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Sample records for 1-ethyl-3-3-dimethylaminopropyl carbodiimide hydrochloride

  1. Comparison of 1-Ethyl-3-(3-Dimethylaminopropyl) Carbodiimide Based Strategies to Crosslink Antibodies on Amine-Functionalized Platforms for Immunodiagnostic Applications.

    PubMed

    Vashist, Sandeep Kumar

    2012-01-01

    1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) alone, and in combination with N-hydroxysuccinimide (NHS) or sulfoNHS were employed for crosslinking anti-human fetuin A (HFA) antibodies on 3-aminopropyltriethoxysilane (APTES)-functionalized surface plasmon resonance (SPR) gold chip and 96-well microtiter plate. The SPR immunoassay and sandwich enzyme linked immunosorbent immunoassay (ELISA) for HFA clearly demonstrated that EDC crosslinks anti-HFA antibodies to APTES-functionalized bioanalytical platforms more efficiently than EDC/NHS and EDC/sulfoNHS at a normal pH of 7.4. Similar results were obtained by sandwich ELISAs for human Lipocalin-2 and human albumin, and direct ELISA for horseradish peroxidase. The more efficient crosslinking of antibodies by EDC to the APTES-functionalized platforms increased the cost-effectiveness and analytical performance of our immunoassays. This study will be of wide interest to researchers developing immunoassays on APTES-functionalized platforms that are being widely used in biomedical diagnostics, biosensors, lab-on-a-chip and point-of-care-devices. It stresses a critical need of an intensive investigation into the mechanisms of EDC-based amine-carboxyl coupling under various experimental conditions. PMID:26859395

  2. Characterization of porous collagen/hyaluronic acid scaffold modified by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide cross-linking.

    PubMed

    Park, Si-Nae; Park, Jong-Chul; Kim, Hea Ok; Song, Min Jung; Suh, Hwal

    2002-02-01

    In order to develop a scaffolding material for tissue regeneration, porous matrices containing collagen and hyaluronic acid were fabricated by freeze drying at -20 degrees C, -70 degrees C or -196 degrees C. The fabricated porous membranes were cross-linked using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in a range of 1-100 mM concentrations for enhancing mechanical stability of the composite matrix. Scanning electron microscope (SEM) views of the matrices demonstrated that the matrices obtained before cross-linking process had interconnected pores with mean diameters of 40, 90 or 230 microm and porosity of 58-66% according to the freezing temperature, and also the porous structures after cross-linking process were retained. The swelling test and IR spectroscopic measurement of different cross-linked membranes were carried out as a measure of the extent of cross-linking. The swelling behavior of cross-linked membranes showed no significant differences as cross-linking degree increased. FT-IR spectra showed the increase of the intensity of the absorbencies at amide bonds (1655, 1546, 1458 cm(-1)) compared to that of CH bond (2930 cm(-1)). In enzymatic degradation test, EDC treated membranes showed significant enhancement of the resistance to collagenase activity in comparison with 0.625% glutaraldehyde treated membranes. In cytotoxicity test using L929 fibroblastic cells, the EDC-cross-linked membranes demonstrated no significant toxicity. PMID:11791924

  3. Effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide concentrations on the mechanical and biological characteristics of cross-linked collagen fibres for tendon repair

    PubMed Central

    Ahmad, Zafar; Shepherd, Jennifer H.; Shepherd, David V.; Ghose, Siddhartha; Kew, Simon J.; Cameron, Ruth E.; Best, Serena M.; Brooks, Roger A.; Wardale, John; Rushton, Neil

    2015-01-01

    Reconstituted type I collagen fibres have received considerable interest as tendon implant materials due to their chemical and structural similarity to the native tissue. Fibres produced through a semi-continuous extrusion process were cross-linked with different concentrations of the zero-length cross-linker 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in combination with N-hydroxysuccinimide (NHS). Tensile properties of the fibres were considered, along with imaging of both surface structure and fibrillar alignment. Resistance of the fibres to bacterial collagenase was investigated and fibre sections seeded with human tendon cells for biological characterization, including cell adhesion and proliferation. The work clearly demonstrated that whilst the concentration of EDC and NHS had no significant effect on the mechanics, a higher concentration was associated with higher collagenase resistance, but also provided a less attractive surface for cell adhesion and proliferation. A lower cross-linking concentration offered a more biocompatible material without reduction in mechanics and with a potentially more optimal degradability. PMID:26816633

  4. Structural changes in photosystem II after treatment with the zero-length bifunctional cross-linker 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide: an electron microscopic study.

    PubMed Central

    Collins, R F; Flint, T D; Holzenburg, A; Ford, R C

    1996-01-01

    Two-dimensional (2D) crystals of photosystem II (PS II) treated with various concentrations of the zero-length crosslinker 1-ethyl-3-(3-dimethylaminopropyl))carbodi-imide (EDC) were analysed by electron microscopy in conjunction with crystallographic image processing. The preparations were characterized by SDS/PAGE and oxygen-evolution measurements, and the effectiveness of cross-linking was monitored by measuring the level of protection afforded against high concentrations of NaCl and CaCl2, which normally remove extrinsic proteins from PS II. We found that low concentrations of EDC (0.25%) increase the order of 2D crystals of PS II. Treatments with EDC concentrations higher than 0.5% did not improve the order of 2D crystals but induced gross structural changes, which were correlated with a decrease in oxygen evolution activity. Structural changes due to cross-linking did not affect packing or symmetry of the 2D crystals, further supporting the conclusion that PS II has a monomeric nature in vivo. PMID:8912698

  5. Development and evaluation of buccoadhesive tablet for selegiline hydrochloride based on thiolated polycarbophil.

    PubMed

    Wasnik, Mangesh N; Godse, Rutika D; Nair, Hema A

    2014-05-01

    Selegiline hydrochloride (SHCl), a monoamine oxidase B inhibitor, is used as an adjunct in the therapy of Parkinson's disease. This study is concerned with the preparation and evaluation of mucoadhesive buccal tablet for controlled systemic delivery of SHCl. Buccal absorption of selegiline can bypass its first-pass metabolism and improve bioavailability accompanied by greatly reduced metabolite formation, which is potentially of enhanced therapeutic value in patients with Parkinson's disease. Polycarbophil-cysteine (PCP-cys) conjugate, which is a thiolated derivative of the mucoadhesive polymer polycarbophil, was synthesized by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride-mediated amide bond coupling. Tablets of SHCl based on native and thiolated polycarbophil were prepared. The prepared tablets were evaluated for drug content, swelling behavior, mucoadhesive strength, in vitro drug release, ex vivo permeation and in vitro cytotoxicity. PCP-cys tablets showed enhanced mucoadhesion and retarded drug release compared to polycarbophil tablets. Permeation data of SHCl from matrices prepared using the PCP-cys polymer revealed a significantly higher value of apparent permeability in comparison to polycarbophil, which supported the information in literature that thiolation imparts permeation enhancing properties to mucoadhesive polymers. In vitro cytotoxicity studies on PCP-cys using L-929 mouse fibroblast cell line indicated that conjugation with cysteine does not impart any apparent toxicity to polycarbophil. The results from the study indicate that the buccal delivery of SHCl using thiolated polycarbophil tablet could provide a way for improved therapy of Parkinson's disease. PMID:24517570

  6. Long-term effect of carbodiimide on dentin matrix and resin-dentin bonds

    PubMed Central

    Bedran-Russo, Ana Karina B.; Vidal, Cristina M.P.; Dos Santos, Paulo H.; Castellan, Carina S.

    2010-01-01

    Objectives To characterize the interaction of 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide Hydrochloride (EDC) with dentin matrix and its effect on the resin-dentin bond. Methods Changes to the stiffness of demineralized dentin fragments treated with EDC/N-hydroxysuccinimide (NHS) in different solutions were evaluated at different time points. The resistance against enzymatic degradation was indirectly evaluated by ultimate tensile strength (UTS) test of demineralized dentin treated or not with EDC/NHS and subjected to collagenase digestion. Short- and long-term evaluations of the strength of resin-dentin interfaces treated with EDC/NHS for 1 hour were performed using microtensile bond strength (µTBS) test. All data (MPa) were individually analyzed using ANOVA and Tukey HSD tests (α=0.05). Results The different exposure times significantly increased the stiffness of dentin (p<0.0001, control - 5.15 and EDC/NHS - 29.50), while no differences were observed among the different solutions of EDC/NHS (p=0.063). Collagenase challenge did not affect the UTS values of EDC/NHS group (6.08) (p>0.05), while complete degradation was observed for the control group (p=0.0008, control - 20.84 and EDC/NHS - 43.15). EDC/NHS treatment did not significantly increase resin-dentin µTBS, but the values remained stable after 12 months water storage (p<0.05). Conclusions Biomimetic use of EDC/NHS to induce exogenous collagen cross-links resulted in increased mechanical properties and stability of dentin matrix and dentin-resin interfaces. PMID:20524201

  7. Quantum dot-antibody conjugates via carbodiimide-mediated coupling for cellular imaging.

    PubMed

    East, Daniel Alistair; Todd, Michael; Bruce, Ian James

    2014-01-01

    This chapter describes the processes of antibody (Ab) production, purification, conjugation to quantum dots (QDs), and the use of the conjugates produced in intracellular imaging of cell components and structures. Specifically, information is provided on the conjugation of carboxyl surface-terminated QDs to Abs via a one-step reaction using the water-soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The chapter details the process of conjugate optimization in terms of its final fluorescence and biological activity. The method described should guarantee the production of QD-Ab conjugates, which outperform classic organic fluorophore-Ab conjugates in terms of both image definition produced and the longevity of the imaging agent. PMID:25103800

  8. Stability of water-soluble carbodiimides in aqueous solution.

    PubMed

    Gilles, M A; Hudson, A Q; Borders, C L

    1990-02-01

    A dimethylbarbituric acid reagent has been used to follow the kinetics of loss of two water-soluble carbodiimides, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and the structurally related 1-ethyl-3-(4-azonia-4,4-dimethylpentyl) carbodiimide (EAC), in aqueous solution as a function of pH and added chemical reagents. In 50 mM 2-(N-morpholino)ethanesulfonic acid at 25 degrees C, EDC has t1/2 values of 37, 20, and 3.9 h at pH 7.0, 6.0, and 5.0, respectively, while the corresponding values for EAC are 12, 2.9, and 0.32 h. Iodide, bromide, or chloride, at 0.1 M, has very little or no effect on carbodiimide stability. However, 0.1 M glycine methyl ester or 0.1 M ethylenediamine causes a significant increase in the rate of loss of EAC and EDC, while the presence of 0.1 M phosphate, 0.1 M hydroxylamine, or 0.01 M ATP decreases the half-lives to less than or equal to 0.4 h at all pH values. PMID:2158246

  9. Carbodiimide Inactivation of MMPs and Effect on Dentin Bonding

    PubMed Central

    Mazzoni, A.; Apolonio, F.M.; Saboia, V.P.A.; Santi, S.; Angeloni, V.; Checchi, V.; Curci, R.; Di Lenarda, R.; Tay, F.R.; Pashley, D.H.; Breschi, L.

    2014-01-01

    The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. This study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linker to inhibit matrix metalloproteinase (MMP) activity. The hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) EDC pre-treatment prevents this enzymatic activity. The zymographic assay was performed on protein extracts obtained from dentin powder treated with Optibond FL or Scotchbond 1XT with or without 0.3M EDC pre-treatment. For in situ zymography, adhesive/dentin interfaces were created with the same adhesives applied to acid-etched dentin slabs pre-treated or not with EDC conditioner. Zymograms revealed increased expression of dentin endogenous MMP-2 and -9 after adhesive application, while the use of EDC as a primer inactivated dentin gelatinases. Results of in situ zymograpy showed that hybrid layers of tested adhesives exhibited intense collagenolytic activity, while almost no fluorescence signal was detected when specimens were pre-treated with EDC. The correlative analysis used in this study demonstrated that EDC could contribute to inactivate endogenous dentin MMPs within the hybrid layer created by etch-and-rinse adhesives. PMID:24334409

  10. Carbodiimide inactivation of MMPs and effect on dentin bonding.

    PubMed

    Mazzoni, A; Apolonio, F M; Saboia, V P A; Santi, S; Angeloni, V; Checchi, V; Curci, R; Di Lenarda, R; Tay, F R; Pashley, D H; Breschi, L

    2014-03-01

    The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. This study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linker to inhibit matrix metalloproteinase (MMP) activity. The hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) EDC pre-treatment prevents this enzymatic activity. The zymographic assay was performed on protein extracts obtained from dentin powder treated with Optibond FL or Scotchbond 1XT with or without 0.3M EDC pre-treatment. For in situ zymography, adhesive/dentin interfaces were created with the same adhesives applied to acid-etched dentin slabs pre-treated or not with EDC conditioner. Zymograms revealed increased expression of dentin endogenous MMP-2 and -9 after adhesive application, while the use of EDC as a primer inactivated dentin gelatinases. Results of in situ zymograpy showed that hybrid layers of tested adhesives exhibited intense collagenolytic activity, while almost no fluorescence signal was detected when specimens were pre-treated with EDC. The correlative analysis used in this study demonstrated that EDC could contribute to inactivate endogenous dentin MMPs within the hybrid layer created by etch-and-rinse adhesives. PMID:24334409

  11. The effect of solvent composition on grafting gallic acid onto chitosan via carbodiimide.

    PubMed

    Guo, Ping; Anderson, John D; Bozell, Joseph J; Zivanovic, Svetlana

    2016-04-20

    The primary antioxidant (AOX) activity of chitosan can be introduced by grafting of phenolic compound - gallic acid (GA) to its amino and/or hydroxyl groups. The objective of this study was to investigate the effect of ethanol (EtOH) concentration (0%, 25%, 50%, and 75% in water) on efficiency of grafting GA onto chitosan in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/N-hydroxysuccinimide (NHS). The grafting was confirmed by FTIR and the efficiency was quantified as Folin's total phenolics. When pure deionized water was used as a sole solvent (0% EtOH), GA was grafted to chitosan at the largest extent (285.9mg GA/g chitosan). As the concentration of EtOH increased, the grafting efficiency proportionally decreased. NMR studies showed that EtOH inhibited grafting of GA by prohibiting the production of the intermediate - NHS ester. The results confirm that the concentration of EtOH in grafting solution significantly affects grafting efficiency of GA on chitosan. PMID:26876841

  12. Effect of carbodiimide cross-linking of decellularized porcine pulmonary artery valvular leaflets.

    PubMed

    Xu, Xiu-Fang; Guo, Hai-Ping; Ren, Xue-Jun; Gong, Da; Ma, Jin-Hui; Wang, Ai-Ping; Shi, Hai-Feng; Xin, Yi; Wu, Ying; Li, Wen-Bin

    2014-01-01

    Decellularization provides low immunogenicity and is only slightly subject to calcification in tissue engineering. However, the mechanical properties of the tissues are weakened after decellularization. We adopted cross-linking agent 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) to treat decellularized porcine pulmonary artery valvular leaflets to improve their mechanical properties. Twenty porcine pulmonary artery valvular leaflets were divided into three groups: the fresh control group A, group B treated with trypsin and Triton X-100 to remove cells, and group C cross-linked with EDC after decellularization. All samples were evaluated the physical and mechanical properties and were then subcutaneously embedded in rabbits. These valvular leaflets were removed after 1, 2, or 4 weeks and checked for pathological changes. The cells of the valvular leaflets were completely removed. The thickness of the valvular leaflets was thinner in group B than in group A (P<0.01). In the subcutaneous embedding of the group B samples, there was mild immunological response after 1-2 weeks, and parts of the scaffolds were degraded. After 4 weeks, fibroblasts had grown into the scaffolds. In group C, there was an increase in the tensile strength and thermal shrinkage temperature in group C compared with group B (P<0.01). In subcutaneous embedding of the group C samples, there was a mild immunological response after 1-2 weeks. The fibroblasts had grown into the samples. The EDC-based cross-linking procedure can enhance the tensile strength of decellularized pulmonary artery valvular leaflets and both decrease the valvular leaflets' rejection and promote tissue regeneration in vivo. PMID:24753759

  13. Effect of Carbodiimide on Bonding Durability of Adhesive-cemented Fiber Posts in Root Canals.

    PubMed

    Shafiei, F; Yousefipour, B; Mohammadi-Bassir, M

    2016-01-01

    This study was undertaken to investigate whether using a protein cross-linker, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), improves bonding stability of fiber posts to root dentin using three resin cements. Sixty human maxillary central incisor roots were randomly divided into six groups after endodontic treatment, according to the cements used with and without EDC pretreatment. In the etch-and-rinse group, 0.3 M EDC aqueous solution was applied on acid-etched root dentin prior to Excite DSC/Variolink II for post cementation. In the self-etch and self-adhesive groups, EDC was used on EDTA-conditioned root space prior to application of ED Primer II/Panavia F2.0 and Clearfil SA, respectively. After microslicing the root dentin, a push-out bond strength (BS) test was performed immediately or after one-year of water storage for each group. Data were analyzed using three-way analysis of variance and Tukey tests (α=0.05). A significant effect of cement type, time, EDC, and Time × Cement and Time × EDC interactions were observed (p≤0.001). EDC pretreatment did not affect immediate bonding of the three cements (p>0.05). Aging significantly reduced the BS in all the groups (p≤0.001), but EDC groups exhibited a higher BS compared with the respective control groups (p<0.001). Despite the significant effect of aging on decreasing the BS of fiber post to radicular dentin, EDC could diminish this effect for the three tested cements. PMID:26794191

  14. Carbodiimide Cross-linking Inactivates Soluble and Matrix-bound MMPs, in vitro

    PubMed Central

    Tezvergil-Mutluay, A.; Mutluay, M.M.; Agee, K.A.; Seseogullari-Dirihan, R.; Hoshika, T.; Cadenaro, M.; Breschi, L.; Vallittu, P.; Tay, F.R.; Pashley, D.H.

    2012-01-01

    Matrix metalloproteinases (MMPs) cause collagen degradation in hybrid layers created by dentin adhesives. This in vitro study evaluated the feasibility of using a cross-linking agent, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), to inactivate soluble rhMMP-9, as an example of dentin MMPs, and matrix-bound dentin proteases. The inhibitory effects of 5 EDC concentrations (0.01-0.3 M) and 5 incubation times (1-30 min) on soluble rhMMP-9 were screened with an MMP assay kit. The same EDC concentrations were used to evaluate their inhibitory effects on endogenous proteinases from completely demineralized dentin beams that were incubated in simulated body fluid for 30 days. Decreases in modulus of elasticity (E) and dry mass of the beams, and increases in hydroxyproline content of hydrolysates derived from the incubation medium were used as indirect measures of matrix collagen hydrolysis. All EDC concentrations and pre-treatment times inactivated MMP-9 by 98% to 100% (p < 0.05) compared with non-cross-linked controls. Dentin beams incubated in 0.3 M EDC showed only a 9% decrease in E (45% decrease in control), a 3.6% to 5% loss of dry mass (18% loss in control), and significantly less solubilized hydroxyproline when compared with the control without EDC cross-linking (p < 0.05). It is concluded that EDC application for 1 min may be a clinically relevant and effective means for inactivating soluble rhMMP-9 and matrix-bound dentin proteinases if further studies demonstrate that EDC is not toxic to pulpal tissues. PMID:22058118

  15. Integrated reactive ion etching to pattern cross-linked hydrophilic polymer structures for protein immobilization

    NASA Astrophysics Data System (ADS)

    Bhatnagar, Parijat; Strickland, Aaron D.; Kim, Il; Malliaras, George G.; Batt, Carl A.

    2007-04-01

    Patterning of cross-linked hydrophilic polymer features using reactive ion etching (RIE) capable of covalently immobilizing proteins has been achieved. Projection photolithography was used to pattern photoresist to create micromolds. Vapor phase molecular self-assembly of polymerizable monolayer in molds allowed covalent binding of hydrogel on surface during free-radical polymerization. Excess hydrogel blanket film was consumed with oxygen RIE resulting into hydrogel pattern of 1μm size aligned to prefabricated silicon oxide structures. Proteins were finally coupled through their primary amine groups selectively to acid functionalized hydrogel features through stable amide linkages using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride and N-hydroxysulfosuccinimide.

  16. Comparison of EDC and DMTMM efficiency in glycoconjugate preparation.

    PubMed

    Farkaš, Pavol; Čížová, Alžbeta; Bekešová, Slávka; Bystrický, Slavomír

    2013-09-01

    A series of mono- or disaccharide-protein conjugates were prepared by amide bond formation. Incorporation efficiency of the aminosaccharides on bovine serum albumin was determined by colorimetry and matrix assisted laser desorption/ionization mass spectrometry. Study compares two amide bond coupling agents, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. Paper demonstrates a practical usefulness of natural bovine serum albumin succinylation. Large number of its carboxyl groups results in its superior reactivity towards simple aminosaccharides. PMID:23791662

  17. The Anti-calcification Effect of Dithiobispropionimidate, Carbodiimide and Ultraviolet Irradiation Cross-linking Compared to Glutaraldehyde in Rabbit Implantation Models

    PubMed Central

    Park, Samina; Kim, Soo Hwan; Lim, Hong-Gook; Lim, Cheong

    2013-01-01

    Background Glutaraldehyde (GA) is a widely used cross-linking agent for improving mechanical properties and resistance to enzymatic degradation of collagenous tissue, but it has several drawbacks such as calcification and cytotoxicity. The aim of this study was to find the alternative effective cross-linking methods to GA. Materials and Methods Bovine pericardium was processed with GA with ethanol+octanol and glycine detoxification, and polyethylene glycol (PG) space filler, dimethyl 3,3'-dithiobispropionimidate (DTBP), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) treatment, and the physical fixation of ultraviolet irradiation were done. The biologic material properties of variously treated pericardial tissues were assessed by biochemical, mechanical and histological tests. Treated pericardial tissues were also implanted subcutaneously or intramuscularly into the rabbit for 10 weeks to assess the xenoreactive antibody response of immunoglobulin G and M, their anti-calcification effect. Results The biochemical and mechanical properties of EDC fixed pericardial tissues were comparable to the GA fixed tissue. The cytotoxicity was lowest in space filler treated GA fixed group. In rabbit subcutaneous or intramuscular implantation models, decellularization, space filler, EDC treatment group showed significantly lower calcium content than GA only and DTBP treatment group (p<0.05, analysis of variance). The titer of anti Galα1-3Galβ1-4GlcNAc-R antibodies did not change in the postimplantation serial enzyme-linked immunosorbent assay. Hematoxylin and eosin and von Kossa staining showed that decellularization, space filler, EDC, and ultraviolet treatment had less inflammatory cell infiltration and calcium deposits. Conclusion The decellularization process, PG filler, and EDC treatments are good alternative cross-linking methods compared to GA only fixation and primary amine of DTBP treatment for cardiovascular xenograft preservation in terms of the collagen cross

  18. Protein immobilization on the surface of polydimethylsiloxane and polymethyl methacrylate microfluidic devices.

    PubMed

    Khnouf, Ruba; Karasneh, Dina; Albiss, Borhan Aldeen

    2016-02-01

    PDMS and PMMA are two of the most used polymers in the fabrication of lab-on-chip or microfluidic devices. In order to use these polymers in biological applications, it is sometimes essential to be able to bind biomolecules such as proteins and DNA to the surface of these materials. In this work, we have evaluated a number of processes that have been developed to bind protein to PDMS surfaces which include passive adsorption, passive adsorption with glutaraldehyde cross-linking, (3-aminopropyl) triethoxysilane functionalization followed by glutaraldehyde or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride cross-linkers. It has been shown that the latter technique--using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride--results in more than twice the bonding of protein to the surface of PDMS microchannels than proteins binding passively. We have also evaluated a few techniques that have been tested for the functionalization of PMMA microchannels where we have found that the use of polyethyleneimine (PEI) has led to the strongest protein-PMMA microchannel bond. We finally demonstrated the effect of PDMS curing methodology on protein adsorption to its surface, and showed that increased curing time is the factor that reduces passive adsorption the most. PMID:26534833

  19. Preparation of thin film nanofibrous composite NF membrane based on EDC/NHS modified PAN-AA nanofibrous substrate

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Wang, X.; Hsiao, B. S.

    2016-07-01

    A novel kind of thin-film nanofibrous composite (TFNC) nanofiltration (NF) membranes consisting of a polyamide (PA) barrier layer were successfully fabricated by interfacial polymerization (IFP) based on electrospun double-layer nanofibrous substrates, which have an ultrathin poly (acrylonitrile-co-acrylic acid) (PAN-AA) nanofibrous layer as top layer and a thicker polyacrylonitrile (PAN) nanofiber layer as bottom porous support layer. Immersing PAN/PAN-AA nanofibrous substrates into 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) aqueous solution and piperazine (PIP) aqueous solution (0.20 wt%) sequentially for a period of time, the carboxyl groups on PAN-AA nanofibers were activated by carbodiimide and then reacted with the amide groups. The as prepared composite membrane has an integrated structure with high rejection rate (98.0%); high permeate flux (40.4 L/m2h) for MgSO4 aqueous solution (2 g/L).

  20. Oxidized SWCNT chemically attached to a modified copper substrate

    NASA Astrophysics Data System (ADS)

    Hernandez, Dionne; Cabrera, Carlos R.; Mendez, Laura; Diaz-Serrano, Madeline; Vega, Omar; Weiner, Brad R.; Rosa, Luis G.

    2015-08-01

    Oxidized single-wall carbon nanotubes were chemically attached to a modified copper substrate by means of a 4-aminothiophenol (4-ATP) self-assembly monolayer (SAM). This bottom up approach offers a low cost route to attach carbon nanotubes by using a condensation reaction. Here, the exposed amine from the 4-ATP SAM reacts with the carboxylic group (COOH) on the CNT. The reaction was followed using ATR-FTIR and the surface was characterized using SEM, XPS, and Raman. The analytical techniques used on this study suggest that the condensation reaction employed using a carbodiimide such as 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) produced SWCNT attached to the copper substrate.

  1. Antifouling ultrafiltration membranes via post-fabrication grafting of biocidal nanomaterials.

    PubMed

    Mauter, Meagan S; Wang, Yue; Okemgbo, Kaetochi C; Osuji, Chinedum O; Giannelis, Emmanuel P; Elimelech, Menachem

    2011-08-01

    Ultrafiltration (UF) membranes perform critical pre-treatment functions in advanced water treatment processes. In operational systems, however, biofouling decreases membrane performance and increases the frequency and cost of chemical cleaning. The present work demonstrates a novel technique for covalently or ionically tethering antimicrobial nanoparticles to the surface of UF membranes. Silver nanoparticles (AgNPs) encapsulated in positively charged polyethyleneimine (PEI) were reacted with an oxygen plasma modified polysulfone UF membrane with and without 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) present. The nucleophilic primary amines of the PEI react with the electrophilic carboxyl groups on the UF membrane surface to form electrostatic and covalent bonds. The irreversible modification process imparts significant antimicrobial activity to the membrane surface. Post-synthesis functionalization methods, such as the one presented here, maximize the density of nanomaterials at the membrane surface and may provide a more efficient route for fabricating diverse array of reactive nanocomposite membranes. PMID:21736330

  2. The Dimerization State of the Mammalian High Mobility Group Protein AT-Hook 2 (HMGA2)

    PubMed Central

    Frost, Lorraine; Baez, Maria A. M.; Harrilal, Christopher; Garabedian, Alyssa; Fernandez-Lima, Francisco; Leng, Fenfei

    2015-01-01

    The mammalian high mobility group protein AT-hook 2 (HMGA2) is a chromosomal architectural transcription factor involved in cell transformation and oncogenesis. It consists of three positively charged “AT-hooks” and a negatively charged C-terminus. Sequence analyses, circular dichroism experiments, and gel-filtration studies showed that HMGA2, in the native state, does not have a defined secondary or tertiary structure. Surprisingly, using combined approaches of 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) chemical cross-linking, analytical ultracentrifugation, fluorescence resonance energy transfer (FRET), and mass spectrometry, we discovered that HMGA2 is capable of self-associating into homodimers in aqueous buffer solution. Our results showed that electrostatic interactions between the positively charged “AT-hooks” and the negatively charged C-terminus greatly contribute to the homodimer formation. PMID:26114780

  3. DNA attachment to nanocrystalline diamond films

    NASA Astrophysics Data System (ADS)

    Wenmackers, S.; Christiaens, P.; Daenen, M.; Haenen, K.; Nesládek, M.; van Deven, M.; Vermeeren, V.; Michiels, L.; Ameloot, M.; Wagner, P.

    2005-09-01

    A biochemical method to immobilize DNA on synthetic diamond for biosensor applications is developed. Nanocrystalline diamond is grown using microwave plasma-enhanced chemical vapour deposition. On the hydrogen-terminated surface 10-undecenoic acid is tethered photochemically under 254 nm illumination, followed by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide crosslinker-mediated attachment of amino modified DNA. The attachment is functionally confirmed by comparison of supernatant fluorescence and gel electrophoresis. The linking procedure allowed for 35 denaturation and rehybridisation steps.

  4. Development of an ELISA and Immunochromatographic Strip for Highly Sensitive Detection of Microcystin-LR

    PubMed Central

    Liu, Liqiang; Xing, Changrui; Yan, Huijuan; Kuang, Hua; Xu, Chuanlai

    2014-01-01

    A monoclonal antibody for microcystin–leucine–arginine (MC-LR) was produced by cell fusion. The immunogen was synthesized in two steps. First, ovalbumin/ bovine serum albumin was conjugated with 6-acetylthiohexanoic acid using a carbodiimide EDC (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride)/ NHS (N-hydroxysulfosuccinimide) reaction. After dialysis, the protein was reacted with MC-LR based on a free radical reaction under basic solution conditions. The protein conjugate was used for immunization based on low volume. The antibodies were identified by indirect competitive (ic)ELISA and were subjected to tap water and lake water analysis. The concentration causing 50% inhibition of binding of MC-LR (IC50) by the competitive indirect ELISA was 0.27 ng/mL. Cross-reactivity to the MC-RR, MC-YR and MC-WR was good. The tap water and lake water matrices had no effect on the detection limit. The analytical recovery of MC-LR in the water samples in the icELISA was 94%–110%. Based on this antibody, an immunochromatographic biosensor was developed with a cut-off value of 1 ng/mL, which could satisfy the requirement of the World Health Organization for MC-LR detection in drinking water. This biosensor could be therefore be used as a fast screening tool in the field detection of MC-LR. PMID:25120158

  5. Collagen-hyaluronic acid scaffolds for adipose tissue engineering.

    PubMed

    Davidenko, N; Campbell, J J; Thian, E S; Watson, C J; Cameron, R E

    2010-10-01

    Three-dimensional (3-D) in vitro models of the mammary gland require a scaffold matrix that supports the development of adipose stroma within a robust freely permeable matrix. 3-D porous collagen-hyaluronic acid (HA: 7.5% and 15%) scaffolds were produced by controlled freeze-drying technique and crosslinking with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride. All scaffolds displayed uniform, interconnected pore structure (total porosity approximately 85%). Physical and chemical analysis showed no signs of collagen denaturation during the formation process. The values of thermal characteristics indicated that crosslinking occurred and that its efficiency was enhanced by the presence of HA. Although the crosslinking reduced the swelling of the strut material in water, the collagen-HA matrix as a whole tended to swell more and show higher dissolution resistance than pure collagen samples. The compressive modulus and elastic collapse stress were higher for collagen-HA composites. All the scaffolds were shown to support the proliferation and differentiation 3T3-L1 preadipocytes while collagen-HA samples maintained a significantly increased proportion of cycling cells (Ki-67+). Furthermore, collagen-HA composites displayed significantly raised Adipsin gene expression with adipogenic culture supplementation for 8 days vs. control conditions. These results indicate that collagen-HA scaffolds may offer robust, freely permeable 3-D matrices that enhance mammary stromal tissue development in vitro. PMID:20466086

  6. Direct competitive chemiluminescence immunoassays based on gold-coated magnetic particles for detection of chloramphenicol.

    PubMed

    Liang, Xiaohui; Fang, Xiangyi; Yao, Manwen; Yang, Yucong; Li, Junfeng; Liu, Hongjun; Wang, Linyu

    2016-02-01

    Direct competitive chemiluminescence immunoassays (CLIA) based on gold-coated magnetic nanospheres (Au-MNPs) were developed for rapid analysis of chloramphenicol (CAP). The Au-MNPs were modified with carboxyl groups and amino groups by 11-mercaptoundecanoic acid (MUA) and cysteamine respectively, and then were respectively conjugated with CAP base and CAP succinate via an activating reaction using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). NSP-DMAE-NHS, a new and effective luminescence reagent, was employed to label anti-CAP antibody (mAb) as a tracer in direct CLIA for CAP detection using a 'homemade' luminescent measurement system that was set up with a photomultiplier tube (PMT) and a photon counting unit linked to a computer. The sensitivities and limits of detection (LODs) of the two methods were obtained and compared according to the inhibition curves. The 50% inhibition concentration (IC50 ) values of the two methods were about 0.044 ng/mL and 0.072 ng/mL respectively and LODs were approximately 0.001 ng/mL and 0.006 ng/mL respectively. To our knowledge, they were much more sensitive than any traditional enzyme-linked immunosorbent assay (ELISA) ever reported. Moreover, the new luminescence reagent NSP-DMAE-NHS is much more sensitive and stable than luminol and its derivatives, contributing to the sensitivity enhancement. PMID:26031849

  7. Three-Dimensional Supermacroporous Carrageenan-Gelatin Cryogel Matrix for Tissue Engineering Applications

    PubMed Central

    Sharma, Archana; Bhat, Sumrita; Vishnoi, Tanushree; Nayak, Vijayashree; Kumar, Ashok

    2013-01-01

    A tissue-engineered polymeric scaffold should provide suitable macroporous structure similar to that of extracellular matrix which can induce cellular activities and guide tissue regeneration. Cryogelation is a technique in which appropriate monomers or polymeric precursors frozen at sub-zero temperature leads to the formation of supermacroporous cryogel matrices. In this study carrageenan-gelatin (natural polymers) cryogels were synthesized by using glutaraldehyde and 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride and N-hydroxysuccinimide (EDC-NHS) as crosslinking agent at optimum concentrations. Matrices showed large and interconnected pores which were in the range of 60–100 μm diameter. Unconfined compression analysis showed elasticity and physical integrity of all cryogels, as these matrices regained their original length after 90% compressing from the original size. Moreover Young's modulus was found to be in the range of 4–11 kPa for the dry cryogel sections. These cryogels also exhibited good in vitro degradation capacity at 37 °C within 4 weeks of incubation. Supermacroporous carrageenan-gelatin cryogels showed efficient cell adherence and proliferation of Cos-7 cells which was examined by SEM. PI nuclear stain was used to observe cell-matrix interaction. Cytotoxicity of the scaffolds was checked by MTT assay which showed that cryogels are biocompatible and act as a potential material for tissue engineering and regenerative medicine. PMID:23936806

  8. Binding of mouse immunoglobulin G to polylysine-coated glass substrate for immunodiagnosis

    NASA Astrophysics Data System (ADS)

    Vashist, Sandeep Kumar; Tewari, Rupinder; Bajpai, Ram Prakash; Bharadwaj, Lalit Mohan; Raiteri, Roberto

    2006-12-01

    We report a method for immobilizing mouse immunoglobulin G (IgG) on polylysine-coated glass substrate for immunodiagnostic applications. Mouse IgG molecules were immobilized on polylysine-coated glass substrate employing 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and protein A. The amino groups of the polylysine-coated glass slide were cross linked to the carboxyl groups of protein A employing EDC crosslinker. Protein A was employed as it binds to the constant Fc region of antibodies keeping their antigen binding sites on the variable F ab region free to bind to antigens. The qualitative analysis of surface immobilized mouse IgG was done by fluorescent microscopy employing fluorescein isothiocyanate (FITC) labeled mouse IgG molecules. The immobilization densities of protein A and mouse IgG were determined by 3, 3', 4, 4'-tetramethyl benzidine (TMB) substrate assay employing horse radish peroxidise labelled molecules and were found to be 130 +/- 17 ng/cm2 and 596 +/- 31 ng/cm2 respectively. The biomolecular coatings analyzed by atomic force microscopy (AFM) were found to be uniform.

  9. Preparation of cross-linked carboxymethyl chitosan for repairing sciatic nerve injury in rats.

    PubMed

    Wang, Gan; Lu, Guangyuan; Ao, Qiang; Gong, Yandao; Zhang, Xiufang

    2010-01-01

    A successful nerve regeneration process was achieved with nerve repair tubes made up of 1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) cross-linked carboxymethyl chitosan (CM-chitosan) with improved biodegradability. Chitosan has a very slow degradation rate, while the EDC cross-linked CM-chitosan tubes degraded to 30% of original weight during 8 weeks of incubation in lysozyme solution. In vitro cell culture indicated that the CM-chitosan films presented no cytotoxicity to Schwann cells. From in vivo studies using a 10 mm rat sciatic nerve defect model investigated by histomorphometry analysis, the average diameter of the fibers and the average thickness of myelin sheath in the CM-chitosan tubes were 3.7 +/- 0.33 and 0.33 +/- 0.04 mum, respectively, which demonstrated equivalence to nerve autografts (the current "gold" standard); furthermore, the average fiber density in the CM-chitosan tubes was 20.5 x 10(3)/mm(2), which was similar to that of autografts (21 x 10(3)/mm(2)) and significantly higher than that of common chitosan tubes (15.3 x 10(3)/mm(2)). PMID:19760120

  10. Surface plasmon resonance-based immunoassay for procalcitonin.

    PubMed

    Vashist, Sandeep Kumar; Schneider, E Marion; Barth, Eberhard; Luong, John H T

    2016-09-28

    A surface plasmon resonance (SPR) biosensor has been developed for rapid immunoassay of procalcitonin (PCT) with high detection sensitivity and reproducibility. The 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC)-activated protein A (PrA), diluted in 1% (v/v) 3-aminopropyltriethoxysilane (APTES) was dispensed on a KOH-treated Au-coated SPR chip, resulting in the covalent binding of PrA in 30 min. This "single-step" PrA immobilization strategy led to the oriented binding of the anti-PCT antibody (Ab) on a PrA-functionalized gold (Au) chip. The leach-proof immobilization procedure is five-fold faster than conventional counterparts, enabling high detection specificity and reproducibility. The IA detects 4-324 ng mL(-1) of PCT with a limit of detection (LOD) and a limit of quantification (LOQ) of 4.2 ng mL(-1) and 9.2 ng mL(-1), respectively. It was capable of detecting PCT in real sample matrices and patient samples with high precision. The Ab-bound SPR chips were stable for more than five weeks. PMID:27619095

  11. In vitro characterization of MG-63 osteoblast-like cells cultured on organic-inorganic lyophilized gelatin sponges for early bone healing.

    PubMed

    Rodriguez, Isaac A; Saxena, Gunjan; Hixon, Katherine R; Sell, Scott A; Bowlin, Gary L

    2016-08-01

    The development of three-dimensional porous scaffolds with enhanced osteogenic and angiogenic potential would be beneficial for inducing early-stage bone regeneration. Previous studies have demonstrated the advantages of mineralized and nonmineralized acellular 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) cross-linked gelatin sponges enhanced with preparations rich in growth factors, hydroxyapatite, and chitin whiskers. In this study, those same scaffolds were mineralized and dynamically seeded with MG-63 cells. Cell proliferation, protein/cytokine secretion, and compressive mechanical properties of scaffolds were evaluated. It was found that mineralization and the addition of growth factors increased cell proliferation compared to gelatin controls. Cells on all scaffolds responded in an appropriate bone regenerative fashion as shown through osteocalcin secretion and little to no secretion of bone resorbing markers. However, compressive mechanical properties of cellularized scaffolds were not significantly different from acellular scaffolds. The combined results of increased cellular attachment, infiltration, and bone regenerative protein/cytokine secretion on scaffolds support the need for the addition of a bone-like mineral surface. Cellularized scaffolds containing growth factors reported similar advantages and mechanical values in the range of native tissues present in the early stages of bone healing. These results suggest that the developed composite sponges exhibited cellular responses and mechanical properties appropriate for promoting early bone healing in various applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2011-2019, 2016. PMID:27038217

  12. Effectiveness of tobramycin conjugated to iron oxide nanoparticles in treating infection in cystic fibrosis

    NASA Astrophysics Data System (ADS)

    Brandt, Yekaterina I.; Armijo, Leisha M.; Rivera, Antonio C.; Plumley, John B.; Cook, Nathaniel C.; Smolyakov, Gennady A.; Smyth, Hugh D. C.; Osiński, Marek

    2013-02-01

    Cystic fibrosis (CF) is an inherited childhood-onset life-shortening disease. It is characterized by increased respiratory production, leading to airway obstruction, chronic lung infection and inflammatory reactions. The most common bacteria causing persisting infections in people with CF is Pseudomonas aeruginosa. Superparamagnetic Fe3O4 iron oxide nanoparticles (NPs) conjugated to the antibiotic (tobramycin), guided by a gradient of the magnetic field or subjected to an oscillating magnetic field, show promise in improving the drug delivery across the mucus and P. aeruginosa biofilm to the bacteria. The question remains whether tobramycin needs to be released from the NPs after the penetration of the mucus barrier in order to act upon the pathogenic bacteria. We used a zero-length 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) crosslinking agent to couple tobramycin, via its amine groups, to the carboxyl groups on Fe3O4 NPs capped with citric acid. The therapeutic efficiency of Fe3O4 NPs attached to the drug versus that of the free drug was investigated in P. aeruginosa culture.

  13. Bioconjugate functionalization of thermally carbonized porous silicon using a radical coupling reaction†

    PubMed Central

    Sciacca, Beniamino; Alvarez, Sara D.; Geobaldo, Francesco; Sailor, Michael J.

    2011-01-01

    The high stability of Salonen’s thermally carbonized porous silicon (TCPSi) has attracted attention for environmental and biochemical sensing applications, where corrosion-induced zero point drift of porous silicon-based sensor elements has historically been a significant problem. Prepared by the high temperature reaction of porous silicon with acetylene gas, the stability of this silicon carbide-like material also poses a challenge—many sensor applications require a functionalized surface, and the low reactivity of TCPSi has limited the ability to chemically modify its surface. This work presents a simple reaction to modify the surface of TCPSi with an alkyl carboxylate. The method involves radical coupling of a dicarboxylic acid (sebacic acid) to the TCPSi surface using a benzoyl peroxide initiator. The grafted carboxylic acid species provides a route for bioconjugate chemical modification, demonstrated in this work by coupling propylamine to the surface carboxylic acid group through the intermediacy of pentafluorophenol and 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC). The stability of the carbonized porous Si surface, both before and after chemical modification, is tested in phosphate buffered saline solution and found to be superior to either hydrosilylated (with undecylenic acid) or thermally oxidized porous Si surfaces. PMID:20967329

  14. Application of suspension array for simultaneous detection of four different mycotoxins in corn and peanut.

    PubMed

    Wang, Ying; Ning, Baoan; Peng, Yuan; Bai, Jialei; Liu, Ming; Fan, Xianjun; Sun, Zhiyong; Lv, Zhiqiang; Zhou, Caihong; Gao, Zhixian

    2013-03-15

    Mycotoxins are highly toxic contaminants in foodstuffs and feedstuffs. The study presents a novel suspension array technology for quantifying four mycotoxins, namely, aflatoxin B1, deoxynivalenol, T-2 toxin, and zearalenone, in corn and peanut. Using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, the complete antigens of the mycotoxins became attached to the microspheres with viable activity. The optimal concentrations of each antibody and biotin-rabbit anti-goat IgG were obtained through chessboard titration. The four mycotoxins were detected simultaneously and quantitatively in corn and peanut using indirect competitive immunoassay. Multi-channel standard curves with appropriate logistic correlation (R(2)>0.9819) were respectively plotted. The broad working ranges with three to four orders of magnitude were calculated, and limits of detection at the pg level were found to be better than those obtained using high-performance liquid chromatography. The recovery rates in the actual samples generally ranged from 80.16% to 117.65%, with an intra-assay coefficient of variation lower than 15%, which indicated high accuracy and repeatability. A suspension array method for the simultaneous detection of the four mycotoxins within 4h was successfully developed using minimal samples; the method was proven to have high throughput, flexibility, accuracy and reproducibility. The approach could detect multiple contaminants in actual samples. PMID:23017676

  15. Identification of AFB1-interacting proteins and interactions between RPSA and AFB1.

    PubMed

    Zhuang, Zhenhong; Huang, Yaling; Yang, Yanling; Wang, Shihua

    2016-01-15

    A method using immobilized affinity chromatography (IAC) was developed to screen for aflatoxin B1 (AFB1)-binding proteins. AFB1 and bovine serum albumin (BSA) coupled protein (BSA-AFB1) was prepared using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The resulting coupled compound was immobilized onto PVDF transfer membranes, which were then incubated with total protein from mouse liver. AFB1-binding proteins were eluted, after non-specific washing, by specific elution, and the eluted proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two candidate AFB1-binding proteins were identified by liquid chromatography-tandem mass spectrometry as the 40S ribosomal protein SA (RPSA) and a putative uncharacterized protein. RPSA and AFB1 interactions were further analyzed by ELISA in vitro and laser confocal immunofluorescence analysis in vivo. The results from ELISA and immunofluorescence showed that RPSA efficiently bound AFB1 in vitro and in vivo. This study's conclusion laid the foundation for further exploration of the role of AFB1-binding proteins in AFB1 toxicology towards hepatocytes and the entry pathway of AFB1 into hepatocytes. PMID:26372695

  16. Application of quantum-dots for analysis of nanosystems by either utilizing or preventing FRET

    NASA Astrophysics Data System (ADS)

    Kim, Joong H.; Chaudhary, Sumit; Stephens, Jared P.; Singh, Krishna V.; Ozkan, Mihrimah

    2005-04-01

    We have developed conjugates with quantum-dots (QDs) for the purpose of analysis of nanosystems that are organic or inorganic in nature such as DNA and carbon nanotubes. First, by employing Florescence Resonant Energy Transfer (FRET) principles, a hybrid molecular beacon conjugates are synthesized. For water- solubilization of QDs, we modified the surface of CdSe-ZnS core-shell QD by using mercaptoacetic acid ligand. This modification does not affect the size of QDs from that of unmodified QDs. After linking molecular beacons to the carboxyl groups of the modified QDs using 1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, hybrid molecular beacons are prepared as a DNA probe. After hybridization with specific target DNA and non-specific target DNA, the hybrid conjugates show high specificity to the target DNA with 5-fold increase in the intensity of fluorescence. By developing atomic model of the conjugates, we calculated with 8 numbers of molecular beacons on a single quantum dots, we could increase the efficiency of FRET up to 90%. In other hands, for application of quantum dots to the carbon nanotubes, FRET is a barrier. Thus, after employing 1 % sodium-dodecyl-sulfonate (SDS), single-walled carbon nanotubes are decorated with QDs at their outer surface. This enables fluorescent microscopy imaging of single-walled carbon nanotubes which is a more common technique than electron microscopy. In summary, QDs can be used for analysis or detection of both organic and inorganic based nanosystems.

