], (ii) carrier [Avicel® PH102] to coat [Aerosil® 200] ratio (15, 20, 25) and (iii) FXD concentration in vehicle (30, 35, 40 %, w/w). Pre-compression studies involved identification of physicochemical interactions and FXD crystallinity (FT-IR, DSC, XRD), topographic visualization (SEM) and estimation of flow properties (angle of repose, Carr’s index, Hausner’s ratio). CR-based liquisolid powders were compressed as liquisolid tablets (LST 9 – 18) and evaluated for weight-variation, drug-content, friability-percentage, disintegration-time and drug-release. The pharmacokinetics of LST-18 was evaluated in healthy volunteers relative to Allegra® tablets. Results: Pre-compression studies confirmed FXD dispersion in vehicles, conversion to amorphous form and formation of liquisolid powders. CR-based liquisolid powders showed acceptable-to-good flow properties suitable for compaction. CR-based LSTs had appropriate physicochemical properties and short disintegration times. Release profile of LST-18 showed a complete drug release within 5 min. Conclusion: LST-18 succeeded in increasing oral FXD bioavailability by 62% and reducing Tmax to 2.16 h. PMID:26819931

A comparative study of vitamin E TPGS/HPMC supersaturated system and other solubilizer/polymer combinations to enhance the permeability of a poorly soluble drug through the skin.

PubMed

Ghosh, Indrajit; Michniak-Kohn, Bozena

2012-11-01

In transdermal drug delivery systems (TDDS), it is a challenge to achieve stable and prolonged high permeation rates across skin, because the concentration of the drug dissolved in the matrix has to be high in order to maintain zero order release kinetics of the drug. In case of poorly soluble drugs, due to thermodynamic challenges, there is a high tendency for the drug to nucleate immediately after formulating or even during storage. The present study focuses on the efficiency of vitamin E TPGS/HPMC supersaturated solution and other solubilizer/polymer systems to improve the solubility of the drug and inhibit crystal growth in the transdermal formulation. Effect of several solubilizers, for example, Pluronic F-127, vitamin E TPGS and co-solvent, for example, propylene glycol (PG) were studied on the supersaturated systems of ibuprofen as model drug. Various stabilizers such as hydroxylpropyl methylcellulose (HPMC 3 cps) and polyvinylpyrrolidone (PVP K-30) were examined to evaluate their crystal inhibitory effects. Different analytical tools were used in this study to detect the growth of crystals in the systems. Vitamin E TPGS and HPMC 3 cps formulation produced the highest permeation rate of the drug as compared to other systems. In addition, the onset of crystallization time was shown to be longer with this formulation as compared to other solubilizer/polymer combinations.

Evaluation of 14 Organic Solvents and Carriers for Screening Applications in Zebrafish Embryos and Larvae

PubMed Central

Maes, Jan; Verlooy, Lien; Buenafe, Olivia E.; de Witte, Peter A. M.; Esguerra, Camila V.; Crawford, Alexander D.

2012-01-01

Zebrafish are rapidly growing in popularity as an in vivo model system for chemical genetics, drug discovery, and toxicology, and more recently also for natural product discovery. Experiments involving the pharmacological evaluation of small molecules or natural product extracts in zebrafish bioassays require the effective delivery of these compounds to embryos and larvae. While most samples to be screened are first solubilized in dimethyl sulfoxide (DMSO), which is then diluted in the embryo medium, often this method is not sufficient to prevent the immediate or eventual precipitation of the sample. Certain compounds and extracts are also not highly soluble in DMSO. In such instances the use of carriers and/or other solvents might offer an alternative means to achieve the required sample concentration. Towards this end, we determined the maximum tolerated concentration (MTC) of several commonly used solvents and carriers in zebrafish embryos and larvae at various developmental stages. Solvents evaluated for this study included acetone, acetonitrile, butanone, dimethyl formamide, DMSO, ethanol, glycerol, isopropanol, methanol, polyethylene glycol (PEG-400), propylene glycol, and solketal, and carriers included albumin (BSA) and cyclodextrin (2-hydroxypropyl-beta-cyclodextrin, or HPBCD). This study resulted in the identification of polyethylene glycol (PEG400), propylene glycol, and methanol as solvents that were relatively well-tolerated over a range of developmental stages. In addition, our results showed that acetone was well-tolerated by embryos but not by larvae, and 1% cyclodextrin (HPBCD) was well-tolerated by both embryos and larvae, indicating the utility of this carrier for compound screening in zebrafish. However, given the relatively small differences (2–3 fold) between concentrations that are apparently safe and those that are clearly toxic, further studies – e.g. omics analyses –should be carried out to determine which cellular processes and signalling pathways are affected by any solvents and carriers that are used for small-molecule screens in zebrafish. PMID:23082109

Toxic Hazards Research Unit Annual Report: 1986

DTIC Science & Technology

1987-04-01

ileum-duodenum mandibular and mesenteric lymph nodes bone (sternum and both femurs) pancreas urinary bladder thyroid brain salivary glands lungs...Woodside, E.R. Kinkead, J.M. King, and L.J. Sullivan. 1971. Response of dogs to repeated intravenous injections of propylene glycol 4000 with notes on...Van Abbe. 1979. Safety evaluation of toothpaste containing chloroform. 1II. Long term studies in beagle dogs . J. Environ. Pathol. Toxicol. 2:835-851