  17. Design of a versatile chemical assembly method for patterning colloidal nanoparticles

    NASA Astrophysics Data System (ADS)

    Choi, J. H.; Adams, S. M.; Ragan, R.

    2009-02-01

    Poly(methyl methacrylate) (PMMA) domains in phase-separated polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer thin films were chemically modified for controlled placement of solution synthesized Au nanoparticles having a mean diameter of 24 nm. Colloidal Au nanoparticles functionalized with thioctic acid were immobilized on amine functionalized PMMA domains on the PS-b-PMMA template using 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride linking chemistry and N-hydroxy sulfosuccinimide stabilizer. Atomic force microscopy and scanning electron microscopy images demonstrated immobilization of Au nanoparticles commensurate with PMMA domains. Nanoparticles form into clusters of single particles, dimers, and linear chains as directed by the PMMA domain size and shape. Capillary forces influence the spacing between Au nanoparticles on PMMA domains. Inter-particle spacings below 3 nm were achieved and these assemblies of closely spaced nanoparticle clusters are expected to exhibit strong localized electromagnetic fields. Thus, these processes and material systems provide an experimental platform for studying resonantly enhanced excitations of surface plasmons as a function of material and geometric structure as well as utilization in catalytic applications.

  18. Controlling Stem Cell-mediated Bone Regeneration through Tailored Mechanical Properties of Collagen Scaffolds

    PubMed Central

    Sun, Hongli; Zhu, Feng; Hu, Qingang; Krebsbach, Paul H.

    2014-01-01

    Mechanical properties of the extracellular matrix (ECM) play an essential role in cell fate determination. To study the role of mechanical properties of ECM in stem cell-mediated bone regeneration, we used a 3D in vivo ossicle model that recapitulates endochondral bone formation. Three-dimensional gelatin scaffolds with distinct stiffness were developed using 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) mediated zero-length crosslinking. The mechanical strength of the scaffolds was significantly increased by EDC treatment, while the microstructure of the scaffold was preserved. Cell behavior on the scaffolds with different mechanical properties was evaluated in vitro and in vivo. EDC-treated scaffolds promoted early chondrogenic differentiation, while it promoted both chondrogenic and osteogenic differentiation at later time points. Both micro-computed tomography and histologic data demonstrated that EDC-treatment significantly increased trabecular bone formation by transplanted cells transduced with AdBMP. Moreover, significantly increased chondrogenesis was observed in the EDC-treated scaffolds. Based on both in vitro and in vivo data, we conclude that the high mechanical strength of 3D scaffolds promoted stem cell mediated bone regeneration by promoting endochondral ossification. These data suggest a new method for harnessing stem cells for bone regeneration in vivo by tailoring the mechanical properties of 3D scaffolds. PMID:24211076

  19. Radio frequency glow discharge-induced acidification of fluoropolymers.

    PubMed

    Krawczyk, Benjamin M; Baltrusaitis, Jonas; Yoder, Colin M; Vargo, Terrence G; Bowden, Ned B; Kader, Khalid N

    2011-12-01

    Fluoropolymer surfaces are unique in view of the fact that they are quite inert, have low surface energies, and possess high thermal stabilities. Attempts to modify fluoropolymer surfaces have met with difficulties in that it is difficult to control the modification to maintain bulk characteristics of the polymer. In a previously described method, the replacement of a small fraction of surface fluorine by acid groups through radio frequency glow discharge created a surface with unexpected reactivity allowing for attachment of proteins in their active states. The present study demonstrates that 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) reacts with the acid groups on fluoropolymer surfaces in a novel reaction not previously described. This reaction yields an excellent leaving group in which a primary amine on proteins can substitute to form a covalent bond between a protein and these surfaces. In an earlier study, we demonstrated that collagen IV could be deposited on a modified PTFE surface using EDC as a linker. Once collagen IV is attached to the surface, it assembles to form a functional stratum resembling collagen IV in native basement membrane. In this study, we show data suggesting that the fluorine to carbon ratio determines the acidity of the fluoropolymer surfaces and how well collagen IV attaches to and assembles on four different fluoropolymer surfaces. PMID:21887736

  20. Fish collagen/alginate/chitooligosaccharides integrated scaffold for skin tissue regeneration application.

    PubMed

    Chandika, Pathum; Ko, Seok-Chun; Oh, Gun-Woo; Heo, Seong-Yeong; Nguyen, Van-Tinh; Jeon, You-Jin; Lee, Bonggi; Jang, Chul Ho; Kim, GeunHyung; Park, Won Sun; Chang, Wonseok; Choi, Il-Whan; Jung, Won-Kyo

    2015-11-01

    An emerging paradigm in wound healing techniques is that a tissue-engineered skin substitute offers an alternative approach to create functional skin tissue. Here we developed a fish collagen/alginate (FCA) sponge scaffold that was functionalized by different molecular weights of chitooligosaccharides (COSs) with the use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride as a cross-linking agent. The effects of cross-linking were analyzed by Fourier transform infrared spectroscopy. The results indicate that the homogeneous materials blending and cross-linking intensity were dependent on the molecular weights of COSs. The highly interconnected porous architecture with 160-260μm pore size and over 90% porosity and COS's MW driven swelling and retention capacity, tensile property and in vitro biodegradation behavior guaranteed the FCA/COS scaffolds for skin tissue engineering application. Further improvement of these properties enhanced the cytocompatibility of all the scaffolds, especially the scaffolds containing COSs with MW in the range of 1-3kDa (FCA/COS1) showed the best cytocompatibility. These physicochemical, mechanical, and biological properties suggest that the FCA/COS1 scaffold is a superior candidate that can be used for skin tissue regeneration. PMID:26306410

  1. Effect of curing time and concentration for a chemical treatment that improves surface gliding for extrasynovial tendon grafts in vitro

    PubMed Central

    Tanaka, Toshikazu; Sun, Yu-Long; Zhao, Chunfeng; Zobitz, Mark E.; An, Kai-Nan; Amadio, Peter C.

    2013-01-01

    The purpose of this study was to evaluate whether treatment time and concentration of these reagents have an effect on the resulting gliding resistance. Forty peroneus longus (PL) tendons were used, from 20 adult mongrel dogs, along with the A2 pulley obtained from the ipsilateral hind paw. After the baseline gliding resistance was measured, the PL tendons were treated with one of three concentrations of hyaluronic acid (HA) and 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) or N-hydroxysuccinimide (NHS) mixed with 10% gelatin for various times (5, 30, and 60 min). Tendon friction was measured over 1000 cycles of simulated flexion/extension motion. Gliding resistance of the untreated PL tendons had no significant difference among the groups. After surface treatment with low concentration of HA and EDC/NHS for 5-min cure, the gliding resistance was similar to that of the untreated PL tendon and significantly higher than its 30- and 60-min treatment. For the rest of high concentration of HA and EDC/NHS groups, the gliding resistance was lower than that of untreated PL tendon. However, there was no significant difference among the timing points. It is possible to optimize the effect of surface treatment on friction and durability by regulating cure time and concentration of reagents in a canine extrasynovial tendon in vitro. PMID:16752399

  2. Label-free photoelectrochemical immunosensor for sensitive detection of Ochratoxin A.

    PubMed

    Yang, Jiaojiao; Gao, Picheng; Liu, Yixin; Li, Rongxia; Ma, Hongmin; Du, Bin; Wei, Qin

    2015-02-15

    A general label-free photoelectrochemical (PEC) platform was manufactured by assembly of CdSe nanoparticles (NPs) sensitized anatase TiO2-functionalized electrode via layer-by-layer (LBL) strategy. CdSe NPs were assembled on anatase TiO2-functionalized electrode through dentate binding of TiO2 NPs to -COOH groups. Ascorbic acid (AA) was used as an efficient electron donor for scavenging photogenerated holes under visible-light irradiation. The photocurrent response of the CdSe NPs modified electrode was significantly enhanced as a result of the band alignment of CdSe and TiO2 in electrolyte. Ochratoxin A (OTA), as model analyte, was employed to investigate the performance of the PEC platform. Antibodies of OTA were immobilized on CdSe sensitized electrode by using the classic 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride coupling reactions between -COOH groups on the surfaces of CdSe NPs and -NH2 groups of the antibody. Under the optimized conditions, the photocurrent was proportional to OTA concentration range from 10pg/mL to 50ng/mL with detection limit of 2.0pg/mL. The employed PEC platform established a simple, fast and inexpensive strategy for fabrication of label-free biosensor, which might be widely applied in bioanalysis and biosensing in the future. PMID:25173733

  3. A simple preparation of a stable CdS-polyacrylamide nanocomposite: structure, thermal and optical properties.

    PubMed

    Bach, Long Giang; Islam, M Rafiqul; Hong, Seong-Soo; Lim, Kwon Taek

    2013-11-01

    A facile approach was employed for the preparation of stable luminescent nanocomposites of CdS quantum dots (QDs) and polyacrylamide (PAM) through the cross coupling chemistry. Initially, CdS QDs were synthesized in a well controlled manner using 3-mercaptopropionic acid as a capping agent. Then, carboxylic acid groups on CdS QDs were chemically incorporated into PAM matrices with the assistance of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysulfosuccinimide coupling agents. FT-IR analysis was used to investigate the chemical incorporation of CdS QDs in PAM matrices via the covalent protocol. The XPS elemental mapping studies further suggested the formation of CdS-PAM nanocomposites. FE-SEM and TEM images were engaged to study the morphologies, and distribution of CdS QDs in the PAM networks. The physical structure of the CdS-PAM nanocomposites was investigated by XRD analysis. Thermal stability of the nanocomposites was observed to be enhanced in compare to PAM as evidenced from TGA data. The UV-vis and photoluminescence studies of the CdS-PAM nanocomposites suggested their promising optical applications. PMID:24245319

  4. Permethylated-β-Cyclodextrin Capped CdTe Quantum Dot and its Sensitive Fluorescence Analysis of Malachite Green.

    PubMed

    Cao, Yujuan; Wei, Jiongling; Wu, Wei; Wang, Song; Hu, Xiaogang; Yu, Ying

    2015-09-01

    In the present work, the CdTe quantum dots were covalently conjugated with permethylated-β-cyclodextrin (OMe-β-CD) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride as cross-linking reagent. The obtained functional quantum dots (OMe-β-CD/QDs) showed highly luminescent, water solubility and photostability as well as good inclusion ability to malachite green. A sensitive fluorescence method was developed for the analysis of malachite green in different samples. The good linearity was 2.0 × 10(-7)-1.0 × 10(-5) mol/L and the limit of detect was 1.7 × 10(-8) mol/L. The recoveries for three environmental water samples were 92.0-108.2 % with relative standard deviation (RSD) of 0.24-1.87 %, while the recovery for the fish sample was 94.3 % with RSD of 1.04 %. The results showed that the present method was sensitive and convenient to determine malachite green in complex samples. Graphical Abstract The analytical mechanism of OMe-β-CD/QDs and its linear response to MG. PMID:26250058

  5. Mucoadhesive 4-carboxybenzenesulfonamide-chitosan with antibacterial properties.

    PubMed

    Suvannasara, Phruetchika; Juntapram, Kotchakorn; Praphairaksit, Nalena; Siralertmukul, Krisana; Muangsin, Nongnuj

    2013-04-15

    The mucoadhesive property of chitosan, especially in an acidic (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride as a coupling agent were investigated. The 0.2:1 (w/w) ratio 4-CBS:chitosan revealed a 20-fold stronger mucoadhesion to mucin type II than the native chitosan in the simulated gastric fluid (SGF; pH 1.2), and a swelling ratio after 1 h in water, SGF and simulated intestinal fluid (pH 7.4) of about 2.9-, 3.0- and 3.4-fold higher than that of chitosan, respectively. In tissue culture, the 4-CBS-chitosan, like chitosan, were found to be non-cytotoxic to the Vero, KB, MCF-7 and NCI-H187 cell lines but showed potential antibacterial activity against Escherichia coli and Staphlyococcus aureus as model gram-negative and gram-positive bacteria, respectively. PMID:23544535

  6. Enhanced stability of catalase covalently immobilized on functionalized titania submicrospheres.

    PubMed

    Wu, Hong; Liang, Yanpeng; Shi, Jiafu; Wang, Xiaoli; Yang, Dong; Jiang, Zhongyi

    2013-04-01

    In this study, a novel approach combing the chelation and covalent binding was explored for facile and efficient enzyme immobilization. The unique capability of titania to chelate with catecholic derivatives at ambient conditions was utilized for titania surface functionalization. The functionalized titania was then used for enzyme immobilization. Titania submicrospheres (500-600 nm) were synthesized by a modified sol-gel method and functionalized with carboxylic acid groups through a facile chelation method by using 3-(3,4-dihydroxyphenyl) propionic acid as the chelating agent. Then, catalase (CAT) was covalently immobilized on these functionalized titania submicrospheres through 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. The immobilized CAT retained 65% of its free form activity with a loading capacity of 100-150 mg/g titania. The pH stability, thermostability, recycling stability and storage stability of the immobilized CAT were evaluated. A remarkable enhancement in enzyme stability was achieved. The immobilized CAT retained 90% and 76% of its initial activity after 10 and 16 successive cycles of decomposition of hydrogen peroxide, respectively. Both the Km and the Vmax values of the immobilized CAT (27.4 mM, 13.36 mM/min) were close to those of the free CAT (25.7 mM, 13.46 mM/min). PMID:23827593

  7. Preparation, blood coagulation and cell compatibility evaluation of chitosan-graft-polylactide copolymers.

    PubMed

    Wang, Qi; Liu, Pei; Liu, Peifeng; Gong, Tao; Li, Suming; Duan, Yourong; Zhang, Zhirong

    2014-02-01

    Biodegradable chitosan-graft-polylactide (PLA-CS) copolymers were prepared by the grafting of a poly(L-lactide) (PLLA) or poly(D-lactide) (PDLA) precursor to the backbone of chitosan using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC ⋅ HCl) and N-hydroxysuccinimide (NHS) as a coupling agent. The blood and cell compatibility of the graft copolymers were investigated in comparison to PLLA and PDLA homopolymers. The coagulation properties of PLA-CS were evaluated by hemolysis, plasma recalcification, dynamic blood clotting and protein absorption assays. PLA-CS copolymers present similar hemolysis ratio and plasma recalcification time as PLA, but slower dynamic blood clotting and lower protein absorption. The cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), agar diffusion and lactate dehydrogenase (LDH) experiments. All the samples presented no effect on the viability to cells. Inflammatory cytokine analysis using sandwich ELISAs revealed that PLA-CS would not stimulate inflammatory activity. PMID:24448591

  8. Conjugation behaviours of CdTe quantum dots and antibody by a novel immunochromatographic method.

    PubMed

    Wang, Y; Bai, Y; Wei, X

    2011-03-01

    Three water-soluble CdTe quantum dots (QDs) (green-emitting, yellow-emitting and red-emitting) were synthesised for different refluxing time with 3-mercaptopropionic acid (MPA) as stabiliser. Then the red-emitting CdTe QDs and mouse immunoglobulin G (IgG) were taken as the representative to study the conjugation behaviour of QDs and antibody by a novel immunochromatographic method. After comparing with several methods, that is, direct conjugation, 1-ethyl-3(3-dimethylaminopropyl) carbodiimides hydrochloride (EDC)-mediated conjugation, N-hydroxysuccinimide (NHS)-mediated conjugation, EDC/NHS-mediated conjugation by immunochromatographic strips, EDC and NHS were selected together as coupling agents to conjugate QDs with antibody efficiently. Finally, the K562 leukaemia cells were incubated with the EDC/NHS-mediated conjugates to evaluate the performance in practical application, and the result from fluorescence images showed that it was successfully applied to label cells. The immunochromatographic strip was a superior method to study the conjugation of the fluorophore and antibody. PMID:21241157

  9. Amperometric determination of hydrogen peroxide by functionalized carbon nanotubes through EDC/NHS coupling chemistry.

    PubMed

    Jeykumari, D R Shobha; Narayanan, S Sriman

    2007-06-01

    The electrochemistry of the redox mediator Toluidine blue (TB) which was covalently linked to the carboxyl group of the multiwalled carbon nanotubes (MWNTs) by coupling reactions, in which N-hydroxysuccinimide was used to assist 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride catalyzed amidation reaction is described. The results from cyclic voltammetry (CV) and amperometry suggested that the redox mediator is linked to the surface of the MWNTs and the nanotubes showed an obvious promotion for the direct electron-transfer between the redox mediator and the electrode. A couple of well-defined redox peak of TB was observed in a phosphate buffer solution (pH 7.0). The redox mediator immobilized to MWNTs exhibits remarkable electrocatalytic activity for the reduction of hydrogen peroxide (H2O2). The analytical applicability of the modified electrode for the determination of hydrogen peroxide was examined. A linear response in the concentration range of 6.8 x 10(-7)-3.4 x 10(-2) M (r = 0.9958) was obtained with detection limit of 3.4 x 10(-7) M for the determination of hydrogen peroxide. The modified electrode has advantages of being highly stable, sensitive, ease of construction and use. PMID:17654948

  10. Enzymatic cross-linking of carboxymethylpullulan grafted with ferulic acid.

    PubMed

    Dulong, Virginie; Hadrich, Ahdi; Picton, Luc; Le Cerf, Didier

    2016-10-20

    Carboxymethylpullulan (CMP) has been modified in a two-step grafting reaction of ferulic acid (FA). Acid adipic dihydrazyde (ADH) was first reacted with FA activated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC). Then the product of this first reaction was reacted with CMP (activated with EDC). Grafted polysaccharides structure was confirmed by FTIR and (1)H NMR spectroscopy. Analyses by size-exclusion chromatography (SEC) coupling on-line with a multi-angle light scattering detector (MALS), a viscometer and a differential refractive index detector (DRI) (SEC/MALS/DRI/Visco) showed that associations between FA moieties occurred due to hydrophobic interactions. The grafting rates of FA were determined by the Folin-Ciocalteu method and were found between 1.0% and 11.2% (mol/mol anhydroglucose unit). The CMP-FA were then enzymatically cross-linked with laccase from Pleurotus ostreatus. The crosslinking reactions were followed by rheological measurements, demonstrating the influence of laccase concentration on kinetics. Elastic modulus and swelling rates of hydrogels depends on FA content only for low values. PMID:27474545

  11. Detection of vibrio cholerae O1 by using cerium oxide nanowires - based immunosensor with different antibody immobilization methods

    NASA Astrophysics Data System (ADS)

    Tam, Phuong Dinh; Hoang, Nguyen Luong; Lan, Hoang; Vuong, Pham Hung; Anh, Ta Thi Nhat; Huy, Tran Quang; Thuy, Nguyen Thanh

    2016-05-01

    In this work, we evaluated the effects of different antibody immobilization strategies on the response of a CeO2-nanowires (NWs)-based immunosensor for Vibrio cholerae O1 detection. Accordingly, the changes in the electron-transfer resistance ( R et ) from before to after cells bind to an antibody-modified electrode prepared by using three different methods of antibody immobilization were determined. The values were 16.2%, 8.3%, and 6.65% for the method that utilized protein A, antibodies activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS), and absorption, respectively. Cyclic voltammetry confirmed that the change in the current was highest for the immunosensors prepared using protein A (11%), followed by those prepared with EDC/NHS-activated antibodies (9%), and finally, those prepared through absorption (7.5%). The order of the antibody immobilization strategies in terms of resulting immunosensor detection limit and sensitivity was as follows order: absorption (3.2 × 103 CFU/mL; 45.1 Ω/CFU·mL-1) < EDC/NHS-activated antibody (1.0 × 103 CFU/mL; 50.6 Ω/CFU·mL-1) < protein A (1.0 × 102 CFU/mL; 65.8 Ω/CFU·mL-1). Thus, we confirmed that the protein A - mediated method showed significantly high cell binding efficiencies compared to the random immobilization method.

  12. Magnesium Catalysis for the Hydroboration of Carbodiimides.

    PubMed

    Weetman, Catherine; Hill, Michael S; Mahon, Mary F

    2016-05-17

    A β-diketiminato magnesium alkyl complex, [CH{C(Me)NDipp}2 }MgnBu] (Dipp=2,6-iPr2 C6 H3 ), was shown to be an effective pre-catalyst for the first reported catalytic hydroboration of alkyl- and aryl-substituted carbodiimides with pinacol borane (HBpin). The catalytic reactions proceed under mild conditions to afford the corresponding N-borylated formamidine compounds in good yields. The reactions were observed to proceed through the intermediacy of magnesium amidinate and formamidinatoborate intermediates and an example of one of these latter species has been structurally characterised by an X-ray diffraction analysis. Crucially, no formation of the N-boryl formamidine products was observed in the absence of additional equivalents of the carbodiimide and HBpin substrates. This observation, supported by the evolution of a sigmoidal kinetic profile for the hydroboration of dicyclohexylcarbodiimide, has been rationalised as the consequence of an allosteric effect of the pinacol borane and carbodiimide on the magnesium formamidinatoborate intermediates. PMID:27072429

  13. Polymerization of beta-amino acids in aqueous solution

    NASA Technical Reports Server (NTRS)

    Liu, R.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1998-01-01

    We have compared carbonyl diimidazole (CDI) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as activating agents for the oligomerization of negatively-charged alpha- and beta-amino acids in homogeneous aqueous solution. alpha-Amino acids can be oligomerized efficiently using CDI, but not by EDAC. beta-Amino acids can be oligomerized efficiently using EDAC, but not by CDI. Aspartic acid, an alpha- and beta-dicarboxylic acid is oligomerized efficiently by both reagents. These results are explained in terms of the mechanisms of the reactions, and their relevance to prebiotic chemistry is discussed.

  14. Determination of small halogenated carboxylic acid residues in drug substances by high performance liquid chromatography-diode array detection following derivatization with nitro-substituted phenylhydrazines.

    PubMed

    Hou, Desheng; Fan, Jingjing; Han, Lingfei; Ruan, Xiaoling; Feng, Feng; Liu, Wenyuan; Zheng, Feng

    2016-03-18

    A method for the determination of small halogenated carboxylic acid (HCA) residues in drug substances is urgently needed because of the potential of HCAs for genotoxicity and carcinogenicity in humans. We have now developed a simple method, involving derivatization followed by high performance liquid chromatography-diode array detection (HPLC-DAD), for the determination of six likely residual HCAs (monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, 2-chloropropionic acid, 2-bromopropionic acid and 3-chloropropionic acid) in drug substances. Different nitro-substituted phenylhydrazines (NPHs) derivatization reagents were systematically compared and evaluated. 2-Nitrophenylhydrazine hydrochloride (2-NPH·HCl) was selected as the most suitable choice since its derivatives absorb strongly at 392 nm, a region of the spectrum where most drug substances and impurities absorb very weakly. During the derivatization process, the commonly used catalyst, pyridine, caused rapid dechlorination or chlorine substitution of α-halogenated derivatives. To avoid these unwanted side reactions, a reliable derivatization method that did not use pyridine was developed. Reaction with 2-NPH·HCl using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride as coupling agent in acetonitrile-water (70:30) at room temperature for 2h gave complete reaction and avoided degradation products. The derivatives were analyzed, without any pretreatment, using gradient HPLC with detection in the near visible region. Organic acids commonly found in drug substances and other impurities did not interfere with the analysis. Good linearity (r>0.999) and low limits of quantitation (0.05-0.12 μg mL(-1)) were obtained. The mean recoveries were in the range of 80-115% with RSD <5.81% except for 3-CPA in ibuprofen which was 78.5%. The intra- and inter-day precisions were expressed as RSD <1.98% and <4.39%, respectively. Finally, the proposed method was successfully used for the residue

  15. Glucosamine hydrochloride

    MedlinePlus

    ... or it can be made in the laboratory. Glucosamine hydrochloride is one of several forms of glucosamine. It ... as supplements. These products may contain glucosamine sulfate, glucosamine hydrochloride, or N-acetyl-glucosamine. These different chemicals have ...

  16. Glucosamine hydrochloride

    MedlinePlus

    ... sulfate. People take glucosamine hydrochloride by mouth for osteoarthritis, rheumatoid arthritis, glaucoma, a jaw disorder called temporomandibular ... with chondroitin sulfate, shark cartilage, and camphor for osteoarthritis. Glucosamine hydrochloride is used parenterally and short-term ...

  17. Fluorescent identification and detection of Staphylococcus aureus with carboxymethyl chitosan/CdS quantum dots bioconjugates.

    PubMed

    Wang, Xiaohui; Du, Yumin; Li, Yan; Li, Dong; Sun, Runcang

    2011-01-01

    A fast and sensitive method based on fluorescent carboxymethyl chitosan/CdS quantum dots (CMCS-CdS QDs) composites was developed for specific detection of Staphylococcus aureus in food and the environment. Fluorescent CMCS-CdS QDs were prepared in aqueous solution through a green method. A human immunoglobulin (IgG) antibody was then bioconjugated to the QDs in the presence of 1-ethyl-3-(3)-dimethylaminopropyl carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to make a novel type of mono-dispersed water-soluble fluorescent bioprobes. The fluorescent bioprobes were employed to identify S. aureus by incubating them with the bacteria for a certain time and observing the marked cells under fluorescence microscopy after removing free fluorescent QDs. Fluorescence microscopy images showed the S. aureus cells were successfully recognized by the bioprobes. Several other bacteria commonly found in environment such as Escherichia coli and Bacillus subtilis were also incubated with the bioprobes to test their specificity. It was found that the novel QDs-CMCS-IgG bioprobes had specific identification to S. aureus cells. Fluorescence measurement using a luminescence spectrometer could be applied to quantify S. aureus cells. The fluorescence intensity of the samples at 600 nm was proportional to the cell concentration in the range of 10(3)-10(7) cfu/ml, and the detection limit was as low as 900 cfu/ml. Considering the simplicity and cost-efficiency of this method, its application in the identification and quantification of bacteria in clinical, food and environmental samples is anticipated. PMID:20961493

  18. Localized surface plasmon resonance immunoassay and verification using surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Yonzon, Chanda R.; Zhang, Xiaoyu; Van Duyne, Richard P.

    2003-11-01

    This work exploits the localized surface plasmon resonance (LSPR) spectroscopy of noble metal nanoparticles to achieve sensitive and selective detection of biological analytes. Noble metal nanoparticles exhibit an LSPR that is strongly dependent on their size, shape, material, and the local dielectric environment. The LSPR is also responsible for the intense signals observed in surface-enhanced Raman scattering (SERS). Ag nanoparticles fabricated using the nanosphere lithography (NSL) technique exploits this LSPR sensitivity as a signal transduction method in biosensing applications. The current work implements LSPR biosensing for the anti dinitrophenyl (antiDNP) immunoassay system. Upon forming the 2,4 dinitrobenzoic acid/antiDNP complex, this system shows a large LSPR shift of 44 nm when exposed to antiDNP concentration of 1.5 x 10-6 M. In addition, due to the unique molecular characteristics of the functional groups on the biosensor, it can also be characterized using SERS. First, the nanoparticles are functionalized with a mixed self-assembled monolayer (SAM) comprised of 2:1 octanethiol and 11-amino undecanethiol. The SAM is exposed to 2,4-dinitrobenzoic acid with the 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) coupling reagent. Finally, the 2,4-dinitrophenyl terminated SAM is exposed to various concentration of antiDNP. LSPR shifts indicate the occurrence of a binding event. SER spectra confirm binding of 2,4 dinitrobenzoic acid with amine-terminated SAM. This LSPR/SERS biosensing method can be generalized to a myriad of biologically relevant systems.

  19. Potential role of surface wettability on the long-term stability of dentin bonds after surface biomodification

    PubMed Central

    Leme, Ariene A.; Vidal, Cristina M. P.; Hassan, Lina Saleh; Bedran-Russo, Ana K.

    2015-01-01

    Degradation of the adhesive interface contributes to the failure of resin composite restorations. The hydrophilicity of the dentin matrix during and after bonding procedures may result in an adhesive interface that is more prone to degradation over time. This study assessed the effect of chemical modification of dentin matrix on the wettability and the long-term reduced modulus of elasticity (Er) of the adhesive interfaces. Human molars were divided into groups according to the priming solutions: distilled water (control), 6.5% Proanthocyanidin-rich grape seed extract (PACs), 5.75% 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/1.4% n-hydroxysuccinimide (EDC/NHS) and 5% Glutaraldehyde (GA). The water-surface contact angle was verified before and after chemical modification of the dentin matrix. The demineralized dentin surface was treated with the priming solutions and restored with One Step Plus (OS) and Single Bond Plus (SB) and resin composite. The Er of the adhesive, hybrid layer and underlying dentin was evaluated after 24 h and 30 months in artificial saliva. The dentin hydrophilicity significantly decreased after application of the priming solutions. Aging significantly decreased the Er in the hybrid layer and underlying dentin of control groups. The Er of GA groups remained stable over time at the hybrid layer and underlying dentin. Significant higher Er was observed for PACs and EDC/NHS groups at the hybrid layer after 24 h. The decreased hydrophilicity of the modified dentin matrix likely influence the immediate mechanical properties of the hybrid layer. Dentin biomodification prevented substantial aging at the hybrid layer and underlying dentin after 30 months storage. PMID:25869721

  20. Generation and characterization of phage-GnRH chemical conjugates for potential use in cat and dog immunocontraception.

    PubMed

    Samoylov, A; Cox, N; Cochran, A; Wolfe, K; Donovan, C; Kutzler, M; Petrenko, V; Baker, H; Samoylova, T

    2012-12-01

    Overpopulation of cats and dogs is a serious worldwide problem that demands novel, safe and cost-effective solutions. The objective of this study was to generate and characterize phage-peptide conjugates with gonadotropin-releasing hormone (GnRH) for potential use as an immunocontraceptive. A filamentous phage vector f5-8 with wild-type phage coat proteins was used as a carrier for construction of chemical conjugates with GnRH, a peptide that acts as a master reproductive hormone. In such conjugates, the phage body plays the role of a carrier protein, while multiple copies of GnRH peptide stimulate production of neutralizing anti-GnRH antibodies potentially leading to contraceptive effects. To generate the constructs, four different GnRH-based peptides were synthesized and conjugated to phage particles in a two-step procedure: (i) peptides were reacted with phage to form a conjugate using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride chemistry (EDC) and (ii) the conjugates were separated from remaining free peptides by dialysis. Formation and specificity of phage-GnRH conjugates were confirmed by three independent methods: spectrophotometry, electron microscopy and ELISA. When the conjugates were tested for interaction with sera collected from cats and dogs immunized with GnRH-based vaccines in independent studies, strong specific ELISA signals were obtained, suggesting the potential use of the conjugates for cat and dog immunosterilization. The ability of the conjugates to stimulate production of anti-GnRH antibodies in vivo was evaluated in mice. While optimization of dose, immunization route and adjuvant still requires investigation, our preliminary results demonstrated the presence of anti-GnRH antibodies in sera of mice immunized with such conjugates. Fertility trials in cats and dogs will be needed to evaluate contraceptive potentials of the phage-GnRH peptide chemical conjugates. PMID:23279551

  1. A comparative study of different protein immobilization methods for the construction of an efficient nano-structured lactate oxidase-SWCNT-biosensor

    PubMed Central

    Pagán, Miraida; Suazo, Dámaris; del Toro, Nicole; Griebenow, Kai

    2014-01-01

    We constructed lactate biosensors by immobilization of lactate oxidase (LOx) onto a single-walled carbon nanotube (SWCNT) electrode. The first step of the sensor construction was the immobilization of oxidized SWCNT onto a platinum electrode modified with 4-aminothiophenol (4-ATP). Two enzyme immobilization methods were used to construct the biosensors, i.e., covalent immobilization using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and physical adsorption. Atomic force microscopy (AFM) experiments confirmed the immobilization of SWCNT during the biosensor construction and X-ray photoelectron spectroscopy (XPS) experiments confirmed covalent immobilization of LOx onto the SWCNT in the first method. The biosensor based on covalent enzyme immobilization showed a sensitivity of 5.8 μA/mM, a linearity up to 0.12 mM of L-lactate, and a detection limit of 4.0 μM. The biosensor based on protein adsorption displayed a sensitivity of 9.4 μA/mM, retaining linearity up to 0.18 mM of L-lactate with a detection limit of 3.0 μM. The difference in the biosensor response can be attributed to protein conformational or dynamical changes during covalent immobilization. The stability of the biosensors was tested at different temperatures and after different storage periods. The thermostability of the biosensors after incubation at 60°C demonstrated that the biosensor with covalently immobilized LOx retained a higher response compare with the adsorbed protein. Long-term stability experiments show a better residual activity of 40% for the covalently immobilized protein compared to 20% of residual activity for the adsorbed protein after 25 d storage. Covalent protein immobilization was superior compared to adsorption in preserving biosensor functionality over extended time period. PMID:25216450

  2. Hyaluronidase-sensitive nanoparticle templates for triggered release of HIV/AIDS microbicide in vitro.

    PubMed

    Agrahari, Vivek; Zhang, Chi; Zhang, Tao; Li, Wenjing; Gounev, Todor K; Oyler, Nathan A; Youan, Bi-Botti C

    2014-03-01

    This study was designed to test the hypothesis that a triggered release of a topical microbicide (tenofovir) from hyaluronic acid nanoparticles (HA-NPs) can be achieved under the influence of hyaluronidase (HAase) enzyme. A fractional factorial experimental design was used to examine the factors [molar concentrations of adipic acid dihydrazide (X1) and 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (X2), volume of acetone (X3) and reaction time (X4)] influencing the responses, Y1; particle mean diameter: PMD (nanometers: nm), Y2; polydispersity index: PDI and Y3; zeta (ζ) potential: (millivolts). The amide bond formation between HA and ADH after cross-linking was confirmed by FT-IR and (13)C-NMR analyses. These NPs were also characterized for cytotoxicity on a human vaginal epithelial cell line and L. crispatus. When formulated with factors X1; 2.49 mM, X2; 9.96 mM, X3; 60 mL, X4; 6 h, HA-NPs exhibited a spherical shape with PMD, PDI, ζ potential, encapsulation efficiency, and drug loading of 70.6 ± 4.1 nm, 0.07 ± 0.02, -38.2 ± 2.8 mV, 51.8 ± 2.4% w/w and 26.1 ± 1.2% w/w, respectively, (n = 3). Unlike for HA based gel, HAase significantly triggered the drug release and HA degradation from the NPs after 24 h (~90% w/w and 65% w/w, respectively); whereas, in its absence, these values were ~39% w/w and 26% w/w, respectively. The NPs were non-cytotoxic to human vaginal VK2/E6E7, End1/E6E7 cells and Lactobacillus crispatus. These data highlight the potential of HAase-sensitive HA-NPs templates for the controlled and vaginal delivery of anti-HIV/AIDS microbicides. PMID:24343770

  3. A Novel Europium Chelate Coated Nanosphere for Time-Resolved Fluorescence Immunoassay

    PubMed Central

    Shen, Yifeng; Xu, Shaohan; He, Donghua

    2015-01-01

    A novel europium ligand 2, 2’, 2’’, 2’’’-(4, 7-diphenyl-1, 10-phenanthroline-2, 9-diyl) bis (methylene) bis (azanetriyl) tetra acetic acid (BC-EDTA) was synthesized and characterized. It shows an emission spectrum peak at 610 nm when it is excited at 360 nm, with a large Stock shift (250 nm). It is covalently coated on the surface of a bare silica nanosphere containi free amino groups, using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-Hydroxysuccinimide. We also observed an interesting phenomenon that when BC-EDTA is labeled with a silica nanosphere, the chelate shows different excitation spectrum peaks of about 295 nm. We speculate that the carboxyl has a significant influence on its excitation spectrum. The BC-EDTA/Eu3+coated nanosphere could be used as a fluorescent probe for time-resolved fluorescence immunoassay. We labeled the antibody with the fluorescent nanosphere to develop a nanosphere based hepatitis B surface antigen as a time-resolved fluorescence immunoassay reagent, which is very easy to operate and eliminates potential contamination of Eu3+ contained in the environment. The analytical and functional sensitivities are 0.0037 μg/L and 0.08 μg/L (S/N≥2.0) respectively. The detection range is 0.08-166.67 μg/L, which is much wider than that of ELISA (0.2-5μg/L). It is comparable to the commercial dissociation-enhanced lanthanide fluoro-immunoassay system (DELFIA) reagents (0.2-145μg/L). We propose that it can fulfill clinical applications. PMID:26056826

  4. Coupling Strategies for the Synthesis of Peptide-Oligonucleotide Conjugates for Patterned Synthetic Biomineralization

    PubMed Central

    Carter, Joshua D.; LaBean, Thomas H.

    2011-01-01

    This work describes preparation strategies for peptide-oligonucleotide conjugates that combine the self-assembling behavior of DNA oligonucleotides with the molecular recognition capabilities of peptides. The syntheses include a solution-phase fragment coupling reaction and a solid-phase fragment coupling strategy where the oligonucleotide has been immobilized on DEAE Sepharose. The yield of four coupling reagents is evaluated, two reagents in water, EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride) and DMTMM (4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride), and two in dimethylformamide (DMF), PyBOP ((Benzotriazol-1-yloxy) tripyrrolidinophosphonium hexafluorophosphate) and HBTU (O-benzotriazole-N,N,N′,N′-tetramethyluronium hexafluorophosphate), while the oligonucleotide fragment is either in solution or immobilized on DEAE. These coupling strategies rely on an unprotected 5′ amino linker on the oligonucleotide reacting with the peptide C-terminus. The peptide, selected from a combinatorial library for its gold-binding behavior, was 12 amino acids long with an N-terminus acetyl cap. Formation of the conjugates was confirmed by gel electrophoresis and mass spectrometry while molecular recognition functionality of the peptide portion was verified using atomic force microscopy. Solution-phase yields were superior to their solid-phase counterparts. EDC resulted in the highest yield for both solution-phase (95%) and solid-phase strategies (24%), while the DMF-based reagents, PyBOP and HBTU, resulted in low yields with reduced recovery. All recoverable conjugates demonstrated gold nanoparticle templating capability. PMID:22007290

  5. Coupling strategies for the synthesis of Peptide-oligonucleotide conjugates for patterned synthetic biomineralization.

    PubMed

    Carter, Joshua D; Labean, Thomas H

    2011-01-01

    This work describes preparation strategies for peptide-oligonucleotide conjugates that combine the self-assembling behavior of DNA oligonucleotides with the molecular recognition capabilities of peptides. The syntheses include a solution-phase fragment coupling reaction and a solid-phase fragment coupling strategy where the oligonucleotide has been immobilized on DEAE Sepharose. The yield of four coupling reagents is evaluated, two reagents in water, EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride) and DMTMM (4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride), and two in dimethylformamide (DMF), PyBOP ((Benzotriazol-1-yloxy) tripyrrolidinophosphonium hexafluorophosphate) and HBTU (O-benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate), while the oligonucleotide fragment is either in solution or immobilized on DEAE. These coupling strategies rely on an unprotected 5' amino linker on the oligonucleotide reacting with the peptide C-terminus. The peptide, selected from a combinatorial library for its gold-binding behavior, was 12 amino acids long with an N-terminus acetyl cap. Formation of the conjugates was confirmed by gel electrophoresis and mass spectrometry while molecular recognition functionality of the peptide portion was verified using atomic force microscopy. Solution-phase yields were superior to their solid-phase counterparts. EDC resulted in the highest yield for both solution-phase (95%) and solid-phase strategies (24%), while the DMF-based reagents, PyBOP and HBTU, resulted in low yields with reduced recovery. All recoverable conjugates demonstrated gold nanoparticle templating capability. PMID:22007290

  6. A novel electrospinning approach to fabricate high strength aqueous silk fibroin nanofibers.

    PubMed

    Singh, B N; Panda, N N; Pramanik, K

    2016-06-01

    The present paper describes a rapid method of producing concentrated aqueous regenerated Bombyx mori silk fibroin (RSF) solution by applying mild shearing under forced dehumidified air and generation of electrospun SF nanofibers from concentrated solution with high mechanical strength using free liquid surface electrospinning machine. The shear induced concentrating mechanism favoured the electrospinning process by enhancing the viscosity (>2.43Pas as onset for electrospinning) and decreasing the surface tension of the solution (40.1-37.7mN/m). Shearing reduced the β-turns and random coil molecular conformation and thereby, intensified the β-sheet content from 16.9% to 34% which is the minimum content needed to commence RSF nanofibers formation. Subsequently, electrospun nanofibrous mats were produced from different batches of concentrated SF solutions (15-21wt%). Among the concentrated RSF, 17wt% RSF solution was the most favourable concentration producing electrospun nanofibrous mat having lowest average fiber diameters of 183±55nm and good tensile strength. The mechanical strength of the nanofibrous sheet was further improved by cross-linking with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide (EDC+NHS) which might be due to enhancement of β-sheet content. These nanofibers exhibited 17.57±1.13MPa ultimate tensile strength, 12.48±1.46% tensile strain at break and 37.7% increase in root mean square surface roughness which is favourable feature for cell adhesion and neo-tissue formation. PMID:26905467

  7. Applying graphene oxide nano-film over a polycarbonate nanoporous membrane to monitor E. coli by infrared spectroscopy.

    PubMed

    Singh, Krishna Pal; Dhek, Neeraj Singh; Nehra, Anuj; Ahlawat, Sweeti; Puri, Anu

    2017-01-01

    Nano-biosensors are excellent monitoring tools for rapid, specific, sensitive, inexpensive, in-field, on-line, and/or real-time detection of pathogens in foods, soil, air, and water samples. A variety of nano-materials (metallic, polymeric, and/or carbon-based) were employed to enhance the efficacy, efficiency, and sensitivity of these nano-biosensors, including graphene-based materials, especially graphene oxide (GO)-based materials. GO bears many oxygen-bearing groups, enabling ligand conjugation at the high density critical for sensitive detection. We have fabricated GO-modified nano-porous polycarbonate track-etched (PCTE) membranes that were conjugated to an Escherichia coli-specific antibody (Ab) and used to detect E. coli. The random distribution of nanopores on the PCTE membrane surface and the bright coating of the GO onto the membrane were confirmed by scanning electron microscope. Anti-E. coli β-gal Abs were conjugated to the GO surface via 1-ethyl-3,3-dimethylaminopropyl carbodiimide hydrochloride-N-hydroxysuccinimide chemistry; antibody coating was confirmed by the presence of a characteristic IR peak near 1600cm(-1). A non-corresponding Ab (anti-Pseudomonas) was used as a negative control under identical conditions. When E. coli interacted anti-E.coli β-gal with Ab-coated GO-nano-biosensor units, we observed a clear shift in the IR peak from 3373.14 to 3315cm(-1); in contrast, we did not observe any shift in IR peaks when the GO unit was coated with the non-corresponding Ab (anti-Pseudomonas). Therefore, the detection of E. coli using the described GO-nano-sensor unit is highly specific, is highly selective and can be applied for real-time monitoring of E. coli with a detection limit between 100μg/mL and 10μg/mL, similar to existing detection systems. PMID:27391314

  8. Covalent immobilization of porcine pancreatic lipase on carboxyl-activated magnetic nanoparticles: characterization and application for enzymatic inhibition assays.