Environmental Assessment for the Aeromedical Evacuation Formal Training Unit, Wright-Patterson Air Force Base

DTIC Science & Technology

2012-05-01

adverse health effects (HHS 2010). However, propylene glycol requires oxygen for breakdown, which can deplete surface waters of dissolved oxygen ...and the Human Effectiveness Directorate (RH), plus supporting functions. Facility 20840 contains a high-bay area that houses two C-130 training...aircrew training program that develops and maintains a high state of mission readiness for immediate and effective deployments across the range of

Effects of external applications of fuel oil on hatchability of mallard eggs

USGS Publications Warehouse

Albers, P.H.; Wolfe, Douglas A.

1977-01-01

An experiment was performed to determine the toxicity of oil to incubating eggs. Number 2 fuel oil, a mixture of 9 paraffin compounds, and propylene glycol were applied to the surface of artificially incubated mallard (Anas platyrhynchos) eggs. Embryonic mortality was significantly greater (P 0.01) from the control. Thus, the transfer of even small quantities of oil to the egg surface is sufficient to reduce hatchability.

Proceedings of the Workshop on High Temperature Superconductivity

DTIC Science & Technology

1989-11-01

such magnetic excitations in neutron scattering studies of UPt3 and measured a corresponding Debye energy owc = 2 K, in excellent agreement with the...procedure of Budhani et al. Propylene carbonate has been found to be a suitable vehicle for direct painting, while poly (ethylene glycol methyl ether ...through neutron irradiation and chemical means will also be discussed. Specifically, results of comparative studies on the kinetics of flux motion in

Bifunctional viscous nanovesicles co-loaded with resveratrol and gallic acid for skin protection against microbial and oxidative injuries.

PubMed

Vitonyte, Justina; Manca, Maria Letizia; Caddeo, Carla; Valenti, Donatella; Peris, Josè Esteban; Usach, Iris; Nacher, Amparo; Matos, Maria; Gutiérrez, Gemma; Orrù, Germano; Fernàndez-Busquets, Xavier; Fadda, Anna Maria; Manconi, Maria

2017-05-01

Resveratrol and gallic acid were co-loaded in phospholipid vesicles aiming at protecting the skin from external injuries, such as oxidative stress and microbial infections. Liposomes were prepared using biocompatible phospholipids dispersed in water. To improve vesicle stability and applicability, the phospholipids and the phenols were dispersed in water/propylene glycol or water/glycerol, thus obtaining PEVs and glycerosomes, respectively. The vesicles were characterized by size, morphology, physical stability, and their therapeutic efficacy was investigated in vitro. The vesicles were spherical, unilamellar and small in size: liposomes and glycerosomes were around 70nm in diameter, while PEVs were larger (∼170nm). The presence of propylene glycol or glycerol increased the viscosity of the vesicle systems, positively affecting their stability. The ability of the vesicles to promote the accumulation of the phenols (especially gallic acid) in the skin was demonstrated, as well as their low toxicity and great ability to protect keratinocytes and fibroblasts from oxidative damage. Additionally, an improvement of the antimicrobial activity of the phenols was shown against different skin pathogens. The co-loading of resveratrol and gallic acid in modified phospholipid vesicles represents an innovative, bifunctional tool for preventing and treating skin affections. Copyright © 2017 Elsevier B.V. All rights reserved.

Propylene glycol monomethyl ether (PGME): inhalation toxicity and carcinogenicity in Fischer 344 rats and B6C3F1 mice.

PubMed

Spencer, Pamela J; Crissman, James W; Stott, William T; Corley, Richard A; Cieszlak, Frank S; Schumann, Alan M; Hardisty, Jerry F

2002-01-01

A series of inhalation studies with propylene glycol monomethyl ether (PGME) vapor were undertaken to characterize its subchronic toxicity in mice and chronic toxicity/oncogenicity in rats and mice. Groups of male and female Fischer 344 rats and B6C3F1 mice were exposed to 0, 300, 1,000, or 3,000 ppm vapor from 1 week to 2 years. Primary treatment-related effects included: initial sedation of animals exposed to 3,000 ppm and its subsequent resolution correlating with induction of hepatic mixed function oxidase activity and S-phase DNA synthesis; elevated mortality in high-exposure male rats and mice (chronic study); elevated deposition of alpha2u-globulin (alpha2U-G) and associated nephropathy and S-phase DNA synthesis in male rat kidneys; accelerated atrophy of the adrenal gland X-zone in female mice (subchronic study only); and increased occurrence and/or severity of eosinophilic foci of altered hepatocytes in male rats. No toxicologically relevant statistically significant increases in neoplasia occurred in either species. A numerical increase in the incidence of kidney adenomas occurred in intermediate-exposure male rats; however, the association with alpha2U-G nephropathy, a male rat specific effect, indicated a lack of relevance for human risk assessment.

Design of microemulsion system suitable for the oral delivery of poorly aqueous soluble beta-carotene.