    PubMed

    Zhu, Yuan-Ting; Ren, Xiao-Yun; Liu, Yi-Ming; Wei, Ying; Qing, Lin-Sen; Liao, Xun

    2014-05-01

    Using carboxyl functionalized silica-coated magnetic nanoparticles (MNPs) as carrier, a novel immobilized porcine pancreatic lipase (PPL) was prepared through the 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. Transmission electron microscopic images showed that the synthesized nanoparticles (Fe3O4-SiO2) possessed three dimensional core-shell structures with an average diameter of ~20 nm. The effective enzyme immobilization onto the nanocomposite was confirmed by atomic force microscopic (AFM) analysis. Results from Fourier-transform infrared spectroscopy (FT-IR), Bradford protein assay, and thermo-gravimetric analysis (TGA) indicated that PPL was covalently attached to the surface of magnetic nanoparticles with a PPL immobilization yield of 50mg enzyme/g MNPs. Vibrating sample magnetometer (VSM) analysis revealed that the MNPs-PPL nanocomposite had a high saturation magnetization of 42.25 emu·g(-1). The properties of the immobilized PPL were investigated in comparison with the free enzyme counterpart. Enzymatic activity, reusability, thermo-stability, and storage stability of the immobilized PPL were found significantly superior to those of the free one. The Km and the Vmax values (0.02 mM, 6.40 U·mg(-1) enzyme) indicated the enhanced activity of the immobilized PPL compared to those of the free enzyme (0.29 mM, 3.16 U·mg(-1) enzyme). Furthermore, at an elevated temperature of 70 °C, immobilized PPL retained 60% of its initial activity. The PPL-MNPs nanocomposite was applied in the enzyme inhibition assays using orlistat, and two natural products isolated from oolong tea (i.e., EGCG and EGC) as the test compounds. PMID:24656379

  9. A comparative study of different protein immobilization methods for the construction of an efficient nano-structured lactate oxidase-SWCNT-biosensor.

    PubMed

    Pagán, Miraida; Suazo, Dámaris; Del Toro, Nicole; Griebenow, Kai

    2015-02-15

    We constructed lactate biosensors by immobilization of lactate oxidase (LOx) onto a single-walled carbon nanotube (SWCNT) electrode. The first step of the sensor construction was the immobilization of oxidized SWCNT onto a platinum electrode modified with 4-aminothiophenol (4-ATP). Two enzyme immobilization methods were used to construct the biosensors, i.e., covalent immobilization using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and physical adsorption. Atomic force microscopy (AFM) experiments confirmed the immobilization of SWCNT during the biosensor construction and X-ray photoelectron spectroscopy (XPS) experiments confirmed covalent immobilization of LOx onto the SWCNT in the first method. The biosensor based on covalent enzyme immobilization showed a sensitivity of 5.8 μA/mM, a linearity up to 0.12 mM of L-lactate, and a detection limit of 4.0 μM. The biosensor based on protein adsorption displayed a sensitivity of 9.4 μA/mM, retaining linearity up to 0.18 mM of L-lactate with a detection limit of 3.0 μM. The difference in the biosensor response can be attributed to protein conformational or dynamical changes during covalent immobilization. The stability of the biosensors was tested at different temperatures and after different storage periods. The thermostability of the biosensors after incubation at 60 °C demonstrated that the biosensor with covalently immobilized LOx retained a higher response compared with the adsorbed protein. Long-term stability experiments show a better residual activity of 40% for the covalently immobilized protein compared to 20% of residual activity for the adsorbed protein after 25 d storage. Covalent protein immobilization was superior compared to adsorption in preserving biosensor functionality over extended time period. PMID:25216450

  10. In-Depth Electrochemical Investigation of Surface Attachment Chemistry via Carbodiimide Coupling.

    PubMed

    Booth, Marsilea Adela; Kannappan, Karthik; Hosseini, Ali; Partridge, Ashton

    2015-07-28

    Aminoferrocene is used as an electroactive indicator to investigate carbodiimide coupling reactions on a carboxylic acid-functionalized self-assembled monolayer. The commonly used attachment chemistry with 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) is used for surface activation. A number of conditions are investigated, including EDC and NHS concentration, buffer solutions, incubation timing, and aminoferrocene concentration. Ferrocene is a well-documented electroactive species, and the number of surface-bound ferrocene species can be calculated using electrochemical methods. This capability allows determination of optimal conditions, as well as providing a method for comparing and investigating novel carboxylated surfaces. An EDC-mediated procedure with ∼5 mM EDC and NHS (1:1) made in water, with a full acid monolayer, with 250 μM aminoferrocene for 40 min was found to give the highest ferrocene attachment. An application of this is demonstrated for preparing a probe-DNA-coated surface for DNA sensing. By backfilling with aminoferrocene, a differential quantification of the amount of probe DNA available for sensing can be obtained. This provides an elegant method to monitor an important aspect, namely, probe surface characterization, which will be highly useful for biosensing purposes. PMID:26107592

  11. Investigating thiol-modification on hyaluronan via carbodiimide chemistry using response surface methodology.

    PubMed

    Santhanam, Sruthi; Liang, Jue; Baid, Rinku; Ravi, Nathan

    2015-07-01

    Hyaluronan (HA) is a naturally occurring glycosaminoglycan widely researched for its use as a biomaterial in tissue engineering, drug delivery, angiogenesis, and ophthalmic surgeries. The mechanical properties of this biomaterial can be altered to a required extent by chemically modifying the pendant reactive groups. However, derivatizing these polymers to a predetermined extent has been the Achilles heel for this process. In this study, we have investigated the factors controlling the derivatization of the carboxyl moieties of HA with amine containing thiol, cystamine dihydrochloride (Cys), via carbodiimide crosslinking chemistry. We used fractional factorial design to screen and identify the significant factor(s) affecting the reaction, and response surface methodology (RSM) to develop a model equation for predicting the degree of thiolation of HA. Also, we analyzed the reaction mechanism for potential side reactions. We observed that N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) (mole ratio with repeat unit of HA) is the significant factor controlling the degree of amidation. The quadratic equations developed from RSM predict the formulation for a desired degree of amidation of HA and percentage of potential side product. Hence, derivatizing HA to a predetermined extent with minimal side product can be achieved using the statistical design of experiments. PMID:25369214

  12. Lucanthone hydrochloride

    PubMed Central

    Blair, D. M.

    1958-01-01

    This review of the published work on the treatment of bilharziasis with lucanthone hydrochloride draws attention to the inconclusive nature of many of the trials carried out so far: either the dosage was inadequate or the patients were not followed up for a sufficient length of time. The author stresses the importance of obtaining a high concentration of lucanthone in the body fluids. He suggests that better results might be obtained if the total dose were given in two days or even as a single, massive dose. This method might also reduce the side effects, which do not appear, as a rule, until the second or third day. PMID:13573122

  13. The process of EDC-NHS cross-linking of reconstituted collagen fibres increases collagen fibrillar order and alignment

    SciTech Connect

    Shepherd, D. V. Shepherd, J. H.; Cameron, R. E.; Best, S. M.; Ghose, S.; Kew, S. J.

    2015-01-01

    We describe the production of collagen fibre bundles through a multi-strand, semi-continuous extrusion process. Cross-linking using an EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide), NHS (N-hydroxysuccinimide) combination was considered. Atomic Force Microscopy and Raman spectroscopy focused on how cross-linking affected the collagen fibrillar structure. In the cross-linked fibres, a clear fibrillar structure comparable to native collagen was observed which was not observed in the non-cross-linked fibre. The amide III doublet in the Raman spectra provided additional evidence of alignment in the cross-linked fibres. Raman spectroscopy also indicated no residual polyethylene glycol (from the fibre forming buffer) or water in any of the fibres.

  14. Production and Characterization of Chemically Inactivated Genetically Engineered Clostridium difficile Toxoids.

    PubMed

    Vidunas, Eugene; Mathews, Antony; Weaver, Michele; Cai, Ping; Koh, Eun Hee; Patel-Brown, Sujata; Yuan, Hailey; Zheng, Zi-Rong; Carriere, Marjolaine; Johnson, J Erik; Lotvin, Jason; Moran, Justin

    2016-07-01

    A recombinant Clostridium difficile expression system was used to produce genetically engineered toxoids A and B as immunogens for a prophylactic vaccine against C. difficile-associated disease. Although all known enzymatic activities responsible for cytotoxicity were genetically abrogated, the toxoids exhibited residual cytotoxic activity as measured in an in vitro cell-based cytotoxicity assay. The residual cytotoxicity was eliminated by treating the toxoids with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide. Mass spectrometry and amino acid analysis of the EDC-inactivated toxoids identified crosslinks, glycine adducts, and β-alanine adducts. Surface plasmon resonance analysis demonstrated that modifications resulting from the chemical treatment did not appreciably affect recognition of epitopes by both toxin A- and B-specific neutralizing monoclonal antibodies. Compared to formaldehyde-inactivated toxoids, the EDC/N-hydroxysuccinimide-inactivated toxoids exhibited superior stability in solution with respect to reversion of cytotoxic activity. PMID:27233688

  15. Bioactive and metal uptake studies of carboxymethyl chitosan-graft-D-glucuronic acid membranes for tissue engineering and environmental applications.

    PubMed

    Jayakumar, R; Rajkumar, M; Freitas, H; Sudheesh Kumar, P T; Nair, S V; Furuike, T; Tamura, H

    2009-08-01

    Carboxymethyl chitosan-graft-D-glucuronic acid (CMCS-g-D-GA) was prepared by grafting D-GA onto CMCS in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and then the membranes were made from it. In this work, the bioactivity studies of CMCS-g-D-GA membranes were carried out and then characterized by SEM, CLSM, XRD and FT-IR. The CMCS-g-D-GA membranes were found to be bioactive. The adsorption of Ni2+, Zn2+ and Cu2+ ions onto CMCS-g-D-GA membranes has also been investigated. The maximum adsorption capacity of CMCS-g-D-GA for Ni2+, Zn2+ and Cu2+ was found to be 57, 56.4 and 70.2 mg/g, respectively. Hence, these membranes were useful for tissue engineering, environmental and water purification applications. PMID:19409415

  16. Growth factors-loaded stents modified with hyaluronic acid and heparin for induction of rapid and tight re-endothelialization.

    PubMed

    Choi, Dong Hoon; Kang, Sung Nam; Kim, Seong Min; Gobaa, Samy; Park, Bang Ju; Kim, Ik Hwan; Joung, Yoon Ki; Han, Dong Keun

    2016-05-01

    Rapid re-endothelialization of damaged vessel lining efficiently prevents restenosis and thrombosis and restores original vascular functions. In this study, we designed a novel metallic stent with a heparin-modified surface and used different methods, including 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and divinyl sulfone (DVS), to load growth factors. First we loaded heparin into a dopamine-conjugated hyaluronic acid (HA) coating to serve as a growth factor reservoir. In a second step, we took advantage of the heparin-binding domain of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) to gain advanced re-endothelialization capabilities. We demonstrated that DVS technique offered higher amount of growth factor loading. In vitro assessment also showed better capillary-like structure formation and localized gap junctions when DVS coating was employed. This study suggested that growth factor loaded stent modified by HA and heparin provided the advantage to rapid and tight restoration of endothelium. PMID:26928466

  17. Development of a new antibacterial biomaterial by tetracycline immobilization on calcium-alginate beads.

    PubMed

    Ozseker, Emine Erdogan; Akkaya, Alper

    2016-10-20

    In recent years, increasing risk of infection, caused by resistant microorganism to antibiotics, has become the limelight discovery of new and natural antibacterial materials. Heavy metals, such as silver, copper, mercury and titanium, have antibacterial activity. Products, which improved these metals, do not have stable antibacterial property. Therefore, use of these products is restricted. The aim of this study was to immobilize tetracycline to alginate and improve an antibacterial biomaterial. For this purpose, calcium-alginate beads were formed by dropping to calcium-chloride solution and tetracycline was immobilized to beads using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide at optimum conditions. After immobilization, actualization of immobilization was investigated by analyzing ATR-FTIR spectrum and SEM images. Also, antibacterial property of obtained product was tested. Improved product demonstrated antibacterial property. It has potential for open wound, surgical drapes, bed and pillow sheath in hospitals and it may also be used for increasing human comfort in daily life. PMID:27474587

  18. Polymerization on the rocks: beta-amino acids and arginine

    NASA Technical Reports Server (NTRS)

    Liu, R.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1998-01-01

    We have studied the accumulation of long oligomers of beta-amino acids on the surface of minerals using the 'polymerization on the rocks' protocol. We find that long oligopeptides of beta-glutamic acid which cannot be formed in homogeneous aqueous solution are accumulated efficiently on the surface of hydroxylapatite using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as condensing agent. The EDAC-induced oligomerization of aspartic acid on hydroxylapatite proceeds even more efficiently. Hydroxylapatite can also facilitate the ligation of the tripeptide (glu)3. The 'polymerization on the rocks' scenario is not restricted to negatively-charged amino acids. Oligoarginines are accumulated on the surface of illite using carbonyldiimidizole (CDI) as condensing agent. We find that FeS2 catalyzes the CDI-induced oligomerization of arginine, although it does not adsorb oligoarginines. These results are relevant to the formation of polypeptides on the primitive earth.

  19. Crosslinked hydrogels based on biological macromolecules with potential use in skin tissue engineering.

    PubMed

    Vulpe, Raluca; Popa, Marcel; Picton, Luc; Balan, Vera; Dulong, Virginie; Butnaru, Maria; Verestiuc, Liliana

    2016-03-01

    Zero-length crosslinked hydrogels have been synthesized by covalent linking of three natural polymers (collagen, hyaluronic acid and sericin), in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. The hydrogels have been investigated by FT-IR spectroscopy, microcalorimetry, in vitro swelling, enzymatic degradation, and in vitro cell viability studies. The obtained crosslinked hydrogels showed a macroporous structure, high swelling degree and in vitro enzymatic resistance compared to uncrosslinked collagen. The in vitro cell viability studies performed on normal human dermal fibroblasts assessed the sericin proliferation properties indicating a potential use of the hydrogels based on collagen, hyaluronic acid and sericin in skin tissue engineering. PMID:26704998

  20. Actinide-Catalyzed Intermolecular Addition of Alcohols to Carbodiimides.

    PubMed

    Batrice, Rami J; Kefalidis, Christos E; Maron, Laurent; Eisen, Moris S

    2016-02-24

    The unprecedented actinide-catalyzed addition of alcohols to carbodiimides is presented. This represents a rare example of thorium-catalyzed transformations of an alcoholic substrate and the first example of uranium complexes showing catalytic reactivity with alcohols. Using the uranium and thorium amides U[N(SiMe3)2]3 and [(Me3Si)2N]2An[κ(2)-(N,C)-CH2Si(CH3)2N(SiMe3)] (An = Th or U), alcohol additions to unsaturated carbon-nitrogen bonds are achieved in short reaction times with excellent selectivities and high to excellent yields. Computational studies, supported by experimental thermodynamic data, suggest plausible models of the profile of the reaction which allow the system to overcome the high barrier of scission of the actinide-oxygen bond. Accompanied by experimentally determined kinetic parameters, a plausible mechanism is proposed for the catalytic cycle. PMID:26844823

  1. The effects of hyaluronic acid incorporated as a wetting agent on lysozyme denaturation in model contact lens materials.

    PubMed

    Weeks, Andrea; Boone, Adrienne; Luensmann, Doerte; Jones, Lyndon; Sheardown, Heather

    2013-09-01

    Conventional and silicone hydrogels as models for contact lenses were prepared to determine the effect of the presence of hyaluronic acid on lysozyme sorption and denaturation. Hyaluronic acid was loaded into poly(2-hydroxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) hydrogels, which served as models for conventional and silicone hydrogel contact lens materials. The hyaluronic acid was cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide in the presence of dendrimers. Active lysozyme was quantified using a Micrococcus lysodeikticus assay while total lysozyme was determined using 125-I radiolabeled protein. To examine the location of hyaluronic acid in the gels, 6-aminofluorescein labeled hyaluronic acid was incorporated into the gels using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry and the gels were examined using confocal laser scanning microscopy. Hyaluronic acid incorporation significantly reduced lysozyme sorption in poly(2-hydroxyethyl methacrylate) (p < 0.00001) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.001) hydrogels, with the modified materials sorbing only 20% and 16% that of the control, respectively. More importantly, hyaluronic acid also decreased lysozyme denaturation in poly(2-hydroxyethyl methacrylate) (p < 0.005) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.02) hydrogels. The confocal laser scanning microscopy results showed that the hyaluronic acid distribution was dependent on both the material type and the molecular weight of hyaluronic acid. This study demonstrates that hyaluronic acid incorporated as a wetting agent has the potential to reduce lysozyme sorption and denaturation in contact lens applications. The distribution of hyaluronic acid within hydrogels appears to affect denaturation, with more surface mobile, lower

  2. Bupropion Hydrochloride.

    PubMed

    Khan, S R; Berendt, R T; Ellison, C D; Ciavarella, A B; Asafu-Adjaye, E; Khan, M A; Faustino, P J

    2016-01-01

    Bupropion hydrochloride is a norepinephrine-dopamine disinhibitor (NDDI) approved for the treatment of depression and smoking cessation. Bupropion is a trimethylated monocyclic phenylaminoketone second-generation antidepressant, which differs structurally from most antidepressants, and resides in a novel mechanistic class that has no direct action on the serotonin system. Comprehensive chemical, physical, and spectroscopic profiles are presented. This analytical profile provides an extensive spectroscopic investigation utilizing mass spectrometry, one- and two-dimensional NMR, solid-state NMR, IR, NIR, Raman, UV, and X-ray diffraction. The profile also includes significant wet chemistry studies for pH, solubility, solution, and plasma stability. Both HPLC and UPLC methodology are presented for bupropion and its related impurities or major metabolites. The profile concludes with an overview of biological properties that includes toxicity, drug metabolism, and pharmacokinetics. PMID:26940167

  3. Colesevelam hydrochloride.

    PubMed

    Steinmetz, Karen L

    2002-05-15

    The pharmacology, pharmacodynamics, clinical efficacy, drug interactions, adverse effects, and dosage and administration of colesevelam hydrochloride are reviewed. Colesevelam hydrochloride is a nonabsorbed lipid-lowering agent approved for use alone or in combination with hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors for the reduction of low-density-lipoprotein (LDL) cholesterol in patients with primary hypercholesterolemia. Colesevelam forms nonabsorbable complexes with bile acids in the gastrointestinal (GI) tract, resulting in changes in plasma lipid levels, including total, LDL, and high-density-lipoprotein cholesterol and triglycerides. Colesevelam has been reported to be four to six times as potent as traditional bile acid sequestrants (BASs), perhaps because of its greater binding affinity for glycocholic acid. Unlike cholestyramine and colestipol, colesevelam appears to reduce LDL cholesterol in a dose-dependent manner. In clinical trials, colesevelam demonstrated efficacy either alone or in combination with HMG-CoA reductase inhibitors in the treatment of primary hypercholesterolemia. Combination therapy appeared to be more effective than monotherapy. Although infection, headache, and GI adverse effects have been reported for colesevelam, the rates do not differ significantly from those occurring with placebo. The constipation that typically hinders compliance with traditional BASs is minimal. In one study, the rate of compliance with colesevelam was 93%. There is little evidence of clinically significant interactions involving colesevelam. The maintenance dosage is three 625-mg tablets twice daily or six tablets once daily, taken with meals. Colesevelam provides an effective alternative to cholestyramine and colestipol while offering the potential for fewer adverse effects and better compliance. Studies are needed to directly compare colesevelam with traditional BASs. PMID:12040732

  4. Systemic Administration of Human Bone Marrow-Derived Mesenchymal Stromal Cell Extracellular Vesicles Ameliorates Aspergillus Hyphal Extract-Induced Allergic Airway Inflammation in Immunocompetent Mice

    PubMed Central

    Cruz, Fernanda F.; Borg, Zachary D.; Goodwin, Meagan; Sokocevic, Dino; Wagner, Darcy E.; Coffey, Amy; Antunes, Mariana; Robinson, Kristen L.; Mitsialis, S. Alex; Kourembanas, Stella; Thane, Kristen; Hoffman, Andrew M.; McKenna, David H.; Rocco, Patricia R.M.

    2015-01-01

    An increasing number of studies demonstrate that administration of either conditioned media (CM) or extracellular vesicles (EVs) released by mesenchymal stromal cells (MSCs) derived from bone marrow and other sources are as effective as the MSCs themselves in mitigating inflammation and injury. The goal of the current study was to determine whether xenogeneic administration of CM or EVs from human bone marrow-derived MSCs would be effective in a model of mixed Th2/Th17, neutrophilic-mediated allergic airway inflammation, reflective of severe refractory asthma, induced by repeated mucosal exposure to Aspergillus hyphal extract (AHE) in immunocompetent C57Bl/6 mice. Systemic administration of both CM and EVs isolated from human and murine MSCs, but not human lung fibroblasts, at the onset of antigen challenge in previously sensitized mice significantly ameliorated the AHE-provoked increases in airway hyperreactivity (AHR), lung inflammation, and the antigen-specific CD4 T-cell Th2 and Th17 phenotype. Notably, both CM and EVs from human MSCs (hMSCs) were generally more potent than those from mouse MSCs (mMSCs) in most of the outcome measures. The weak cross-linking agent 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride was found to inhibit release of both soluble mediators and EVs, fully negating effects of systemically administered hMSCs but only partly inhibited the ameliorating effects of mMSCs. These results demonstrate potent xenogeneic effects of CM and EVs from hMSCs in an immunocompetent mouse model of allergic airway inflammation and they also show differences in mechanisms of action of hMSCs versus mMSCs to mitigate AHR and lung inflammation in this model. Significance There is a growing experience demonstrating benefit of mesenchymal stromal cell (MSC)-based cell therapies in preclinical models of asthma. In the current study, conditioned media (CM) and, in particular, the extracellular vesicle fraction obtained from the CM were as potent as the

  5. Antimicrobial activity of four cationic peptides immobilised to poly-hydroxyethylmethacrylate.

    PubMed

    Dutta, Debarun; Kumar, Naresh; D P Willcox, Mark

    2016-04-01

    The objective of this study was to immobilise and characterise a variety of antimicrobial peptides (AMPs) onto poly-hydroxyethylmethacrylate (pHEMA) surfaces to achieve an antibacterial effect. Four AMPs, viz. LL-37, melimine, lactoferricin and Mel-4 were immobilised on pHEMA by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) which assisted covalent attachment. Increasing concentrations of AMPs were immobilised to determine the effect on the adhesion of Pseudomonas aeruginosa and Staphylococcus aureus. The AMP immobilised pHEMAs were characterised by X-ray photoelectron spectroscopy (XPS) to determine the surface elemental composition and by amino acid analysis to determine the total amount of AMP attached. In vitro cytotoxicity of the immobilised pHEMA samples to mouse L929 cells was investigated. Melimine and Mel-4 when immobilised at the highest concentrations showed 3.1 ± 0.6 log and 1.3 ± 0.2 log inhibition against P. aeruginosa, and 3.9 ± 0.6 log and 2.4 ± 0.5 log inhibition against S. aureus, respectively. Immobilisation of LL-37 resulted in up to 2.6 ± 1.0 log inhibition against only P. aeruginosa, but no activity against S. aureus. LFc attachment showed no antibacterial activity. Upon XPS analysis, immobilised melimine, LL-37, LFc and Mel-4 had 1.57 ± 0.38%, 1.13 ± 1.36%, 0.66 ± 0.47% and 0.73 ± 0.32% amide nitrogen attached to pHEMA compared to 0.12 ± 0.14% in the untreated controls. Amino acid analysis determined that the total amount of AMP attachment to pHEMA was 44.3 ± 7.4 nmol, 3.8 ± 0.2 nmol, 6.5 ± 0.6 nmol and 48.9 ± 2.3 nmol for the same peptides respectively. None of the AMP immobilised pHEMA surfaces showed any toxicity towards mouse L929 cells. The immobilisation of certain AMPs at nanomolar concentration to pHEMA is an effective option to develop a stable antimicrobial surface. PMID:26934297

  6. Intra-molecular cross-linking of acidic residues for protein structure studies.

    PubMed

    Novak, Petr; Kruppa, Gary H

    2008-01-01

    Intra-molecular cross-linking has been suggested as a method of obtaining distance constraints that would help to develop structural models of proteins. Recent work published on intra-molecular cross-linking for protein structural studies has employed commercially available primary amine (lysine, the amino terminus) selective reagents. Previous work using these cross-linkers has shown that for several proteins of known structure, the number of cross-links that can be obtained experimentally may be small compared to what would be expected from the known structure, due to the relative reactivity, distribution and solvent accessibility of the lysines in the protein sequence. To overcome these limitations, we have investigated the use of cross-linking reagents that can react with other reactive side chains in proteins. We used 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) to activate the carboxylic acid containing residues, aspartic acid (D), glutamic acid (E) and the carboxy terminus (O), for cross-linking reactions. Once activated, the DEO side chains can react to form "zero-length" cross-links with nearby primary amine containing residues, lysines (K) and the amino terminus (X), via the formation of a new amide bond. We also show that the EDC-activated DEO side chains can be cross-linked to each other using dihydrazides, two hydrazide moieties connected by an alkyl cross-linker arm of variable length. Using these reagents, we have found three new "zero-length" cross-links in ubiquitin consistent with its known structure (M1-E16, M1-E18 and K63-E64). Using the dihydrazide cross-linkers, we have identified two new cross-links (D21-D32 and E24-D32) unambiguously. Using a library of dihydrazide cross-linkers with varying arm length, we have shown that there is a minimum arm length required for the DEO-DEO cross-links of 5.8 A. These results show that additional structural information can be obtained by exploiting new cross-linker chemistry

  7. Intra-molecular cross-linking of acidic residues for protein structure studies.

    SciTech Connect

    Kruppa, Gary Hermann; Young, Malin M.; Novak, Petr; Schoeniger, Joseph S.

    2005-03-01

    Intra-molecular cross-linking has been suggested as a method of obtaining distance constraints that would be useful in developing structural models of proteins. Recent work published on intra-molecular cross-linking for protein structural studies has employed commercially available primary amine selective reagents that can cross-link lysine residues to other lysine residues or the amino terminus. Previous work using these cross-linkers has shown that for several proteins of known structure, the number of cross-links that can be obtained experimentally may be small compared to what would be expected from the known structure, due to the relative reactivity, distribution, and solvent accessibility of the lysines in the protein sequence. To overcome these limitations we have investigated the use of cross-linking reagents that can react with other reactive sidechains in proteins. We used 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) to activate the carboxylic acid containing residues, aspartic acid (D), glutamic acid (E), and the carboxy terminus (O), for cross-linking reactions. Once activated, the DEO sidechains can react to form 'zero-length' cross-links with nearby primary amine containing resides, lysines (K) and the amino terminus (X), via the formation of a new amide bond. We also show that the EDC-activated DEO sidechains can be cross-linked to each other using dihydrazides, two hydrazide moieties connected by an alkyl cross-linker ann of variable length. Using these reagents, we have found three new 'zero-length' cross-links in ubiquitin consistent with its known structure (M1-E16, M1-E18, and K63-E64). Using the dihydrazide cross-linkers, we have identified 2 new cross-links (D21-D32 and E24-D32) unambiguously. Using a library of dihydrazide cross-linkers with varying arm length, we have shown that there is a minimum arm length required for the DEO-DEO cross-links of 5.8 angstroms. These results show that additional structural information

  8. New insights into the effectiveness of alpha-amylase enzyme presentation on the Bacillus subtilis spore surface by adsorption and covalent immobilization.

    PubMed

    Gashtasbi, Fatemeh; Ahmadian, Gholamreza; Noghabi, Kambiz Akbari

    2014-10-01

    Most of the studies in the field of enzyme immobilization have sought to develop a simple, efficient and cost-effective immobilization system. In this study, probiotic Bacillus spores were used as a matrix for enzyme immobilization, because of their inherent resistance to extreme temperatures, UV irradiation, solvents and drying. Above all, their preparation is cost-effective. The alpha-amylase enzyme was immobilized on the spore surface by the covalent and adsorption methods. For the covalent method, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N hydroxysulfosuccinimide (NHS) were used. The maximum concentration of the alpha-amylase immobilized by the two methods onto the spore surface was 360 μg/1.2×10(11) spore. However, maximum activity was achieved at an enzyme concentration of approximately 60 μg/.4×10(10), corresponding to an estimated activity of 8×10(3) IU mg(-1)/1.2×10(11) spore for covalent immobilization and 8.53×10(3) for the adsorption method. After washing the enzyme with 1M NaCl and 0.5% Triton X-100, the enzyme immobilization yield was estimated to be 77% and 20.07% for the covalent and adsorption methods, respectively. The alpha-amylase immobilized by both methods, displayed improved activity in the basic pH range. The optimum pH for the free enzyme was 5 while it shifted to 8 for the immobilized enzyme. The optimum temperatures for the free and immobilized enzymes were 60 °C and 80 °C, respectively. The covalently-immobilized alpha-amylase retained 65% of its initial activity, even after 10 times of recycling. The Km and Vmax values were determined by the GraphPad Prism software, which showed that the Vmax value decreased moderately after immobilization. This is the first study which reports the covalent immobilization of an enzyme on the spore surface. PMID:25152412

  9. Chemical and physical characterization of a novel poly(carbonate urea) urethane surface with protein crosslinker sites.

    PubMed

    Phaneuf, M D; Quist, W C; LoGerfo, F W; Szycher, M; Dempsey, D J; Bide, M J

    1997-10-01

    evaluation slightly increased water vapor permeation through the films. Covalent linkage of the radiolabelled blood protein albumin (125I-BSA) to the cPU segments incubated with the heterobifunctional crosslinker 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) was greatest in the higher percent of ethanol as compared to controls. These results serve as foundation for developing a novel poly(carbonate urea) urethane with physical characteristics comparable to other medical-grade polyurethanes while having protein binding capabilities. PMID:9399137

  10. A novel benign solution for collagen processing

    NASA Astrophysics Data System (ADS)

    Arnoult, Olivier

    Collagen is the main protein constituting the extracellular matrix (ECM) of tissues in the body (skin, cartilage, blood vessels...). It exists many types of collagen, this work studies only fibrillar collagen (e.g. collagen type I contained in the skin) that exhibits a triple helical structure composed of 3 alpha-helical collagen chains. This particular and defined hierarchical structure is essential to the biological and mechanical properties of the collagen. Processing collagen into scaffolds to mimic the ECM is crucial for successful tissue engineering. Recently collagen was processed into fibrous and porous scaffold using electrospinning process. However the solvent (HFIP) used for electrospinning is extremely toxic for the user and expensive. This work shows that HFIP can be replaced by a benign mixture composed of water, salt and alcohol. Yet only three alcohols (methanol, ethanol and iso-propanol) enable the dissolution of large quantity of collagen in the benign mixture, with a wide range of alcohol to buffer ratio, and conserve the collagen hierarchical structure at least as well as the HFIP. Collagen can be electrospun from the benign mixture into sub-micron fibers with concentrations as low as 6 wt-% for a wide range of alcohol to buffer ratio, with at least 10wt-% of salt, and any of the three alcohols. Specific conditions yield nano size fibers. After processing from HFIP or a benign mixture, collagen is water soluble and needs to be chemically crosslink for tissue engineering application. Post-crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) results in the loss of the scaffold fibrous aspect and porosity, hence it is useless for tissue engineering. Such issue could be prevented by incorporating the crosslinker into the mixture prior to electrospinning. When EDC is used alone, collagen forms a gel in the mixture within minutes, preventing electrospinning. The addition of N-hydroxysuccinimide (NHS) in excess to EDC

  11. An Immunoassay for Dibutyl Phthalate Based on Direct Hapten Linkage to the Polystyrene Surface of Microtiter Plates

    PubMed Central

    Wei, Chenxi; Ding, Shumao; You, Huihui; Zhang, Yaran; Wang, Yao; Yang, Xu; Yuan, Junlin

    2011-01-01

    Background Dibutyl phthalate (DBP) is predominantly used as a plasticizer inplastics to make them flexible. Extensive use of phthalates in both industrial processes and other consumer products has resulted in the ubiquitous presence of phthalates in the environment. In order to better determine the level of pollution in the environment and evaluate the potential adverse effects of exposure to DBP, immunoassay for DBP was developed. Methodology/Principal Findings A monoclonal antibody specific to DBP was produced from a stable hybridoma cell line generated by lymphocyte hybridoma technique. An indirect competitive enzyme-linked immunosorbent assay (icELISA) employing direct coating of hapten on polystyrene microtiter plates was established for the detection of DBP. Polystyrene surface was first oxidized by permanganate in dilute sulfuric acid to generate carboxyl groups. Then dibutyl 4-aminophthalate, which is an analogue of DBP, was covalently linked to the carboxyl groups of polystyrene surface with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Compared with conjugate coated format (IC50 = 106 ng/mL), the direct hapten coated format (IC50 = 14.6 ng/mL) improved assay sensitivity after careful optimization of assay conditions. The average recovery of DBP from spiked water sample was 104.4% and the average coefficient of variation was 9.95%. Good agreement of the results obtained by the hapten coated icELISA and gas chromatography-mass spectrometry further confirmed the reliability and accuracy of the icELISA for the detection of DBP in certain plastic and cosmetic samples. Conclusions/Significance The stable and efficient hybridoma cell line obtained is an unlimited source of sensitive and specific antibody to DBP. The hapten coated format is proposed as generally applicable because the carboxyl groups on modified microtiter plate surface enables stable immobilization of aminated or hydroxylated hapten with EDC. The developed hapten

  12. Bacteriorhodopsin protein hybrids for chemical and biological sensing

    NASA Astrophysics Data System (ADS)

    Winder, Eric Michael

    Bacteriorhodopsin (bR), an optoelectric protein found in Halobacterium salinarum, has the potential for use in protein hybrid sensing systems. Bacteriorhodopsin has no intrinsic sensing properties, however molecular and chemical tools permit production of bR protein hybrids with transducing and sensing properties. As a proof of concept, a maltose binding protein-bacteriorhodopsin ([MBP]-bR) hybrid was developed. It was proposed that the energy associated with target molecule binding, maltose, to the hybrid sensor protein would provide a means to directly modulate the electrical output from the MBP-bR bio-nanosensor platform. The bR protein hybrid is produced by linkage between bR (principal component of purified purple membrane [PM]) and MBP, which was produced by use of a plasmid expression vector system in Escherichia coli and purified utilizing an amylose affinity column. These proteins were chemically linked using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), which facilitates formation of an amide bond between a primary carboxylic acid and a primary amine. The presence of novel protein hybrids after chemical linkage was analyzed by SDS-PAGE. Soluble proteins (MBP-only derivatives and unlinked MBP) were separated from insoluble proteins (PM derivatives and unlinked PM) using size exclusion chromatography. The putatively identified MBP-bR protein hybrid, in addition to unlinked bR, was collected. This sample was normalized for bR concentration to native PM and both were deposited onto indium tin oxide (ITO) coated glass slides by electrophoretic sedimentation. The photoresponse of both samples, activated using 100 Watt tungsten lamp at 10 cm distance, were equal at 175 mV. Testing of deposited PM with 1 mM sucrose or 1 mM maltose showed no change in the photoresponse of the material, however addition of 1 mM maltose to the deposited MBP-bR linked hybrid material elicited a 57% decrease in photoresponse

  13. Impact of carbondiimide crosslinker used for magnetic carbon nanotube mediated GFP plasmid delivery

    NASA Astrophysics Data System (ADS)

    Hao, Yuzhi; Xu, Peng; He, Chuan; Yang, Xiaoyan; Huang, Min; Xing, James; Chen, Jie

    2011-07-01

    1-ethyl-3-(3-dimethylaminopropyl) carbondiimide hydrochloride (EDC) is commonly used as a crosslinker to help bind biomolecules, such as DNA plasmids, with nanostructures. However, EDC often remains, after a crosslink reaction, in the micro-aperture of the nanostructure, e.g., carbon nanotube. The remaining EDC shows positive green fluorescent signals and makes a nanostructure with a strong cytotoxicity which induces cell death. The toxicity of EDC was confirmed on a breast cancer cell line (MCF-7) and two leukemic cell lines (THP-1 and KG-1). The MCF-7 cells mainly underwent necrosis after treatment with EDC, which was verified by fluorescein isothiocyanate (FITC) annexin V staining, video microscopy and scanning electronic microscopy (SEM). If the EDC was not removed completely, the nanostructures with remaining EDC produced a green fluorescent background that could interfere with flow cytometry (FACS) measurement and result in false information about GFP plasmid delivery. Effective methods to remove residual EDC on macromolecules were also developed.

  14. Carbodiimide or periodate method to prepare peroxidase hydrazide for its use in immunoassay.

    PubMed

    Shrivastav, Tulsidas G

    2004-01-01

    Peroxidase hydrazides were prepared by conjugating horseradish peroxidase (HRP) to adipic acid dihydrazide (ADH) by carbodiimide or periodate oxidation method. The resulting HRP hydrazides (ADH-HRP) were conjugated to cortisol-21-hemisuccinate (cortisol-21-HS) by forming diimide bonds using the N-hydroxysuccinimide (NHS) carbodiimide mediated reaction. The prepared cortisol-21-HS-ADH-HRP enzyme conjugates were utilized for the development of an enzyme linked immunosorbent assay (ELISA) for direct estimation of cortisol. To the cortisol antibody coated microtiter wells, standard or serum sample (50 microL), along with 100 microL of cortisol-21-HS-ADH-HRP enzyme conjugate (ADH-HRP used is prepared by either carbodiimide or periodate oxidation method), was incubated for 1 hr at 37 degrees C. Bound enzyme activity was measured by using tetramethyl benzidine/hydrogen peroxide (TMB/H202) as substrate. The sensitivity, specificity, and recovery of the assays were found to be identical when ELISAs were employed with cortisol enzyme conjugates prepared by conjugating cortisol-21-HS to HRP hydrazide, made either by the carbodiimide method or periodate oxidation method. PMID:15461389

  15. Netupitant and Palonosetron Hydrochloride

    Cancer.gov

    This page contains brief information about netupitant and palonosetron hydrochloride and a collection of links to more information about the use of this combination drug, research results, and ongoing clinical trials.

  16. Trifluridine and Tipiracil Hydrochloride

    Cancer.gov

    This page contains brief information about trifluridine and tipiracil hydrochloride and a collection of links to more information about the use of this combination drug, research results, and ongoing clinical trials.

  17. Carbodiimide cross-linking of amniotic membranes in the presence of amino acid bridges.

    PubMed

    Lai, Jui-Yang

    2015-06-01

    The purpose of this study was to investigate the carbodiimide cross-linking of amniotic membrane (AM) in the presence of amino acid bridges. The biological tissues were treated with glycine, lysine, or glutamic acid and chemically cross-linked to examine the role of amino acid types in collagenous biomaterial processing. Results of zeta potential measurements showed that the use of uncharged, positively and negatively charged amino acids dictates the charge state of membrane surface. Tensile strength and water content measurements demonstrated that the addition of lysine molecules to the cross-linking system can increase the cross-linking efficiency and dehydration degree while the introduction of glutamic acid in the AM samples decreases the number of cross-links per unit mass of chemically modified tissue collagen. The differences in the cross-linking density further determined the thermal and biological stability by differential scanning calorimetry and in vitro degradation tests. As demonstrated in matrix permeability studies, the improved formation of covalent cross-linkages imposed by lysine facilitated construction of stronger cross-linking structures. In contrast, the added glycine molecules were insufficient to enhance the resistances of the proteinaceous matrices to thermal denaturation and enzymatic degradation. The cytocompatibility of these biological tissue membranes was evaluated by using human corneal epithelial cell cultures. Results of cell viability, metabolic activity, and pro-inflammatory gene expression level showed that the AM materials cross-linked with carbodiimide in the presence of different types of amino acids are well tolerated without evidence of detrimental effect on cell growth. In addition, the amino acid treated and carbodiimide cross-linked AM implants had good biocompatibility in the anterior chamber of the rabbit eye model. Our findings suggest that amino acid type is a very important engineering parameter to mediate

  18. Annulation of thioimidates and vinyl carbodiimides to prepare 2-aminopyrimidines, competent nucleophiles for intramolecular alkyne hydroamination. Synthesis of (-)-crambidine.

    PubMed

    Perl, Nicholas R; Ide, Nathan D; Prajapati, Sudeep; Perfect, Hahdi H; Durón, Sergio G; Gin, David Y

    2010-02-17

    A convergent synthesis of (-)-crambidine is reported. The sequence capitalizes on two novel key transformations, including a [4+2] annulation of thioimidates with vinyl carbodiimides and an alkyne hydroamination employing 2-aminopyrimidine nucleophiles. PMID:20095555

  19. Modification of poly(L-lactic acid) electrospun fibers and films with poly(propylene imine) dendrimer

    NASA Astrophysics Data System (ADS)

    Khaliliazar, Sh.; Akbari, S.; Kish, M. H.

    2016-02-01

    Poly(L-lactic acid) (PLLA) electrospun fibers and films were modified with the second generation of poly(propylene imine) dendrimer (PPI-G2) by three different approaches, namely, sodium hydroxide hydrolysis, plasma treatment and direct application of PPI-G2. For the first and the second approaches, PLLA was modified by sodium hydroxide hydrolysis or plasma treatment to produce carboxylic acid groups. Then, the carboxylic acid groups were activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) and N,N‧-dicyclohexyl carbodiimide (DCC) as a hetero bi-functional cross-linker. The cross-linkers promoted the grafting of carboxylic acid groups on the modified PLLA with NH2 groups of PPI-G2. In the third approach, the PPI-G2 dendrimer was directly used as an aminolysis agent for the functionalization of PLLA in a one step process. FTIR analysis confirmed the presence of sbnd NH2 groups of PPI-G2 on the modified PLLA samples, resulting from each one of the three modification methods. Studies by SEM shows bead free electrospun fibers. Also, FE-SEM shows nano-cracks on the surface of films after modification. Contact angle, drug release tests, antibacterial effects and the dying results confirmed that these functionalization methods increased hydrophilicity and reactive side-chains of PLLA in the wet chemical process resulted in providing host-guest properties on the PLLA surface for adsorbing various kinds of guest molecules.

  20. Ocular biocompatibility of carbodiimide cross-linked hyaluronic acid hydrogels for cell sheet delivery carriers.

    PubMed

    Lai, Jui-Yang; Ma, David Hui-Kang; Cheng, Hsiao-Yun; Sun, Chi-Chin; Huang, Shu-Jung; Li, Ya-Ting; Hsiue, Ging-Ho

    2010-01-01

    Due to its innocuous nature, hyaluronic acid (HA) is one of the most commonly used biopolymers for ophthalmic applications. We recently developed a cell sheet delivery system using carbodiimide cross-linked HA carriers. Chemical cross-linking provides an improvement in stability of polymer gels, but probably causes toxic side-effects. The aim of this study was to investigate the ocular biocompatibility of HA hydrogels cross-linked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC). HA discs without cross-linking and glutaraldehyde (GTA) cross-linked HA samples were used for comparison. The disc implants were inserted in the anterior chamber of rabbit eyes for 24 weeks and characterized by slit-lamp biomicroscopy, histology and scanning electron microscopy. The ophthalmic parameters obtained from biomicroscopic examinations were also scored to provide a quantitative grading system. Results of this study showed that the HA discs cross-linked with EDC had better ocular biocompatibility than those with GTA. The continued residence of GTA cross-linked HA implants in the intraocular cavity elicited severe tissue responses and significant foreign body reactions, whereas no adverse inflammatory reaction was observed after contact with non-cross-linked HA or EDC cross-linked HA samples. It is concluded that the cross-linking agent type gives influence on ocular biocompatibility of cell carriers and the EDC-HA hydrogel is an ideal candidate for use as an implantable material in cell sheet delivery applications. PMID:20178691

  1. New method and characterization of self-assembled gelatin-oleic nanoparticles using a desolvation method via carbodiimide/N-hydroxysuccinimide (EDC/NHS) reaction.

    PubMed

    Park, Chulhun; Vo, Chau Le-Ngoc; Kang, Taehee; Oh, Euichaul; Lee, Beom-Jin

    2015-01-01

    In this study, we investigated a new method for the preparation of gelatin-oleic conjugate (GOC) as an amphiphilic biomaterial to load model anti-cancer drugs into self-assembled nanoparticles (NPs). Oleic acid (OA) was covalently bound to gelatin via carbodiimide/N-hydroxysuccinimide (EDC/NHS) reaction in water-ethanol cosolvent to form a GOC. Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance ((1)H NMR) clearly indicated the successful synthesis of GOC. The percentage of gelatin amino groups reacted with OA was up to 50% as determined using the 2,4,6-trinitrobenzene sulfonic acid (TNBS) method. Subsequently, gelatin-oleic nanoparticles (GONs) were prepared using a desolvation method with glutaraldehyde or genipin used as a crosslinker for comparison. Irinotecan hydrochloride (IRT) was used as a model drug to load into GONs using incubation or an in-process adding method for comparison. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) data showed that the sizes of GONs and IRT-loaded GONs (IRT-GONs) were below 250 nm. The zeta potentials of the GONs and irinotecan-loaded IRT-GONs were below -20 mV, which was found to be stable in suspension against the aggregation process. The incubation method was more suitable for drug loading because it did not affect the process of GON formation and thus did not increase their size much compared to the change in size with the in-process adding method. The lipophilic property of the oleic moiety in the GOC increased the affinity between GOC molecules, thus reducing the amount of crosslinking agents needed to stabilize GONs compared to gelatin nanoparticles (GNs). As novel approaches for the synthesis of protein-fatty acid complexes, chemical reaction has been suggested for the synthesis of GOC. The above results show that GOC synthesized via new method is a promising biomaterial based upon preparation of nanoparticles. PMID:25536111

  2. Photochemistry of phenazopyridine hydrochloride.

    PubMed

    Iqbal, J; Gupta, A; Husain, A

    2006-09-01

    Phenazopyridine hydrochloride (1) is an azo dye with local analgesic and anaesthetic effects on the urinary tract. Its photochemistry was studied in different reaction media including the drug adsorbed on silica gel. This resulted in photochemical cyclodehydrogenation, reductive photodegradation and rearrangement of the drug molecule. Four major products were isolated and identified on the basis of IR, NMR and mass spectral studies. The products are: pyrido[3,4-c]cinnoline-2,4-diamine (2), N3-phenylpyridine-2,3,4,6-tetraamine (3), pyridine-2,3,6-triamine (4), 2,6-diamino-1-(4-aminophenyl)pyridin-4(1H)-one (5). PMID:17020148

  3. In Vitro Selection of Optimal DNA Substrates for Ligation by a Water-Soluble Carbodiimide

    NASA Technical Reports Server (NTRS)

    Harada, Kazuo; Orgel, Leslie E.

    1994-01-01

    We have used in vitro selection to investigate the sequence requirements for efficient template-directed ligation of oligonucleotides at 0 deg C using a water-soluble carbodiimide as condensing agent. We find that only 2 bp at each side of the ligation junction are needed. We also studied chemical ligation of substrate ensembles that we have previously selected as optimal by RNA ligase or by DNA ligase. As anticipated, we find that substrates selected with DNA ligase ligate efficiently with a chemical ligating agent, and vice versa. Substrates selected using RNA ligase are not ligated by the chemical condensing agent and vice versa. The implications of these results for prebiotic chemistry are discussed.

  4. Nitrile imines: matrix isolation, IR spectra, structures, and rearrangement to carbodiimides.

    PubMed

    Bégué, Didier; Qiao, Greg GuangHua; Wentrup, Curt

    2012-03-21

    The structures and reactivities of nitrile imines are subjects of continuing debate. Several nitrile imines were generated photochemically or thermally and investigated by IR spectroscopy in Ar matrices at cryogenic temperatures (Ph-CNN-H 6, Ph-CNN-CH(3)17, Ph-CNN-SiMe(3)23, Ph-CNN-Ph 29, Ph(3)C-CNN-CPh(3)34, and the boryl-CNN-boryl derivative 39). The effect of substituents on the structures and IR absorptions of nitrile imines was investigated computationally at the B3LYP/6-31G* level. IR spectra were analyzed in terms of calculated anharmonic vibrational spectra and were generally in very good agreement with the calculated spectra. Infrared spectra were found to reflect the structures of nitrile imines accurately. Nitrile imines with IR absorptions above 2200 cm(-1) have essentially propargylic structures, possessing a CN triple bond (typically PhCNNSiMe(3)23, PhCNNPh 29, and boryl-CNN-boryl 39). Nitrile imines with IR absorptions below ca. 2200 cm(-1) are more likely to be allenic (e.g., HCNNH 1, PhCNNH 6, HCNNPh 43, PhCNNCH(3)17, and Ph(3)C-CNN-CPh(3)34). All nitrile imines isomerize to the corresponding carbodiimides both thermally and photochemically. Monosubstituted carbodiimides isomerize thermally to the corresponding cyanamides (e.g., Ph-N═C═N-H 5 → Ph-NH-CN 8), which are therefore the thermal end products for nitrile imines of the types RCNNH and HCNNR. This tautomerization is reversible under flash vacuum thermolysis conditions. PMID:22364289

  5. Transition Metal Carbodiimides as Molecular Negative Electrode Materials for Lithium and Sodium Ion Batteries with Excellent Cycling Properties

    SciTech Connect

    Sougrati, M. T.; Darwiche, Ali; Liu, Xiaohiu; Mahmoud, A.; Hermann, Raphael P; Jouen, Samuel; Monconduit, Laure; Dronskowski, Richard; Stievano, L.

    2016-01-01

    We report evidence for the electrochemical activity of transition-metal carbodiimides versus lithium and sodium. In particular, iron carbodiimide, FeNCN, can be efficiently used as a negative electrode material for alkali-metal-ion batteries, similar to its oxide analogue FeO. Based on 57Fe M ssbauer and infrared spectroscopy (IR) data, the electrochemical reaction mechanism can be explained by the reversible transformation of the Fe NCN into Li/Na NCN bonds during discharge and charge. These new electrode materials exhibit higher capacity compared to well-established negative electrode references such as graphite or hard carbon. Contrary to its oxide analogue, iron carbodiimide does not require heavy treatments (nanoscale tailoring, sophisticated textures, coating etc.) to obtain long cycle life with density current as high as 9 A/g for hundreds of charge/discharge cycles. Similar to the iron compound, several other transition-metal carbodiimides Mx(NCN)y with M = Mn, Cr, Zn can cycle successfully versus lithium and sodium. Their electrochemical activity and performances open the way to the design of a novel family of anode materials.

  6. Transition-Metal Carbodiimides as Molecular Negative Electrode Materials for Lithium- and Sodium-Ion Batteries with Excellent Cycling Properties

    DOE PAGESBeta

    Sougrati, Moulay T.; Darwiche, Ali; Liu, Xiaohiu; Mahmoud, Abdelfattah; Hermann, Raphael P.; Jouen, Samuel; Monconduit, Laure; Dronskowski, Richard; Stievano, Lorenzo

    2016-03-16

    Here we report evidence for the electrochemical activity of transition-metal carbodiimides versus lithium and sodium. In particular, iron carbodiimide, FeNCN, can be efficiently used as a negative electrode material for alkali-metal-ion batteries, similar to its oxide analogue FeO. Based on 57Fe M ssbauer and infrared spectroscopy (IR) data, the electrochemical reaction mechanism can be explained by the reversible transformation of the Fe NCN into Li/Na NCN bonds during discharge and charge. These new electrode materials exhibit higher capacity compared to well-established negative electrode references such as graphite or hard carbon. Contrary to its oxide analogue, iron carbodiimide does not requiremore » heavy treatments (nanoscale tailoring, sophisticated textures, coating etc.) to obtain long cycle life with density current as high as 9 A/g-1 for hundreds of charge/discharge cycles. Similar to the iron compound, several other transition-metal carbodiimides Mx(NCN)y with M = Mn, Cr, Zn can cycle successfully versus lithium and sodium. Ultimately, their electrochemical activity and performances open the way to the design of a novel family of anode materials.« less

  7. Transition-Metal Carbodiimides as Molecular Negative Electrode Materials for Lithium- and Sodium-Ion Batteries with Excellent Cycling Properties.

    PubMed

    Sougrati, Moulay T; Darwiche, Ali; Liu, Xiaohiu; Mahmoud, Abdelfattah; Hermann, Raphael P; Jouen, Samuel; Monconduit, Laure; Dronskowski, Richard; Stievano, Lorenzo

    2016-04-11

    We report evidence for the electrochemical activity of transition-metal carbodiimides versus lithium and sodium. In particular, iron carbodiimide, FeNCN, can be efficiently used as negative electrode material for alkali-metal-ion batteries, similar to its oxide analogue FeO. Based on (57)Fe Mössbauer and infrared spectroscopy (IR) data, the electrochemical reaction mechanism can be explained by the reversible transformation of the Fe-NCN into Li/Na-NCN bonds during discharge and charge. These new electrode materials exhibit higher capacity compared to well-established negative electrode references such as graphite or hard carbon. Contrary to its oxide analogue, iron carbodiimide does not require heavy treatments (such as nanoscale tailoring, sophisticated textures, or coating) to obtain long cycle life with current density as high as 9 A g(-1) for hundreds of charge-discharge cycles. Similar to the iron compound, several other transition-metal carbodiimides M(x)(NCN)y with M=Mn, Cr, Zn can cycle successfully versus lithium and sodium. Their electrochemical activity and performance open the way to the design of a novel family of anode materials. PMID:26989882

  8. Electrodeposition of chitosan/gelatin/nanosilver: A new method for constructing biopolymer/nanoparticle composite films with conductivity and antibacterial activity.

    PubMed

    Wang, Yifeng; Guo, Xuecheng; Pan, Ruihao; Han, Di; Chen, Tao; Geng, Zenghua; Xiong, Yanfei; Chen, Yanjun

    2015-08-01

    Electrodeposition of chitosan provides a controllable means to simultaneously assemble biological materials and nanoparticles for various applications. Here, we present a new method to construct biopolymer/nanoparticle composite films with conductivity and antibacterial activity by electrodeposition of chitosan/gelatin/nanosilver. Besides, this method can be employed to build biopolymer/nanoparticle composite hydrogels or coatings on various electrodes or conductive substrates. We initially use a simple approach to prepare the aqueous nanosilver that can be well-dispersed in water. Then, the codeposition mixture containing chitosan, gelatin and nanosilver is prepared, and it can be electrodeposited onto different electrodes or conductive substrates in response to imposed electrical signals. After electrodeposition, it is found that the deposited hydrogels and their dried films are smooth and homogeneous due to the elimination of H2 bubbles by addition of H2O2 in electrodeposition process. Importantly, the composite films are strong enough to completely and readily peel from the electrodes after they reacted with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), which can build a type of biopolymer/nanoparticle film for further applications. Furthermore, the electrodeposition technique is able to offer controllable and convenient method to construct the composite films with diverse shapes. The composite films display improved conductivity and in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus, which may provide attractive applications in biomedical fields such as artificial muscles, skin biomaterials and neuroprosthetic implants. PMID:26042710

  9. The Effect of Sterilization Methods on the Structural and Chemical Properties of Fibrin Microthread Scaffolds.

    PubMed

    Grasman, Jonathan M; O'Brien, Megan P; Ackerman, Kevin; Gagnon, Keith A; Wong, Gregory M; Pins, George D

    2016-06-01

    A challenge for the design of scaffolds in tissue engineering is to determine a terminal sterilization method that will retain the structural and biochemical properties of the materials. Since commonly used heat and ionizing energy-based sterilization methods have been shown to alter the material properties of protein-based scaffolds, the effects of ethanol and ethylene oxide (EtO) sterilization on the cellular compatibility and the structural, chemical, and mechanical properties of uncrosslinked, UV crosslinked, or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) crosslinked fibrin microthreads in neutral (EDCn) or acidic (EDCa) buffers are evaluated. EtO sterilization significantly reduces the tensile strength of uncrosslinked microthreads. Surface chemistry analyses show that EtO sterilization induces alkylation of EDCa microthreads leading to a significant reduction in myoblast attachment. The material properties of EDCn microthreads do not appear to be affected by the sterilization method. These results significantly enhance the understanding of how sterilization or crosslinking techniques affect the material properties of protein scaffolds. PMID:26847494

  10. Chitosan grafted monomethyl fumaric acid as a potential food preservative.

    PubMed

    Khan, Imran; Ullah, Shafi; Oh, Deog-Hwan

    2016-11-01

    The present study aims at in vitro antibacterial and antioxidant activity evaluation of chitosan modified with monomethyl fumaric acid (MFA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as mediator. Three different kinds of chitosan derivatives Ch-Ds-1,Ch-Ds-2 and Ch-Ds-3 were synthesized by feeding different concentration of MFA. The chemical structures of resulting materials were characterized by (1)H NMR, (13)C NMR, HR-XRD, FT-IR and TNBS assay. The results showed that Ch-Ds-1, Ch-Ds-2 and Ch-Ds-3 were successfully synthesized. The % amino groups of chitosan modified by MFA were evaluated by TNBS assay and ranging from 1.82±0.05% to 7.88±0.04%. All the chitosan derivatives are readily soluble in water and swelled by dimethyl sulfoxide (DMSO), toluene and dimethyl formamide (DMF). The antioxidant activity for all the chitosan derivatives have been significantly improved (P<0.05) compared to the chitosan. Upon antibacterial activity at pH 4.0, all the chitosan derivatives showed significant (P<0.05) antibacterial activity against Gram positive Staphylococcus aureus, Listeria monocytogenes strains and Gram negative Escherichia coli and Salmonella enteritidis strains compared to chitosan. In conclusion, MFA modified chitosan has shown enhanced activities along with solubility, and could be used as a novel food preservative and packaging material for long time food safety and security. PMID:27516253

  11. An Optically-Transparent Aptamer-Based Detection System for Colon Cancer Applications Using Gold Nanoparticles Electrodeposited on Indium Tin Oxide

    PubMed Central

    Ahmadzadeh-Raji, Mojgan; Ghafar-Zadeh, Ebrahim; Amoabediny, Ghasem

    2016-01-01

    In this paper, a label-free aptamer based detection system (apta-DS) was investigated for detecting colon cancer cells. For this purpose, we employed an aptamer specific to colon cancer cells like HCT116 expressing carcinoembryonic antigen (CEA) on their surfaces. Capture aptamers were covalently immobilized on the surface of gold nanoparticles (GNPs) through self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA) activated with EDC (1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide)/N-hydroxysuccinimide (NHS). The cyclic voltammetry (CV) and chronopotentiometry (CP) methods were used for electrodeposition of GNPs on the surface of indium tin oxide (ITO). In this work, the CV method was also used to demonstrate the conjugation of GNPs and aptamers and identify the cancer cell capturing events. Additionally, Field Emission Scanning Electron Microscopy (FE-SEM) confirmed the deposition of GNPs on ITO and the immobilization of aptamer on the apta-DS. The electrodeposited GNPs played the role of nanoprobes for cancer cell targeting without losing the optical transparency of the ITO substrate. A conventional optical microscope also verified the detection of captured cancer cells. Based on this study’s results relying on electrochemical and optical microscopic methods, the proposed apta-DS is reliable and high sensitive with a LOD equal to 6 cell/mL for colon cancer detection. PMID:27420059

  12. Porous ovalbumin scaffolds with tunable properties: a resource-efficient biodegradable material for tissue engineering applications.

    PubMed

    Luo, Baiwen; Choong, Cleo

    2015-01-01

    Natural materials are promising alternatives to synthetic materials used in tissue engineering applications as they have superior biocompatibility and promote better cell attachment and proliferation. Ovalbumin, a natural polymer found in avian egg white, is an example of a nature-derived material. Despite the availability and reported biocompatibility of ovalbumin, limited research has been carried out to investigate the efficacy of ovalbumin-based scaffolds for adipose tissue engineering applications. Hence, the current study was carried out to investigate the effect of different crosslinkers on ovalbumin scaffold properties as first step towards the development of ovalbumin-based scaffolds for adipose tissue engineering applications. In this study, highly porous three-dimensional scaffolds were fabricated by using three different crosslinkers: glutaraldehyde, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1,4-butanediol diglycidyl ether. Results showed that the overall scaffold properties such as morphology, pore size and mechanical properties could be modulated based on the type and concentration of crosslinkers used during the fabrication process. Subsequently, the efficacy of the different scaffolds for supporting cell proliferation was investigated. In vitro degradation was also carried on for the best scaffold based on the mechanical and cellular results. Overall, this study is a demonstration of the viability of ovalbumin-based scaffolds as cell carriers for soft tissue engineering applications. PMID:25158688

  13. Radioprotection provides functional mechanics but delays healing of irradiated tendon allografts after ACL reconstruction in sheep.

    PubMed

    Seto, Aaron U; Culp, Brian M; Gatt, Charles J; Dunn, Michael

    2013-12-01

    Successful protection of tissue properties against ionizing radiation effects could allow its use for terminal sterilization of musculoskeletal allografts. In this study we functionally evaluate Achilles tendon allografts processed with a previously developed radioprotective treatment based on (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) crosslinking and free radical scavenging using ascorbate and riboflavin, for ovine anterior cruciate ligament reconstruction. Arthroscopic anterior cruciate ligament (ACL) reconstruction was performed using double looped allografts, while comparing radioprotected irradiated and fresh frozen allografts after 12 and 24 weeks post-implantation, and to control irradiated grafts after 12 weeks. Radioprotection was successful at preserving early subfailure mechanical properties comparable to fresh frozen allografts. Twelve week graft stiffness and anterior-tibial (A-T) translation for radioprotected and fresh frozen allografts were comparable at 30 % of native stiffness, and 4.6 and 5 times native A-T translation, respectively. Fresh frozen allograft possessed the greatest 24 week peak load at 840 N and stiffness at 177 N/mm. Histological evidence suggested a delay in tendon to bone healing for radioprotected allografts, which was reflected in mechanical properties. There was no evidence that radioprotective treatment inhibited intra-articular graft healing. This specific radioprotective method cannot be recommended for ACL reconstruction allografts, and data suggest that future efforts to improve allograft sterilization procedures should focus on modifying or eliminating the pre-crosslinking procedure. PMID:23842952

  14. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    NASA Astrophysics Data System (ADS)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won; Lim, Yun Kyong; Kook, Joong-Ki; Cho, Dong-Lyun; Kim, Byung Hoon

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  15. Mapping the surface-exposed regions of papaya mosaic virus nanoparticles.

    PubMed

    Rioux, Gervais; Majeau, Nathalie; Leclerc, Denis

    2012-06-01

    In general, the structure of the papaya mosaic virus (PapMV) and other members of the potexviruses is poorly understood. Production of PapMV coat proteins in a bacterial expression system and their self-assembly in vitro into nanoparticles is a very useful tool to study the structure of this virus. Using recombinant PapMV nanoparticles that are similar in shape and appearance to the plant virus, we evaluated surface-exposed regions by two different methods, immunoblot assay and chemical modification with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide or diethyl-pyrocarbonate followed by mass spectrometry. Three regions were targeted by the two techniques. The N- and C-termini were shown to be surfaced exposed as expected. However, the region 125-136 was revealed for the first time as the major surface-exposed region of the nanoparticles. The presence of linear peptides at the surface was finally confirmed using antibodies directed to those peptides. It is likely that region 125-136 plays a key role in the lifecycle of PapMV and other members of the potexvirus group. PMID:22524169

  16. Collagen based film with well epithelial and stromal regeneration as corneal repair materials: Improving mechanical property by crosslinking with citric acid.

    PubMed

    Zhao, Xuan; Liu, Yang; Li, Weichang; Long, Kai; Wang, Lin; Liu, Sa; Wang, Yingjun; Ren, Li

    2015-10-01

    Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)-citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col-CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS=60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30±5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin-eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col-CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications. PMID:26117756

  17. An Optically-Transparent Aptamer-Based Detection System for Colon Cancer Applications Using Gold Nanoparticles Electrodeposited on Indium Tin Oxide.

    PubMed

    Ahmadzadeh-Raji, Mojgan; Ghafar-Zadeh, Ebrahim; Amoabediny, Ghasem

    2016-01-01

    In this paper, a label-free aptamer based detection system (apta-DS) was investigated for detecting colon cancer cells. For this purpose, we employed an aptamer specific to colon cancer cells like HCT116 expressing carcinoembryonic antigen (CEA) on their surfaces. Capture aptamers were covalently immobilized on the surface of gold nanoparticles (GNPs) through self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA) activated with EDC (1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide)/N-hydroxysuccinimide (NHS). The cyclic voltammetry (CV) and chronopotentiometry (CP) methods were used for electrodeposition of GNPs on the surface of indium tin oxide (ITO). In this work, the CV method was also used to demonstrate the conjugation of GNPs and aptamers and identify the cancer cell capturing events. Additionally, Field Emission Scanning Electron Microscopy (FE-SEM) confirmed the deposition of GNPs on ITO and the immobilization of aptamer on the apta-DS. The electrodeposited GNPs played the role of nanoprobes for cancer cell targeting without losing the optical transparency of the ITO substrate. A conventional optical microscope also verified the detection of captured cancer cells. Based on this study's results relying on electrochemical and optical microscopic methods, the proposed apta-DS is reliable and high sensitive with a LOD equal to 6 cell/mL for colon cancer detection. PMID:27420059

  18. Increasing Mechanical Strength of Gelatin Hydrogels by Divalent Metal Ion Removal

    PubMed Central

    Xing, Qi; Yates, Keegan; Vogt, Caleb; Qian, Zichen; Frost, Megan C.; Zhao, Feng

    2014-01-01

    The usage of gelatin hydrogel is limited due to its instability and poor mechanical properties, especially under physiological conditions. Divalent metal ions present in gelatin such as Ca2+ and Fe2+ play important roles in the gelatin molecule interactions. The objective of this study was to determine the impact of divalent ion removal on the stability and mechanical properties of gelatin gels with and without chemical crosslinking. The gelatin solution was purified by Chelex resin to replace divalent metal ions with sodium ions. The gel was then chemically crosslinked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Results showed that the removal of divalent metal ions significantly impacted the formation of the gelatin network. The purified gelatin hydrogels had less interactions between gelatin molecules and form larger-pore network which enabled EDC to penetrate and crosslink the gel more efficiently. The crosslinked purified gels showed small swelling ratio, higher crosslinking density and dramatically increased storage and loss moduli. The removal of divalent ions is a simple yet effective method that can significantly improve the stability and strength of gelatin hydrogels. The in vitro cell culture demonstrated that the purified gelatin maintained its ability to support cell attachment and spreading. PMID:24736500

  19. Formulation and characterisation of antibody-conjugated soy protein nanoparticles--implications for neutralisation of snake venom with improved efficiency.

    PubMed

    Renu, Kadali; Gopi, Kadiyala; Jayaraman, Gurunathan

    2014-12-01

    The present study reports the formulation of soy protein nanoparticles and its conjugation to antivenom. The conditions for nanoparticle formation were optimised by considering particle size, count rate, stability and zeta potential. The smallest particle size of 70.9 ± 0.9 nm with a zeta potential of -28.0 ± 1.4 mV was obtained at pH 6.2, with NaOH 5.4 % and 28 μg/mg glutaraldehyde. The nanoparticle was conjugated with antisnake venom immunoglobulins (F(ab')2 fragments) using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide. TEM analysis indicated the increased size of particle to 600 nm after conjugation to antivenom. Further, in vitro studies indicated that conjugated antibodies inhibited the activity of protease, phospholipase and hyaluronidase enzymes of Bungarus caeruleus venom more efficiently than the free antivenom. This is the first report on the use of protein nanoparticles for conjugating snake venom antibodies and their implications for neutralising snake venom enzymes with increased efficiency. PMID:25185504

  20. Injectable pullulan hydrogel for the prevention of postoperative tissue adhesion.

    PubMed

    Bang, Sumi; Lee, Eungjae; Ko, Young-Gwang; Kim, Won Il; Kwon, Oh Hyeong

    2016-06-01

    Methods for reducing and preventing postoperative abdominal adhesions have been researched for decades; however, despite these efforts, the formation of postoperative peritoneal adhesions is continuously reported. Adhesions cause serious complications such as postoperative pain, intestinal obstruction, and infertility. Tissue adhesion barriers have been developed as films, membranes, knits, sprays, and hydrogels. Hydrogels have several advantages when used as adhesion barriers, including flexibility, low tissue adhesiveness, biodegradability, and non-toxic degraded products. Furthermore, compared with preformed hydrogels, injectable hydrogels can fill and cover spaces of any shape and do not require a surgical procedure for implantation. In this study, pullulan was modified through reaction with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) to introduce carboxyl and phenyl groups as crosslinking sites. The grafting of tyramine on pullulan allows crosslinking branches on pullulan backbone. We successfully fabricated pullulan hydrogel with an enzymatic reaction using horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). The chemical structure of modified pullulan was analyzed with ATR-FTIR and (1)H NMR spectroscopies. Rheological properties were tested by measuring storage modulus with varying H2O2, HRP, polymer solution concentrations and tyramine substitution rates. Cell viability and animal tests were performed. The modified pullulan hydrogel is an invaluable advance in anti-adhesion agents. PMID:26879910

  1. Thermostable trypsin conjugates immobilized to biogenic magnetite show a high operational stability and remarkable reusability for protein digestion

    NASA Astrophysics Data System (ADS)

    Pečová, M.; Šebela, M.; Marková, Z.; Poláková, K.; Čuda, J.; Šafářová, K.; Zbořil, R.

    2013-03-01

    In this work, magnetosomes produced by microorganisms were chosen as a suitable magnetic carrier for covalent immobilization of thermostable trypsin conjugates with an expected applicability for efficient and rapid digestion of proteins at elevated temperatures. First, a biogenic magnetite was isolated from Magnetospirillum gryphiswaldense and its free surface was coated with the natural polysaccharide chitosan containing free amino and hydroxy groups. Prior to covalent immobilization, bovine trypsin was modified by conjugating with α-, β- and γ-cyclodextrin. Modified trypsin was bound to the magnetic carriers via amino groups using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling reagents. The magnetic biomaterial was characterized by magnetometric analysis and electron microscopy. With regard to their biochemical properties, the immobilized trypsin conjugates showed an increased resistance to elevated temperatures, eliminated autolysis, had an unchanged pH optimum and a significant storage stability and reusability. Considering these parameters, the presented enzymatic system exhibits properties that are superior to those of trypsin forms obtained by other frequently used approaches. The proteolytic performance was demonstrated during in-solution digestion of model proteins (horseradish peroxidase, bovine serum albumin and hen egg white lysozyme) followed by mass spectrometry. It is shown that both magnetic immobilization and chemical modification enhance the characteristics of trypsin making it a promising tool for protein digestion.

  2. Biodistribution and pharmacokinetics of uniform magnetite nanoparticles chemically modified with polyethylene glycol

    NASA Astrophysics Data System (ADS)

    Ruiz, A.; Hernández, Y.; Cabal, C.; González, E.; Veintemillas-Verdaguer, S.; Martínez, E.; Morales, M. P.

    2013-11-01

    The influence of polyethylene glycol (PEG) grafting on the pharmacokinetics, biodistribution and elimination of iron oxide nanoparticles is studied in this work. Magnetite nanoparticles (12 nm) were obtained via thermal decomposition of an iron coordination complex as a precursor. Particles were coated with meso-2,3-dimercaptosuccinic acid (DMSA) and conjugated to PEG-derived molecules by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC) chemistry. Using a rat model, we explored the nanoparticle biodistribution pattern in blood and in different organs (liver, spleen and lungs) after intravenous administration of the product. The time of residence in blood was measured from the evolution of water proton relaxivities with time and Fe analysis in blood samples. The results showed that the residence time was doubled for PEG coated nanoparticles and consequently particle accumulation in liver and spleen was reduced. Post-mortem histological analyses showed no alterations in the liver and confirm heterogeneous distribution of NPs in the organ, in agreement with magnetic measurements and iron analysis. Finally, by successive magnetic resonance images we studied the evolution of contrast in the liver and measured the absorption, time of residence and excretion of nanoparticles in the liver during a one month period. On the basis of these results we propose different metabolic routes that determine the fate of magnetic nanoparticles.

  3. Effect of condensation agents and minerals for oligopeptide formation under mild and hydrothermal conditions in related to chemical evolution of proteins

    NASA Astrophysics Data System (ADS)

    Kawamura, Kunio; Takeya, Hitoshi; Kushibe, Takao

    2009-07-01

    The role of condensation agents and minerals for oligopeptide formation was inspected to see whether minerals possess catalytic activity under mild and hydrothermal conditions. Under mild conditions, oligopeptide formation from negatively charged amino acids (Asp and Glu) using different minerals and the elongation of alanine oligopeptides ((Ala) 2-(Ala) 5) were attempted using apatite minerals. Oligo(Asp) up to 10 amino acid units from Asp were observed in the presence of 1-ethyl-3-(3-dimethylaminopropyl carbodiimide (EDC). Notable influence of minerals was not detected for the oligo(Asp) formation. Oligo(Asp) was gradually degraded by the further incubation in the presence of EDC in both the absence and presence of minerals. The formation of oligo(Glu) was less efficient in the presence of carbonyldiimidazole. The elongation from (Ala) 3, (Ala) 4, and (Ala) 5 and the formation of diketopiperazine from (Ala) 2 proceeded immediately in the presence of EDC in the meantime of the sample preparations. In addition, it was unexpected that the disappearance of the products and the reformation of the reactants occurred by the further incubation for 24 h; for instance, (Ala) 5 decreased but (Ala) 4 increased with increasing the reaction time in the reaction of (Ala) 4 with EDC. These facts suggest that the activation of the reactant amino acids or peptides immediately occurs. Under the simulated hydrothermal conditions, EDC did not enhance the formation of oligopeptides from Asp, Glu or Ala nor the spontaneous formation of (Ala) 5 from (Ala) 4.

  4. The synthesis and coupling of photoreactive collagen-based peptides to restore integrin reactivity to an inert substrate, chemically-crosslinked collagen.

    PubMed

    Malcor, Jean-Daniel; Bax, Daniel; Hamaia, Samir W; Davidenko, Natalia; Best, Serena M; Cameron, Ruth E; Farndale, Richard W; Bihan, Dominique

    2016-04-01

    Collagen is frequently advocated as a scaffold for use in regenerative medicine. Increasing the mechanical stability of a collagen scaffold is widely achieved by cross-linking using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). However, this treatment consumes the carboxylate-containing amino acid sidechains that are crucial for recognition by the cell-surface integrins, abolishing cell adhesion. Here, we restore cell reactivity to a cross-linked type I collagen film by covalently linking synthetic triple-helical peptides (THPs), mimicking the structure of collagen. These THPs are ligands containing an active cell-recognition motif, GFOGER, a high-affinity binding site for the collagen-binding integrins. We end-stapled peptide strands containing GFOGER by coupling a short diglutamate-containing peptide to their N-terminus, improving the thermal stability of the resulting THP. A photoreactive Diazirine group was grafted onto the end-stapled THP to allow covalent linkage to the collagen film upon UV activation. Such GFOGER-derivatized collagen films showed restored affinity for the ligand-binding I domain of integrin α2β1, and increased integrin-dependent cell attachment and spreading of HT1080 and Rugli cell lines, expressing integrins α2β1 and α1β1, respectively. The method we describe has wide application, beyond collagen films or scaffolds, since the photoreactive diazirine will react with many organic carbon skeletons. PMID:26854392

  5. The synthesis and coupling of photoreactive collagen-based peptides to restore integrin reactivity to an inert substrate, chemically-crosslinked collagen

    PubMed Central

    Malcor, Jean-Daniel; Bax, Daniel; Hamaia, Samir W.; Davidenko, Natalia; Best, Serena M.; Cameron, Ruth E.; Farndale, Richard W.; Bihan, Dominique

    2016-01-01

    Collagen is frequently advocated as a scaffold for use in regenerative medicine. Increasing the mechanical stability of a collagen scaffold is widely achieved by cross-linking using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). However, this treatment consumes the carboxylate-containing amino acid sidechains that are crucial for recognition by the cell-surface integrins, abolishing cell adhesion. Here, we restore cell reactivity to a cross-linked type I collagen film by covalently linking synthetic triple-helical peptides (THPs), mimicking the structure of collagen. These THPs are ligands containing an active cell-recognition motif, GFOGER, a high-affinity binding site for the collagen-binding integrins. We end-stapled peptide strands containing GFOGER by coupling a short diglutamate-containing peptide to their N-terminus, improving the thermal stability of the resulting THP. A photoreactive Diazirine group was grafted onto the end-stapled THP to allow covalent linkage to the collagen film upon UV activation. Such GFOGER-derivatized collagen films showed restored affinity for the ligand-binding I domain of integrin α2β1, and increased integrin-dependent cell attachment and spreading of HT1080 and Rugli cell lines, expressing integrins α2β1 and α1β1, respectively. The method we describe has wide application, beyond collagen films or scaffolds, since the photoreactive diazirine will react with many organic carbon skeletons. PMID:26854392

  6. Increasing Mechanical Strength of Gelatin Hydrogels by Divalent Metal Ion Removal

    NASA Astrophysics Data System (ADS)

    Xing, Qi; Yates, Keegan; Vogt, Caleb; Qian, Zichen; Frost, Megan C.; Zhao, Feng

    2014-04-01

    The usage of gelatin hydrogel is limited due to its instability and poor mechanical properties, especially under physiological conditions. Divalent metal ions present in gelatin such as Ca2+ and Fe2+ play important roles in the gelatin molecule interactions. The objective of this study was to determine the impact of divalent ion removal on the stability and mechanical properties of gelatin gels with and without chemical crosslinking. The gelatin solution was purified by Chelex resin to replace divalent metal ions with sodium ions. The gel was then chemically crosslinked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Results showed that the removal of divalent metal ions significantly impacted the formation of the gelatin network. The purified gelatin hydrogels had less interactions between gelatin molecules and form larger-pore network which enabled EDC to penetrate and crosslink the gel more efficiently. The crosslinked purified gels showed small swelling ratio, higher crosslinking density and dramatically increased storage and loss moduli. The removal of divalent ions is a simple yet effective method that can significantly improve the stability and strength of gelatin hydrogels. The in vitro cell culture demonstrated that the purified gelatin maintained its ability to support cell attachment and spreading.

  7. In Situ Imidazole Activation of Ribonucleotides for Abiotic RNA Oligomerization Reactions

    NASA Astrophysics Data System (ADS)

    Burcar, Bradley T.; Jawed, Mohsin; Shah, Hari; McGown, Linda B.

    2015-06-01

    The hypothesis that RNA played a significant role in the origin of life requires effective and efficient abiotic pathways to produce RNA oligomers. The most successful abiotic oligomerization reactions to date have utilized high-energy, modified, or pre-activated ribonucleotides to generate strands of RNA up to 50-mers in length. In spite of their success, these modifications and pre-activation reactions significantly alter the ribonucleotides in ways that are highly unlikely to have occurred on a prebiotic Earth. This research seeks to address this problem by exploring an aqueous based method for activating the canonical ribonucleotides in situ using 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and imidazole. The reactions were run with and without a montmorillonite clay catalyst and compared to reactions that used ribonucleotides that were pre-activated with imidazole. The effects of pH and ribonucleotide concentration were also investigated. The results demonstrate the ability of in situ activation of ribonucleotides to generate linear RNA oligomers in solution, providing an alternative route to produce RNA for use in prebiotic Earth scenarios.

  8. Quartz crystal microbalance (QCM) as biosensor for the detecting of Escherichia coli O157:H7

    NASA Astrophysics Data System (ADS)

    Thanh Ngo, Vo Ke; Giang Nguyen, Dang; Phuong Uyen Nguyen, Hoang; Tran, Van Man; Nguyen, Thi Khoa My; Phat Huynh, Trong; Lam, Quang Vinh; Dat Huynh, Thanh; Truong, Thi Ngoc Lien

    2014-12-01

    Although Escherichia coli (E. coli) is a commensalism organism in the intestine of humans and warm-blooded animals, it can be toxic at higher density and causes diseases, especially the highly toxic E. coli O157:H7. In this paper a quartz crystal microbalance (QCM) biosensor was developed for the detection of E. coli O157:H7 bacteria. The anti-E. coli O157:H7 antibodies were immobilized on a self-assembly monolayer (SAM) modified 5 MHz AT-cut quartz crystal resonator. The SAMs were activated with 16-mercaptopropanoic acid, in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and ester N-hydroxysuccinimide (NHS). The result of changing frequency due to the adsorption of E. coli O157:H7 was measured by the QCM biosensor system designed and fabricated by ICDREC-VNUHCM. This system gave good results in the range of 102-107 CFU mL-1 E. coli O157:H7. The time of bacteria E. coli O157:H7 detection in the sample was about 50 m. Besides, QCM biosensor from SAM method was comparable to protein A method-based piezoelectric immunosensor in terms of the amount of immobilized antibodies and detection sensitivity.

  9. ncd and kinesin motor domains interact with both alpha- and beta-tubulin.

    PubMed Central

    Walker, R A

    1995-01-01

    Motor domains of the Drosophila minus-end-directed microtubule (MT) motor protein ncd, were found to saturate microtubule binding sites at a stoichiometry of approximately one motor domain per tubulin dimer. To determine the tubulin subunit(s) involved in binding to ncd, mixtures of ncd motor domain and MTs were treated with the zero-length cross-linker 1-ethyl-3-(3-dimethylaminopropyl-carbodiimide) (EDC). EDC treatment generated covalently cross-linked products of ncd and alpha-tubulin and of ncd and beta-tubulin, indicating that the ncd motor domain interacts with both alpha- and beta-tubulin. When the Drosophila kinesin motor domain protein was substituted for the ncd motor domain, cross-linked products of kinesin and alpha-tubulin and of kinesin and beta-tubulin were produced. EDC treatment of mixtures of ncd motor domain and unassembled tubulin dimers or of kinesin motor domain and unassembled tubulin dimers produced the same motor-tubulin products generated in the presence of MTs. These results indicate that kinesin family motors of opposite polarity interact with both tubulin monomers and support a model in which some portion of each protein's motor domain overlaps adjacent alpha- and beta-tubulin subunits. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:7597061

  10. Preparation and characterization of nanoparticles based on histidine-hyaluronic acid conjugates as doxorubicin carriers.

    PubMed

    Wu, Jing-liang; Liu, Chen-guang; Wang, Xiao-lei; Huang, Zhen-hua

    2012-08-01

    Histidine-hyaluronic acid (His-HA) conjugates were synthesized using hyaluronic acid (HA) as a hydrophilic segment and histidine (His) as hydrophobic segment by 1-ethyl-3(3-dimethylaminopropyl)carbodiimide (EDC) mediated coupling reactions. The structural characteristics of the His-HA conjugates were investigated using (1)H NMR. His-HA nanoparticles (HH-NPs) were prepared based on His-HA conjugates, and the characteristics of HH-NPs were investigated using dynamic light scattering, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and fluorescence spectroscopy. The particles were between 342 and 732 nm in size, depending on the degree of substitution (DS) of the His. TEM and SEM images indicated that the morphology of HH-NPs was spherical in shape. The critical aggregation concentrations of HH-NPs ranged from 0.034 to 0.125 mg/ml, which decreased with an increase in the DS of the His. Images of fluorescence microscopy indicate that HH-NPs were taken up by the cancer cell line (MCF-7), and significantly decreased by competition inhibition of free HA. From the cytotoxicity test, it was found that DOX-loaded HH-NPs exhibited similar dose and time-dependent cytotoxicity against MCF-7 cells with free DOX. PMID:22580754

  11. Synthesis and characterization of Pseudomonas aeruginosa alginate-tetanus toxoid conjugate.

    PubMed

    Kashef, Nasim; Behzadian-Nejad, Qorban; Najar-Peerayeh, Shahin; Mousavi-Hosseini, Kamran; Moazzeni, Mohammad; Djavid, Gholamreza Esmaeeli

    2006-10-01

    Chronic infection with Pseudomonas aeruginosa is the main proven perpetrator of lung function decline and ultimate mortality in cystic fibrosis (CF) patients. Mucoid strains of this bacterium elaborate mucoid exopolysaccharide, also referred to as alginate. Alginate-based immunization of naïve animals elicits opsonic antibodies and leads to clearance of mucoid P. aeruginosa from the lungs. Alginate was isolated from mucoid P. aeruginosa strain 8821M by repeated ethanol precipitation, dialysis, proteinase and nuclease digestion, and chromatography. To improve immunogenicity, the purified antigen was coupled to tetanus toxoid (TT) with adipic acid dihydrazide (ADH) as a spacer and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDAC) as a linker. The reaction mixture was passed through a Sepharose CL-4B column. The resulting conjugate was composed of TT and large-size alginate polymer at a ratio of about 3 : 1; it was non-toxic and non-pyrogenic, and elicited high titres of alginate-specific IgG. Antisera raised against the conjugate had high opsonic activity against the vaccine strain. The alginate conjugate was also able to protect mice against a lethal dose of mucoid P. aeruginosa. These data indicate that an alginate-based vaccine has significant potential to protect against chronic infection with mucoid P. aeruginosa in the CF host. PMID:17005795

  12. Evaluation of synthetic schemes to prepare immunogenic conjugates of Vibrio cholerae O139 capsular polysaccharide with chicken serum albumin.