PubMed

Peng, Cheng; Svirskis, Darren; Lee, Sung Je; Oey, Indrawati; Kwak, Hae-Soo; Chen, Guanyu; Bunt, Craig; Wen, Jingyuan

2017-02-14

Beta-carotene is a potent antioxidant for maintaining human health. However, its oral absorption is low due to poor aqueous solubility of less than 1 μg/ml. A microemulsion delivery system was designed to solubilize beta-carotene toward enhancing its oral bioavailability. From seven pseudoternary diagrams constructed, three systems were selected with large microemulsion areas suitable for oral administration and dilution in the predominately aqueous gastrointestinal fluids. Conductivity and rheology characterization were conducted along four dilution lines within the selected systems. Three pseudoternary-phase diagrams were selected with large microemulsion regions, >60% of the total phase diagram area, which provide microemulsions with higher drug-loading capacity. A phenomenon was observed by which both propylene glycol and Capmul MCM EP stabilize the microstructure of the microemulsions has been proposed based on the characterization studies. An optimal bicontinuous microemulsion formulation was selected comprising 12% orange oil, 24% Capmul MCM, 18% Tween 20, 6% Labrasol, 20% propylene glycol and 20% water, with a high beta-carotene loading capacity of 140.8 μg/ml and droplet size of 117.4 nm. In conclusion, the developed novel microemulsion formulation allows solubilizing beta-carotene and is a promising basis for further development as a functional beverage.

Effect of age on toxicokinetics among human volunteers exposed to propylene glycol methyl ether (PGME).

PubMed

Hopf, Nancy B; Vernez, David; Berthet, Aurelie; Charriere, Nicole; Arnoux, Christine; Tomicic, Catherine

2012-05-20

Aging adults represent the fastest growing population segment in many countries. Physiological and metabolic changes in the aging process may alter how aging adults biologically respond to pollutants. In a controlled human toxicokinetic study (exposure chamber; 12 m³), aging volunteers (n=10; >58 years) were exposed to propylene glycol monomethyl ether (PGME, CAS no. 107-98-2) at 50 ppm for 6 h. The dose-dependent renal excretion of oxidative metabolites, conjugated and free PGME could potentially be altered by age. (1) Compare PGME toxicokinetic profiles between aging and young volunteers (20-25 years) and gender; (2) test the predictive power of a compartmental toxicokinetic (TK) model developed for aging persons against urinary PGME concentrations found in this study. Urine samples were collected before, during, and after the exposure. Urinary PGME was quantified by capillary GC/FID. Differences in urinary PGME profiles were not noted between genders but between age groups. Metabolic parameters had to be changed to fit the age adjusted TK model to the experimental results, implying a slower enzymatic pathway in the aging volunteers. For an appropriate exposure assessment, urinary total PGME should be quantified. Age is a factor that should be considered when biological limit values are developed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The influence of selected excipients on the rheological behaviour of chitosan based ocular pharmaceutical systems

NASA Astrophysics Data System (ADS)

Budai, L.; Szabadi, E.; Hajdú, M.; Budai, M.; Klebovich, I.; Antal, I.

2015-04-01

Aims: Chitosan, a modified natural carbohydrate polymer, has received great attention in diverse scientific fields including pharmaceutical and biomedical research areas. Besides its low toxicity, mucoadhesiveness and biodegradability its special favourable rheological feature makes it a unique gelling agent for the design of ocular systems. Chitosan based (2.0 w/v %) ocular systems containing selected excipients were formulated in order to investigate the rheological influence of applied auxiliary materials. Rotational and oscillatory rheological properties of propylene glycol (1.0-20.0 w/v %), glycerin (1.0-5.0 w/v %) and castor oil (1.0-5.0 w/v %) containing chitosan gels were evaluated. The rheological behaviour of formulated ocular gels were compared before and after steam sterilization. Methods: Rotational and oscillatory rheological measurements were carried out with Kinexus Pro Rheometer. Comparison of flow curves and oscillatory frequency sweep measurements in the linear viscoelastic region made possible the evaluation of rheological effect of selected excipients. Results: In the applied concentration range the effect of propylene glycol among the selected excipients presents the most significant impact on rheology of chitosan formulations. Steam sterilization results in reduced viscosity in most of chitosan gels. However, the presence of polyols appears to prevent the degradation of chitosan after steam sterilization.

Self-assembly of block copolymer micelles: synthesis via reversible addition-fragmentation chain transfer polymerization and aqueous solution properties.

PubMed

Mya, Khine Y; Lin, Esther M J; Gudipati, Chakravarthy S; Gose, Halima B A S; He, Chaobin

2010-07-22

Poly(hexafluorobutyl methacrylate) (PHFBMA) homopolymer was synthesized by reversible addition-fragmentation chain transfer (RAFT)-mediated living radical polymerization in the presence of cyano-2-propyl dithiobenzoate (CPDB) RAFT agent. A block copolymer of PHFBMA-poly(propylene glycol acrylate) (PHFBMA-b-PPGA) with dangling poly(propylene glycol) (PPG) side chains was then synthesized by using CPDB-terminated PHFBMA as a macro-RAFT agent. The amphiphilic properties and self-assembly of PHFBMA-b-PPGA block copolymer in aqueous solution were investigated by dynamic and static light scattering (DLS and SLS) studies, in combination with fluorescence spectroscopy and transmission electron microscopy (TEM). Although PPG shows moderately hydrophilic character, the formation of nanosize polymeric micelles was confirmed by fluorescence and TEM studies. The low value of the critical aggregation concentration exhibited that the tendency for the formation of copolymer aggregates in aqueous solution was very high due to the strong hydrophobicity of the PHFBMA(145)-b-PPGA(33) block copolymer. The combination of DLS and SLS measurements revealed the existence of micellar aggregates in aqueous solution with an association number of approximately 40 +/- 7 for block copolymer micelles. It was also found in TEM observation that there are 40-50 micelles accumulated into one aggregate and these micelles are loosely packed inside the aggregate.

Study on cryopreservation of Porphyra yezoensis conchocelis

NASA Astrophysics Data System (ADS)

Zhou, Wenjun; Li, Yun; Dai, Jixun

2007-07-01

Cryopreservation of Porphyra yezoensis conchocelis was conducted with cryoprotectants and a proposed pretreatment procedure and thawing methods explored. Six cryoprotectants combined by DMSO with ethylene glycol (EG), propylene glycol (PEG), sorbitol and sucrose were developed. The effect of prefreezing at -40°C or -20°C for different time durations was compared and the thawing methods were screened. It was shown that the cryoprotectant including 10% DMSO with 0.5 molL-1 sorbitol exhibited the optimal effect. The ideal pretreatment was that conchocelis segments were stayed for 20 min at -40°C before stored in liquid nitrogen, and 40°C water bath was proper for quick thawing. The highest recovery rate of cryopreserved P. yezoensis conchocelis reached 89.41%.

Thermochemical analysis of intermolecular interactions between N-acetylglycine and polyols in aqueous solutions

NASA Astrophysics Data System (ADS)

Mezhevoi, I. N.; Badelin, V. G.

2017-05-01

The integral enthalpies of dissolution Δsol H m for N-acetylglycine in aqueous solutions of glycerol, ethylene glycol and 1,2-propylene glycol are measured via solution calorimetry. The standard enthalpies of dissolution (Δsol H 0) and transfer (Δtr H 0) for N-acetylglycine from water to aqueous solutions of polyhydric alcohols are calculated from experimental data. Positive values of enthalpy coefficients of pair interactions h xy for amino acids and polyol molecules are calculated using the McMillan-Mayer theory. The results are discussed using an approach for evaluating different types of interactions in ternary systems and the effect the structural features of interacting biomolecules have on the thermochemical characteristics of N-acetylglycine dissolution.

Enthalpic parameters of interaction between diglycylglycine and polyatomic alcohols in aqueous solutions

NASA Astrophysics Data System (ADS)

Mezhevoi, I. N.; Badelin, V. G.

2015-12-01

Integral enthalpies of solution Δsol H m of diglycylglycine in aqueous solutions of glycerol, ethylene glycol, and 1,2-propylene glycol are measured via solution calorimetry. The experimental data are used to calculate the standard enthalpies of solution (Δsol H°) and transfer (Δtr H°) of the tripeptide from water to aqueous solutions of polyatomic alcohols. The enthalpic pairwise coefficients h xy of interactions between the tripeptide and polyatomic alcohol molecules are calculated using the McMillan-Mayer solution theory and are found to have positive values. The findings are discussed using the theory of estimating various types of interactions in ternary systems and the effect the structural features of interacting biomolecules have on the thermochemical parameters of diglycylglycine dissolution.

Water and UV degradable lactic acid polymers

DOEpatents

Bonsignore, Patrick V.; Coleman, Robert D.

1996-01-01

A water and UV light degradable copolymer of monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene glycol, propylene glycol, P-dioxanone, 1,5 dioxepan-2-one, 1,4-oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2 by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.

An evaluation of disinfectants for the sanitation of porcine reproductive and respiratory syndrome virus-contaminated transport vehicles at cold temperatures

PubMed Central

2005-01-01

Abstract The objective of this study was to evaluate the efficacy of commercially available disinfectants to sanitize porcine reproductive and respiratory syndrome virus (PRRSV) contaminated trailer models in cold climates (−20°C and 4°C). Disinfectants evaluated included Synergize, Aseptol 2000, Biophene, Sentramax, Virkon, Tek Trol, and DC&R. All products were applied to trailers via fumigation at 4°C. Following experimental contamination of model trailers with PRRSV MN 30-100 (5 × 105 TCID50), models were tested for the presence or absence of PRRSV-RNA by polymerase chain reaction (PCR) on swabs collected 0, 30, and 60 min after treatment. Treatments included washing only, washing plus disinfectant fumigation, washing plus fumigation, and washing plus overnight drying. The PRRSV-RNA detected across trailers ranged from 0/12 replicates in trailers treated with Synergize or allowed to dry for 8 h. These trailers were also negative for the presence of infectious PRRSV, based on the lack of sentinel pig infection (0/4 replicates). In contrast, the detection of PRRSV-positive swabs by PCR ranged from 3/12 (Aseptol) to 10/12 (Biophene). Based on these results, the efficacy of Synergize was evaluated at −20°C. In an attempt to reduce the impact of freezing on disinfectant activity, 30 mL of disinfectant was added to a 3840 mL of a 40% methanol solution, a 10% propylene glycol (PG) solution, or water alone. The PRRSV-contaminated trailers were treated with 1 of 3 disinfectant mixtures via fumigation, stored for 8 h at −20°C, allowed to thaw, and sampled as described. Trailers treated with 40% methanol or 10% PG did not freeze and were negative for PRRSV-RNA and infectious virus following thawing. In contrast, trailers treated with disinfectant and water were frozen within 60 min at −20°C, and decontamination was not successful. PMID:15745225