    PubMed

    Kossaczka, Z; Szu, S C

    2000-06-01

    Vibrio cholerae serotype O139 is a new etiologic agent of epidemic cholera. There is no vaccine available against cholera caused by this serotype. V. cholerae O139 is an encapsulated bacterium, and its polysaccharide capsule is an essential virulent factor and likely protective antigen. This study evaluated several synthetic schemes for preparation of conjugates of V. cholerae O139 capsular polysaccharide (CPS) with chicken serum albumin as the carrier protein (CSA) using 1-ethyl-3(3-dimethylaminopropyl)carbodiimide (EDC) or 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) as activating agents. Four conjugates described here as representative of many experiments were synthesized in 2 steps: 1) preparation of adipic acid hydrazide derivative of CPS (CPS(AH)) or of CSA (CSA(AH)), and 2) binding of CPS(AH) to CSA or of CPS to CSA(AH). Although all conjugates induced CPS antibodies, the conjugate prepared by EDC-mediated binding of CPS and CSA(AH) (EDC:CPS-CSA(AH)) was statistically significantly less immunogenic than the other three conjugates. Representative sera from mice injected with these three conjugates contained antibodies that mediated the lysis of V. cholerae O139 inoculum. Evaluation of the different synthetic schemes and reaction conditions in relation to the immunogenicity of the resultant conjugates provided the basis for the preparation of a V. cholerae O139 conjugate vaccine with a medically useful carrier protein such as diphtheria toxin mutant. PMID:11294508

  13. Optimization of the conjugation method for a serogroup B/C meningococcal vaccine.

    PubMed

    Fukasawa, Lucila O; Schenkman, Rocilda P F; Perciani, Catia T; Carneiro, Sylvia M; Dias, Waldely O; Tanizaki, Martha M

    2006-11-01

    A conjugate meningococcal vaccine against serogroup B/C consisting of capsular PS (polysaccharide) from serogroup C conjugated to OMV (outer membrane vesicle) from serogroup B would be a very useful vaccine in regions where there is a prevalence of both serogroups, for example in Brazil. For this purpose, the conjugation method that uses ADHy (adipic acid dihydrazide) as spacer and a carbodi-imide derivative, EDAC [1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide], as catalyser was optimized looking for synthesis yield and maintenance of the antigenicity of both components. The best synthesis conditions preserving the vaccine immunogenicity resulted in a final yield of approx. 17%. Immunogenicity of the vaccine was highest when 10% of the sialic acid residues of the PS were occupied by the ADHy spacer. Sterilization of the conjugate by filtration through a 0.22-microm-pore-size membrane resulted in a low recovery of protein and PS (approximately 50%), although the vaccine immunogenicity was maintained. Using gamma irradiation on freeze-dried sample, it was possible to maintain the integrity of OMV structure and, consequently, its ability to induce bactericidal antibodies. PMID:16776648

  14. Pseudomonas aeruginosa PAO-1 Lipopolysaccharide-Diphtheria Toxoid Conjugate Vaccine: Preparation, Characterization and Immunogenicity

    PubMed Central

    Najafzadeh, Faezeh; Shapouri, Reza; Rahnema, Mehdi; Rokhsartalab Azar, Shadi; Kianmehr, Anvarsadat

    2015-01-01

    Background: Treatment of Pseudomonas aeruginosa PAO-1 infections through immunological means has been proved to be efficient and protective. Objectives: The purpose of this study was to produce a conjugate vaccine composed of detoxified lipopolysaccharide (D-LPS) P. aeruginosa and diphtheria toxoid (DT). Materials and Methods: Firstly, LPS was purified and characterized from P. aeruginosa PAO1 and then detoxified. D-LPS was covalently coupled to DT as a carrier protein via amidation method with adipic acid dihydrazide (ADH) as a spacer molecule and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDAC) as a linker. The molar ratio of LPS to DT in the prepared conjugate was 3:1. The immunogenicity of D-LPS-DT conjugate vaccine in mice model was evaluated as well. Results: The conjugate was devoid of endotoxin activity and 0.125 U/mL of D-LPS was acceptable for immunization. D-LPS-DT conjugate was nonpyrogenic for rabbits and nontoxic for mice. Mice immunization with D-LPS-DT conjugate vaccine elicited the fourfold higher IgG antibody compared to D-LPS. Anti-LPS IgG antibody was predominantly IgG1 subclass and then IgG3, IgG2a and IgG2b, respectively. Conclusions: Vaccine based on the conjugation of P. aeruginosa PAO-1 LPS with DT increased anti-LPS antibodies and had a significant potential to protect against Pseudomonas infections. PMID:26301059

  15. Synthesis, characterization and immunological properties of Escherichia coli 0157:H7 lipopolysaccharide- diphtheria toxoid conjugate vaccine

    PubMed Central

    Rokhsartalab-Azar, Shadi; Shapouri, Reza; Rahnema, Mehdi; Najafzadeh, Faezeh

    2015-01-01

    Background and Objective: Escherichia coli O157:H7, an emerging pathogen, causes severe enteritis and the extraintestinal complication of hemolytic-uremic syndrome. The goal of this study was to evaluate the conjugate of E. coli O157: H7 lipopolysaccharide (LPS) with diphtheria toxoid (DT) as a candidate vaccine in mice model. Material and Methods: LPS from E. coli O157:H7 was extracted by hot phenol method and then detoxified. Purified LPS was coupled to DT with adipic acid dihydrazide (ADH) as a spacer and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as a linker. The coupling molar ratio of LPS to DT was 3:1. Clinical evaluation of E. coli O157:H7 LPS-DT conjugate was also performed. Results: The conjugate was devoid of endotoxin activity and indicated 0.125 U/ml of D-LPS. Mice immunization with D-LPS DT conjugate elicited fourfold higher IgG antibody in comparison to D-LPS. Also, in vivo protection of mice with conjugate provided high protection against the LD50 of E. coli O157:H7, which indicated a good correlation with the IgG titer. Conclusion: Our results showed that the suggested vaccine composed of E. coli O157:H7 LPS and DT had a significant potential to protect against E. coli infections. PMID:26668702

  16. Effect of hyaluronic acid molecular weight on the morphology of quantum dot-hyaluronic acid conjugates.

    PubMed

    Kim, Jiseok; Park, Kitae; Hahn, Sei Kwang

    2008-01-01

    The morphological analysis of novel quantum dot-hyaluronic acid (QDot-HA) conjugates was carried out with a transmission electron microscope (TEM). Adipic acid dihydrazide-modified HA (HA-ADH) was synthesized and conjugated to quantum dots (QDots) having carboxyl terminal ligands which were activated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysulfosuccinimide (sulfo-NHS). HA molecules with a molecular weight (MW) of 20K, 234 K and 3000 K were used to investigate the effect of MW on the morphology of QDot-HA conjugates. The TEM micrographs of QDot-HA conjugates showed branched and multi-layered chain type morphology formed by inter- and intra-molecular conjugation of QDots to HA molecules. The size of QDot-HA conjugate increased with the MW of HA. QDot-HA conjugate could be successfully used for real-time bio-imaging of HA derivatives in nude mice. The novel QDot-HA conjugate will be further used to investigate the biological roles of HA with a different MW in the body. PMID:17936350

  17. Films prepared from electrosterically stabilized nanocrystalline cellulose.

    PubMed

    Yang, Han; Tejado, Alvaro; Alam, Nur; Antal, Miro; van de Ven, Theo G M

    2012-05-22

    Electrosterically stabilized nanocrystalline cellulose (ENCC) was modified in three ways: (1) the hydroxyl groups on C2 and C3 of glucose repeat units of ENCC were converted to aldehyde groups by periodate oxidation to various extents; (2) the carboxyl groups in the sodium form on ENCC were converted to the acid form by treating them with an acid-type ion-exchange resin; and (3) ENCC was cross-linked in two different ways by employing adipic dihydrazide as a cross-linker and water-soluble 1-ethyl-3-[3-(dimethylaminopropyl)] carbodiimide as a carboxyl-activating agent. Films were prepared from these modified ENCC suspensions by vacuum filtration. The effects of these three modifications on the properties of films were investigated by a variety of techniques, including UV-visible spectroscopy, a tensile test, thermogravimetric analysis (TGA), the water vapor transmission rate (WVTR), and contact angle (CA) studies. On the basis of the results from UV spectra, the transmittance of these films was as high as 87%, which shows them to be highly transparent. The tensile strength of these films was increased with increasing aldehyde content. From TGA and WVTR experiments, cross-linked films showed much higher thermal stability and lower water permeability. Furthermore, although the original cellulose is hydrophilic, these films also exhibited a certain hydrophobic behavior. Films treated by trichloromethylsilane become superhydrophobic. The unique characteristics of these transparent films are very promising for potential applications in flexible packaging and other high-technology products. PMID:22482733

  18. Cytotoxic evaluation of biomechanically improved crosslinked ovine collagen on human dermal fibroblasts.

    PubMed

    Awang, M A; Firdaus, M A B; Busra, M B; Chowdhury, S R; Fadilah, N R; Wan Hamirul, W K; Reusmaazran, M Y; Aminuddin, M Y; Ruszymah, B H I

    2014-01-01

    Earlier studies in our laboratory demonstrated that collagen extracted from ovine tendon is biocompatible towards human dermal fibroblast. To be able to use this collagen as a scaffold in skin tissue engineering, a mechanically stronger scaffold is required that can withstand manipulation before transplantation. This study was conducted to improve the mechanical strength of this collagen sponge using chemical crosslinkers, and evaluate their effect on physical, chemical and biocompatible properties. Collagen sponge was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glutaraldehyde (GA). Tensile test, FTIR study and mercury porosimetry were used to evaluate mechanical properties, chemical property and porosity, respectively. MTT assay was performed to evaluate the cytotoxic effect of crosslinked collagen sponge on human dermal fibroblasts. The FTIR study confirmed the successful crosslinking of collagen sponge. Crosslinking with EDC and GA significantly increased the mechanical strength of collagen sponge, with GA being more superior. Crosslinking of collagen sponge significantly reduced the porosity and the effect was predominant in GA-crosslinked collagen sponge. The GA-crosslinked collagen showed significantly lower, 60% cell viability towards human dermal fibroblasts compared to that of EDC-crosslinked collagen, 80% and non-crosslinked collagen, 100%. Although the mechanical strength was better when using GA but the more toxic effect on dermal fibroblast makes EDC a more suitable crosslinker for future skin tissue engineering. PMID:24948455

  19. Hypromellose succinate-crosslinked chitosan hydrogel films for potential wound dressing.

    PubMed

    Jiang, Qiong; Zhou, Wei; Wang, Jun; Tang, Rupei; Zhang, Di; Wang, Xin

    2016-10-01

    The objective of this study was to develop novel hydrogel films based on carboxyl-modified hypromellose-crosslinked chitosan for potential wound dressing. Hypromellose (HPMC) was grafted with succinic acid to yield hypromellose succinate (HPMCS), and then the reinforced hydrogel films of HPMCS-crosslinked chitosan (HPMCS-CS) were prepared through amide bond formation using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N- hydroxysuccinimide (NHS) as a catalyst. Compared to that of blend film, mechanical properties of HPMCS-CS hydrogel films were significantly enhanced both in dry and swollen state. To assess the applicability of HPMCS-CS hydrogel films as wound dressing, the swelling behavior, water vapor transmission rate (WVTR), oxygen permeability, biocompatibility (cytotoxicity and hemolysis), in vitro drug release and bactericidal properties were analyzed. The results indicated that HPMCS-CS hydrogel films with good biocompatibility possess high swelling ratio, proper WVTR, and oxygen permeability, which might accelerate tissue regeneration. Meanwhile, gentamycin sulfate release from drug-loaded HPMCS-CS hydrogel films were sustained, which would help to protect wound from infection. PMID:27222285

  20. Optical mechanical refinement of human amniotic membrane by dehydration and cross-linking.

    PubMed

    Tanaka, Yuji; Kubota, Akira; Yokokura, Shunji; Uematsu, Masafumi; Shi, Dong; Yamato, Masayuki; Okano, Teruo; Quantock, Andrew J; Nishida, Kohji

    2012-10-01

    The aim of this study was to develop a method for refining the optical and mechanical properties of human amniotic membrane (AM) to provide ophthalmic transparent implants for use during severe donor cornea shortages. AM was allowed to gradually dehydrate at 4-8 °C with and without chemical cross-linking. To improve the transparency of AM, a simple dehydration process using a refrigerator at 4-8 °C overnight was examined. For further improvements, dehydrated AM was then cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxy-succimide before rehydration. Light transmittance and tensile strength of individual specimens were evaluated. Light transmittance of AM improved from 50.9-77.7% at 550 nm by this simple low temperature dehydration process. Its high light transmittance was partially maintained at 70.1%, even after rehydration with normal saline. Interestingly, chemically cross-linked AM showed a significantly greater light transmittance of 81.5% under wet conditions. In addition, tensile strength was significantly increased after cross-linking from 2.32 N/mm(2) (native tissue) to 11.78 N/mm(2) (cross-linked specimens). Light transmittance and tensile strength were successfully improved by these approaches, including low temperature dehydration with and without chemical cross-linking. The use of refined AM could be feasible for use in current and future ophthalmic treatments. PMID:22489071

  1. Label Free QCM Immunobiosensor for AFB1 Detection Using Monoclonal IgA Antibody as Recognition Element.

    PubMed

    Ertekin, Özlem; Öztürk, Selma; Öztürk, Zafer Ziya

    2016-01-01

    This study introduces the use of an IgA isotype aflatoxin (AF) specific monoclonal antibody for the development of a highly sensitive Quartz Crystal Microbalance (QCM) immunobiosensor for the detection of AF in inhibitory immunoassay format. The higher molecular weight of IgA antibodies proved an advantage over commonly used IgG antibodies in label free immunobiosensor measurements. IgA and IgG antibodies with similar affinity for AF were used in the comparative studies. Sensor surface was prepared by covalent immobilization of AFB1, using self assembled monolayer (SAM) formed on gold coated Quartz Crystal, with 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxy succinimide (EDC/NHS) method using a diamine linker. Nonspecific binding to the surface was decreased by minimizing the duration of EDC/NHS activation. Sensor surface was chemically blocked after AF immobilization without any need for protein blocking. This protein free sensor chip endured harsh solutions with strong ionic detergent at high pH, which is required for the regeneration of the high affinity antibody-antigen interaction. According to the obtained results, the detection range with IgA antibodies was higher than IgG antibodies in QCM immunosensor developed for AFB1. PMID:27529243

  2. Crosslinked chitosan-dextran sulfate nanoparticle for improved topical ocular drug delivery

    PubMed Central

    Chaiyasan, Wanachat; Srinivas, Sangly P.

    2015-01-01

    Purpose To examine the benefits of chitosan-dextran sulfate nanoparticles (CDNs) as a topical ocular delivery system with lutein as a model drug. Methods CDNs were developed by polyelectrolyte complexation of positively charged chitosan (CS) and negatively charged dextran sulfate (DS). 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and polyethylene glycol 400 (PEG400) were used as co-crosslinking and stabilizing agents, respectively. The influence of these on the properties of CDNs, including drug release and mucoadhesiveness, was examined. The chemical stability of lutein in CDNs (LCDNs) was also examined. Results Typically, LCDNs showed a spherical shape, possessing a mean size of ~400 nm with a narrow size distribution. The entrapment efficiency of lutein was in the range of 60%–76%. LCDNs possessing a positive surface charge (+46 mV) were found to be mucoadhesive. The release profile of LCDNs followed Higuchi’s square root model, suggesting drug release by diffusion from the polymer matrix. Lutein in LCDNs showed increased chemical stability during storage compared to its solution form. Conclusions These characteristics of CDNs make them suitable for drug delivery to the ocular surface. PMID:26604662

  3. Preparation and characterization of self-assembled nanoparticles based on low-molecular-weight heparin and stearylamine conjugates for controlled delivery of docetaxel

    PubMed Central

    Kim, Dong-Hwan; Termsarasab, Ubonvan; Cho, Hyun-Jong; Yoon, In-Soo; Lee, Jae-Young; Moon, Hyun Tae; Kim, Dae-Duk

    2014-01-01

    Low-molecular-weight heparin (LMWH)–stearylamine (SA) conjugates (LHSA)-based self-assembled nanoparticles were prepared for intravenous delivery of docetaxel (DCT). 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide were used as coupling agents for synthesis of LHSA conjugates. The physicochemical properties, in vitro antitumor efficacy, in vitro cellular uptake efficiency, in vivo antitumor efficacy, and in vivo pharmacokinetics of LHSA nanoparticles were investigated. The LHSA nanoparticles exhibited a spherical shape with a mean diameter of 140–180 nm and a negative surface charge. According to in vitro release and in vivo pharmacokinetic test results, the docetaxel-loaded LHSA5 (LMWH:SA =1:5) nanoparticles exhibited sustained drug release profiles. The blank LHSA nanoparticles demonstrated only an insignificant cytotoxicity in MCF-7 and MDAMB 231 human breast cancer cells; additionally, higher cellular uptake of coumarin 6 (C6) in MCF-7 and MDAMB 231 cells was observed in the LHSA5 nanoparticles group than that in the C6 solution group. The in vivo tumor growth inhibition efficacy of docetaxel-loaded LHSA5 nanoparticles was also significantly higher than the Taxotere®-treated group in the MDAMB 231 tumor-xenografted mouse model. These results indicated that the LHSA5-based nanoparticles could be a promising anticancer drug delivery system. PMID:25525355

  4. Development of indirect competitive ELISA for quantification of mitragynine in Kratom (Mitragyna speciosa (Roxb.) Korth.).

    PubMed

    Limsuwanchote, Supattra; Wungsintaweekul, Juraithip; Keawpradub, Niwat; Putalun, Waraporn; Morimoto, Satoshi; Tanaka, Hiroyuki

    2014-11-01

    Monoclonal antibody (MAb) against mitragynine (MG), an analgesic alkaloid from Kratom leaves (Mitragyna speciosa), was produced. MG was coupled to carrier proteins employing either 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS), a zero-length cross linker or a 5-carbon length glutaraldehyde cross linker. To confirm the immunogenicity, the hapten numbers were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Preparation of the MAb was accomplished by the electrofusion method. Hybridoma 1A6 that was constructed from the fusion between splenocytes of EDC/NHS conjugate immunized mice and SP2/0-Ag14 myeloma cells was selected, cloned twice and expanded. The cross-reactivities (CRs) of this MAb 1A6 with a series of indole alkaloids were 30.54%, 24.83% and 8.63% for speciogynine, paynantheine and mitraciliatine, respectively. Using this MAb, an indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed with a measurement range of 32.92-250 μg/mL. Quantitative analysis of the MG contents in plant samples by icELISA correlated well with the standard high performance liquid chromatography method (R(2)=0.994). The MAb against mitragynine provided a tool for detection of MG in Kratom preparations. PMID:25216455

  5. Relevance of fiber integrated gelatin-nanohydroxyapatite composite scaffold for bone tissue regeneration

    NASA Astrophysics Data System (ADS)

    Halima Shamaz, Bibi; Anitha, A.; Vijayamohan, Manju; Kuttappan, Shruthy; Nair, Shantikumar; Nair, Manitha B.

    2015-10-01

    Porous nanohydroxyapatite (nanoHA) is a promising bone substitute, but it is brittle, which limits its utility for load bearing applications. To address this issue, herein, biodegradable electrospun microfibrous sheets of poly(L-lactic acid)-(PLLA)-polyvinyl alcohol (PVA) were incorporated into a gelatin-nanoHA matrix which was investigated for its mechanical properties, the physical integration of the fibers with the matrix, cell infiltration, osteogenic differentiation and bone regeneration. The inclusion of sacrificial fibers like PVA along with PLLA and leaching resulted in improved cellular infiltration towards the center of the scaffold. Furthermore, the treatment of PLLA fibers with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide enhanced their hydrophilicity, ensuring firm anchorage between the fibers and the gelatin-HA matrix. The incorporation of PLLA microfibers within the gelatin-nanoHA matrix reduced the brittleness of the scaffolds, the effect being proportional to the number of layers of fibrous sheets in the matrix. The proliferation and osteogenic differentiation of human adipose-derived mesenchymal stem cells was augmented on the fibrous scaffolds in comparison to those scaffolds devoid of fibers. Finally, the scaffold could promote cell infiltration, together with bone regeneration, upon implantation in a rabbit femoral cortical defect within 4 weeks. The bone regeneration potential was significantly higher when compared to commercially available HA (Surgiwear™). Thus, this biomimetic, porous, 3D composite scaffold could be offered as a promising candidate for bone regeneration in orthopedics.

  6. Structural analysis of photosystem I polypeptides using chemical crosslinking

    NASA Technical Reports Server (NTRS)

    Armbrust, T. S.; Odom, W. R.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Thylakoid membranes, obtained from leaves of 14 d soybean (Glycine max L. cv. Williams) plants, were treated with the chemical crosslinkers glutaraldehyde or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) to investigate the structural organization of photosystem I. Polypeptides were resolved using lithium dodecyl sulfate polyacrylamide gel electrophoresis, and were identified by western blot analysis using a library of polyclonal antibodies specific for photosystem I subunits. An electrophoretic examination of crosslinked thylakoids revealed numerous crosslinked products, using either glutaraldehyde or EDC. However, only a few of these could be identified by western blot analysis using subunit-specific polyclonal antibodies. Several glutaraldehyde dependent crosslinked species were identified. A single band was identified minimally composed of PsaC and PsaD, documenting the close interaction between these two subunits. The most interesting aspect of these studies was a crosslinked species composed of the PsaB subunit observed following EDC treatment of thylakoids. This is either an internally crosslinked species, which will provide structural information concerning the topology of the complex PsaB protein, a linkage with a polypeptide for which we do not yet have an immunological probe, or a masking of epitopes by the EDC linkage at critical locations in the peptide which is linked to PsaB.

  7. Phosphatidylcholine covalently linked to a methacrylate-based monolith as a biomimetic stationary phase for capillary liquid chromatography.

    PubMed

    Moravcová, Dana; Carrasco-Correa, Enrique Javier; Planeta, Josef; Lämmerhofer, Michael; Wiedmer, Susanne K

    2015-07-10

    In this study a strategy to immobilize phospholipids onto a polymer-based stationary phase is described. Methacrylate-based monoliths in capillary format (150×0.1mm) were modified by soybean phosphatidylcholine through 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide coupling to obtain stationary phases suitable to mimic cell surface membranes. The covalent coupling reaction involves the phosphate group in phospholipids; therefore, the described methodology is suitable for all types of phospholipids. Immobilization of soy bean phosphatidylcholine on the monolith was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry of the fatty alcohol profile, generated upon reductive cleavage of the fatty acyl side chains of the phospholipid on the monolith surface with lithium aluminium hydride. The prepared stationary phases were evaluated through studies on the retention of low-molar mass model analytes including neutral, acidic, and basic compounds. Liquid chromatographic studies confirmed predominant hydrophobic interactions between the analytes and the synthesized stationary phase; however, electrostatic interactions contributed to the retention as well. The synthesized columns showed high stability even with fully aqueous mobile phases such as Dulbecco's phosphate-buffered saline solution. PMID:26024990

  8. Folic acid-CdTe quantum dot conjugates and their applications for cancer cell targeting

    SciTech Connect

    Suriamoorthy, Preethi; Zhang, Xing; Hao, Guiyang; Joly, Alan G.; Singh, S.; Hossu, Marius; Sun, Xiankai; Chen, Wei

    2010-12-01

    In this study, we report the preparation,luminescence, and targeting properties of folic acid- CdTe quantum dot conjugates. Water-soluble CdTe quantum dots were synthesized and conjugated with folic acid using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide chemistry. The in-fluence of folic acid on the luminescence properties of CdTe quantum dots was investigated, and no energy transfer between them was observed. To investigate the efficiency of folic acid-CdTe nanoconjugates for tumor targeting, pure CdTe quantum dots and folic acid-coated CdTe quantum dots were incubated with human naso- pharyngeal epidermal carcinoma cell line with positive expressing folic acid receptors (KB cells) and lung cancer cells without expression of folic acid receptors (A549 cells). For the cancer cells with positive folate receptors (KB cells), the uptake for CdTe quantum dots is very low, but for folic acid-CdTe nanoconjugates, the uptake is very high. For the lung cancer cells without folate receptors (A549 cells), the uptake for folic acid- CdTe nanoconjugates is also very low. The results indicate that folic acid is an effective targeting molecule for tumor cells with overexpressed folate receptors.

  9. Hyaluronic acid as an internal wetting agent in model DMAA/TRIS contact lenses.

    PubMed

    Weeks, Andrea; Luensmann, Doerte; Boone, Adrienne; Jones, Lyndon; Sheardown, Heather

    2012-11-01

    Model silicone hydrogel contact lenses, comprised of N,N-dimethylacrylamide and methacryloxypropyltris (trimethylsiloxy) silane, were fabricated and hyaluronic acid (HA) was incorporated as an internal wetting agent using a dendrimer-based method. HA and dendrimers were loaded into the silicone hydrogels and cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. The presence and location of HA in the hydrogels was confirmed using X-ray photoelectron spectroscopy and confocal laser scanning microscopy, respectively. The effects of the presence of HA on the silicone hydrogels on hydrophilicity, swelling behavior, transparency, and lysozyme sorption and denaturation were evaluated. The results showed that HA increased the hydrophilicity and the equilibrium water content of the hydrogels without affecting transparency. HA also significantly decreased the amount of lysozyme sorption (p < 0.002). HA had no effect on lysozyme denaturation in hydrogels containing 0% and 1.7% methacrylic acid (MAA) (by weight) but when the amount of MAA was increased to 5%, the level of lysozyme denaturation was significantly lower compared to control materials. These results suggest that HA has great potential to be used as a wetting agent in silicone hydrogel contact lenses to improve wettability and to decrease lysozyme sorption and denaturation. PMID:21750182

  10. Fast self-assembly kinetics of alkanethiols on gold nanoparticles: simulation and characterization by localized surface plasmon resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Asiaei, Sasan; Denomme, Ryan C.; Marr, Chelsea; Nieva, Patricia M.; Vijayan, Mathilakath M.

    2012-03-01

    This study demonstrates improved kinetics for the formation of self-assembled monolayers (SAMs) of alkanethiols on gold nanoparticle substrates. A computational model was developed to predict SAM growth kinetics. Based on the predictions from the model, SAMs of 11-mercaptoundecanoic acid (11-MUA) and 1-octanethiol (1-OT) were formed by incubation of gold nanoparticle chips in an ethanolic 10 mM solution within 20 min. The performance of this novel rapid SAM formation protocol was compared with a conventional 24 hour incubation protocol. Binding capacity of the alkanethiol SAM was investigated for a 20 min incubation protocol using biotin-streptavidin. For this purpose, the SAM loaded gold nanoparticle chips were modified with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) to allow attachment of EZ-Link amine PEG3 biotin to the 11-MUA molecules. Binding reactions were monitored in real time using localized surface plasmon resonance (LSPR) spectroscopy. The resulting LSPR absorbance peak shift was comparable to the experimental results for biotin-streptavidin reported in literature. Results of this study suggest that formation of a high quality alkanethiol SAM within 20 min on gold nanoparticles surfaces is possible and could greatly reduce the time and cost compared to conventional 24 h incubation protocols.

  11. Use of Protein Cross-Linking and Radiolytic Labeling To Elucidate the Structure of PsbO within Higher-Plant Photosystem II.

    PubMed

    Mummadisetti, Manjula P; Frankel, Laurie K; Bellamy, Henry D; Sallans, Larry; Goettert, Jost S; Brylinski, Michal; Bricker, Terry M

    2016-06-14

    We have used protein cross-linking with the zero-length cross-linker 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and radiolytic footprinting coupled with high-resolution tandem mass spectrometry, to examine the structure of higher-plant PsbO when it is bound to Photosystem II. Twenty intramolecular cross-linked residue pairs were identified. On the basis of this cross-linking data, spinach PsbO was modeled using the Thermosynechococcus vulcanus PsbO structure as a template, with the cross-linking distance constraints incorporated using the MODELLER program. Our model of higher-plant PsbO identifies several differences between the spinach and cyanobacterial proteins. The N-terminal region is particularly interesting, as this region has been suggested to be important for oxygen evolution and for the specific binding of PsbO to Photosystem II. Additionally, using radiolytic mapping, we have identified regions on spinach PsbO that are shielded from the bulk solvent. These domains may represent regions on PsbO that interact with other components, as yet unidentified, of the photosystem. PMID:27203407

  12. VEGF-conjugated alginate hydrogel prompt angiogenesis and improve pancreatic islet engraftment and function in type 1 diabetes.

    PubMed

    Yin, Nina; Han, Yongming; Xu, Hanlin; Gao, Yisen; Yi, Tao; Yao, Jiale; Dong, Li; Cheng, Dejun; Chen, Zebin

    2016-02-01

    Type 1 diabetes was a life-long disease that affected numerous people around the world. Insulin therapy has its limitations that may involve hyperglycemia and heavy burden of patient by repeated dose. Islet transplantation emerged as a promising approach to reach periodical reverse of diabetes, however, transplanted islets suffer from foreign body reaction and lack of nutrition and oxygen supply, especially in the blood-vessel-shortage subcutaneous site which was preferred by patient and surgeon. In this study, we designed and synthesized a vascular endothelial growth factor (VEGF) conjugated alginate material to encapsulate the transplanted islets via 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) reaction, and successful conjugation was confirmed by Nuclear Magnetic Resonance H1 spectrum. The best VEGF concentration (100ng/ml) was determined by the combined studies of the mechanical property and endothelial cell growth assay. In vivo study, conjugated VEGF on alginate exhibited sustained promoting angiogenesis property after subcutaneous transplantation by histology study and islets encapsulated in this material achieved long term therapeutic effect (up to 50days) in the diabetic mice model. In conclusion, this study establishes a simple biomaterial strategy for islet transplantation to enhance islet survival and function, which could be a feasible therapeutic alternative for type 1 diabetes. PMID:26652453

  13. Cellular behaviour of hepatocyte-like cells from nude mouse bone marrow-derived mesenchymal stem cells on galactosylated poly(D,L-lactic-co-glycolic acid).

    PubMed

    Roh, Hyun; Yang, Dae Hyeok; Chun, Heung Jae; Khang, Gilson

    2015-07-01

    Previously, the galactosylation of poly(d,l-lactic-co-glycolic acid) (PLGA) surface was accomplished by grafting allylamine (AA), using inductively coupled plasma-assisted chemical vapour deposition (ICP-CVD) and conjugating lactobionic acid (LA) with AA via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) activation for hepatic tissue-engineering purposes. As a continuation study, the cellular behaviour of hepatocyte-like cells (HLCs) on the surface of the galactosylated PLGA were investigated. Nude mouse bone marrow-derived mesenchymal stem cells (MSCs) were cultured under hepatogenic conditions and the differentiated cells were characterized by reverse-transcription polymerase chain reaction (RT-PCR), immunofluorescence and periodic acid-Schiff (PAS) staining. Galactosylated PLGA enhanced the proliferation rate of HLCs compared to the control; HLCs on the surface of the sample became aggregated and formed spheroids after 3 days of culture. A large number of cells on the surface of the sample exhibited increased liver-specific functional activities, such as albumin and urea secretions. In addition, multicellular spheroids in the sample strongly expressed phospholyated focal adhesion kinase (pFAK) (cell-matrix interactions), E-cadherin (cell-cell interactions) and connexin 32 (Cox32; gap junction). PMID:23784953

  14. Transition mode long period grating biosensor with functional multilayer coatings.

    PubMed

    Pilla, Pierluigi; Malachovská, Viera; Borriello, Anna; Buosciolo, Antonietta; Giordano, Michele; Ambrosio, Luigi; Cutolo, Antonello; Cusano, Andrea

    2011-01-17

    We report our latest research results concerning the development of a platform for label-free biosensing based on overlayered Long Period Gratings (LPGs) working in transition mode. The main novelty of this work lies in a multilayer design that allows to decouple the problem of an efficient surface functionalization from that of the tuning in transition region of the cladding modes. An innovative solvent/nonsolvent strategy for the dip-coating technique was developed in order to deposit on the LPG multiple layers of transparent polymers. In particular, a primary coating of atactic polystyrene was used as high refractive index layer to tune the working point of the device in the so-called transition region. In this way, state-of-the-art-competitive sensitivity to surrounding medium refractive index changes was achieved. An extremely thin secondary functional layer of poly(methyl methacrylate-co-methacrylic acid) was deposited onto the primary coating by means of an original identification of selective solvents. This approach allowed to obtain desired functional groups (carboxyls) on the surface of the device for a stable covalent attachment of bioreceptors and minimal perturbation of the optical design. Standard 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide / N-hydrosuccinimide (EDC / NHS) coupling chemistry was used to link streptavidin on the surface of the coated LPG. Highly sensitive real-time monitoring of multiple affinity assays between streptavidin and biotinylated bovine serum albumin was performed by following the shift of the LPGs attenuation bands. PMID:21263591

  15. Protein-functionalized hairy diamond nanoparticles.

    PubMed

    Dahoumane, Si Amar; Nguyen, Minh Ngoc; Thorel, Alain; Boudou, Jean-Paul; Chehimi, Mohamed M; Mangeney, Claire

    2009-09-01

    Diazonium salt chemistry and atom transfer radical polymerization (ATRP) were combined in view of preparing new bioactive hairy diamond nanoparticles containing, or potentially containing, nitrogen-vacancy (NV) fluorescent centers (fluorescent nanodiamonds, or fNDs). fNDs were modified by ATRP initiators using the electroless reduction of the diazonium salt BF(4)(-),(+)N(2)-C(6)H(4)-CH(CH(3))-Br. The strongly bound aryl groups -C(6)H(4)-CH(CH(3))-Br efficiently initiated the ATRP of tert-butyl methacrylate (tBMA) at the surface of the nanodiamonds, which resulted in obtaining ND-PtBMA hybrids. The grafted chain thickness, estimated from X-ray photoelectron spectroscopy (XPS), was found to increase linearly with respect to time before reaching a plateau value of ca. 2 nm. These nanoobjects were further hydrolyzed into ND-PMAA (where PMAA is the poly(methacrylic acid) graft) and further decorated by bovine serum albumin through the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling procedure. PMID:19634873

  16. Real-time monitoring of peptide grafting onto chitosan films using capillary electrophoresis.

    PubMed

    Taylor, Danielle L; Thevarajah, Joel J; Narayan, Diksha K; Murphy, Patricia; Mangala, Melissa M; Lim, Seakcheng; Wuhrer, Richard; Lefay, Catherine; O'Connor, Michael D; Gaborieau, Marianne; Castignolles, Patrice

    2015-03-01

    Chitosan, being antimicrobial and biocompatible, is attractive as a cell growth substrate. To improve cell attachment, arginine-glycine-aspartic acid-serine (RGDS) peptides were covalently grafted to chitosan films, through the widely used coupling agents 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC-HCl) and N-hydroxysuccinimide (NHS), via the carboxylic acid function of the RGDS molecule. The grafting reaction was monitored, for the first time, in real time using free-solution capillary electrophoresis (CE). This enabled fast separation and determination of the peptide and all other reactants in one separation with no sample preparation. Covalent RGDS peptide grafting onto the chitosan film surface was demonstrated using solid-state NMR of swollen films. CE indicated that oligomers of RGDS, not simply RGDS, were grafted on the film, with a likely hyperbranched structure. To assess the functional properties of the grafted films, cell growth was compared on control and peptide-grafted chitosan films. Light microscopy and polymerase chain reaction (PCR) analysis demonstrated greatly improved cell attachment to RGDS-grafted chitosan films. PMID:25680633

  17. 21 CFR 522.1222b - Ketamine hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... hydrochloride and aminopentamide hydrogen sulfate injection. 522.1222b Section 522.1222b Food and Drugs FOOD AND... hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection. (a) Chemical name... hydrochloride, 10- phenothiazine monohydrochloride, and aminopentamide hydrogen sulfate. (b) Specifications....

  18. 21 CFR 522.1222b - Ketamine hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... hydrochloride and aminopentamide hydrogen sulfate injection. 522.1222b Section 522.1222b Food and Drugs FOOD AND... hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection. (a) Chemical name... hydrochloride, 10- phenothiazine monohydrochloride, and aminopentamide hydrogen sulfate. (b) Specifications....

  19. 21 CFR 522.1222b - Ketamine hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... hydrochloride and aminopentamide hydrogen sulfate injection. 522.1222b Section 522.1222b Food and Drugs FOOD AND... hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection. (a) Chemical name... hydrochloride, 10- phenothiazine monohydrochloride, and aminopentamide hydrogen sulfate. (b) Specifications....

  20. 21 CFR 522.1222b - Ketamine hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... hydrochloride and aminopentamide hydrogen sulfate injection. 522.1222b Section 522.1222b Food and Drugs FOOD AND... hydrochloride with promazine hydrochloride and aminopentamide hydrogen sulfate injection. (a) Chemical name... hydrochloride, 10- phenothiazine monohydrochloride, and aminopentamide hydrogen sulfate. (b) Specifications....

  1. 21 CFR 582.5875 - Thiamine hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5875 Thiamine hydrochloride. (a) Product. Thiamine hydrochloride. (b) Conditions of...

  2. 21 CFR 582.5676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Pyridoxine hydrochloride. 582.5676 Section 582.5676 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5676 Pyridoxine hydrochloride. (a) Product. Pyridoxine hydrochloride....

  3. 21 CFR 582.5676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Pyridoxine hydrochloride. 582.5676 Section 582.5676 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5676 Pyridoxine hydrochloride. (a) Product. Pyridoxine hydrochloride....

  4. 21 CFR 582.5676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Pyridoxine hydrochloride. 582.5676 Section 582.5676 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5676 Pyridoxine hydrochloride. (a) Product. Pyridoxine hydrochloride....

  5. 21 CFR 582.5676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Pyridoxine hydrochloride. 582.5676 Section 582.5676 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5676 Pyridoxine hydrochloride. (a) Product. Pyridoxine hydrochloride....

  6. Conjugation of ampicillin and enrofloxacin residues with bovine serum albumin and raising of polyclonal antibodies against them

    PubMed Central

    Kumar, B. Sampath; Ashok, Vasili; Kalyani, P.; Nair, G. Remya

    2016-01-01

    Aim: The aim of this study is to test the potency of bovine serum albumin (BSA) conjugated ampicillin (AMP) and enrofloxacin (ENR) antigens in eliciting an immune response in rats using indirect competitive enzyme-linked immunosorbent assay (icELISA). Materials and Methods: AMP and ENR antibiotics were conjugated with BSA by carbodiimide reaction using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linker. The successful conjugation was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sprague-Dawley rats were immunized with the conjugates and blood samples were collected serially at 15 days time interval after first immunization plus first booster, second booster, third booster, and the fourth sampling was done 1½ month after the third booster. The antibody titres in the antisera of each antibiotic in all the four immunization cycles (ICs) were determined by an icELISA at various serum dilutions ranging from 1/100 to 1/6400. Results: Analysis of antibiotic-BSA conjugates by sodium dodecyl sulfate polyacrylamide gel electrophoresis and coomassie blue staining revealed high molecular weight bands of 85 kDa and 74 kDa for AMP-BSA and ENR-BSA respectively when compared to 68 kDa band of BSA. Both the antibiotic conjugates elicited a good immune response in rats but comparatively the response was more with AMP-BSA conjugate than ENR-BSA conjugate. Maximum optical density 450 value of 2.577 was recorded for AMP-BSA antisera, and 1.723 was recorded for ENR-BSA antisera at 1/100th antiserum dilution in third IC. Conclusion: AMP and ENR antibiotics proved to be good immunogens when conjugated to BSA by carbodiimide reaction with EDC as crosslinker. The polyclonal antibodies produced can be employed for detecting AMP and ENR residues in milk and urine samples. PMID:27182138

  7. New enolate-carbodiimide rearrangement in the concise synthesis of 6-amino-2,3-dihydro-4-pyridinones from homoallylamines.

    PubMed

    Kuznetsov, N Yu; Tikhov, R M; Godovikov, I A; Khrustalev, V N; Bubnov, Yu N

    2016-05-01

    Three-step synthesis of 6-amino-2,3-dihydro-4-pyridinones from homoallylamines involving NBS-mediated cyclization of N-(3-butenyl)ureas to 6-(bromomethyl)-2-iminourethanes, dehydrohalogenation and a novel rearrangement as a key step has been developed. The scope and limitations of the method, as well as the mechanism of the rearrangement, supported by kinetic studies and the isolation of N-(1-adamantyl)carbodiimide, are discussed. The final products, imino-analogues of well known piperidine-2,4-diones, are promising building blocks in the synthesis of bio-/pharmacological compounds. PMID:27080757

  8. Impact of carbondiimide crosslinker used for magnetic carbon nanotube mediated GFP plasmid delivery.

    PubMed

    Hao, Yuzhi; Xu, Peng; He, Chuan; Yang, Xiaoyan; Huang, Min; Xing, James; Chen, Jie

    2011-07-15

    1-Ethyl-3-(3-dimethylaminopropyl) carbondiimide hydrochloride (EDC) is commonly used as a crosslinker to help bind biomolecules, such as DNA plasmids, with nanostructures. However, EDC often remains, after a crosslink reaction, in the micro-aperture of the nanostructure, e.g., carbon nanotube. The remaining EDC shows positive green fluorescent signals and makes a nanostructure with a strong cytotoxicity which induces cell death. The toxicity of EDC was confirmed on a breast cancer cell line (MCF-7) and two leukemic cell lines (THP-1 and KG-1). The MCF-7 cells mainly underwent necrosis after treatment with EDC, which was verified by fluorescein isothiocyanate (FITC) annexin V staining, video microscopy and scanning electronic microscopy (SEM). If the EDC was not removed completely, the nanostructures with remaining EDC produced a green fluorescent background that could interfere with flow cytometry (FACS) measurement and result in false information about GFP plasmid delivery. Effective methods to remove residual EDC on macromolecules were also developed. PMID:21654030

  9. Solving the puzzling competition of the thermal C2–C6 vs Myers–Saito cyclization of enyne-carbodiimides

    PubMed Central

    Rana, Anup; Cinar, Mehmet Emin; Samanta, Debabrata

    2016-01-01

    Summary The mechanism of the thermal cyclization of enyne-carbodiimides 7a–c has been studied computationally by applying the DFT method. The results indicate that enyne-carbodiimides preferentially follow the C2–C6 (Schmittel) cyclization pathway in a concerted fashion although the Myers–Saito diradical formation is kinetically preferred. The experimentally verified preference of the C2–C6 over the Myers–Saito pathway is guided by the inability of the Myers–Saito diradical to kinetically compete in the rate-determining trapping reactions, either inter- or intramolecular, with the concerted C2–C6 cyclization. As demonstrated with enyne-carbodiimide 11, the Myers–Saito channel can be made the preferred pathway if the trapping reaction by hydrogen transfer is no more rate determining. PMID:26877807

  10. Rhenium-Catalyzed Synthesis of 1,3-Diiminoisoindolines via Insertion of Carbodiimides into a C-H Bond of Aromatic and Heteroaromatic Imidates.

    PubMed

    Wang, Zijia; Sueki, Shunsuke; Kanai, Motomu; Kuninobu, Yoichiro

    2016-05-20

    The rhenium-catalyzed synthesis of 1,3-diiminoisoindolines and their related compounds from aromatic or heteroaromatic imidates and carbodiimides are reported via C-H bond activation. This reaction is the first example of a transition-metal-catalyzed insertion of carbodiimides into an aromatic or heteroaromatic C-H bond and a novel method for synthesizing 1,3-diiminoisoindolines and their related compounds. Unsymmetrical 1,3-diiminoisoindolines were easily obtained using this method. The reaction proceeded in good to excellent yield using a variety of substrates. PMID:27153181

  11. 21 CFR 556.410 - Metoserpate hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Metoserpate hydrochloride. 556.410 Section 556.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.410 Metoserpate hydrochloride. A tolerance of 0.02 part...

  12. 21 CFR 556.350 - Levamisole hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Levamisole hydrochloride. 556.350 Section 556.350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.350 Levamisole hydrochloride. A tolerance of 0.1 part...

  13. 21 CFR 556.410 - Metoserpate hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Metoserpate hydrochloride. 556.410 Section 556.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.410 Metoserpate hydrochloride. A tolerance of 0.02 part...

  14. 21 CFR 556.350 - Levamisole hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Levamisole hydrochloride. 556.350 Section 556.350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.350 Levamisole hydrochloride. A tolerance of 0.1 part...

  15. 21 CFR 556.350 - Levamisole hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Levamisole hydrochloride. 556.350 Section 556.350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.350 Levamisole hydrochloride. A tolerance of 0.1 part...

  16. 21 CFR 556.410 - Metoserpate hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Metoserpate hydrochloride. 556.410 Section 556.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.410 Metoserpate hydrochloride. A tolerance of 0.02 part...

  17. 21 CFR 556.410 - Metoserpate hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Metoserpate hydrochloride. 556.410 Section 556.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.410 Metoserpate hydrochloride. A tolerance of 0.02 part...

  18. 21 CFR 556.350 - Levamisole hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Levamisole hydrochloride. 556.350 Section 556.350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Tolerances for Residues of New Animal Drugs § 556.350 Levamisole hydrochloride. A tolerance of 0.1 part...

  19. Synthesis and immunological properties of Vi and di-O-acetyl pectin protein conjugates with adipic acid dihydrazide as the linker.

    PubMed Central

    Kossaczka, Z; Bystricky, S; Bryla, D A; Shiloach, J; Robbins, J B; Szu, S C

    1997-01-01

    The Vi capsular polysaccharide of Salmonella typhi, a licensed vaccine for typhoid fever in individuals > or = 5 years old, induces low and short-lived antibodies in children, and reinjection does not elicit booster responses at any age. Its immunogenicity was improved by binding Vi to proteins by using N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) as a linker. Similar findings were observed with the structurally related, di-O-acetyl derivative of pectin [poly-alpha(1-->4)-D-GalpA] designated OAcP. Protein conjugates of Vi and OAcP were synthesized by carbodiimide-mediated synthesis with adipic acid dihydrazide (ADH) as the linker. Hydrazide groups were introduced into proteins (bovine serum albumin or recombinant Pseudomonas aeruginosa exoprotein A) by treatment with ADH and 1-ethyl-3(3-dimethylaminopropyl carbodiimide (EDC). The resultant adipic acid hydrazide derivatives (AH-proteins), containing 2.3 to 3.4% AH, had antigenic and physicochemical properties similar to those of the native proteins. The AH-proteins were bound to Vi and OAcP by treatment with EDC. The immunogenicity of Vi or OAcP, alone or as protein conjugates, was evaluated in young outbred mice and guinea pigs by subcutaneous injection of 2.5 and 5.0 microg, respectively, of polysaccharide, and antibodies were measured by enzyme-linked immunosorbent assay. All conjugates were significantly more immunogenic than Vi or OAcP alone and induced booster responses with 5- to 25-fold increases of antibodies. Vi conjugates were significantly more immunogenic than their OAcP analogs. A carboxymethyl derivative of yeast beta-glucan enhanced the anti-Vi response elicited by an OAcP conjugate but had no effect on the immunogenicity of Vi or of OAcP alone. Vi and OAcP conjugates synthesized by this scheme will be evaluated clinically. PMID:9169736

  20. A New Methodology for the Detection of Low-Abundance Species in the Ism: Detection of Interstellar Carbodiimide (HNCNH)

    NASA Astrophysics Data System (ADS)

    McGuire, Brett A.; Loomis, Ryan A.; Charness, Cameron M.; Corby, Joanna F.; Blake, Geoffrey A.; Hollis, Jan M.; Lovas, Frank J.; Jewell, Philip R.; Remijan, Anthony J.

    2013-06-01

    We present the first interstellar detection of carbodiimide (HNCNH) in observations towards Sgr B2(N) using data from the publicly available Green Bank Telescope PRebiotic Interstellar MOlecular Survey project. Recent laboratory work predicts an abundance of HNCNH of ˜10% of the abundance of its tautomer, cyanamide (NH_2CN), or ˜ 2× 10^{13} cm^{-2} in Sgr B2(N). Given this abundance at LTE conditions, the strongest rotational transitions of HNCNH have intensities at or below the noise level of current observations of this source. A thermal population of HNCNH is therefore likely undetectable. Instead, HNCNH is identified via maser emission features at centimeter wavelengths. This detection presents a new methodology for the detection of low-abundance species and further demonstrates the power of cm-wave observations to make definitive identifications based on a small number of observed features.

  1. 21 CFR 522.883 - Etorphine hydrochloride injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... milliliter of etorphine hydrochloride injection, veterinary, contains 1 mg of etorphine hydrochloride in... use the drug unless diprenorphine hydrochloride injection, veterinary, as provided for in § 522.723, is available for use in reversing the effects of etorphine hydrochloride injection, veterinary....

  2. 21 CFR 522.883 - Etorphine hydrochloride injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... milliliter of etorphine hydrochloride injection, veterinary, contains 1 mg of etorphine hydrochloride in... use the drug unless diprenorphine hydrochloride injection, veterinary, as provided for in § 522.723, is available for use in reversing the effects of etorphine hydrochloride injection, veterinary....

  3. Yohimbine hydrochloride as an antagonist to xylazine hydrochloride-ketamine hydrochloride immobilization of white-tailed deer

    USGS Publications Warehouse

    Mech, L.D.; DelGiudice, G.D.; Karns, P.D.; Seal, U.S.

    1985-01-01

    Thirteen captive and one free-ranging white-tailed deer (Odocoileus virginianus) were immobilized one to six times each with ketamine hydrochloride and xylazine hydrochloride during winter and spring in northern Minnesota. Administration of 0.09 to 0.53 mg of yohimbine hydrochloride per kg IV after each trial reversed the immobilization. The deer raised their heads within a median time of 2.0 min, stood in 6.0 min and walked away in 9.5 min. No adverse side effects were observed for several weeks following the immobilization.

  4. Immobilization of swift foxes with ketamine hydrochloride-xylazine hydrochloride

    USGS Publications Warehouse

    Telesco, R.L.; Sovada, M.A.

    2002-01-01

    There is an increasing need to develop field immobilization techniques that allow researchers to handle safely swift foxes (Vulpes velox) with minimal risk of stress or injury. We immobilized captive swift foxes to determine the safety and effectiveness of ketamine hydrochloride and xylazine hydrochloride at different dosages. We attempted to determine appropriate dosages to immobilize swift foxes for an adequate field-handling period based on three anesthesia intervals (induction period, immobilization period, and recovery period) and physiologic responses (rectal temperature, respiration rate, and heart rate). Between October 1998-July 1999, we conducted four trials, evaluating three different dosage ratios of ketamine and xylazine (2.27:1.2, 5.68:1.2, and 11.4:1.2 mg/kg ketamine:mg/kg xylazine, respectively), followed by a fourth trial with a higher dosage at the median ratio (11.4 mg/kg ketamine:2.4 mg/kg xylazine). We found little difference in induction and recovery periods among trials 1-3, but immobilization time increased with increasing dosage (P<0.08). Both the immobilization period and recovery period increased in trial 4 compared with trials 1-3 (P???0.03). There was a high variation in responses of individual foxes across trials, making it difficult to identify an appropriate dosage for field handling. Heart rate and respiration rates were depressed but all physiologic measures remained within normal parameters established for domestic canids. We recommend a dosage ratio of 10 mg/kg ketamine to 1 mg/kg xylazine to immobilize swift foxes for field handling.

  5. Bridged bis(amidinate) lanthanide aryloxides: syntheses, structures, and catalytic activity for addition of amines to carbodiimides.

    PubMed

    Tu, Jing; Li, Wenbo; Xue, Mingqiang; Zhang, Yong; Shen, Qi

    2013-04-28

    Various lanthanide aryloxide complexes supported by bridged bis(amidinate) ligand L, LLnOAr(DME) (L = Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3, DME = dimethoxyethane, Ln = Y, Ar = 2,6-(Me)2C6H3 (1), 2,6-((i)Pr)2C6H3 (2), 2,6-((t)Bu)2-4-(Me)C6H2 (3); Ar = 2,6-((t)Bu)2-4-(Me)C6H2, Ln = Nd (4), Sm (5), Yb (6)) were synthesized, and complexes 1, 2 and 4–6 were characterized by single crystal X-ray diffraction. All the complexes are efficient precatalysts for catalytic addition of amines to carbodiimides. The catalytic activity is influenced by lanthanide metals and the aryloxide groups (Nd (4) Sm (5) < Y (3) Yb (6) and -2,6-(Me)2C6H3 < -2,6-((i)Pr)2C6H3 < -2,6-((t)Bu)2-4-(Me)C6H2). The catalytic addition reaction with 3 showed a good scope of substrates. The mechanism investigation revealed the real active intermediate being the monoguanidinate complexes supported by an aryloxide and an amidine-functionalized amidinate group, L′Ln[O2,6-((t)Bu)2-4-(Me)C6H2][RNCNHRN(Ar′)] (L′ = Me3SiNHC(Ph)N(CH2)3NC(Ph)NSiMe3, R = (i)Pr, Ar′ = phenyl, Ln = Yb (8), Y (11); R = Cy, Ar′ = phenyl, Ln = Yb (10), Y (12); R = (i)Pr, Ar′ = 4-ClC6H4, Ln = Yb (9)), which were isolated from the reactions of 6 (or 3) with amine and carbodiimide in a molar ratio of 1:1:1 and structurally characterized. The Ln-active group in the present precatalyst is a Ln–amidinate species, not the Ln–OAr group. PMID:23459864

  6. 21 CFR 520.222 - Bunamidine hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (a) Chemical name. N,N-Dibutyl-4-(hexyloxy)-1-naphthamidine hydrochloride. (b) Specifications. The... kilogram of body weight. The drug should be given on an empty stomach and food should not be given for...

  7. 21 CFR 520.1962 - Promazine hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (a)(1) Chemical name. 10- phenothiazine monohydrochloride. (2) Specifications. Conforms to N.F. XII... of 0.45 to 0.9 milligrams of promazine hydrochloride per pound of body weight mixed with an amount...

  8. 21 CFR 184.1676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... hydrochloride that is prepared by chemical synthesis. (b) The ingredient meets the specifications of the Food...)(31) of this chapter; plant protein products as defined in § 170.3(n)(33) of this chapter; and...

  9. 21 CFR 184.1676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... hydrochloride that is prepared by chemical synthesis. (b) The ingredient meets the specifications of the Food...)(31) of this chapter; plant protein products as defined in § 170.3(n)(33) of this chapter; and...

  10. 21 CFR 184.1676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... hydrochloride that is prepared by chemical synthesis. (b) The ingredient meets the specifications of the Food...)(31) of this chapter; plant protein products as defined in § 170.3(n)(33) of this chapter; and...

  11. 21 CFR 184.1676 - Pyridoxine hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... hydrochloride that is prepared by chemical synthesis. (b) The ingredient meets the specifications of the Food...)(31) of this chapter; plant protein products as defined in § 170.3(n)(33) of this chapter; and...

  12. 21 CFR 520.2002 - Propiopromazine hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... propiopromazine hydrochloride per pound of body weight once or twice daily depending upon the degree of... may produce significant depression. (3) For use only by or on the order of a licensed veterinarian....

  13. Covalent immobilization of molecularly imprinted polymer nanoparticles on a gold surface using carbodiimide coupling for chemical sensing.

    PubMed

    Kamra, Tripta; Chaudhary, Shilpi; Xu, Changgang; Montelius, Lars; Schnadt, Joachim; Ye, Lei

    2016-01-01

    One challenging task in building (bio)chemical sensors is the efficient and stable immobilization of receptor on a suitable transducer. Herein, we report a method for covalent immobilization of molecularly imprinted core-shell nanoparticles for construction of robust chemical sensors. The imprinted nanoparticles with a core-shell structure have selective molecular binding sites in the core and multiple amino groups in the shell. The model Au transducer surface is first functionalized with a self-assembled monolayer of 11-mercaptoundecanoic acid. The 11-mercaptoundecanoic acid is activated by treatment with carbodiimide/N-hydroxysuccinimide and then reacted with the core-shell nanoparticles to form amide bonds. We have characterized the process by studying the treated surfaces after each preparation step using atomic force microscopy, scanning electron microscopy, fluorescence microscopy, contact angle measurements and X-ray photoelectron spectroscopy. The microscopy results show the successful immobilization of the imprinted nanoparticles on the surface. The photoelectron spectroscopy results further confirm the success of each functionalization step. Further, the amino groups on the MIP surface were activated by electrostatically adsorbing negatively charged Au colloids. The functionalized surface was shown to be active for surface enhanced Raman scattering detection of propranolol. The particle immobilization and surface enhanced Raman scattering approach described here has a general applicability for constructing chemical sensors in different formats. PMID:26397901

  14. Comparison of the properties of collagen-chitosan scaffolds after γ-ray irradiation and carbodiimide cross-linking.

    PubMed

    Chen, Zihao; Du, Tianming; Tang, Xiangyu; Liu, Changjun; Li, Ruixin; Xu, Cheng; Tian, Feng; Du, Zhenjie; Wu, Jimin

    2016-07-01

    The property of collagen-chitosan porous scaffold varies according to cross-linking density and scaffold composition. This study was designed to compare the properties of collagen-chitosan porous scaffolds cross-linked with γ-irradiation and carbodiimide (CAR) for the first time. Eleven sets of collagen-chitosan scaffolds containing different concentrations of chitosan at a 5% increasing gradient were fabricated. Fourier transform infrared spectroscopy was performed to confirm the success of cross-linking in the scaffolds. The scaffold morphology was evaluated under scanning electron microscope (SEM). SEM revealed that chitosan was an indispensable material for the fabrication of γ-ray irradiation scaffold. The microstructure of γ-ray irradiation scaffold was less stable than those of alternative scaffolds. Based upon swelling ratio, porosity factor, and collagenase degradation, γ-ray irradiation scaffold was less stable than CAR and 25% proportion of chitosan scaffolds. Mechanical property determines the orientation in γ-irradiation and CAR scaffold. In vitro degradation test indicated that γ-irradiation and CAR cross-linking can elevate the scaffold biocompatibility. Compared with γ-ray irradiation, CAR cross-linked scaffold containing 25% chitosan can more significantly enhance the bio-stability and biocompatibility of collagen-chitosan scaffolds. CAR cross-linked scaffold may be the best choice for future tissue engineering. PMID:27122297

  15. Effect of EDTA Conditioning and Carbodiimide Pretreatment on the Bonding Performance of All-in-One Self-Etch Adhesives

    PubMed Central

    Singh, Shipra; Nagpal, Rajni; Tyagi, Shashi Prabha; Manuja, Naveen

    2015-01-01

    Objective. This study evaluated the effect of ethylenediaminetetraacetic acid (EDTA) conditioning and carbodiimide (EDC) pretreatment on the shear bond strength of two all-in-one self-etch adhesives to dentin. Methods. Flat coronal dentin surfaces were prepared on one hundred and sixty extracted human molars. Teeth were randomly divided into eight groups according to two different self-etch adhesives used [G-Bond and OptiBond-All-In-One] and four different surface pretreatments: (a) adhesive applied following manufacturer's instructions; (b) dentin conditioning with 24% EDTA gel prior to application of adhesive; (c) EDC pretreatment followed by application of adhesive; (d) application of EDC on EDTA conditioned dentin surface followed by application of adhesive. Composite restorations were placed in all the samples. Ten samples from each group were subjected to immediate and delayed (6-month storage in artificial saliva) shear bond strength evaluation. Data collected was subjected to statistical analysis using three-way ANOVA and post hoc Tukey's test at a significance level of p < 0.05.  Results and Conclusion. EDTA preconditioning as well as EDC pretreatment alone had no significant effect on the immediate and delayed bond strengths of either of the adhesives. However, EDC pretreatment on EDTA conditioned dentin surface resulted in preservation of resin-dentin bond strength of both adhesives with no significant fall over six months. PMID:26557850

  16. 21 CFR 522.2470 - Tiletamine hydrochloride and zolazepam hydrochloride for injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... reconstituted with sterile distilled water provides tiletamine hydrochloride and zolazepam hydrochloride... analgesia. (2) Amount. Expressed as milligrams of the drug combination: (i) In healthy dogs: An initial... healthy cats: An initial intramuscular dosage of 4.4 to 5.4 milligrams per pound of body weight...

  17. 21 CFR 522.2470 - Tiletamine hydrochloride and zolazepam hydrochloride for injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... reconstituted with sterile distilled water provides tiletamine hydrochloride and zolazepam hydrochloride... analgesia. (2) Amount. Expressed as milligrams of the drug combination: (i) In healthy dogs: An initial... healthy cats: An initial intramuscular dosage of 4.4 to 5.4 milligrams per pound of body weight...

  18. 21 CFR 522.2470 - Tiletamine hydrochloride and zolazepam hydrochloride for injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... reconstituted with sterile distilled water provides tiletamine hydrochloride and zolazepam hydrochloride... analgesia. (2) Amount. Expressed as milligrams of the drug combination: (i) In healthy dogs: An initial... healthy cats: An initial intramuscular dosage of 4.4 to 5.4 milligrams per pound of body weight...

  19. 21 CFR 522.2470 - Tiletamine hydrochloride and zolazepam hydrochloride for injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... reconstituted with sterile distilled water provides tiletamine hydrochloride and zolazepam hydrochloride... analgesia. (2) Amount. Expressed as milligrams of the drug combination: (i) In healthy dogs: An initial... healthy cats: An initial intramuscular dosage of 4.4 to 5.4 milligrams per pound of body weight...

  20. Improved fibronectin-immobilized fibrinogen microthreads for the attachment and proliferation of fibroblasts

    PubMed Central

    Rajangam, Thanavel; An, Seong Soo A

    2013-01-01

    The aim of this study was to fabricate fibrinogen (Fbg) microfibers with different structural characteristics for the development of 3-D tissue-engineering scaffolds. Fabricated Fbg microfibers were investigated for their biomolecule encapsulation, cell adhesion, and proliferations. Microfibers with three different concentrations of Fbg (5, 10, and 15 wt%) were prepared by a gel solvent-extraction method using a silicone rubber tube. Fbg microfibers were covalently modified with fibronectin (FN) by using water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as the cross-linking agent. Fbg microfibers were characterized by their FN cross-linking properties, structural morphology, and in vitro degradation. Furthermore, FN/Fbg microfibers were evaluated for cell attachment and proliferation. The bio-compatibility and cell proliferation of the microfibers were assessed by measuring adenosine triphosphate activity in C2C12 fibroblast cells. Cell attachment and proliferation on microfibers were further examined using fluorescence and scanning electron microscopic images. FN loading on the microfibers was confirmed by fluorescence and infrared spectroscopy. Surface morphology was characterized by scanning electron microscopy, and showed highly aligned nanostructures for fibers made with 15 wt% Fbg, a more porous structure for fibers made with 10 wt% Fbg, and a less porous structure for those made with 5 wt% Fbg. Controlled biodegradation of the fiber was observed for 8 weeks by using an in vitro proteolytic degradation assay. Fbg microfibers with highly aligned nanostructures (15 wt%) showed enhanced biomolecule encapsulation, as well as higher cell adhesion and proliferation than another two types of FN/Fbg fibers (5 and 10 wt%) and unmodified Fbg fibers. The promising results obtained from the present study reveal that optimal structure of Fbg microfibers could be used as a potential substratum for growth factors or drug release, especially in wound healing and

  1. Microfluidic Generation of Haptotactic Gradients through 3D Collagen Gels for Enhanced Neurite Growth

    PubMed Central

    Sundararaghavan, Harini G.; Masand, Shirley N.

    2011-01-01

    Abstract We adapted a microfluidic system used previously to generate durotactic gradients of stiffness in a 3D collagen gel, to produce haptotactic gradients of adhesive ligands through the collagen gel. Oligopeptide sequences that included bioactive peptide sequences from laminin, YIGSR, or IKVAV, were grafted separately onto type I collagen using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Solutions of peptide-grafted collagen and untreated collagen were then used as source and sink input solutions, respectively, in an H-shaped microfluidic network fabricated using traditional soft lithography. One-dimensional gradients of the peptide-grafted collagen solution were generated in the channel that connected the source and sink channels, and these gradients became immobilized upon self-assembly of the collagen into a 3D fibrillar gel. The slope and average concentration of the gradients were adjusted by changing the concentration of the source solutions and by changing the length of the cross-channel. A separate, underlying channel in the microfluidic construct allowed the introduction of a chick embryo dorsal root ganglion into the network. Neurites from these explants grew significantly longer up steep gradients of YIGSR, but shallow gradients of IKVAV in comparison to untreated collagen controls. When these two gradients were presented in combination, the bias in growth acceleration was the largest and most consistent. No differences were observed in the number of neurites choosing to grow up or down the gradients in any condition. These results suggest that the incorporation of distinct gradients of multiple bioactive ligands can improve directional acceleration of regenerating axons. PMID:21473683

  2. Synthesis and characterization of gibberellin-chitosan conjugate for controlled-release applications.

    PubMed

    Liu, Yao; Sun, Yan; He, Shun; Zhu, Yuncong; Ao, Mingming; Li, Jianqiang; Cao, Yongsong

    2013-06-01

    Controlled release formulations (CRFs) are promising in improving the efficiency of pesticide and minimizing the spreading of hazardous residues in environment. By coupling with the pesticide covalently, chitosan can be used as a carrier material for the vulnerable ingredient. For the first time, gibberellic acid (GA3), one of plant growth regulators, was attached to chitosan (CS) to form a GA3-CS conjugate via the formation of an amide bound using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide. The novel conjugate was structurally characterized by fourier transform infrared spectroscopy, ultraviolet spectrophotometer, and thermal gravimetric analysis. Effects of pH, temperature, and UV irradiation on the release of this conjugate were investigated. The results showed that the new conjugate had a remarkable modification degree for CS (more than 60%, w/w) and the optimal coupling conditions were defined as: the molar ratio of GA3:EDC/NHS:CS was 1:1.2:1.2, at pH 6.0 for 24 h. The release data showed the novel conjugate protected GA3 against photo- and thermal-degradation effectively and the concentration of GA3 in GA3-CS kept unchangeable about 60 d in different pH conditions. Compared with GA3 technical, the conjugate had better water solubility and stability and have potential applications. The present study also provides a novel preparation method of CRFs comprising a pesticide with long duration, sustained-release performance and good environmental compatibility. This method may be extended to other pesticides that possess a carboxyl group. PMID:23511059

  3. Three-dimensional printing of soy protein scaffolds for tissue regeneration.

    PubMed

    Chien, Karen B; Makridakis, Emmanuella; Shah, Ramille N

    2013-06-01

    Fabricating three-dimensional (3D) porous scaffolds with controlled structure and geometry is crucial for tissue regeneration. To date, exploration in printing 3D natural protein scaffolds is limited. In this study, soy protein slurry was successfully printed using the 3D Bioplotter to form scaffolds. A method to verify the structural integrity of resulting scaffolds during printing was developed. This process involved measuring the mass extrusion flow rate of the slurry from the instrument, which was directly affected by the extrusion pressure and the soy protein slurry properties. The optimal mass flow rate for printing soy slurry at 27°C was 0.0072±0.0002 g/s. The addition of dithiothreitol to soy slurries demonstrated the importance of disulfide bonds in forming solid structures upon printing. Resulting Bioplotted soy protein scaffolds were cured using 95% ethanol and post-treated using dehydrothermal treatment (DHT), a combination of freeze-drying and DHT, and chemical crosslinking using 1-ethyl-3-(3 dimethylaminopropyl)carbodiimide (EDC) chemistry. Surface morphologies of the different treatment groups were characterized using scanning electron microscopy. Scaffold properties, including relative crosslink density, mass loss upon rinsing, and compressive modulus revealed that EDC crosslinked scaffolds were the most robust with moduli of approximately 4 kPa. Scaffold geometry (45° and 90° layer rotations) affected the mechanical properties for DHT and EDC crosslinked scaffolds. Seeding efficiency of human mesenchymal stem cells (hMSC) was highest for nontreated and thermally treated scaffolds, and all scaffolds supported hMSC viability over time. PMID:23102234

  4. Enzymatic specificities and modes of action of the two catalytic domains of the XynC xylanase from Fibrobacter succinogenes S85.

    PubMed Central

    Zhu, H; Paradis, F W; Krell, P J; Phillips, J P; Forsberg, C W

    1994-01-01

    The xylanase XynC of Fibrobacter succinogenes S85 was recently shown to contain three distinct domains, A, B, and C (F. W. Paradis, H. Zhu, P. J. Krell, J. P. Phillips, and C. W. Forsberg, J. Bacteriol. 175:7666-7672, 1993). Domains A and B each bear an active site capable of hydrolyzing xylan, while domain C has no enzymatic activity. Two truncated proteins, each containing a single catalytic domain, named XynC-A and XynC-B were purified to homogeneity. The catalytic domains A and B had similar pH and temperature parameters of 6.0 and 50 degrees C for maximum hydrolytic activity and extensively degraded birch wood xylan to xylose and xylobiose. The Km and Vmax values, respectively, were 2.0 mg ml-1 and 6.1 U mg-1 for the intact enzyme, 1.83 mg ml-1 and 689 U mg-1 for domain A, and 2.38 mg ml-1 and 91.8 U mg-1 for domain B. Although domain A had a higher specific activity than domain B, domain B exhibited a broader substrate specificity and hydrolyzed rye arabinoxylan to a greater extent than domain A. Furthermore, domain B, but not domain A, was able to release xylose at the initial stage of the hydrolysis. Both catalytic domains cleaved xylotriose, xylotetraose, and xylopentaose but had no activity on xylobiose. Bond cleavage frequencies obtained from hydrolysis of xylo-alditol substrates suggest that while both domains have a strong preference for internal linkages of the xylan backbone, domain B has fewer subsites for substrate binding than domain A and cleaves arabinoxylan more efficiently. Chemical modification with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide methiodide and N-bromosuccinimide inactivated both XynC-A and XynC-B in the absence of xylan, indicating that carboxyl groups and tryptophan residues in the catalytic site of each domain have essential roles. Images PMID:8021170

  5. A reinforced composite structure composed of polydiacetylene assemblies deposited on polystyrene microspheres and its application to H5N1 virus detection

    PubMed Central

    Dong, Wenjie; Luo, Jing; He, Hongxuan; Jiang, Long

    2013-01-01

    In this study, we immobilized polydiacetylene vesicles (PDAVs) onto the surface of polystyrene (PS) microspheres (1 μm in diameter) by using both electrical charge and conjugated forces to form a reinforced composite structure. These reinforced complexes could be easily washed, separated by centrifugation, and resuspended by gentle agitation. After passing through a narrow 200 μm-diameter channel, the composite structures maintained their original shape, demonstrating their resilience and potential for use in microfluidic technologies. The number of PDAVs in the composite structure could be mediated by changing the extent of layer deposition, which affected the sensitivity of detection. It showed that PDAVs did not change their blue color after addition of detecting probes such as anti-H5N1, which was of great importance in the fabrication and modification of stable color-changeable biosensors based on PDAVs. By conjugating anti-H5N1 antibodies to the PS@PDAV via N -hydroxysuccinimide and 1-ethyl3-(3-dimethylaminopropyl) carbodiimide chemistry, a stable blue complex, anti-H5N1 microsphere (PS@PDAV-anti-H5N1) was formed. A target antigen of H5N1 (HAQ [H5N1 strain A/ environment/Qinghai/1/2008{H5N1} in clade 0]) was detected by PS@PDAV-anti-H5N1. At an optimal PDAV deposition level of three layers, the limit of detection was determined to be approximately 3 0 ng/mL of HAQ by using optical spectrum measurement and visual inspection, meeting the needs of fast and simple color-changeable detection. However, a much lower limitation of detection (1 ng/mL) was able to be obtained using laser-scanning confocal microscopy, which could be compared with the results obtained with other sophisticated equipment. PMID:23403826

  6. Growth Factors Cross-Linked to Collagen Microcarriers Promote Expansion and Chondrogenic Differentiation of Human Mesenchymal Stem Cells.

    PubMed

    Bertolo, Alessandro; Arcolino, Fanny; Capossela, Simona; Taddei, Anna Rita; Baur, Martin; Pötzel, Tobias; Stoyanov, Jivko

    2015-10-01

    Tissue engineering is a field in progressive expansion and requires constant updates in methods and devices. One of the central fields is the development of biocompatible, biodegradable, and injectable scaffolds, such as collagen microcarriers. To enhance cell attachment and produce a cost-effective cell culture solution with local stimulation of cells, basic fibroblast growth factor (bFGF) or transforming growth factor-β1 (TGF-β1) was covalently immobilized on microcarriers either by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) or riboflavin/UV (RB/UV) light-mediated cross-linking. Collagen microcarriers cross-linked with bFGF or TGF-β1 were used for expansion and chondrogenic differentiation of human mesenchymal stem cells (MSCs). Evaluation methods included cell viability test, chondrogenic marker expression (aggrecan and collagen type I and type II), histological detection of proteoglycans, and immunohistochemical analysis. Cross-linking strengthened the collagen structure of the microcarriers and reduced collagenase-mediated degradation. MSCs effectively proliferated on microcarriers cross-linked with bFGF, especially by EDC/NHS cross-linking. Chondrogenic differentiation of MSCs was induced by TGF-β1 cross-linked on microcarriers, promoting gene expression and protein accumulation of aggrecan and collagen type I and type II, as well as proteoglycans. Cross-linking by RB/UV enhanced chondrogenesis more than any other group. In addition, cross-linking reduced scaffold shrinkage exerted by MSCs during chondrogenesis, a desirable feature for microcarriers if used as tissue defect filler. In conclusion, cross-linking of bFGF or TGF-β1 to collagen microcarriers supported in vitro proliferation and chondrogenesis, respectively. If translated in vivo and in clinical practice, such approach might lead a step closer to development of a cost-effective and locally acting device for cell-based therapy. PMID:26222829

  7. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    NASA Astrophysics Data System (ADS)

    Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

    2012-12-01

    A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface with HPDLCs. The Col-immobilized titanium surface could be used for forming ligament-like tissues around titanium dental implants.

  8. 2,2'Dithiodinicotinyl ligands: Key to more reactive thiomers.

    PubMed

    Menzel, Claudia; Silbernagl, Jennifer; Laffleur, Flavia; Leichner, Christina; Jelkmann, Max; Huck, Christian W; Hussain, Shah; Bernkop-Schnürch, Andreas

    2016-04-30

    The aim of this study was to establish a novel type of preactivated thiomers exhibiting a comparatively higher reactivity with mucus and consequently improved mucoadhesive properties. In order to achieve this goal, the dimeric form of 2-mercaptonicotinic acid (MNA-MNA) was directly attached to the polymeric backbone of chitosan (CHI) via amide bond formation mediated by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDAC) used as a coupling reagent. The remaining free amino groups were in the following reacted with succinic anhydride (Succ) in order to obtain a uniformly anionically charged polymer (CHI-Succ-MNA-MNA). Within this study, different coupling rates of up to 170 μmol MNA-MNA per gram polymer were achieved. The attachment of the dimeric ligand resulted in a preactivated thiomer with a comparatively more reactive disulfide substructure due to the additional nitrogen atom in conjugation over the aromatic moieties. Furthermore, the obtained polymer is entirely preactivated and thus prevented against undesired oxidation reactions. Kinetic studies of disulfide exchange reactions showed a 3.8-fold higher reactivity of CHI-Succ-MNA-MNA in comparison to a state-of-the-art preactivated thiomer. Within rheological measurements, CHI-Succ-MNA-MNA with a coupling rate of 170 μmol (CHI-Succ-MNA-MNA 170) led to a 5.7-fold higher mucus viscosity than the non-thiolated control polymer (CHI-Succ) indicating a rheological synergism due to mucoadhesive properties. These results were confirmed by a second mucoadhesion study, which showed a significantly prolonged retention time of CHI-Succ-MNA-MNA on the small intestinal mucosa compared to CHI-Succ (P<0.02). Accordingly, the double preactivation seems to be a promising strategy in order to obtain entirely preactivated polymers with enhanced mucoadhesive properties. PMID:26972378

  9. Endosomal proteolysis of glucagon at neutral pH generates the bioactive degradation product miniglucagon-(19-29).

    PubMed

    Authier, Francois; Cameron, Pamela H; Merlen, Clemence; Kouach, Mostafa; Briand, Gilbert

    2003-12-01

    We have investigated the proteolytic mechanisms of glucagon degradation within hepatic endosomes at neutral pH before lumen acidification. Hepatic endosomes incubated at neutral pH rapidly degraded native glucagon into 13 intermediate products, one of which corresponded to the bioactive fragment glucagon-(19-29) (miniglucagon). The serine protease inhibitor phenylmethylsulfonyl fluoride as well as the nonspecific protease inhibitor bacitracin inhibited the endosomal degradation of glucagon at pH 7. In purified endosomal fractions, miniglucagon endopeptidase was undetectable as evaluated by immunoblotting, and immunoprecipitation with antibodies to insulin-degrading enzyme, cathepsins B and D, or furin failed to remove the endosomal neutral glucagonase activity. Incubation of endosomal fractions and [125I]iodoglucagon with the zero-length bifunctional cross-linker 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide resulted in specific labeling of a 170-kDa polypeptide. The labeling was completely inhibited by unlabeled glucagon (IC50 value, 5 x 10-7 m) and bacitracin (IC50 value, 1 microg/ml), suggesting that it may correspond to a bacitracin-sensitive glucagon-degrading enzyme. Treatment of the 125I-labeled 170-kDa cross-linked polypeptide with N-glycanase demonstrated that the cross-linked complex contained approximately 30 kDa of N-linked oligosaccharides. Specific cross-linking of the 170-kDa polypeptide was also observed using [125I]Tyr12-miniglucagon as the radioligand. Together, these data suggest that the 170-kDa glycoprotein represents a novel glucagon-degrading activity that could mediate glucagon proteolysis within endosomes before the acidification step and generate the bioactive (19-29) miniglucagon peptide. PMID:12959981

  10. In vivo real-time bioimaging of hyaluronic acid derivatives using quantum dots.

    PubMed

    Kim, Jiseok; Kim, Ki Su; Jiang, Ge; Kang, Hyungu; Kim, Sungjee; Kim, Byung-Soo; Park, Moon Hyang; Hahn, Sei Kwang

    2008-12-01

    The effect of chemical modification of hyaluronic acid (HA) on its distribution throughout the body was successfully visualized in nude mice through real-time bioimaging using quantum dots (QDots). Adipic acid dihydrazide modified HA (HA-ADH) was synthesized and conjugated with QDots having carboxyl terminal ligands activated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide. The formation of HA-QDot conjugates could be confirmed by gel permeation chromatography, fluorometry, transmission electron microscopy, and zeta-size analysis. According to the real-time bioimaging of HA-QDot conjugates after subcutaneous injection to nude mice, the fluorescence of HA-QDot conjugates with a near infrared wavelength of 800 nm could be detected up to 2 months, whereas that with an emission wavelength of 655 nm disappeared almost completely within 5 days. The results can be ascribed to the fact that near-infrared light has a high penetration depth of about 5-6 cm in the body compared to that of about 7-10 mm for visible light. Thereby, using QDots with a near-infrared emission wavelength of 800 nm, the distribution of HA-QDot conjugates throughout the body was bioimaged in real-time after their tail-vein injection into nude mice. HA-QDot conjugates with 35 mol% ADH content maintaining enough binding sites for HA receptors were mainly accumulated in the liver, while those with 68 mol% ADH content losing much of HA characteristics were evenly distributed to the tissues in the body. The results are well matched with the fact that HA receptors are abundantly present in the liver with a high specificity to HA molecules. PMID:18690665

  11. Investigation and characterization of oxidized cellulose and cellulose nanofiber films

    NASA Astrophysics Data System (ADS)

    Yang, Han

    Over the last two decades, a large amount of research has focused on natural cellulose fibers, since they are "green" and renewable raw materials. Recently, nanomaterials science has attracted wide attention due to the large surface area and unique properties of nanoparticles. Cellulose certainly is becoming an important material in nanomaterials science, with the increasing demand of environmentally friendly materials. In this work, a novel method of preparing cellulose nanofibers (CNF) is being presented. This method contains up to three oxidation steps: periodate, chlorite and TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) oxidation. The first two oxidation steps are investigated in the first part of this work. Cellulose pulp was oxidized to various extents by a two step-oxidation with sodium periodate, followed by sodium chlorite. The oxidized products can be separated into three different fractions. The mass ratio and charge content of each fraction were determined. The morphology, size distribution and crystallinity index of each fraction were measured by AFM, DLS and XRD, respectively. In the second part of this work, CNF were prepared and modified under various conditions, including (1) the introduction of various amounts of aldehyde groups onto CNF by periodate oxidation; (2) the carboxyl groups in sodium form on CNF were converted to acid form by treated with an acid type ion-exchange resin; (3) CNF were cross-linked in two different ways by employing adipic dihydrazide (ADH) as cross-linker and water-soluble 1-ethyl-3-[3-(dimethylaminopropyl)] carbodiimide (EDC) as carboxyl-activating agent. Films were fabricated with these modified CNF suspensions by vacuum filtration. The optical, mechanical and thermo-stability properties of these films were investigated by UV-visible spectrometry, tensile test and thermogravimetric analysis (TGA). Water vapor transmission rates (WVTR) and water contact angle (WCA) of these films were also studied.

  12. Preparation and characterization of group A meningococcal capsular polysaccharide conjugates and evaluation of their immunogenicity in mice.

    PubMed

    Jin, Zhigang; Chu, Chiayung; Robbins, John B; Schneerson, Rachel

    2003-09-01

    Epidemic and endemic meningitis caused by group A Neisseria meningitidis remains a problem in sub-Saharan Africa. Although group A meningococcal capsular polysaccharide (GAMP) vaccine confers immunity at all ages, the improved immunogenicity of a conjugate and its compatibility with the World Health Organization's Extended Program on Immunization offers advantages over GAMP alone. Conjugates of GAMP bound to bovine serum albumin (BSA) were synthesized, characterized, and evaluated for their immunogenicities in mice. Two methods, involving adipic acid dihydrazide (ADH) as a linker, were used. First, ADH was bound to GAMP activated with cyanogen bromide (CNBr) or with 1-cyano-4(dimethylamino)-pyridinium tetrafluoroborate (CDAP) to form GAMP(CNBr)AH and GAMP(CDAP)AH. These derivatives were bound to BSA by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) to form GAMP(CNBr)AH-BSA and GAMP(CDAP)AH-BSA. Second, ADH was bound to BSA with EDC to form AHBSA. AHBSA was bound to activated GAMP to form GAMP(CNBr)-AHBSA and GAMP(CDAP)-AHBSA. The yield of GAMP(CDAP)-AHBSA (35 to 40%) was higher than those of the other conjugates (5 to 20%). GAMP conjugates elicited immunoglobulin G (IgG) anti-GAMP in all mice after three injections of 2.5 or 5.0 microg of GAMP: the geometric mean (GM) was highest in recipients of GAMP(CDAP)-AHBSA (11.40 enzyme-linked immunosorbent assay units). Although the difference was not statistically significant, the 5.0- microg dose elicited a higher GM IgG anti-GAMP than the 2.5- microg dose. Low levels of anti-GAMP were elicited by GAMP alone. GAMP(CDAP)-AHBSA elicited bactericidal activity roughly proportional to the level of IgG anti-GAMP. PMID:12933854

  13. Conjugation of an antibody to cross-linked fibrin for targeted delivery of anti-restenotic drugs.

    PubMed

    Thomas, Anita C; Campbell, Julie H

    2004-12-10

    There is an urgent need to treat restenosis, a major complication of the treatment of arteries blocked by atherosclerotic plaque, using local delivery techniques. We observed that cross-linked fibrin (XLF) is deposited at the site of surgical injury of arteries. An antibody to XLF, conjugated to anti-restenotic agents, should deliver the drugs directly and only to the site of injury. An anti-XLF antibody (H93.7C.1D2/48; 1D2) was conjugated to heparin (using N-succinimidyl 3-(2-pyridyldithio)propionate), low molecular weight heparin (LMWH) (adipic acid dihydrazide) and rapamycin (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide), and the conjugates purified and tested for activity before use in vivo. Rabbits had their right carotid arteries de-endothelialised and then given a bolus of 1D2-heparin, 1D2-LMWH or 1D2-rapamycin conjugate or controls of saline, heparin, LMWH, rapamycin or 1D2 (+/-heparin bolus) and sacrificed after 2 or 4 weeks (12 groups, n=6/group). Rabbits given any of the conjugates had minimal neointimal development in injured arteries, with up to 59% fewer neointimal cells than those given control drugs. Rabbits given 1D2-heparin or 1D2-LMWH had an increased or insignificant reduction in luminal area, with positive remodelling, while the medial and total arterial areas of rabbits given 1D2-rapamycin were not affected by injury. Arteries exposed to 1D2-heparin or 1D2-rapamycin had more endothelial cells than rabbits given control drugs. Thus, XLF-antibodies can site-deliver anti-restenotic agents to injured areas of the artery wall, where the conjugates can influence remodelling, re-endothelialisation and neointimal cell density, with reduced neointimal formation. PMID:15567502

  14. Vibrio cholerae O139 conjugate vaccines: synthesis and immunogenicity of V. cholerae O139 capsular polysaccharide conjugates with recombinant diphtheria toxin mutant in mice.

    PubMed

    Kossaczka, Z; Shiloach, J; Johnson, V; Taylor, D N; Finkelstein, R A; Robbins, J B; Szu, S C

    2000-09-01

    Epidemiologic and experimental data provide evidence that a critical level of serum immunoglobulin G (IgG) antibodies to the surface polysaccharide of Vibrio cholerae O1 (lipopolysaccharide) and of Vibrio cholerae O139 (capsular polysaccharide [CPS]) is associated with immunity to the homologous pathogen. The immunogenicity of polysaccharides, especially in infants, may be enhanced by their covalent attachment to proteins (conjugates). Two synthetic schemes, involving 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) as activating agents, were adapted to prepare four conjugates of V. cholerae O139 CPS with the recombinant diphtheria toxin mutant, CRMH21G. Adipic acid dihydrazide was used as a linker. When injected subcutaneously into young outbred mice by a clinically relevant dose and schedule, these conjugates elicited serum CPS antibodies of the IgG and IgM classes with vibriocidal activity to strains of capsulated V. cholerae O139. Treatment of these sera with 2-mercaptoethanol (2-ME) reduced, but did not eliminate, their vibriocidal activity. These results indicate that the conjugates elicited IgG with vibriocidal activity. Conjugates also elicited high levels of serum diphtheria toxin IgG. Convalescent sera from 20 cholera patients infected with V. cholerae O139 had vibriocidal titers ranging from 100 to 3,200: absorption with the CPS reduced the vibriocidal titer of all sera to < or =50. Treatment with 2-ME reduced the titers of 17 of 20 patients to < or =50. These data show that, like infection with V. cholerae O1, infection with V. cholerae O139 induces vibriocidal antibodies specific to the surface polysaccharide of this bacterium (CPS) that are mostly of IgM class. Based on these data, clinical trials with the V. cholerae O139 CPS conjugates with recombinant diphtheria toxin are planned. PMID:10948122

  15. Stiffness-controlled three-dimensional collagen scaffolds for differentiation of human Wharton's jelly mesenchymal stem cells into cardiac progenitor cells.

    PubMed

    Lin, Yun-Li; Chen, Chie-Pein; Lo, Chun-Min; Wang, Hwai-Shi

    2016-09-01

    Stem cell-based regenerative therapy has emerged as a promising treatment for myocardial infarction. The aim of this study is to develop stiffness-controlled collagen scaffolds to allow proliferation and differentiation of mesenchymal stem cell (MSCs) into cardiac progenitor cells. In this study transforming growth factor β2 (TGF-β2), was used to induce stem cell differentiation into cardiac lineage cells. Collagen scaffolds were cross-linked with cross-linkers, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), and N-Hydroxysuccinimide (NHS). The results showed that collagen scaffolds cross-linked with 25/50 and 50/50 of EDC mM/NHS mM cross-linkers exhibited little difference in shape and size, the scaffold cross-linked with 50/50 of cross-linkers demonstrated better interconnectivity and higher Young's modulus (31.8 kPa) than the other (15.4 kPa). SEM observation showed that MSCs could grow inside the scaffolds and interact with collagen scaffolds. Furthermore, greater viability and cardiac lineage differentiation were achieved in MSCs cultured on stiffer scaffolds. The results suggest that three-dimensional type I collagen scaffolds with suitable cross-linking to adjust for stiffness can affect MSC fate and direct the differentiation of MSCs into cardiac progenitor cells with/without TGF-β2. These stiffness-controlled collagen scaffolds hold great potential as carriers for delivering MSCs differentiated cardiac progenitor cells into infracted hearts. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2234-2242, 2016. PMID:27120780

  16. Role of the Dinitrogenase Reductase Arginine 101 Residue in Dinitrogenase Reductase ADP-Ribosyltransferase Binding, NAD Binding, and Cleavage

    PubMed Central

    Ma, Yan; Ludden, Paul W.

    2001-01-01

    Dinitrogenase reductase is posttranslationally regulated by dinitrogenase reductase ADP-ribosyltransferase (DRAT) via ADP-ribosylation of the arginine 101 residue in some bacteria. Rhodospirillum rubrum strains in which the arginine 101 of dinitrogenase reductase was replaced by tyrosine, phenylalanine, or leucine were constructed by site-directed mutagenesis of the nifH gene. The strain containing the R101F form of dinitrogenase reductase retains 91%, the strain containing the R101Y form retains 72%, and the strain containing the R101L form retains only 28% of in vivo nitrogenase activity of the strain containing the dinitrogenase reductase with arginine at position 101. In vivo acetylene reduction assays, immunoblotting with anti-dinitrogenase reductase antibody, and [adenylate-32P]NAD labeling experiments showed that no switch-off of nitrogenase activity occurred in any of the three mutants and no ADP-ribosylation of altered dinitrogenase reductases occurred either in vivo or in vitro. Altered dinitrogenase reductases from strains UR629 (R101Y) and UR630 (R101F) were purified to homogeneity. The R101F and R101Y forms of dinitrogenase reductase were able to form a complex with DRAT that could be chemically cross-linked by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide. The R101F form of dinitrogenase reductase and DRAT together were not able to cleave NAD. This suggests that arginine 101 is not critical for the binding of DRAT to dinitrogenase reductase but that the availability of arginine 101 is important for NAD cleavage. Both DRAT and dinitrogenase reductase can be labeled by [carbonyl-14C]NAD individually upon UV irradiation, but most 14C label is incorporated into DRAT when both proteins are present. The ability of R101F dinitrogenase reductase to be labeled by [carbonyl-14C]NAD suggested that Arg 101 is not absolutely required for NAD binding. PMID:11114923

  17. Biotinylated recombinant human erythropoietins: Bioactivity and utility as receptor ligand

    SciTech Connect

    Wojchowski, D.M.; Caslake, L. )

    1989-08-15

    Recombinant human erythropoietin labeled covalently with biotin at sialic acid moieties has been prepared, and has been shown to possess high biological activity plus utility as a receptor ligand. Initially, the effects on biological activity of covalently attaching biotin to erythropoietin alternatively at carboxylate, amino, or sialic acid groups were compared. Biotinylation of erythropoietin at carboxylate groups using biotin-amidocaproyl hydrazide plus 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide led to substantial biological inactivation, although biotinylated molecules retained detectable activity when prepared at low stoichiometries. Biotinylation at amino groups using sulfosuccinimidyl 6-(biotinamido) hexanoate resulted in a high level of biological inactivation with little, if any, retention of biological activity, regardless of labeling stoichiometries. Biotinylation at sialic acid moieties using periodate and biotinamidocaproyl hydrazide proceeded efficiently (greater than 95% and 80% labeling efficiencies for human urinary and recombinant erythropoietin, respectively) and yielded stably biotinylated erythropoietin molecules possessing comparably high biological activity (ie, 45% of the activity of unmodified hormone). Utility of recombinant biotin-(sialyl)-erythropoietin (in combination with 125I-streptavidin) in the assay of cell surface receptors was demonstrated using two distinct murine erythroleukemia cell lines, Friend 745 and Rauscher Red 1. The densities and affinities of specific hormone binding sites were 116 +/- 4 sites, 3.3 +/- 0.4 nmol/L kd and 164 +/- 5 sites, 2.7 +/- 0.4 nmol/L kd, respectively. It is predicted that the present development of biotin-(sialyl)-erythropoietin as a chemically and biologically stable, bioactive ligand will assist in advancing an understanding of the regulated expression and physicochemistry of the human and murine erythropoietin receptors.