Focus-tunable low-power electrowetting lenses with thin parylene films.

PubMed

Watson, Alexander M; Dease, Kevin; Terrab, Soraya; Roath, Christopher; Gopinath, Juliet T; Bright, Victor M

2015-07-10

Electrowetting lenses with record low power consumption (microwatts) have been demonstrated using high-quality parylene AF-4 dielectric layers and large dodecyl sulfate ions. Water and propylene glycol are interchanged as the polar liquid to enable diverging and converging lens operation achievable with the application of 15 V. The optical quality of the lenses is comparable to conventional microlenses and the tuning exhibits very little (<0.5°) contact angle hysteresis.

Poly(propylene glycol) and urethane dimethacrylates improve conversion of dental composites and reveal complexity of cytocompatibility testing.

PubMed

Walters, Nick J; Xia, Wendy; Salih, Vehid; Ashley, Paul F; Young, Anne M

2016-02-01

To determine the effects of various monomers on conversion and cytocompatibility of dental composites and to improve these properties without detrimentally affecting mechanical properties, depth of cure and shrinkage. Composites containing urethane dimethacrylate (UDMA) or bisphenol A glycidyl methacrylate (Bis-GMA) with poly(propylene glycol) dimethacrylate (PPGDMA) or triethylene glycol dimethacrylate (TEGDMA) were characterized using the following techniques: conversion (FTIR at 1 and 4mm depths), depth of cure (BS EN ISO 4049:2009 and FTIR), shrinkage (BS EN ISO 17304:2013 and FTIR), strength and modulus (biaxial flexural test) and water sorption. Cytocompatibility of composites and their liquid phase components was assessed using three assays (resazurin, WST-8 and MTS). UDMA significantly improved conversion, BFS and depth of cure compared to Bis-GMA, without increasing shrinkage. UDMA was cytotoxic at lower concentrations than Bis-GMA, but extracts of Bis-GMA-containing composites were less cytocompatible than of those containing UDMA. PPGDMA improved conversion and depth of cure compared to TEGDMA, without detrimentally affecting shrinkage. TEGDMA was shown by all assays to be highly toxic. Resazurin, but not WST-8 and MTS, suggested that PPGDMA exhibited improved cytocompatibility compared to TEGDMA. The use of UDMA and PPGDMA results in composites with excellent conversion, depth of cure and mechanical properties, without increasing shrinkage. Composites containing UDMA appear to be slightly more cytocompatible than those containing Bis-GMA. These monomers may therefore improve the material properties of dental restorations, particularly bulk fill materials. The effect of diluent monomer on cytocompatibility requires further investigation. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Optimization of reactive simulated moving bed systems with modulation of feed concentration for production of glycol ether ester.

PubMed

Agrawal, Gaurav; Oh, Jungmin; Sreedhar, Balamurali; Tie, Shan; Donaldson, Megan E; Frank, Timothy C; Schultz, Alfred K; Bommarius, Andreas S; Kawajiri, Yoshiaki

2014-09-19

In this article, we extend the simulated moving bed reactor (SMBR) mode of operation to the production of propylene glycol methyl ether acetate (DOWANOL™ PMA glycol ether) through the esterification of 1-methoxy-2-propanol (DOWANOL™ PM glycol ether) and acetic acid using AMBERLYST™ 15 as a catalyst and adsorbent. In addition, for the first time, we integrate the concept of modulation of the feed concentration (ModiCon) to SMBR operation. The performance of the conventional (constant feed) and ModiCon operation modes of SMBR are analyzed and compared. The SMBR processes are designed using a model based on a multi-objective optimization approach, where a transport dispersive model with a linear driving force for the adsorption rate has been used for modeling the SMBR system. The adsorption equilibrium and kinetics parameters are estimated from the batch and single column injection experiments by the inverse method. The multiple objectives are to maximize the production rate of DOWANOL™ PMA glycol ether, maximize the conversion of the esterification reaction and minimize the consumption of DOWANOL™ PM glycol ether which also acts as the desorbent in the chromatographic separation. It is shown that ModiCon achieves a higher productivity by 12-36% over the conventional operation with higher product purity and recovery. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis of bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles

PubMed Central

Li, Xue-Mei; Liu, Hong-Ling; Liu, Xiao; Fang, Ning; Wang, Xian-Hong; Wu, Jun-Hua

2015-01-01

Bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles were synthesized by a modified nanoemulsion process using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The morphology and crystal structure of the nanoparticles were studied by TEM/HRTEM and XRD. The nanoparticles manifest soft ferromagnetic and/or near superparamagnetic behavior with a small coercivity of ~19 Oe at room temperature. The corresponding magnetic hysteresis curves were elucidated by the modified Langevin equation. The FTIR study confirms the PEO-PPO-PEO molecules on the surface of the nanoparticles. The UV-vis and PL results reveal the well-behaved absorption bands including surface plasmon resonance and multiple visible fingerprint photoluminescent emissions of the nanoparticles dispersed in both hydrophilic and hydrophobic solvents. Moreover, the processes of solvent dispersion-collection of the nanoparticles were demonstrated for application readiness of such core-shell nanostructures. PMID:26548369

Synthesis of bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles

NASA Astrophysics Data System (ADS)

Li, Xue-Mei; Liu, Hong-Ling; Liu, Xiao; Fang, Ning; Wang, Xian-Hong; Wu, Jun-Hua

2015-11-01

Bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles were synthesized by a modified nanoemulsion process using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The morphology and crystal structure of the nanoparticles were studied by TEM/HRTEM and XRD. The nanoparticles manifest soft ferromagnetic and/or near superparamagnetic behavior with a small coercivity of ~19 Oe at room temperature. The corresponding magnetic hysteresis curves were elucidated by the modified Langevin equation. The FTIR study confirms the PEO-PPO-PEO molecules on the surface of the nanoparticles. The UV-vis and PL results reveal the well-behaved absorption bands including surface plasmon resonance and multiple visible fingerprint photoluminescent emissions of the nanoparticles dispersed in both hydrophilic and hydrophobic solvents. Moreover, the processes of solvent dispersion-collection of the nanoparticles were demonstrated for application readiness of such core-shell nanostructures.

Dermal Sensitization Potential of Niclosamide in Guinea Pigs

DTIC Science & Technology

1988-09-01

al--3 sterile water, from the same lot as for DNCB stock solution, were used to prepare the dilutions of FCA. Sodium lauryl sulfate (SLS) was obtained...test agent was non- irritating, the area was pretreated with 10% sodium lauryl sulfate in petrolatum immediately after the clipping and shaving. The SLS...control combination was prepared by adding 0.25 ml of FCA stock to 4.75 ml of propylene glycol. Topical Induction and Challenge: The sodium lauryl

Hydrogenolysis of 6-carbon sugars and other organic compounds

DOEpatents

Werpy, Todd A.; Frye, Jr., John G.; Zacher, Alan H.; Miller, Dennis J.

2005-01-11

Methods for hydrogenolysis are described which use a Re-containing multimetallic catalyst for hydrogenolysis of both C--O and C--C bonds. Methods and compositions for reactions of hydrogen over a Re-containing catalyst with compositions containing a 6-carbon sugar, sugar alcohol, or glycerol are described. It has been surprisingly discovered that reaction with hydrogen over a Re-containing multimetallic catalyst resulted in superior conversion and selectivity to desired products such as propylene glycol.

High-etch-rate bottom-antireflective coating and gap-fill materials using dextrin derivatives in via first dual-Damascene lithography process

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Sakaida, Yasushi; Shinjo, Tetsuya; Hashimoto, Keisuke; Nakajima, Yasuyuki

2008-03-01

The present paper describes a novel class of bottom antireflective coating (BARC) and gap fill materials using dextrin derivatives. The general trend of interconnect fabrication for such a high performance LSI is to apply cupper (Cu)/ low-dielectric-constant (low-k) interconnect to reduce RC delay. A via-first dual damascene process is one of the most promising processes to fabricate Cu/ low-k interconnect due to its wide miss-alignment margin. The sacrificial materials containing dextrin derivatives under resist for lithography were developed in via-first dual damascene process. The dextrin derivatives in this study was obtained by the esterification of the hydroxyl groups of dextrin resulting in improved solubility in the resist solvents such as propylene glycol monomethylether, propylene glycol monomethylether acetate, and ethyl lactate due to avoid the issue of defects that were caused by incompatability. The etch rate of our developed BARC and gap fill materials using dextrin derivatives was more than two times faster than one of the ArF resists evaluated in a CF4 gas condition using reactive ion etching. The improved etch performance was also verified by comparison with poly(hydroxystyrene), acrylate-type materials and latest low-k materials as a reference. In addition to superior etch performance, these materials showed good resist profiles and via filling performance without voids in via holes.

The effects of repeated nitroglycerin administrations in rats; modeling migraine-related endpoints and chronification.