  18. Preparation of aminated chitosan/alginate scaffold containing halloysite nanotubes with improved cell attachment.

    PubMed

    Amir Afshar, Hamideh; Ghaee, Azadeh

    2016-10-20

    The chemical nature of biomaterials play important role in cell attachment, proliferation and migration in tissue engineering. Chitosan and alginate are biodegradable and biocompatible polymers used as scaffolds for various medical and clinical applications. Amine groups of chitosan scaffolds play an important role in cell attachment and water adsorption but also associate with alginate carboxyl groups via electrostatic interactions and hydrogen bonding, consequently the activity of amine groups in the scaffold decreases. In this study, chitosan/alginate/halloysite nanotube (HNTs) composite scaffolds were prepared using a freeze-drying method. Amine treatment on the scaffold occurred through chemical methods, which in turn caused the hydroxyl groups to be replaced with carboxyl groups in chitosan and alginate, after which a reaction between ethylenediamine, 1-ethyl-3,(3-dimethylaminopropyl) carbodiimide (EDC) and scaffold triggered the amine groups to connect to the carboxyl groups of chitosan and alginate. The chemical structure, morphology and mechanical properties of the composite scaffolds were investigated by FTIR, CHNS, SEM/EDS and compression tests. The electrostatic attraction and hydrogen bonding between chitosan, alginate and halloysite was confirmed by FTIR spectroscopy. Chitosan/alginate/halloysite scaffolds exhibit significant enhancement in compressive strength compared with chitosan/alginate scaffolds. CHNS and EDS perfectly illustrate that amine groups were effectively introduced in the aminated scaffold. The growth and cell attachment of L929 cells as well as the cytotoxicity of the scaffolds were investigated by SEM and Alamar Blue (AB). The results indicated that the aminated chitosan/alginate/halloysite scaffold has better cell growth and cell adherence in comparison to that of chitosan/alginate/halloysite samples. Aminated chitosan/alginate/halloysite composite scaffolds exhibit great potential for applications in tissue engineering, ideally in

  19. Development of a simple bioelectrode for the electrochemical detection of hydrogen peroxide using Pichia pastoris catalase immobilized on gold nanoparticle nanotubes and polythiophene hybrid.

    PubMed

    Nandini, Seetharamaiah; Nalini, Seetharamaiah; Sanetuntikul, Jakkid; Shanmugam, Sangaraju; Niranjana, Pathappa; Melo, Jose Savio; Suresh, Gurukar Shivappa

    2014-11-21

    In this paper, a simple and innovative electrochemical hydrogen peroxide biosensor has been proposed using catalase (CATpp) derived from Pichia pastoris as bioelectrocatalyst. The model biocomponent was immobilized on gold nanoparticle nanotubes (AuNPNTs) and polythiophene composite using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide (EDC-NHS) coupling reagent. In this present work, we have successfully synthesized gold nanoparticles (AuNPs) by ultrasonic irradiation. The tubular gold nanostructures containing coalesced AuNPs were obtained by sacrificial template synthesis. The assembly of AuNPNTs onto the graphite (Gr) electrode was achieved via S-Au chemisorption. The latter was pre-coated with electropolymerized thiophene (PTh) to enable S groups to bind AuNPNTs. The combination of AuNPNTs-PTh, i.e., an inorganic-organic hybrid, provides a stable enzyme immobilization platform. The physical morphology of the fabricated biosensor Gr/PTh/AuNPNTs/EDC-NHS/CATpp was investigated using scanning electron microscopy and energy-dispersive microscopy. The analytical performance of the bioelectrode was examined using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. Operational parameters such as working potential, pH, and thermal stability of the modified electrode were examined. The beneficial analytical characteristics of the proposed electrode were demonstrated. Our results indicate that the Gr/PTh/AuNPNTs/EDC-NHS/CATpp bioelectrode exhibits a wide linear range from 0.05 mM to 18.5 mM of H2O2, fast response time of 7 s, excellent sensitivity of 26.2 mA mM(-1) cm(-2), good detection limit of 0.12 μM and good Michaelis-Menten constant of 1.4 mM. In addition, the bioelectrode displayed good repeatability, high stability and acceptable reproducibility, which can be attributed to the AuNPNTs-PTh composite that provides a biocompatible micro-environment. PMID:25208248

  20. 21 CFR 522.1465 - Naltrexone hydrochloride injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Naltrexone hydrochloride injection. 522.1465... § 522.1465 Naltrexone hydrochloride injection. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of naltrexone hydrochloride. (b) Sponsor. See 053923 in § 510.600(c)...

  1. 21 CFR 522.1465 - Naltrexone hydrochloride injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Naltrexone hydrochloride injection. 522.1465... § 522.1465 Naltrexone hydrochloride injection. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of naltrexone hydrochloride. (b) Sponsor. See 053923 in § 510.600(c)...

  2. 21 CFR 522.1465 - Naltrexone hydrochloride injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Naltrexone hydrochloride injection. 522.1465... § 522.1465 Naltrexone hydrochloride injection. (a) Specifications. Each milliliter of sterile aqueous solution contains 50 milligrams of naltrexone hydrochloride. (b) Sponsor. See 053923 in § 510.600(c)...

  3. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  4. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  5. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  6. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride. (b) (c) Limitations, restrictions, or explanation....

  7. 21 CFR 182.1047 - Glutamic acid hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Glutamic acid hydrochloride. 182.1047 Section 182.1047 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1047 Glutamic acid hydrochloride. (a) Product. Glutamic acid hydrochloride....

  8. Identification and determination of ketotifen hydrogen fumarate, azelastine hydrochloride, dimetindene maleate and promethazine hydrochloride by densitometric method.

    PubMed

    Wyszomirska, Elzbieta; Czerwińska, Krystyna; Kublin, Elzbieta; Mazurek, Aleksander P

    2013-01-01

    Conditions for determination of: ketotifen hydrogen fumarate, azelastine hydrochloride, dimetindene maleate and promethazine hydrochloride by densitometric method in substances and pharmaceuticals were provided. Maximum wavelenghts were: 228 nm for ketotifen hydrogen fumarate, 295 nm for azelastine hydrochloride, 265 nm for dimetindene maleate and 255 nm for promethazine hydrochloride. The limits of quantification were in the ranges of 0.2-5 microg/spot. The statistical data showed adequate accuracy and precision of developed methods. PMID:24383318

  9. RP-HPLC and Spectrophotometric Estimation of Ambroxol Hydrochloride and Cetirizine Hydrochloride in Combined Dosage Form.

    PubMed

    Bhatia, Neela M; Ganbavale, S K; Bhatia, M S; More, H N; Kokil, S U

    2008-09-01

    Rapid, precise, accurate, specific and sensitive reverse phase liquid chromatographic and absorbance ratio spectrophotometric methods have been developed for the simultaneous analysis of ambroxol hydrochloride and cetirizine hydrochloride in their tablet formulation. The chromatographic methods were standardized using a HIQ SIL-C(18) column (250×4.6 mm i.d., 10 μm particle size) with UV detection at 229 nm and mobile phase consisting of methanol-acetonitrile-water (40:40:20, v/v/v). Ambroxol hydrochloride and cetirizine hydrochloride have absorbance maxima at 243 nm and 229 nm, respectively. The isoabsorptive wavelength for both the drugs was 236 nm. For absorbance ratio method developed, wavelengths selected were 243 nm and 236 nm. The proposed methods were successfully applied to the determination of ambroxol hydrochloride and cetirizine hydrochloride in tablets, with high percentage of recovery, good accuracy and acceptable precision. Different analytical performance parameters such as linearity, precision, accuracy, limit of detection, limit of quantitation and robustness were determined according to International Conference on Harmonization ICH Q2B guidelines. Results of analysis of the developed method were compared by performing ANOVA. PMID:21394256

  10. 21 CFR 556.580 - Robenidine hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Robenidine hydrochloride. 556.580 Section 556.580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD...

  11. 21 CFR 556.580 - Robenidine hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Robenidine hydrochloride. 556.580 Section 556.580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD...

  12. 21 CFR 556.580 - Robenidine hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Robenidine hydrochloride. 556.580 Section 556.580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD...

  13. 21 CFR 558.515 - Robenidine hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Federal Register citations affecting § 558.515, see the List of CFR Sections Affected, which appears in... chapter. (d) Conditions of use. It is used in feed for chickens as follows: Robenidine hydrochloride in... and fryer chickens: As an aid in the prevention of coccidiosis caused by E. mivati, E. brunetti,...

  14. 21 CFR 558.515 - Robenidine hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Federal Register citations affecting § 558.515, see the List of CFR Sections Affected, which appears in... chapter. (d) Conditions of use. It is used in feed for chickens as follows: Robenidine hydrochloride in... and fryer chickens: As an aid in the prevention of coccidiosis caused by E. mivati, E. brunetti,...

  15. 21 CFR 558.515 - Robenidine hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Federal Register citations affecting § 558.515, see the List of CFR Sections Affected, which appears in... chapter. (d) Conditions of use. It is used in feed for chickens as follows: Robenidine hydrochloride in... and fryer chickens: As an aid in the prevention of coccidiosis caused by E. mivati, E. brunetti,...

  16. 21 CFR 558.515 - Robenidine hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Federal Register citations affecting § 558.515, see the List of CFR Sections Affected, which appears in... chapter. (d) Conditions of use. It is used in feed for chickens as follows: Robenidine hydrochloride in... and fryer chickens: As an aid in the prevention of coccidiosis caused by E. mivati, E. brunetti,...

  17. 21 CFR 556.410 - Metoserpate hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Metoserpate hydrochloride. 556.410 Section 556.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs §...

  18. 21 CFR 556.580 - Robenidine hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Robenidine hydrochloride. 556.580 Section 556.580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD...

  19. 21 CFR 556.580 - Robenidine hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Robenidine hydrochloride. 556.580 Section 556.580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs...

  20. 21 CFR 556.350 - Levamisole hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Levamisole hydrochloride. 556.350 Section 556.350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs...

  1. Stabilization of collagen nanofibers with l-lysine improves the ability of carbodiimide cross-linked amniotic membranes to preserve limbal epithelial progenitor cells

    PubMed Central

    Lai, Jui-Yang; Wang, Pei-Ran; Luo, Li-Jyuan; Chen, Si-Tan

    2014-01-01

    To overcome the drawbacks associated with limited cross-linking efficiency of carbodiimide modified amniotic membrane, this study investigated the use of l-lysine as an additional amino acid bridge to enhance the stability of a nanofibrous tissue matrix for a limbal epithelial cell culture platform. Results of ninhydrin assays and zeta potential measurements showed that the amount of positively charged amino acid residues incorporated into the tissue collagen chains is highly correlated with the l-lysine-pretreated concentration. The cross-linked structure and hydrophilicity of amniotic membrane scaffolding materials affected by the lysine molecular bridging effects were determined. With an increase in the l-lysine-pretreated concentration from 1 to 30 mM, the cross-linking density was significantly increased and water content was markedly decreased. The variations in resistance to thermal denaturation and enzymatic degradation were in accordance with the number of cross-links per unit mass of amniotic membrane, indicating l-lysine-modulated stabilization of collagen molecules. It was also noteworthy that the carbodiimide cross-linked tissue samples prepared using a relatively high l-lysine-pretreated concentration (ie, 30 mM) appeared to have decreased light transmittance and biocompatibility, probably due to the influence of a large nanofiber size and a high charge density. The rise in stemness gene and protein expression levels was dependent on improved cross-link formation, suggesting the crucial role of amino acid bridges in constructing suitable scaffolds to preserve limbal progenitor cells. It is concluded that mild to moderate pretreatment conditions (ie, 3–10 mM l-lysine) can provide a useful strategy to assist in the development of carbodiimide cross-linked amniotic membrane as a stable stem cell niche for corneal epithelial tissue engineering. PMID:25395849

  2. Stability of esmolol hydrochloride in intravenous solutions.

    PubMed

    Baaske, D M; Dykstra, S D; Wagenknecht, D M; Karnatz, N N

    1994-11-01

    The stability of esmolol hydrochloride in a variety of i.v. solutions was studied. Solutions of esmolol hydrochloride 10 mg/mL were prepared separately in 0.45% sodium chloride injection, 0.9% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.45% sodium chloride injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose with lactated Ringer's injection, lactated Ringer's injection, 5% sodium bicarbonate injection, and 5% dextrose injection with potassium chloride 40 meq/L. One glass and one polyvinyl chloride container of each solution (except glass only in the case of the solution in 5% sodium bicarbonate injection) were stored in the dark at 5 degrees C, under ambient room light at 23-27 degrees C, in the dark at 40 degrees C, and under intense light at 25-30 degrees C. At storage intervals up to 168 hours, samples were tested for esmolol hydrochloride concentration by high-performance liquid chromatography. Optical density and pH were also measured. Esmolol hydrochloride was stable in the various i.v. fluids for at least 168 hours when stored at 5 degrees C or 23-27 degrees C, for at least 24 hours when stored under intense light, and, with one exception, for at least 48 hours when stored at 40 degrees C. When mixed with 5% sodium bicarbonate injection, the drug was stable for only about 24 hours at 40 degrees C. There were no substantial changes in optical density or pH. The type of container had no effect on stability. With one exception, esmolol hydrochloride was stable in all the i.v. solutions under all the conditions tested. PMID:7856582

  3. Clean photodecomposition of 1-methyl-4-phenyl-1H-tetrazole-5(4H)-thiones to carbodiimides proceeds via a biradical

    PubMed Central

    Alawode, Olajide E.; Robinson, Colette; Rayat, Sundeep

    2010-01-01

    The photochemistry of 1-methyl-4-phenyl-1H-tetrazole-5(4H)-thione (1a) and 1-(3-methoxyphenyl)-4-methyl-1H-tetrazole-5(4H)-thione (1b) was studied in acetonitrile at 254 and 300 nm which involves expulsion of dinitrogen and sulfur to form the respective carbodiimides 5a – b as sole photoproducts. Photolysis of the title compounds in the presence of 1,4-cyclohexadiene trap led to the formation of respective thioureas, providing strong evidence for the intermediacy of a 1,3-biradical formed by the loss of dinitrogen. In contrast, a trapping experiment with cyclohexene provided no evidence to support an alternative pathway of photodecomposition involving initial desulfurization followed by loss of dinitrogen via the intermediacy of a carbene. Triplet sensitization and triplet quenching studies argue against the involvement of a triplet excited state. While the quantum yields for the formation of the carbodiimides 5a – b were modest, and showed little change on going from a C6H5 (1a) to mOMeC6H4 (1b) substituent on the tetrazolethione ring, the highly clean photodecomposition of these compounds to a photostable end product makes them promising lead structures for industrial, agricultural and medicinal applications. PMID:21142194

  4. Reactions of titanocene bis(trimethylsilyl)acetylene complexes with carbodiimides: an experimental and theoretical study of complexation versus C-N bond activation.

    PubMed

    Haehnel, Martin; Ruhmann, Martin; Theilmann, Oliver; Roy, Subhendu; Beweries, Torsten; Arndt, Perdita; Spannenberg, Anke; Villinger, Alexander; Jemmis, Eluvathingal D; Schulz, Axel; Rosenthal, Uwe

    2012-09-26

    The reaction of the low valent metallocene(II) sources Cp'(2)Ti(η(2)-Me(3)SiC(2)SiMe(3)) (Cp' = η(5)-cyclopentadienyl, 1a or η(5)-pentamethylcyclopentadienyl, 1b) with different carbodiimide substrates RN═C═NR' 2-R-R' (R = t-Bu; R' = Et; R = R' = i-Pr; t-Bu; SiMe(3); 2,4,6-Me-C(6)H(2) and 2,6-i-Pr-C(6)H(3)) was investigated to explore the frontiers of ring strained, unusual four-membered heterometallacycles 5-R. The product complexes show dismantlement, isomerization, or C-C coupling of the applied carbodiimide substrates, respectively, to form unusual mono-, di-, and tetranuclear titanium(III) complexes. A detailed theoretical study revealed that the formation of the unusual complexes can be attributed to the biradicaloid nature of the unusual four-membered heterometallacycles 5-R, which presents an intriguing situation of M-C bonding. The combined experimental and theoretical study highlights the delicate interplay of electronic and steric effects in the stabilization of strained four-membered heterometallacycles, accounting for the isolation of the obtained complexes. PMID:22891968

  5. Study on fluorescence characteristics of duloxetine hydrochloride

    NASA Astrophysics Data System (ADS)

    Liu, Xiangping; Du, Yingxiang; Wu, Xiulan

    2008-12-01

    The fluorescence characteristics of duloxetine hydrochloride are studied in this paper. The fluorescence emission spectra of duloxetine demonstrate that intramolecular charge-transfer takes place between thiophene ring and napthalenyloxy group upon irradiation. The effects of excitation light, solvent system, variation of solution pH value, metal ions and vitamin C on the fluorescence spectra of duloxetine hydrochloride are elucidated, respectively. A spectrofluorometric method of quantitative determination of duloxetine in dosage form is reported for the first time, the linear range is 7.14 × 10 -8 mol/L to 1.43 × 10 -5 mol/L, the linear correlation coefficient r is equal to 0.9997, and the detection limit is 3.5 × 10 -8 mol/L. The accuracy and the precision are satisfactory.

  6. Flow injection potentiometric determination of pipazethate hydrochloride.

    PubMed

    Abdel-Ghani, N T; Shoukry, A F; el Nashar, R M

    2001-01-01

    New plastic membrane electrodes for pipazethate hydrochloride based on pipazethatium phosphotungstate, pipazethatium phosphomolybdate and a mixture of the two were prepared. The electrodes were fully characterized in terms of composition, life span, pH and temperature and were then applied to the potentiometric determination of the pipazethate ion in its pure state and pharmaceutical preparations under batch and flow injection conditions. The selectivity of the electrodes towards many inorganic cations, sugars and amino acids was also tested. PMID:11205518

  7. 21 CFR 520.2345a - Tetracycline hydrochloride capsules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... organisms sensitive to tetracycline hydrochloride, such as bacterial gastroenteritis due to E. coli and urinary tract infections due to Staphylococcus spp. and E. coli. (3) Limitations. Federal law...

  8. 21 CFR 520.2345a - Tetracycline hydrochloride capsules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... organisms sensitive to tetracycline hydrochloride, such as bacterial gastroenteritis due to E. coli and urinary tract infections due to Staphylococcus spp. and E. coli. (3) Limitations. Federal law...

  9. 21 CFR 520.2345a - Tetracycline hydrochloride capsules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... organisms sensitive to tetracycline hydrochloride, such as bacterial gastroenteritis due to E. coli and urinary tract infections due to Staphylococcus spp. and E. coli. (3) Limitations. Federal law...

  10. 21 CFR 520.2345a - Tetracycline hydrochloride capsules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... organisms sensitive to tetracycline hydrochloride, such as bacterial gastroenteritis due to E. coli and urinary tract infections due to Staphylococcus spp. and E. coli. (3) Limitations. Federal law...

  11. 21 CFR 520.2345a - Tetracycline hydrochloride capsules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... organisms sensitive to tetracycline hydrochloride, such as bacterial gastroenteritis due to E. coli and urinary tract infections due to Staphylococcus spp. and E. coli. (3) Limitations. Federal law...

  12. Effect of Ractopamine Hydrochloride and Zilpaterol Hydrochloride on tenderness of longissimus steaks of Bos Taurus steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: Three experiments were conducted to determine 1) the interaction of ractopamine hydrochloride (RH) inclusion rate (0 or 300 mg·hd-1·d-1 for last 30 to 34 d before harvest) and dietary protein level (13.5 or 17.5% CP) on LM slice shear force (SSF) at 14 d postmortem (Exp. 1); 2) the inter...

  13. 21 CFR 522.2474 - Tolazoline hydrochloride injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Tolazoline hydrochloride injection. 522.2474 Section 522.2474 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... solution contains tolazoline hydrochloride equivalent to 100 milligrams of base activity. (b) Sponsor....

  14. 21 CFR 522.2474 - Tolazoline hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tolazoline hydrochloride injection. 522.2474 Section 522.2474 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... solution contains tolazoline hydrochloride equivalent to 100 milligrams of base activity. (b) Sponsor....

  15. 21 CFR 522.2474 - Tolazoline hydrochloride injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Tolazoline hydrochloride injection. 522.2474 Section 522.2474 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... solution contains tolazoline hydrochloride equivalent to 100 milligrams of base activity. (b) Sponsor....

  16. 21 CFR 522.2474 - Tolazoline hydrochloride injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Tolazoline hydrochloride injection. 522.2474 Section 522.2474 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... solution contains tolazoline hydrochloride equivalent to 100 milligrams of base activity. (b) Sponsor....

  17. 40 CFR 180.276 - Formetanate hydrochloride; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., wet pomace 1.5 Grapefruit 1.5 Lemon 0.60 Lime 0.03 Nectarine 0.40 Orange 1.5 Peach 0.40 Pear 0.50... established for residues of the insecticide formetanate hydrochloride (m- amino ]phenyl methylcarbamate... for residues of the insecticide formetanate hydrochloride (m- amino ]phenyl...

  18. 21 CFR 522.536 - Detomidine hydrochloride injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Detomidine hydrochloride injection. 522.536 Section 522.536 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.536 Detomidine hydrochloride...

  19. 21 CFR 522.1222 - Ketamine hydrochloride injectable dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ketamine hydrochloride injectable dosage forms. 522.1222 Section 522.1222 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1222 Ketamine hydrochloride injectable dosage forms....

  20. 21 CFR 522.1222 - Ketamine hydrochloride injectable dosage forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ketamine hydrochloride injectable dosage forms. 522.1222 Section 522.1222 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1222 Ketamine hydrochloride injectable dosage forms....

  1. 21 CFR 522.1222 - Ketamine hydrochloride injectable dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ketamine hydrochloride injectable dosage forms. 522.1222 Section 522.1222 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1222 Ketamine hydrochloride injectable dosage forms....

  2. 40 CFR 721.4460 - Amidinothiopropionic acid hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amidinothiopropionic acid... Specific Chemical Substances § 721.4460 Amidinothiopropionic acid hydrochloride. (a) Chemical substance and... amidinothiopropionic acid hydrochloride (PMN P-91-102) is subject to reporting under this section for the...

  3. 21 CFR 522.1222 - Ketamine hydrochloride injectable dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ketamine hydrochloride injectable dosage forms. 522.1222 Section 522.1222 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1222 Ketamine hydrochloride injectable dosage forms....

  4. 21 CFR 520.1263c - Lincomycin hydrochloride soluble powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lincomycin hydrochloride soluble powder. 520.1263c Section 520.1263c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Lincomycin hydrochloride soluble powder. (a) Specifications. Each gram of soluble powder contains...

  5. 21 CFR 520.1263c - Lincomycin hydrochloride soluble powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lincomycin hydrochloride soluble powder. 520.1263c Section 520.1263c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Lincomycin hydrochloride soluble powder. (a) Specifications. Each gram of soluble powder contains...

  6. 21 CFR 520.1263c - Lincomycin hydrochloride soluble powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lincomycin hydrochloride soluble powder. 520.1263c Section 520.1263c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1263c Lincomycin hydrochloride soluble powder....

  7. 21 CFR 520.2098 - Selegiline hydrochloride tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selegiline hydrochloride tablets. 520.2098 Section 520.2098 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... hydrochloride tablets. (a) Specifications. Each tablet contains either 2, 5, 10, 15, or 30 milligrams...

  8. 21 CFR 520.2098 - Selegiline hydrochloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Selegiline hydrochloride tablets. 520.2098 Section 520.2098 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... hydrochloride tablets. (a) Specifications. Each tablet contains either 2, 5, 10, 15, or 30 milligrams...

  9. 21 CFR 520.1242e - Levamisole hydrochloride effervescent tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Levamisole hydrochloride effervescent tablets. 520....1242e Levamisole hydrochloride effervescent tablets. (a) Specifications. Each tablet contains 907... water from pigs before treatment is not necessary. Add one tablet for each 21/2 gallons of water;...

  10. 21 CFR 520.2582 - Triflupromazine hydrochloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Triflupromazine hydrochloride tablets. 520.2582 Section 520.2582 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Triflupromazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  11. 21 CFR 520.1242e - Levamisole hydrochloride effervescent tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Levamisole hydrochloride effervescent tablets. 520....1242e Levamisole hydrochloride effervescent tablets. (a) Specifications. Each tablet contains 907... water from pigs before treatment is not necessary. Add one tablet for each 21/2 gallons of water;...

  12. 21 CFR 520.863 - Ethylisobutrazine hydrochloride tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethylisobutrazine hydrochloride tablets. 520.863 Section 520.863 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Ethylisobutrazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  13. 21 CFR 520.863 - Ethylisobutrazine hydrochloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ethylisobutrazine hydrochloride tablets. 520.863 Section 520.863 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Ethylisobutrazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  14. 21 CFR 520.863 - Ethylisobutrazine hydrochloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ethylisobutrazine hydrochloride tablets. 520.863 Section 520.863 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Ethylisobutrazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  15. 21 CFR 520.2098 - Selegiline hydrochloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Selegiline hydrochloride tablets. 520.2098 Section 520.2098 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... hydrochloride tablets. (a) Specifications. Each tablet contains either 2, 5, 10, 15, or 30 milligrams...

  16. 21 CFR 520.2098 - Selegiline hydrochloride tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Selegiline hydrochloride tablets. 520.2098 Section 520.2098 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... hydrochloride tablets. (a) Specifications. Each tablet contains either 2, 5, 10, 15, or 30 milligrams...

  17. 21 CFR 520.863 - Ethylisobutrazine hydrochloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ethylisobutrazine hydrochloride tablets. 520.863 Section 520.863 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Ethylisobutrazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  18. 21 CFR 520.2582 - Triflupromazine hydrochloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Triflupromazine hydrochloride tablets. 520.2582 Section 520.2582 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Triflupromazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  19. 21 CFR 520.863 - Ethylisobutrazine hydrochloride tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ethylisobutrazine hydrochloride tablets. 520.863 Section 520.863 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Ethylisobutrazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  20. 21 CFR 520.2098 - Selegiline hydrochloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Selegiline hydrochloride tablets. 520.2098 Section 520.2098 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... hydrochloride tablets. (a) Specifications. Each tablet contains either 2, 5, 10, 15, or 30 milligrams...

  1. 21 CFR 520.2582 - Triflupromazine hydrochloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Triflupromazine hydrochloride tablets. 520.2582 Section 520.2582 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Triflupromazine hydrochloride tablets. (a) Specifications. Each tablet contains either 10 milligrams or...

  2. Identification of polymorphism in ethylone hydrochloride: synthesis and characterization.

    PubMed

    Maheux, Chad R; Alarcon, Idralyn Q; Copeland, Catherine R; Cameron, T Stanley; Linden, Anthony; Grossert, J Stuart

    2016-08-01

    Ethylone, a synthetic cathinone with psychoactive properties, is a designer drug which has appeared on the recreational drug market in recent years. Since 2012, illicit shipments of ethylone hydrochloride have been intercepted with increasing frequency at the Canadian border. Analysis has revealed that ethylone hydrochloride exists as two distinct polymorphs. In addition, several minor impurities were detected in some seized exhibits. In this study, the two conformational polymorphs of ethylone hydrochloride have been synthesized and fully characterized by FTIR, FT-Raman, powder XRD, GC-MS, ESI-MS/MS and NMR ((13) C CPMAS, (1) H, (13) C). The two polymorphs can be distinguished by vibrational spectroscopy, solid-state nuclear magnetic resonance spectroscopy and X-ray diffraction. The FTIR data are applied to the identification of both polymorphs of ethylone hydrochloride (mixed with methylone hydrochloride) in a laboratory submission labelled as 'Ocean Snow Ultra'. The data presented in this study will assist forensic scientists in the differentiation of the two ethylone hydrochloride polymorphs. This report, alongside our recent article on the single crystal X-ray structure of a second polymorph of this synthetic cathinone, is the first to confirm polymorphism in ethylone hydrochloride. © 2015 Canada Border Services Agency. Drug Testing and Analysis published by John Wiley & Sons, Ltd. © 2015 Canada Border Services Agency. Drug Testing and Analysis published by John Wiley & Sons, Ltd. PMID:26344849

  3. Stability of admixture containing morphine sulfate, bupivacaine hydrochloride, and clonidine hydrochloride in an implantable infusion system.

    PubMed

    Classen, Ashley M; Wimbish, Gary H; Kupiec, Thomas C

    2004-12-01

    Intrathecal infusion is often performed using drug combinations. This study was conducted to evaluate the stability of the admixture of morphine sulfate, bupivacaine hydrochloride, and clonidine hydrochloride when used in an implantable pump under simulated clinical use conditions. SynchroMed implantable pumps were filled with an admixture and incubated at 37 degrees C for a period of 90 days. Drug admixture stored in glass vials at 4 degrees C and at 37 degrees C served as controls. Samples which included pump reservoir and catheter delivered aliquots were collected every 30 days and analyzed for drug concentrations using a stability-indicating HPLC method. All drugs contained in the admixture were stable and the original concentrations remained greater than 96%. Over 90 days, and with the pump at the simulated body temperature of 37 degrees C, there were no evident heat catalyzed or device catalyzed reactions. PMID:15589086

  4. Simultaneous determination of pseudoephedrine hydrochloride and diphenhydramine hydrochloride in cough syrup by gas chromatography (GC).

    PubMed

    Raj, S V; Kapadia, S U; Argekar, A P

    1998-05-01

    A simple, rapid and precise gas chromatographic method has been developed for the simultaneous determination of pseudoephedrine hydrochloride and diphenhydramine hydrochloride in cough syrup, using a SS column of 10% OV 1 on chromosorb W-HP (80-100 mesh) and nitrogen as a carrier gas at a flow rate of 30 ml min(-1). The oven temperature was programmed at 135 degrees C for 1 min, with a rise of 10 degrees C min(-1) up to 250 degrees C (held for 5 min). The injector and detector port temperatures were maintained at 280 degrees C. Detection was carried out using Flame ionization detector. Guaphenesin was used as an internal standard. Results of assay and recovery studies were statistically evaluated for its accuracy and precision. PMID:18967146

  5. Simultaneous UV Spectrophotometric Estimation of Ambroxol Hydrochloride and Levocetirizine Dihydrochloride.

    PubMed

    Prabhu, S Lakshmana; Shirwaikar, A A; Shirwaikar, Annie; Kumar, C Dinesh; Kumar, G Aravind

    2008-01-01

    A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of ambroxol hydrochloride and levocetirizine dihydrochloride. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths 242 nm and 231 nm, the gamma max of ambroxol hydrochloride and levocetirizine dihydrochloride, respectively. Beer's law was obeyed in the concentration range 10-50 mug/ml and 8-24 mug/ml for ambroxol hydrochloride and levocetirizine dihydrochloride respectively. Results of the method were validated statistically and by recovery studies. PMID:20046721

  6. Simultaneous UV Spectrophotometric Estimation of Ambroxol Hydrochloride and Levocetirizine Dihydrochloride

    PubMed Central

    Prabhu, S. Lakshmana; Shirwaikar, A. A.; Shirwaikar, Annie; Kumar, C. Dinesh; Kumar, G. Aravind

    2008-01-01

    A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of ambroxol hydrochloride and levocetirizine dihydrochloride. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths 242 nm and 231 nm, the γ max of ambroxol hydrochloride and levocetirizine dihydrochloride, respectively. Beer's law was obeyed in the concentration range 10–50 μg/ml and 8–24 μg/ml for ambroxol hydrochloride and levocetirizine dihydrochloride respectively. Results of the method were validated statistically and by recovery studies. PMID:20046721

  7. Effect of ractopamine hydrochloride and zilpaterol hydrochloride on cardiac electrophysiologic and hematologic variables in finishing steers.

    PubMed

    Frese, Daniel A; Reinhardt, Christopher D; Bartle, Steven J; Rethorst, David N; Bawa, Bhupinder; Thomason, Justin D; Loneragan, Guy H; Thomson, Daniel U

    2016-09-15

    OBJECTIVE To investigate the effects of dietary supplementation with the β-adrenoceptor agonists ractopamine hydrochloride and zilpaterol hydrochloride on ECG and clinicopathologic variables of finishing beef steers. DESIGN Randomized controlled trial. ANIMALS 30 Angus steers. PROCEDURES Steers were grouped by body weight and randomly assigned to receive 1 of 3 diets for 23 days: a diet containing no additive (control diet) or a diet containing ractopamine hydrochloride (300 mg/steer/d) or zilpaterol hydrochloride (8.3 mg/kg [3.8 mg/lb] of feed on a dry-matter basis), beginning on day 0. Steers were instrumented with an ambulatory ECG monitor on days -2, 6, 13, and 23, and continuous recordings were obtained for 72, 24, 24, and 96 hours, respectively. At the time of instrumentation, blood samples were obtained for CBC and serum biochemical and blood lactate analysis. Electrocardiographic recordings were evaluated for mean heart rate and arrhythmia rates. RESULTS Steers fed zilpaterol or ractopamine had greater mean heart rates than those fed the control diet. Mean heart rates were within reference limits for all steers, with the exception of those in the ractopamine group on day 14, in which mean heart rate was high. No differences in arrhythmia rates were identified among the groups, nor were any differences identified when arrhythmias were classified as single, paired, or multiple (> 2) beats. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that dietary supplementation of cattle with ractopamine or zilpaterol at FDA-approved doses had no effect on arrhythmia rates but caused an increase in heart rate that remained within reference limits. PMID:27585105

  8. Spectrophotometric methods for the simultaneous analysis of meclezine hydrochloride and pyridoxine hydrochloride in bulk drug and pharmaceutical formulations.

    PubMed

    Arayne, M Saeed; Sultana, Najma; Siddiqui, Farhan Ahmed; Zuberi, M Hashim; Mirza, Agha Zeeshan

    2007-04-01

    Three new spectrophotometric procedures for the simultaneous determination of pyridoxine hydrochloride and meclezine hydrochloride are described. The first method depends on the application of simultaneous equation to resolve the interference due to spectral overlapping. The analytical signals were measured at 231 and 220 nm. Calibration graphs were established for 1 to 20 microGmL(-1) for pyridoxine hydrochloride and 0.5 to 10 microGmL(-1) for meclezine hydrochloride in binary mixture. In the second method, the determination of pyridoxine hydrochloride and meclezine hydrochloride was performed by measuring the absorbances at 290 and 235 nm in the simple absorbance spectra of their mixture. In third method a yellowish orange complex of pyridoxine hydrochloride was formed with ferric chloride, which absorbs in the visible region with lambda(max) at 445 nm. Calibration curve of complex formation range was conducted in between 20 to 250 microGmL(-1). These methods were validated with respect to accuracy, precision, linearity, limit of detection and quantification. Regression analysis of Beer's plot showed good correlation in a general concentration range of 1 to 20 microGml(-1) with correlation coefficient (r = 0.9999 and 0.9999; CV < 0.858) for pyridoxine hydrochloride, whereas meclezine hydrochloride concentration range 0.5 to 10 microGmL(-1) with correlation coefficient (r = 0.9998 and 0.9998; CV < 0.826). These methods can be readily applied, without any interference from the excipients. The suggested procedures were successfully applied to the determination of these compounds in synthetic mixtures and in pharmaceutical preparations, with high percentage of recovery, good accuracy and precision. PMID:17416572

  9. Stability of Revex, nalmefene hydrochloride injection.

    PubMed

    Brittain, H G; Lafferty, L; Bousserski, P; Diegnan, G; Lessor, R; Small, C; Pejaver, S

    1996-01-01

    The stability of Revex, nalmefene hydrochloride injection, has been studied at several temperatures for periods up to 36 months. The data were obtained using a HPLC method for the potency determination, and for the level of the sole degradation product (2,2'-bisnalmefene). These methods were found to be characterized by excellent precision, linearity, and accuracy over the analyte concentration ranges established. The stability data were found to be interpretable using first-order kinetics, and essentially comparable rate constants were calculated for both the potency loss and the formation of 2,2'-bisnalmefene. Applying the Arrhenius equation to these data, a rate constant of 0.00441 month-1 was deduced for the reactions taking place at 25 degrees C. This low value is consistent with the excellent stability exhibited by the product, and amply justifies its shelf life. PMID:8846056

  10. A novel and practical asymmetric synthesis of dapoxetine hydrochloride.

    PubMed

    Zhu, Yijun; Liu, Zhenren; Li, Hongyan; Ye, Deyong; Zhou, Weicheng

    2015-01-01

    A novel and practical asymmetric synthesis of dapoxetine hydrochloride by using the chiral auxiliary (S)-tert-butanesulfinamide was explored. The synthesis was concise, mild, and easy to perform. The overall yield and stereoselectivity were excellent. PMID:26734109

  11. 21 CFR 522.1642 - Oxymorphone hydrochloride injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... milligrams of oxymorphone hydrochloride per milliliter of aqueous solution containing 0.8 percent sodium chloride. (b) Sponsor. See No. 060951 in § 510.600(c) of this chapter. (c) Conditions of use. (1) The...

  12. 21 CFR 522.1642 - Oxymorphone hydrochloride injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... milligrams of oxymorphone hydrochloride per milliliter of aqueous solution containing 0.8 percent sodium chloride. (b) Sponsor. See No. 060951 in § 510.600(c) of this chapter. (c) Conditions of use. (1) The...

  13. 21 CFR 522.1642 - Oxymorphone hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... milligrams of oxymorphone hydrochloride per milliliter of aqueous solution containing 0.8 percent sodium chloride. (b) Sponsor. See No. 060951 in § 510.600(c) of this chapter. (c) Conditions of use. (1) The...

  14. A novel and practical asymmetric synthesis of dapoxetine hydrochloride

    PubMed Central

    Zhu, Yijun; Liu, Zhenren; Li, Hongyan

    2015-01-01

    Summary A novel and practical asymmetric synthesis of dapoxetine hydrochloride by using the chiral auxiliary (S)-tert-butanesulfinamide was explored. The synthesis was concise, mild, and easy to perform. The overall yield and stereoselectivity were excellent. PMID:26734109

  15. 21 CFR 522.1335 - Medetomidine hydrochloride injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... solution contains 1.0 milligram of medetomidine hydrochloride. (b) Sponsor. See 052483 in § 510.600(c) of... diseases, dogs in shock, dogs which are severly debilitated, or dogs which are stressed due to extreme...

  16. 21 CFR 520.1242e - Levamisole hydrochloride effervescent tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...: (1) Amount. The equivalent of 8 milligrams of levamisole hydrochloride per kilogram of body weight... thoroughly. Allow 1 gallon of medicated water for each 100 pounds body weight of pigs to be treated. No...

  17. Effect of carbodiimide-derivatized hyaluronic acid gelatin on preventing postsurgical intra-abdominal adhesion formation and promoting healing in a rat model.

    PubMed

    Yuan, Fang; Lin, Long-Xiang; Zhang, Hui-Hui; Huang, Dan; Sun, Yu-Long

    2016-05-01

    Adhesions often occur after abdominal surgery. It could cause chronic pelvic pain, intestinal obstruction, and infertility. A hydrogel biomaterial, carbodiimide-derivatized hyaluronic acid gelatin (cd-HA gelatin), has been successfully used to reduce adhesion formation after flexor tendon grafting. This study investigated the efficacy of cd-HA gelatin in preventing postsurgical peritoneal adhesions in a rat model. The surgical traumas were created on the underlying muscle of the abdominal wall and the serosal layer of the cecum. The wounds were covered with or without cd-HA gelatin. Animals were euthanized at day 14 after surgery. Adhesion formation was assessed with adhesion degree and adhesion breaking strength. The healing of abdominal wall was evaluated with biomechanical testing and histological analysis. The adhesions occurred in all rats (n = 12) without cd-HA gelatin treatment. The application of cd-HA gelatin significantly reduced the adhesion rate from 100% to 58%. The decrease of adhesion breaking strength also manifested that cd-HA gelatin could reduce postsurgical intra-abdominal adhesion formation. Moreover, it was found that cd-HA gelatin was a safe material and could promote tissue healing. The cd-HA gelatin hydrogel could reduce the formation of intra-abdominal adhesions without adversely effects on wound healing. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1175-1181, 2016. PMID:26749008

  18. 2-pyrazinylnitrene and 4-pyrimidylnitrene. Ring expansion to 1,3,5-triazacyclohepta-1,2,4,6-tetraene and ring opening to (2-Isocyanovinyl)carbodiimide.

    PubMed

    Addicott, Chris; Wong, Ming Wah; Wentrup, Curt

    2002-11-29

    Tetrazolo[1,5-a]pyrazine/2-azidopyrazine 9T/9A undergo photolysis in Ar matrix at cryogenic temperatures to yield 1,3,5-triazacyclohepta-1,2,4,6-tetraene 21 as the first observable intermediate, and 1-cyanoimidazole 11 and (2-isocyanovinyl)carbodiimide 22 as the final products. The latter tautomerizes to 2-(isocyanovinyl)cyanamide 23 on warming to 40 K. The same intermediate 21 and the same final products are obtained on matrix photolysis of the isomeric tetrazolo[1,5-c]pyrimidine/4-azidopyrimidine 24T/24A. These photolysis results as well as those of the previously reported thermal ring contraction of (15)N-labeled 2-pyrazinyl- and 4-pyrimidylnitrenes to 1-cyanoimidazoles can all be rationalized in terms of selective ring opening of 21 or nitrine 10 to a nitrile ylide zwitterion 28 prior to formation of the final products, 11 and 22. The results are supported by high-level ab initio and DFT calculations (CASPT2-CASSCF(6,6), G3(MP2), and B3LYP/6-31+G) of the energies and IR spectra of the intermediates and products. PMID:12444636

  19. Mechanical and structural properties underlying contraction of skeletal muscle fibers after partial 1-ethyl-3-[3-dimethylamino)propyl]carbodiimide cross-linking.

    PubMed Central

    Bershitsky, S; Tsaturyan, A; Bershitskaya, O; Mashanov, G; Brown, P; Webb, M; Ferenczi, M A

    1996-01-01

    We show prolonged contraction of permeabilized muscle fibers of the frog during which structural order, as judged from low-angle x-ray diffraction, was preserved by means of partial cross-linking of the fibers using the zero-length cross-linker 1-ethyl-3-[3-dimethylamino)propyl]carbodiimide. Ten to twenty percent of the myosin cross-bridges were cross-linked, allowing the remaining 80-90% to cycle and generate force. These fibers displayed a well-preserved sarcomeric order and mechanical characteristics similar to those of intact muscle fibers. The intensity of the brightest meridional reflection at 14.5 nm, resulting from the projection of cross-bridges evenly spaced along the myofilament length, decreased by 60% as a relaxed fiber was deprived of ATP and entered the rigor state. Upon activation of a rigorized fiber by the addition of ATP, the intensity of this reflection returned to 97% of the relaxed value, suggesting that the overall orientation of cross-bridges in the active muscle was more perpendicular to the filament axis than in rigor. Following a small-amplitude length step applied to the active fibers, the reflection intensity decreased for both releases and stretches. In rigor, however, a small stretch increased the amplitude of the reflection by 35%. These findings show the close link between cross-bridge orientation and tension changes. Images FIGURE 1 FIGURE 6 PMID:8874020

  20. A Post Hoc Analysis of D-Threo-Methylphenidate Hydrochloride (Focalin) Versus D,l-Threo-Methylphenidate Hydrochloride (Ritalin)

    ERIC Educational Resources Information Center

    Weiss, Margaret; Wasdell, Michael; Patin, John

    2004-01-01

    Objective: To evaluate clinical measures of the benefit/risk ratio in a post hoc analysis of a clinical trial of d-threo-methylphenidate hydrochloride (d-MPH) and d,l-threo-methylphenidate hydrochloride (d,l-MPH). Method: Data from a phase III clinical trial was used to compare equimolar doses of d-MPH and d,l-MPH treatment for…

  1. Intramolecular [2+2+2] cycloaddition of bis(propargylphenyl)carbodiimides: synthesis of L-shaped π-extended compounds with pyrrolo[1,2-a][1,8]naphthyridine corner units.

    PubMed

    Otani, Takashi; Saito, Takao; Sakamoto, Ryota; Osada, Hiroyuki; Hirahara, Akihito; Furukawa, Naoki; Kutsumura, Noriki; Matsuo, Tsukasa; Tamao, Kohei

    2013-07-14

    L-shaped π-extended penta-, hexa-, and heptacycles with a pyrrolo[1,2-a][1,8]naphthyridine junction were prepared from N,N'-bis[2-(2-alkyn-1-yl)phenyl]carbodiimides or their naphthyl analogs via Rh(I)-catalyzed intramolecular [2+2+2] cycloaddition and dehydrogenative aromatization. These L-shaped compounds emit sky-blue, yellow-green, or golden-orange fluorescence, with high quantum yields. PMID:23736526

  2. 77 FR 20987 - Oral Dosage Form New Animal Drugs; Change of Sponsor; Lincomycin Hydrochloride Soluble Powder...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ... Sponsor; Lincomycin Hydrochloride Soluble Powder; Penicillin G Potassium in Drinking Water; Tetracycline Powder AGENCY: Food and Drug Administration, HHS. ACTION: Final rule; technical amendment. SUMMARY: The...; penicillin G potassium, USP; and tetracycline hydrochloride soluble powders administered in drinking...