PubMed

Harris, Hannah M; Carpenter, Jessica M; Black, Jonathan R; Smitherman, Todd A; Sufka, Kenneth J

2017-06-01

Rodent models typically use a single nitroglycerin injection to induce migraine, yet migraine in clinical populations presents as recurrent episodes. Further, these models quantify behavioral endpoints that do not align with the clinical features of episodic migraine or migraine chronification and therefore may limit translational relevance. Rats received 5 nitroglycerin (10mg/kg/2ml), propylene glycol/ethanol vehicle, or saline injections every third day over 15days. Behavioral endpoints were assessed 110min post nitroglycerin administration and included time spent light/dark chambers for photophobia as well as activity, facial pain expressions, and tactile allodynia. Animals administered nitroglycerin displayed photophobia, decreased activity, and increased facial pain expression. Similar alterations in photophobia and activity were seen in the vehicle treated animals, but these tended to diminish by the 4th or 5th injection. The presentation of spontaneous tactile allodynia was observed in the nitroglycerin group by the 5th episode. Most NTG migraine models entail a single NTG administration and quantification of evoked allodynia. This paradigm employs recurring NTG episodes and clinically-relevant measures of photophobia, hypoactivity and facial grimace endpoints as well as introduces a novel arena apparatus to quantify spontaneous allodynia. This repeated NTG procedure and endpoint measures aligns with the frequency and clinical presentation of episodic migraine and its chronification, respectively. Further, propylene glycol ethanol vehicle contributes to migraine endpoints. Copyright © 2017 Elsevier B.V. All rights reserved.

Antibacterial SnO2 nanorods as efficient fillers of poly(propylene fumarate-co-ethylene glycol) biomaterials.

PubMed

Díez-Pascual, Ana M; Díez-Vicente, Angel L

2017-09-01

Antibacterial and biocompatible SnO 2 nanorods have been easily synthesized through a hydrothermal process with the aid of a cationic surfactant, and incorporated as nanoreinforcements in poly(propylene fumarate-co-ethylene glycol) (P(PF-co-EG)) copolymer crosslinked with N-vinyl-pyrrolidone (NVP) by sonication and thermal curing. The nanorods were randomly and individually dispersed inside the P(PF-co-EG) network, and noticeably increased the thermal stability, hydrophilicity, degree of crystallinity, protein absorption capability as well as stiffness and strength of the matrix, whilst decreased its level of porosity and biodegradation rate. More importantly, the resulting nanocomposites retained adequate rigidity and strength after immersion in a simulated body fluid (SBF) at 37°C. They also exhibited biocide action against Gram-positive and Gram-negative bacteria; their antibacterial effect was strong under UV-light illumination whilst in dark conditions was only moderate. Further, they did not cause toxicity on human dermal fibroblasts. The friction coefficient and wear rate strongly decreased with increasing nanorod loading under both dry and SBF conditions; the greatest drops in SBF were about 18-fold and 13-fold, respectively, compared to those of the copolymer network. These novel biomaterials are good candidates to be applied in the field of soft-tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

D-lactic acidosis in humans: systematic literature review.

PubMed

Bianchetti, Davide G A M; Amelio, Giacomo S; Lava, Sebastiano A G; Bianchetti, Mario G; Simonetti, Giacomo D; Agostoni, Carlo; Fossali, Emilio F; Milani, Gregorio P

2018-04-01

D-lactic acidosis is an uncommon and challenging form of metabolic acidosis that may develop in short bowel syndrome. It has been documented exclusively in case reports and small case series. We performed a review of the literature in the National Library of Medicine and Excerpta Medica databases. We identified 84 original reports published between 1977 and 2017. D-lactic acidosis was observed in 98 individuals ranging in age from 7 months to 86 years with short bowel syndrome. The clinical presentation included Kussmaul breathing, confusion, slurred speech, and gait disturbances. Furthermore, among 99 consecutive patients with short bowel syndrome, 21 reported having episodes with symptoms consistent with D-lactic acidosis. In addition, D-lactic acid might also contribute to acidosis in diabetes mellitus. Finally, abnormally high D-lactic acid was documented after administration or ingestion of large amounts of propylene glycol, as paraneoplastic phenomenon and perhaps also in a so far poorly characterized inherited inborn error of metabolism. In humans with short bowel syndrome (or carbohydrate malabsorption), D-lactic acidosis is likely rather common and under-recognized. This condition should be included in the differential diagnosis of unexplained high-gap metabolic acidosis where the anion causing the acidosis is not known. Furthermore, diabetic acidosis might be caused by accumulation of both ketone bodies and D-lactic acid. Finally, there are endogenous sources of D-lactic acid in subjects with propylene glycol intoxication.

In vitro cytotoxicity assessment of a West Virginia chemical spill mixture involving 4-methylcyclohexanemethanol and propylene glycol phenyl ether.

PubMed

Han, Alice A; Fabyanic, Emily B; Miller, Julie V; Prediger, Maren S; Prince, Nicole; Mouch, Julia A; Boyd, Jonathan

2017-04-01

Thousands of gallons of industrial chemicals, crude 4-methylcyclohexanemethanol (MCHM) and propylene glycol phenyl ether (PPh), leaked from industrial tanks into the Elk River in Charleston, West Virginia, USA, on January 9, 2014. A considerable number of people were reported to exhibit symptoms of chemical exposure and an estimated 300,000 residents were advised not to use or drink tap water. At the time of the spill, the existing toxicological data of the chemicals were limited for a full evaluation of the health risks, resulting in concern among those in the impacted regions. In this preliminary study, we assessed cell viability and plasma membrane degradation following a 24-h exposure to varying concentrations (0-1000 μM) of the two compounds, alone and in combination. Evaluation of different cell lines, HEK-293 (kidney), HepG2 (liver), H9c2 (heart), and GT1-7 (brain), provided insight regarding altered cellular responses in varying organ systems. Single exposure to MCHM or PPh did not affect cell viability, except at doses much higher than the estimated exposure levels. Certain co-exposures significantly reduced metabolic activity and increased plasma membrane degradation in GT1-7, HepG2, and H9c2 cells. These findings highlight the importance of examining co-exposures to fully understand the potential toxic effects.

Pretreatment with propylene glycol alginate sodium sulfate ameliorated concanavalin A-induced liver injury by regulating the PI3K/Akt pathway in mice.

PubMed

Xu, Shizan; Wu, Liwei; Zhang, Qinghui; Feng, Jiao; Li, Sainan; Li, Jingjing; Liu, Tong; Mo, Wenhui; Wang, Wenwen; Lu, Xiya; Yu, Qiang; Chen, Kan; Xia, Yujing; Lu, Jie; Xu, Ling; Zhou, Yingqun; Fan, Xiaoming; Guo, Chuanyong

2017-09-15

Propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide possesses anti-inflammatory effects. Here, we investigated the effect of PSS on concanavalin A (Con A)-induced liver injury in mice and examined the underlying mechanisms. Balb/C mice were injected intravenously with Con A (25mg/kg) to generate a model of acute liver injury. PSS (25 or 50mg/kg) was injected intraperitoneally 1h before the Con A administration. The levels of serum liver enzymes, inflammatory cytokines, and other marker proteins were determined, and liver injury was assessed histopathologically 2, 8, and 24h after Con A injection. Pretreatment with PSS reduced the levels of serum liver enzymes, inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and attenuated histopathological damage in Con A-induced liver injury in mice. The effects of Con A were mediated by apoptosis and autophagy, as indicated by changes in protein and gene expression of related factors after Con A injection. PSS activated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway and showed a protective function against apoptosis and autophagy. PSS ameliorated Con A-induced liver injury by downregulating inflammatory cytokines including TNF-α and IL-1β and regulating apoptosis and autophagy via the PI3K/Akt pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Study of O/W micro- and nano-emulsions based on propylene glycol diester as a vehicle for geranic acid.

PubMed

Jaworska, Małgorzata; Sikora, Elżbieta; Ogonowski, Jan; Konieczna, Monika

2015-01-01

Nano- and microemulsions containing as the oil phase caprylic/capric propylene glycol diesters (Crodamol PC) were investigated as potential vehicle for controlled release of geranic acid. The influence of emulsifiers and co-surfactants on stability of the emulsions was investigated. Different kind of polysorbates (ethoxylated esters of sorbitan and fatty acids) were applied as the emulsifiers. The short-chain alcohols (ethanol, 1-propanol, 1-butanol) were used as co-surfactants. The emulsions were prepared at ambient temperature (25°C), by the phase inversion composition method (PIC). The stable O/W high dispersed emulsion systems based on Crodamol PC, of mean droplets size less than 200 nm, were prepared. Microemulsions stabilized by the mixture of Polisorbat 80 and 1-butanol were characterized by the largest degree of dispersion (137 nm) and the lowest PDI value (0.094), at surfactant/co-surfactant: oil weight ratio 90:10. The stable nano-emulsion (mean droplet size of 33 nm) was obtained for surfactant: oil (S:O) weight ratio 90:10, without co-surfactant addition. This nano-emulsion was chosen to release studies. The obtained results showed that the prepared stable nano-emulsion can be used as a carrier for controlled release of geranic acid. The active substance release from the nano-emulsion and the oil solution, after 24 hours was 22%.

Nanocrystals of medium soluble actives--novel concept for improved dermal delivery and production strategy.

PubMed

Zhai, Xuezhen; Lademann, Jürgen; Keck, Cornelia M; Müller, Rainer H

2014-08-15

After use in oral pharmaceutical products, nanocrystals are meanwhile applied to improve the dermal penetration of cosmetic actives (e.g. rutin, hesperidin) and of drugs. By now, nanocrystals are only dermally applied made from poorly soluble actives. The novel concept is to formulate nanocrystals also from medium soluble actives, and to apply a dermal formulation containing additionally nanocrystals. The nanocrystals should act as fast dissolving depot, increase saturation solubility and especially accumulate in the hair follicles, to further increase skin penetration. Caffeine was used as model compound with relevance to market products, and a particular process was developed for the production of caffeine nanocrystals to overcome the supersaturation related effect of crystal growth and fiber formation - typical with medium soluble compounds. It is based on low energy milling (pearl milling) in combination with low dielectric constant dispersion media (water-ethanol or ethanol-propylene glycol mixtures) and optimal stabilizers. Most successful was Carbopol(®) 981 (e.g. 20% caffeine in ethanol-propylene glycol 3:7 with 2% Carbopol, w/w). Nanocrystals with varied sizes can now be produced in a controlled process e.g. 660 nm (optimal for hair follicle accumulation) to 250 nm (optimal for fast dissolution). The short term test proved stability over 2 months of the present formulation being sufficient to perform in vivo testing of the novel concept. Copyright © 2014 Elsevier B.V. All rights reserved.