  3. Stability of cefozopran hydrochloride in aqueous solutions.

    PubMed

    Zalewski, Przemysław; Skibiński, Robert; Paczkowska, Magdalena; Garbacki, Piotr; Talaczyńska, Alicja; Cielecka-Piontek, Judyta; Jelińska, Anna

    2016-01-01

    The influence of pH on the stability of cefozopran hydrochloride (CZH) was investigated in the pH range of 0.44-13.00. Six degradation products were identified with a hybrid ESI-Q-TOF mass spectrometer. The degradation of CZH as a result of hydrolysis was a pseudo-first-order reaction. As general acid-base hydrolysis of CZH was not occurred in the solutions of hydrochloric acid, sodium hydroxide, acetate, borate and phosphate buffers, kobs = kpH because specific acid-base catalysis was observed. Specific acid-base catalysis of CZH consisted of the following reactions: hydrolysis of CZH catalyzed by hydrogen ions (kH+), hydrolysis of dications (k1H2O), monocations (k2H2O) and zwitter ions (k3H2O) and hydrolysis of zwitter ions (k1OH-) and monoanions (k2OH-) of CZH catalyzed by hydroxide ions. The total rate of the reaction was equal to the sum of partial reactions: [Formula: see text]. CZH similarly like other fourth generation cephalosporin was most stable at slightly acidic and neutral pH and less stable in alkaline pH. The cleavage of the β-lactam ring resulting from a nucleophilic attack on the carbonyl carbon in the β-lactam moiety is the preferred degradation pathway of β-lactam antibiotics in aqueous solutions. PMID:26079426

  4. Nalbuphine hydrochloride dependence in anabolic steroid users.

    PubMed

    Wines, J D; Gruber, A J; Pope, H G; Lukas, S E

    1999-01-01

    Nalbuphine hydrochloride, a nonscheduled opioid agonist/antagonist analgesic, is currently approved for the treatment of pain. Recently, nalbuphine dependence was reported in three anabolic steroid users in Britain. To further document this phenomenon, we conducted interviews on eleven subjects who reported nalbuphine use. Eight subjects were clinically dependent on nalbuphine, and seven of the subjects who were asked about tolerance and withdrawal with nalbuphine acknowledged these symptoms. Eight subjects, who had never used drugs intravenously before, reported using nalbuphine by this route. Nalbuphine-related morbidity was extensive and included medical complications and psychiatric symptoms. Nalbuphine users also exhibited a high rate of comorbid Axis I disorders, including other substance misuse. Virtually all subjects described widespread nalbuphine use in the gymnasiums they frequented. These observations, together with the recent increase in nalbuphine-related articles in the lay press, suggest that nalbuphine may represent a new drug of abuse among athletes, especially those using anabolic steroids, and that nalbuphine's scheduling status may need to be re-evaluated. PMID:10365196

  5. Sapropterin Hydrochloride: Enzyme Enhancement Therapy for Phenylketonuria

    PubMed Central

    Lachmann, Robin

    2011-01-01

    Phenylketonuria (PKU) is an inherited disorder of amino acid metabolism caused by deficiency of the enzyme phenylalanine hydroxylase (PAH). Historically PKU was a common genetic cause of severe learning difficulties and developmental delay, but with the introduction of newborn screening and early dietary management, it has become a treatable disease and people born with PKU should now have IQs and achievements similar to their peers. Dietary treatment, however, involves lifestyle changes that pervade most aspects of daily life for an individual and their family. A simple pharmacological treatment for PKU would have a great appeal. Sapropterin hydrochloride is a synthetic form of tetrahydrobiopterin, the cofactor for PAH. A proportion of mutant PAH enzymes show enhanced activity in the presence of pharmacological doses of sapropterin and, for some patients with milder forms of PKU, sapropterin can effectively lower plasma phenylalanine levels. This article discusses the potential place for sapropterin in the management of PKU and how this expensive orphan drug is being integrated into patient care in different healthcare systems. PMID:23148178

  6. Immobilizing wild mountain lions (Felis concolor) with ketamine hydrochloride and xylazine hydrochloride.

    PubMed

    Logan, K A; Thorne, E T; Irwin, L L; Skinner, R

    1986-01-01

    A mixture of 120 mg ketamine hydrochloride (KHCL)/20 mg xylazine hydrochloride (XHCL)/ml was used to immobilize 37 wild mountain lions (Felis concolor) 46 times. Observations were recorded during 37 trials that included kittens, adult females, and adult males. Dosages were based on 11 mg KHCL and 1.8 mg XHCL/kg estimated body weight. Actual doses for 24 lions requiring a single injection for immobilization ranged from 4.7-15.8 mg KHCL/kg and 0.8-2.6 mg XHCL/kg. Induction, duration, and recovery times did not differ (P greater than 0.05) between the sex and age classes. Two kittens were overdosed with the drug combination, but the effects were not life threatening. Eleven other lions, nine of which were initially underdosed, required additional injections of the drug combination for safe handling. Immobilization was characterized initially by semi-consciousness, open eyelids, pupillary dilation, and muscle rigidity. Later, most lions appeared unconscious, muscles relaxed, and breathing slowed considerably. No convulsions or hypersalivation occurred. The KHCL/XHCL mixture given at approximately 11 mg KHCL and 1.8 mg XHCL/kg body weight proved useful for immobilizing wild mountain lions for research purposes. Suggestions for case of immobilized cats are included. PMID:3951066

  7. Compatibility of cholecalciferol, haloperidol, imipramine hydrochloride, levodopa/carbidopa, lorazepam, minocycline hydrochloride, tacrolimus monohydrate, terbinafine, tramadol hydrochloride and valsartan in SyrSpend SF PH4 oral suspensions.

    PubMed

    Polonini, H C; Silva, S L; Cunha, C N; Brandão, M A F; Ferreira, A O

    2016-04-01

    A challenge with compounding oral liquid formulations is the limited availability of data to support the physical, chemical and microbiological stability of the formulation. This poses a patient safety concern and a risk for medication errors. The objective of this study was to evaluate the compatibility of the following active pharmaceutical ingredients (APIs) in 10 oral suspensions, using SyrSpend SF PH4 (liquid) as the suspending vehicle: cholecalciferol 50,000 IU/mL, haloperidol 0.5 mg/mL, imipramine hydrochloride 5.0 mg/mL, levodopa/carbidopa 5.0/1.25 mg/mL, lorazepam 1.0 mg/mL, minocycline hydrochloride 10.0 mg/mL, tacrolimus monohydrate 1.0 mg/mL, terbinafine 25.0 mg/mL, tramadol hydrochloride 10.0 mg/mL and valsartan 4.0 mg/mL. The suspensions were stored both refrigerated (2 - 8 degrees C) and at controlled room temperature (20 - 25 degrees C). This is the first stability study for these APIs in SyrSpend SF PH4 (liquid). Further, the stability of haloperidol,ilmipramine hydrochloride, minocycline, and valsartan in oral suspension has not been previously reported in the literature. Compatibility was assessed by measuring percent recovery at varying time points throughout a 90 days period. Quantification of the APIs was performed by high performance liquid chromatography (HPLC-UV). Given the percentage of recovery of the APIs within the suspensions, the beyond-use date of the final preparations was found to be at least 90 days for most suspensions both refrigerated and at room temperature. Exceptions were: Minocycline hydrochloride at both storage temperatures (60 days), levodopa/carbidopa at room temperature (30 days), and lorazepam at room temperature (60 days). This suggests that compounded suspensions of APIs from different pharmacological classes in SyrSpend SF PH4 (liquid) are stable. PMID:27209697

  8. Acute dermal toxicity of guanidine hydrochloride in rabbits. Report for 18 May-1 August 1984

    SciTech Connect

    Hiatt, G.F.; Sanso, S.K.; Korte, D.W.

    1989-12-01

    The acute dermal toxicity of guanidine hydrochloride was evaluated in five male and five female New Zealand White rabbits. Guanidine hydrochloride (2 g/kg) was applied topically to the clipped dorsal skin surface for 24 hours. No compound-related deaths or clinical signs were observed; however, guanidine hydrochloride did produce dermal irritation, necrosis, and eschar formation under conditions of the study.

  9. 21 CFR 524.1662a - Oxytetracycline hydrochloride and hydrocortisone spray.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride and hydrocortisone... NEW ANIMAL DRUGS § 524.1662a Oxytetracycline hydrochloride and hydrocortisone spray. (a) Specifications. Each 3-ounce unit of oxytetracycline hydrochloride and hydrocortisone spray contains...

  10. Validated Colorimetric Assay of Clonidine Hydrochloride from Pharmaceutical Preparations.

    PubMed

    Corciova, Andreia

    2016-01-01

    Clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and Tourette syndrome. The quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. Therefore, the aim of this study was to establish the conditions for two spectrophotometric methods for clonidine determination, based on the formation of the ion pair complex between clonidine hydrochloride and thymol blue/bromophenol blue. A Jasco UV-Vis 530 spectrophotometer was used for the analysis and the maxim absorbance was measured at 418 nm/448 nm against blank solution. After validation, the methods were used for quantification of clonidine hydrochloride in two commercial samples (tablets). The recovery of active substance varies between 98.06 and 100.13 % without interferences from the excipients. PMID:27610155

  11. Temperature-dependent THz vibrational spectra of clenbuterol hydrochloride

    NASA Astrophysics Data System (ADS)

    Yang, YuPing; Lei, XiangYun; Yue, Ai; Zhang, Zhenwei

    2013-04-01

    Using the high-resolution Terahertz Time-domain spectroscopy (THz-TDS) and the standard sample pellet technique, the far-infrared vibrational spectra of clenbuterol hydrochloride (CH), a β 2-adrenergic agonist for decreasing fat deposition and enhancing protein accretion, were measured in temperature range of 77-295 K. Between 0.2 and 3.6 THz (6.6-120.0 cm-1), seven highly resolved spectral features, strong line-narrowing and a frequency blue-shift were observed with cooling. However, ractopamine hydrochloride, with some structural and pharmacological similarities to clenbuterol hydrochloride, showed no spectral features, indicating high sensitivity and strong specificity of THz-TDS. These results could be used for the rapid and nondestructive CH residual detection in food safety control.

  12. Colestipol hydrochloride prophylaxis of diarrhea during pelvic radiotherapy

    SciTech Connect

    Stryker, J.A.; Chung, C.K.; Layser, J.D.

    1983-02-01

    Thirty-three patients were randomized prior to pelvic radiotherapy to receive the bile acid-sequestering resin colestipol hydrochloride, 5 grams qid, during the entire time of their therapy or diphenoxylate hydrochloride and atropine sulfate 2.5-20 mg per day (control) if they experienced diarrhea. The colestipol patients also took diphenoxylate if they had diarrhea. The patients in the colestipol group often experienced nausea, vomiting, and abdominal cramps and 8 were forced to discontinue the drug. There was no difference in the weekly stool frequency between the colestipol and the control patients but the colestipol patients who took at least 50% of the prescribed dose required fewer diphenoxylate tablets than the controls. The data suggest that colestipol hydrochloride is not of value in preventing radiation-induced diarrhea because of the side effects associated with the drug, but the theory on which the use of bile acid-sequestering agents is based may be correct.

  13. Validated Colorimetric Assay of Clonidine Hydrochloride from Pharmaceutical Preparations

    PubMed Central

    Corciova, Andreia

    2016-01-01

    Clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and Tourette syndrome. The quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. Therefore, the aim of this study was to establish the conditions for two spectrophotometric methods for clonidine determination, based on the formation of the ion pair complex between clonidine hydrochloride and thymol blue/bromophenol blue. A Jasco UV-Vis 530 spectrophotometer was used for the analysis and the maxim absorbance was measured at 418 nm/448 nm against blank solution. After validation, the methods were used for quantification of clonidine hydrochloride in two commercial samples (tablets). The recovery of active substance varies between 98.06 and 100.13 % without interferences from the excipients. PMID:27610155

  14. Propranolol hydrochloride release behaviour of crosslinked chitosan membranes.

    PubMed

    Thacharodi, D; Rao, K P

    1993-01-01

    Chitosan membranes of 20 microns thickness were prepared by a solvent evaporation technique and crosslinked with different concentrations of glutaraldehyde to obtain membranes of various degrees of crosslinking. These membranes were characterized by thermogravimetric (TG) analysis, differential scanning calorimetry (DSC) and tensile strength studies. The effect of crosslinking on the permeability of membranes to propranolol hydrochloride was evaluated by permeation studies conducted in static glass diffusion cells. A decrease in the thermal stability of chitosan membranes due to crosslinking was observed. The tensile strength of the membranes was improved by crosslinking. The introduction of crosslink points within the membrane reduced its permeability to propranolol hydrochloride as evidenced by decreased permeability and diffusion coefficients. Permeability studies revealed the operation of a pore mechanism in the transport of hydrophilic agents such as propranolol hydrochloride through chitosan and crosslinked chitosan membranes. PMID:7764115

  15. Stability of ondansetron hydrochloride and 12 medications in plastic syringes.

    PubMed

    Stewart, J T; Warren, F W; King, D T; Venkateshwaran, T G; Fox, J L

    1998-12-15

    The stability and compatibility of ondansetron hydrochloride with neostigmine methylsulfate, naloxone hydrochloride, midazolam hydrochloride, fentanyl citrate, alfentanil hydrochloride, atropine sulfate, morphine sulfate, meperidine hydrochloride, propofol, droperidol, metoclopramide monohydrochloride, and glycopyrrolate were studied. Ondansetron 1.33 or 1.0 mg/mL was combined with 0.9% sodium chloride injection and each of the 12 drugs in duplicate in plastic syringes (or glass for propofol). The syringes were stored at 21.8-23.4 or 4 degrees C in the dark, except for those containing propofol, which were stored at ambient temperature. Samples were removed at 0, 4, 8, and 24 hours for analysis by high-performance liquid chromatography and pH measurement; the propofol-containing samples were removed at 0, 1, 2, and 4 hours. Syringes were visually assessed for color and clarity, and particulate content was measured with a particle counter at the end of the study period. All solutions containing ondansetron retained more than 90% of their initial ondansetron concentration. Solutions containing each of the other drugs except droperidol retained more than 90% of their initial concentration of these drugs. The solutions containing droperidol retained more than 90% of their initial droperidol concentration for up to eight hours at ambient temperature but precipitated quickly at 4 degrees C. In combinations of ondansetron 1.33 or 1.0 mg/mL and 10 of 12 drugs, all drugs were stable for 24 hours in plastic syringes at 23 and 4 degrees C; ondansetron hydrochloride 1.0 mg/mL and propofol 1.0 and 5.0 mg/mL in admixtures were stable for 4 hours, and droperidol on its own and combined with ondansetron 1.0 mg/mL was stable for no more than 8 hours at ambient temperature. PMID:9872702

  16. PREDICTIVE PHARMACOKINETICS OF TRAMADOL HYDROCHLORIDE FLOATING TABLETS.

    PubMed

    Wang, Jianming; Zhang, Yanzhen; Guo, Zhiling; Tao, Qingwen; Wang, Yongjun; Zhou, Wei; Ma, Xiao; Li, Zhihong

    2016-01-01

    The purpose of this study was to propose the effectiveness of convolution approach to predict pharmacokinetics of tramadol hydrochloride floating tablets, prepared by using various ratios of carbopol, HPMC K100M, and Hibiscus rosa Sinensis as excipient. The in vitro dissolution test was conducted using paddle method in 900 mL of HCl buffer with pH 1.2 to simulate the gastric condition. The stirring speed of paddles was set at 70 rpm. Temperature of dissolution medium was adjusted at 37 ± 5 °C. At predetermined time points, 5 mL of dissolution samples were taken with a replacement of same volume using fresh medium. The obtained samples were analyzed at 271 nm using UV visible spectrophotometer. The values of predicted pharmacokinetic parameters like Cmax (maximum blood drug level), Tmax (time required to attain maximum blood drug level), and AUC (area under blood drug concentration curve) ranged between 80.8 ± 3.2-119.6 ± 4.7 ng/mL, 11.4 ± 0.2-12.2 ± 0.2 h, and 1430.5 ± 209.5-1970.6 ± 287.4 ng.h/mL, respectively. This certainly is a desired feature required at the formulation development step, where the formulator requires the development of a formulation using desired in vivo features on the basis of only accessible in vitro data. It can be concluded from the results that convolution method is a practical method for the prediction of drug concentration in blood and for quality control. PMID:27476294

  17. Medium effects on fluorescence of ciprofloxacin hydrochloride

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Fu, Yan; Li, Long-Di; Liu, Jia-Ming

    2003-10-01

    The medium (pH, organic solvents, cyclodextrin (CD) or surfactants) effects on the fluorescence of ciprofloxacin hydrochloride (CPFX·HCl) were studied in detail. It is found that the three acid constants of ciprofloxacin (CPFX) are near to each other. Therefore the relation curve between pH and fluorescence intensity has no strident change and keeps relative stable in the pH range of 2-7. When pH was in the range of 5.5-6.0, the fluorescence intensity of CPFX reached the max. The kind and amount of organic solvent added to the luminescent system have various effects. Ethanol quenched fluorescence and the fluorescence excitation wavelength is red shift at first and then blue shift. Acetone has complicated effects on the fluorescence properties of CPFX·HCl solution. The experiment result shows that acetone is really a quencher when its volume content in the system is from 0 to 20%, but when its content is 90%, the signal intensity is unexpectedly one and a half times as much as that of no acetone. This means that there is a strong interaction between the acetone and CPFX; CPFX·H + could be included into the γ-CD but the capping effect is not notable. The effect of cationic surfactant cetyltrimethylammonium bromide and non-ionic surfactant TX-100 and TX-80 on CPFX fluorescence was unimpressive, but the anionic surfactant's effect is aberrant. The fluorescence intensity of CPFX·HCl solution experiences three stages of increasing, decreasing and increasing in turn, as sodium dodecyl sulfate is adding gradually. But for sodium lauryl sulfonate, there are only two stages of decreasing and increasing with the concentration increasing. It is problematic to illustrate clearly the effect mechanism of acetone and anionic surfactant at present. Undoubtedly, the experimental results in this paper should be useful in practice works and the research is worth studying still further.

  18. Psb27, a transiently associated protein, binds to the chlorophyll binding protein CP43 in photosystem II assembly intermediates

    PubMed Central

    Liu, Haijun; Huang, Richard Y.-C.; Chen, Jiawei; Gross, Michael L.; Pakrasi, Himadri B.

    2011-01-01

    Photosystem II (PSII), a large multisubunit pigment–protein complex localized in the thylakoid membrane of cyanobacteria and chloroplasts, mediates light-driven evolution of oxygen from water. Recently, a high-resolution X-ray structure of the mature PSII complex has become available. Two PSII polypeptides, D1 and CP43, provide many of the ligands to an inorganic Mn4Ca center that is essential for water oxidation. Because of its unusual redox chemistry, PSII often undergoes degradation followed by stepwise assembly. Psb27, a small luminal polypeptide, functions as an important accessory factor in this elaborate assembly pathway. However, the structural location of Psb27 within PSII assembly intermediates has remained elusive. Here we report that Psb27 binds to CP43 in such assembly intermediates. We treated purified genetically tagged PSII assembly intermediate complexes from the cyanobacterium Synechocystis 6803 with chemical cross-linkers to examine intermolecular interactions between Psb27 and various PSII proteins. First, the water-soluble 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was used to cross-link proteins with complementary charged groups in close association to one another. In the His27△ctpAPSII preparation, a 58-kDa cross-linked species containing Psb27 and CP43 was identified. This species was not formed in the HT3△ctpA△psb27PSII complex in which Psb27 was absent. Second, the homobifunctional thiol-cleavable cross-linker 3,3′-dithiobis(sulfosuccinimidylpropionate) (DTSSP) was used to reversibly cross-link Psb27 to CP43 in His27△ctpAPSII preparations, which allowed the use of liquid chromatography/tandem MS to map the cross-linking sites as Psb27K63↔CP43D321 (trypsin) and CP43K215↔Psb27D58AGGLK63↔CP43D321 (chymotrypsin), respectively. Our data suggest that Psb27 acts as an important regulatory protein during PSII assembly through specific interactions with the luminal domain of CP43. PMID:22031695

  19. Psb27, a transiently associated protein, binds to the chlorophyll binding protein CP43 in photosystem II assembly intermediates.

    PubMed

    Liu, Haijun; Huang, Richard Y-C; Chen, Jiawei; Gross, Michael L; Pakrasi, Himadri B

    2011-11-01

    Photosystem II (PSII), a large multisubunit pigment-protein complex localized in the thylakoid membrane of cyanobacteria and chloroplasts, mediates light-driven evolution of oxygen from water. Recently, a high-resolution X-ray structure of the mature PSII complex has become available. Two PSII polypeptides, D1 and CP43, provide many of the ligands to an inorganic Mn(4)Ca center that is essential for water oxidation. Because of its unusual redox chemistry, PSII often undergoes degradation followed by stepwise assembly. Psb27, a small luminal polypeptide, functions as an important accessory factor in this elaborate assembly pathway. However, the structural location of Psb27 within PSII assembly intermediates has remained elusive. Here we report that Psb27 binds to CP43 in such assembly intermediates. We treated purified genetically tagged PSII assembly intermediate complexes from the cyanobacterium Synechocystis 6803 with chemical cross-linkers to examine intermolecular interactions between Psb27 and various PSII proteins. First, the water-soluble 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was used to cross-link proteins with complementary charged groups in close association to one another. In the His27△ctpAPSII preparation, a 58-kDa cross-linked species containing Psb27 and CP43 was identified. This species was not formed in the HT3△ctpA△psb27PSII complex in which Psb27 was absent. Second, the homobifunctional thiol-cleavable cross-linker 3,3'-dithiobis(sulfosuccinimidylpropionate) (DTSSP) was used to reversibly cross-link Psb27 to CP43 in His27△ctpAPSII preparations, which allowed the use of liquid chromatography/tandem MS to map the cross-linking sites as Psb27K(63)↔CP43D(321) (trypsin) and CP43K(215)↔Psb27D(58)AGGLK(63)↔CP43D(321) (chymotrypsin), respectively. Our data suggest that Psb27 acts as an important regulatory protein during PSII assembly through specific interactions with the luminal domain of CP43. PMID:22031695

  20. Identification of the Binding Region of the [2Fe-2S] Ferredoxin in Stearoyl-Acyl Carrier Protein Desaturase

    PubMed Central

    Sobrado, Pablo; Lyle, Karen S.; Kaul, Steven P.; Turco, Michelle M.; Arabshahi, Ida; Marwah, Ashok; Fox, Brian G.

    2008-01-01

    Stearoyl-acyl carrier protein desaturase (Δ9D) catalyzes the O2 and 2e- dependent desaturation of stearoyl-acyl carrier protein (18:0-ACP) to yield oleoyl-ACP (18:1-ACP). The 2e- are provided by essential interactions with reduced plant-type [2Fe-2S] ferredoxin (Fd). We have investigated the protein-protein interface involved in the Fd-Δ9D complex by use of chemical cross-linking, site-directed mutagenesis, steady-state kinetic approaches and molecular docking studies. Treatment of the different proteins with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide revealed that carboxylate residues from Fd and lysine residues from Δ9D contribute to the cross-linking. The single substitutions of K60A, K56A, and K230A on Δ9D decreased the kcat/KM for Fd by 4-, 22- and 2,400-fold, respectively, as compared to wt Δ9D and a K41A substitution. The double substitution K56A/K60A decreased the kcat/KM for Fd by 250-fold, while the triple mutation K56A/K60A/K230A decreased the kcat/KM for Fd by at least 700,000-fold. These results strongly implicate the triad of K56, K60 and K230 of Δ9D in the formation of a catalytic complex with Fd. Molecular docking studies indicate that electrostatic interactions between K56 and K60 and carboxylate groups on Fd may situate the [2Fe-2S] cluster of Fd near to W62, a surface residue that is structurally conserved in both ribonucleotide reductase and mycobacterial putative acyl-ACP desaturase DesA2. Owing to the considerably larger effects on catalysis, K230 appears to have other contributions to catalysis arising from its positioning in helix-7 and its close spatial location to the diiron center ligands E229 and H232. These results are considered in the light of the presently available models for Fd-mediated electron transfer in Δ9D and other protein-protein complexes. PMID:16605252

  1. Preparation and preclinical evaluation of experimental group B streptococcus type III polysaccharide-cholera toxin B subunit conjugate vaccine for intranasal immunization.

    PubMed

    Shen, X; Lagergård, T; Yang, Y; Lindblad, M; Fredriksson, M; Holmgren, J

    2000-11-22

    Streptococcus group B (GBS) is usually carried asymptomatically in the vaginal tract of women and can be transferred to the newborn during parturition. Serum antibodies to the capsular polysaccharide (CPS) can prevent invasive diseases, whereas immunity acting at the mucosal surface may be more important to inhibit the mucosal colonization of GBS and thus the risk of infection for the newborn. We prepared different GBS type III CPS-protein conjugate vaccines and evaluated their systemic and mucosal immunogenicity in mice. GBS type III CPS was conjugated to tetanus toxoid (TT) or recombinant cholera toxin B subunit (rCTB) either directly or to rCTB indirectly via TT. The conjugation was performed by different methods: (1) CPS was coupled to TT with 1-ethyl-3 (3-dimethylaminopropyl)-carbodiimide (EDAC), using adipic acid dihydrazide (ADH) as a spacer; (2) CPS was conjugated with rCTB using reductive amination; or, (3) N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) was used to bind rCTB to the TT of the CPS-TT conjugate. Mice were immunized with these conjugates or purified CPS by subcutaneous (s.c.) and intranasal (i. n.) routes. Antibodies to GBS III in serum, lungs and vagina were measured with ELISA. All of the CPS-protein conjugates were superior to unconjugated CPS in eliciting CPS-specific immune responses in serum and mucosal tissue extracts. The conjugates, when administrated s.c., induced only IgG responses in serum, lung and vagina, while i.n. vaccination also elicited IgA responses in the lungs and vagina. The CPS-TT conjugate administrated i.n. induced a strong serum IgG, but only a weak mucosal IgA response, while the CPS-rCTB conjugate elicited high IgG as well as IgA antibodies in the lungs after i.n. immunization. GBS III CPS-TT conjugated with rCTB produced a strong systemic and local anti-CPSIII response after i.n. administration. Co-administration of CT as adjuvant enhanced the anti-CPS systemic and mucosal immune responses further after i

  2. Development of antibody directed nanoparticles for cancer therapy

    NASA Astrophysics Data System (ADS)

    Ivkov, R.; DeNardo, S. J.; Meirs, L. A.; Natarajan, A.; DeNardo, G. L.; Gruettner, C.; Foreman, A. R.

    2007-02-01

    The pharmacokinetics, tumor uptake, and biologic effects of inductively heating 111In-chimeric L6 (ChL6) monoclonal antibody (mAb)-linked iron oxide nanoparticle (bioprobes) by externally applied alternating magnetic fields (AMF) were studied in athymic mice bearing human breast cancer HBT 3477 xenografts. In addition, response was correlated with calculated total deposited heat dose. Methods: Using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide HCl, 111In-7,10-tetraazacyclododecane-N, N',N'',N'''-tetraacetic acid-ChL6 was conjugated to the carboxylated polyethylene glycol on dextran-coated iron oxide 20-nm particles, one to two mAbs per nanoparticle. After magnetic purification and sterile filtration, pharmacokinetics, histopathology, and AMF/bioprobe therapy were done using 111In-ChL6 bioprobe doses (20 mcg/2.2 mg ChL6/ bioprobe), i.v. with 50 mcg ChL6 in athymic mice bearing HBT 3477; a 153 kHz AMF was given 72 hours postinjection for therapy with amplitudes of 1,300, 1,000, or 700 Oe. Weights, blood counts, and tumor size were monitored and compared with control mice receiving nothing, or AMF, or bioprobes alone. Results: 111In-ChL6 bioprobe binding in vitro to HBT 3477 cells was 50% to 70% of that of 111In-ChL6. At 48 hours, tumor, lung, kidney, and marrow uptakes of the 111In-ChL6 bioprobes were not different from that observed in prior studies of 111In-ChL6. Significant therapeutic responses from AMF/bioprobe therapy were shown compared with no treatment. In addition, greatest therapeutic benefit was observed for the 700 Oe treatment cohort. Toxicity was only seen in the 1,300 Oe AMF cohort, with 4 of 12 immediate deaths associated with skin erythema and petechiae. Conclusion: This study shows that mAb-conjugated nanoparticles (bioprobes), when given i.v., escape into the extravascular space and bind to cancer cell membrane antigen.Thus, bioprobes can be used in concert with externally applied AMF to deliver thermoablative cancer therapy. Therapeutic benefit

  3. Improved drug targeting of cancer cells by utilizing actively targetable folic acid-conjugated albumin nanospheres.

    PubMed

    Shen, Zheyu; Li, Yan; Kohama, Kazuhiro; Oneill, Brian; Bi, Jingxiu

    2011-01-01

    Folic acid-conjugated albumin nanospheres (FA-AN) have been developed to provide an actively targetable drug delivery system for improved drug targeting of cancer cells with reduced side effects. The nanospheres were prepared by conjugating folic acid onto the surface of albumin nanospheres using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as a catalyst. To test the efficacy of these nanospheres as a potential delivery platform, doxorubicin-loaded albumin nanospheres (DOX-AN) and doxorubicin-loaded FA-AN (FA-DOX-AN) were prepared by entrapping DOX (an anthracycline, antibiotic drug widely used in cancer chemotherapy that works by intercalating DNA) into AN and FA-AN nanoparticles. Cell uptake of the DOX was then measured. The results show that FA-AN was incorporated into HeLa cells (tumor cells) only after 2.0h incubation, whereas HeLa cells failed to incorporate albumin nanospheres without conjugated folic acid after 4.0h incubation. When HeLa cells were treated with the DOX-AN, FA-DOX-AN nanoparticles or free DOX, cell viability decreased with increasing culture time (i.e. cell death increases with time) over a 70h period. Cell viability was always the lowest for free DOX followed by FA-DOX-AN4 and then DOX-AN. In a second set of experiments, HeLa cells washed to remove excess DOX after an initial incubation for 2h were incubated for 70h. The corresponding cell viability was slightly higher when the cells were treated with FA-DOX-AN or free DOX whilst cells treated with DOX-AN nanoparticles remained viable. The above experiments were repeated for non-cancerous, aortic smooth muscle cells (AoSMC). As expected, cell viability of the HeLa cells (with FA receptor alpha, FRα) and AoSMC cells (without FRα) decreased rapidly with time in the presence of free DOX, but treatment with FA-DOX-AN resulted in selective killing of the tumor cells. These results indicated that FA-AN may be used as a promising actively targetable drug delivery system to improve drug

  4. Response of human macrophages to wound matrices in vitro.

    PubMed

    Witherel, Claire E; Graney, Pamela L; Freytes, Donald O; Weingarten, Michael S; Spiller, Kara L

    2016-05-01

    Chronic wounds remain a major burden to the global healthcare system. Myriad wound matrices are commercially available but their mechanisms of action are poorly understood. Recent studies have shown that macrophages are highly influenced by their microenvironment, but it is not known how different biomaterials affect this interaction. Here, it was hypothesized that human macrophages respond differently to changes in biomaterial properties in vitro with respect to phenotype, including pro-inflammatory M1, anti-inflammatory M2a, known for facilitating extracellular matrix deposition and proliferation, and M2c, which has recently been associated with tissue remodeling. Using multiple donors, it was found that collagen scaffolds cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) promoted the least inflammatory phenotype in primary human macrophages compared with scaffolds cross-linked with formaldehyde or glutaraldehyde. Importantly, gene expression analysis trends were largely conserved between donors, especially TNFa (M1), CCL22 (M2a), and MRC1 (M2a). Then the response of primary and THP1 monocyte-derived macrophages to four commercially available wound matrices were compared-Integra Dermal Regeneration Template (Integra), PriMatrix Dermal Repair Scaffold (PriMatrix), AlloMend Acellular Dermal Matrix (AlloMend), and Oasis Wound Matrix (Oasis). Gene expression trends were different between primary and THP1 monocyte-derived macrophages for all six genes analyzed in this study. Finally, the behavior of primary macrophages cultured onto the wound matrices over time was analyzed. Integra and Oasis caused down-regulation of M2a markers CCL22 and TIMP3. PriMatrix caused up-regulation of TNFa (M1) and CD163 (M2c) and down-regulation of CCL22 and TIMP3 (both M2a). AlloMend caused up-regulation in CD163 (M2c). Lastly, Oasis promoted the largest increase in the combinatorial M1/M2 score, defined as the sum of M1 genes divided by

  5. Folate-conjugated polymer micelles for active targeting to cancer cells: preparation, in vitro evaluation of targeting ability and cytotoxicity

    NASA Astrophysics Data System (ADS)

    You, Jian; Li, Xin; de Cui, Fu; Du, Yong-Zhong; Yuan, Hong; Hu, Fu qiang

    2008-01-01

    To obtain an active-targeting carrier to cancer cells, folate-conjugated stearic acid grafted chitosan oligosaccharide (Fa-CSOSA) was synthesized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. The substitution degree is 22.1%. The critical micelle concentrations (CMCs) of Fa-CSOSA were 0.017 and 0.0074 mg ml-1 in distilled water and PBS (pH 7.4), respectively. The average volume size range of Fa-CSOSA micelles was 60-120 nm. The targeting ability of Fa-CSOSA micelles was investigated against two kinds of cell lines (A549 and Hela), which have different amounts of folate receptors in their surface. The results indicated that Fa-CSOSA micelles presented a targeting ability to the cells (Hela) with a higher expression of folate receptor during a short-time incubation (<6 h). As incubation proceeded, the special spatial structure of the micelles gradually plays a main role in cellular internalization of the micelles. Good internalization of the micelles into both Hela and A549 cells was shown. Then, paclitaxel (PTX) was encapsulated into the micelles, and the content of PTX in the micelles was about 4.8% (w/w). The average volume size range of PTX-loaded micelles was 150-340 nm. Furthermore, the anti-tumor efficacy in vitro was investigated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method. The IC50 of Taxol (a clinical formulation containing PTX) on A549 and Hela cells was 7.0 and 11.0 µg ml-1, respectively. The cytotoxicity of PTX-loaded micelles was improved sharply (IC50 on A549: 0.32 µg ml-1 IC50 on Hela: 0.268 µg ml-1). This is attributed to the increased intracellular delivery of the drug. The Fa-CSOSA micelles that are presented may be a promising active-targeting carrier candidate via folate mediation.

  6. Degradation of Verapamil hydrochloride in water by gliding arc discharge.

    PubMed

    Krishna, Syam; Maslani, Alan; Izdebski, Tomasz; Horakova, Marta; Klementova, Sarka; Spatenka, Petr

    2016-06-01

    This study investigated the influence of gliding arc plasma discharge on the degradation of Verapamil hydrochloride in water. The plasma discharge was characterized by means of optical emission spectroscopy. Spectra of various atomic and molecular species were observed. Aqueous solution of Verapamil hydrochloride was exposed to gliding arc discharge operated in continuous discharge at atmospheric pressure and room temperature. The identification of Verapamil, the degradation mechanisms of Verapamil and its transformation products were performed using liquid chromatography - mass spectrometry (HPLC-MS). Experimental results indicate that the atmospheric pressure gliding arc plasma treatment has noticeable effects on Verapamil with satisfactory degradation efficiency. Plausible mechanisms of the degradation were discussed. PMID:26953731

  7. Field application of Telazol (tiletamine hydrochloride and zolazepam hydrochloride) to immobilize wild red howler monkeys (Alouatta seniculus) in Venezuela.

    PubMed

    Agoramoorthy, G; Rudran, R

    1994-07-01

    Telazol (TEL) (tiletamine hydrochloride and zolazepam hydrochloride combination) was used to immobilize 50 wild red howler monkeys (Alouatta seniculus) in Venezuela between October 1989 and February 1991. The mean (+/- SD) dosages of TEL used for adult males and adult females were 22.4 (+/- 7.3) mg/kg and 22.5 (+/- 5.0) mg/kg, respectively. Juveniles of both sexes received a mean dose of 30.5 (+/- 5.6) mg/kg. The induction time for TEL ranged from 1 to 6.2 min. Thirteen animals were given an additional dosage of ketamine hydrochloride manually when they recovered from the first injection of TEL. Total recovery times ranged from 39 to 308 min. There were no apparent side effects to the fetuses of two pregnant females. PMID:7933286

  8. Formulation and Evaluation of Multilayered Tablets of Pioglitazone Hydrochloride and Metformin Hydrochloride

    PubMed Central

    Chowdary, Y. Ankamma; Raparla, Ramakrishna; Madhuri, Muramshetty

    2014-01-01

    In the treatment of type 2 diabetes mellitus a continuous therapy is required which is a more complex one. As in these patients there may be a defect in both insulin secretion and insulin action exists. Hence, the treatment depends on the pathophysiology and the disease state. In the present study, multilayered tablets of pioglitazone hydrochloride 15 mg and metformin hydrochloride 500 mg were prepared in an attempt for combination therapy for the treatment of type 2 diabetes mellitus. Pioglitazone HCl was formulated as immediate release layer to show immediate action by direct compression method using combination of superdisintegrants, namely, crospovidone and avicel PH 102. Crospovidone at 20% concentration showed good drug release profile at 2 hrs. Metformin HCl was formulated as controlled release layer to prolong the drug action by incorporating hydrophilic polymers such as HPMC K4M by direct compression method and guar gum by wet granulation method in order to sustain the drug release from the tablets and maintain its integrity so as to provide a suitable formulation. The multilayered tablets were prepared after carrying out the optimization of immediate release layer and were evaluated for various precompression and postcompression parameters. Formulation F13 showed 99.97% of pioglitazone release at 2 hrs in 0.1 N HCl and metformin showed 98.81% drug release at 10 hrs of dissolution in 6.8 pH phosphate buffer. The developed formulation is equivalent to innovator product in view of in vitro drug release profile. The results of all these evaluation tests are within the standards. The procedure followed for the formulation of these tablets was found to be reproducible and all the formulations were stable after accelerated stability studies. Hence, multilayered tablets of pioglitazone HCl and metformin HCl can be a better alternative way to conventional dosage forms. PMID:26556204

  9. Formulation and Evaluation of Multilayered Tablets of Pioglitazone Hydrochloride and Metformin Hydrochloride.

    PubMed

    Chowdary, Y Ankamma; Raparla, Ramakrishna; Madhuri, Muramshetty

    2014-01-01

    In the treatment of type 2 diabetes mellitus a continuous therapy is required which is a more complex one. As in these patients there may be a defect in both insulin secretion and insulin action exists. Hence, the treatment depends on the pathophysiology and the disease state. In the present study, multilayered tablets of pioglitazone hydrochloride 15 mg and metformin hydrochloride 500 mg were prepared in an attempt for combination therapy for the treatment of type 2 diabetes mellitus. Pioglitazone HCl was formulated as immediate release layer to show immediate action by direct compression method using combination of superdisintegrants, namely, crospovidone and avicel PH 102. Crospovidone at 20% concentration showed good drug release profile at 2 hrs. Metformin HCl was formulated as controlled release layer to prolong the drug action by incorporating hydrophilic polymers such as HPMC K4M by direct compression method and guar gum by wet granulation method in order to sustain the drug release from the tablets and maintain its integrity so as to provide a suitable formulation. The multilayered tablets were prepared after carrying out the optimization of immediate release layer and were evaluated for various precompression and postcompression parameters. Formulation F13 showed 99.97% of pioglitazone release at 2 hrs in 0.1 N HCl and metformin showed 98.81% drug release at 10 hrs of dissolution in 6.8 pH phosphate buffer. The developed formulation is equivalent to innovator product in view of in vitro drug release profile. The results of all these evaluation tests are within the standards. The procedure followed for the formulation of these tablets was found to be reproducible and all the formulations were stable after accelerated stability studies. Hence, multilayered tablets of pioglitazone HCl and metformin HCl can be a better alternative way to conventional dosage forms. PMID:26556204

  10. 21 CFR 524.1982 - Proparacaine hydrochloride ophthalmic solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Proparacaine hydrochloride ophthalmic solution. 524.1982 Section 524.1982 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1982...

  11. Amides and Hydrazides from Amine and Hydrazine Hydrochlorides.

    ERIC Educational Resources Information Center

    Shama, Sami A.; Tran, Thuan L.

    1978-01-01

    This safe and efficient procedure for the synthesis of N-substituted amides and hydrazides is a modification of the Schotten-Bausmann procedure in which the amine or hydrazide is replaced by the corresponding hydrochloride salt, and the use of alkali is eliminated. (Author/BB)

  12. 21 CFR 522.1335 - Medetomidine hydrochloride injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Medetomidine hydrochloride injection. 522.1335 Section 522.1335 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1335 Medetomidine...

  13. 21 CFR 522.1465 - Naltrexone hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Naltrexone hydrochloride injection. 522.1465 Section 522.1465 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1465 Naltrexone...

  14. 21 CFR 522.863 - Ethylisobutrazine hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethylisobutrazine hydrochloride injection. 522.863 Section 522.863 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL...

  15. Cradle-to-gate life cycle inventory of vancomycin hydrochloride.

    PubMed

    Ponder, Celia; Overcash, Michael

    2010-02-15

    A life cycle analysis on the cradle-to-gate production of vancomycin hydrochloride, which begins at natural resource extraction and spans through factory (gate) production, not only shows all inputs, outputs, and energy usage to manufacture the product and all related supply chain chemicals, but can highlight where process changes would have the greatest impact on raw material and energy consumption and emissions. Vancomycin hydrochloride is produced by a low-yield fermentation process that accounts for 47% of the total cradle-to-gate energy. The fermentation step consumes the most raw materials and energy cradle-to-gate. Over 75% of the total cradle-to-gate energy consumption is due to steam use; sterilization within fermentation is the largest user of steam. Aeration and agitation in the fermentation vessels use 65% of the cradle-to-gate electrical energy. To reduce raw materials, energy consumption, and the associated environmental footprint of producing vancomycin hydrochloride, other sterilization methods, fermentation media, nutrient sources, or synthetic manufacture should be investigated. The reported vancomycin hydrochloride life cycle inventory is a part of a larger life cycle study of the environmental consequences of the introduction of biocide-coated medical textiles for the prevention of MRSA (methicillin-resistant Staphylococcus aureus) nosocomial infections. PMID:19942254

  16. 21 CFR 522.2615 - Tripelennamine hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tripelennamine hydrochloride injection. 522.2615 Section 522.2615 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL...

  17. 21 CFR 522.1462 - Naloxone hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Naloxone hydrochloride injection. 522.1462 Section 522.1462 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL...

  18. 21 CFR 522.2002 - Propiopromazine hydrochloride injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propiopromazine hydrochloride injection. 522.2002 Section 522.2002 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.2002...

  19. Chemical Immobilization of Sloth Bears (Melursus ursinus) with Ketamine Hydrochloride and Xylazine Hydrochloride: Hematology and Serum Biochemical Values

    PubMed Central

    Veeraselvam, M.; Sridhar, R.; Perumal, P.; Jayathangaraj, M. G.

    2014-01-01

    The present study was conducted to define the physiological responses of captive sloth bears immobilized with ketamine hydrochloride and xylazine hydrochloride and to determine and compare the values of hematology and serum biochemical parameters between sexes. A total of 15 sloth bears were immobilized using combination of ketamine hydrochloride and xylazine hydrochloride drugs at the dose rate of 5.0 milligram (mg) per kg body weight and 2.0 mg per kg body weight, respectively. The use of combination of these drugs was found satisfactory for the chemical immobilization of captive sloth bears. There were no significant differences observed in induction time and recovery time and physiological parameters such as heart rate, respiratory rate, and rectal temperature between sexes. Health related parameters comprising hematological values like packed cell volume (PCV), hemoglobin (Hb), red blood cell count (RBC), erythrocyte indices, and so forth and biochemical values like total protein, blood urea nitrogen (BUN), creatinine, alkaline amino-transferase (ALT), aspartate amino-transferase (AST), and so forth were estimated in 11 (5 males and 6 females) apparently healthy bears. Comparison between sexes revealed significant difference in PCV (P < 0.05) and mean corpuscular hemoglobin concentration (MCHC) (P < 0.05). The study might help to evaluate health profiles of sloth bears for appropriate line treatment. PMID:24876990

  20. Effect of thiamine hydrochloride, pyridoxine hydrochloride and calcium-d-pantothenate on the patulin content of apple juice concentrate.

    PubMed

    Yazici, Serafettin; Velioglu, Y Sedat

    2002-08-01

    Thiamine hydrochloride, pyridoxine hydrochloride and calcium-d-pantothenate were applied apple juice concentrates (AJC) at various doses in order to reduce the patulin content. AJC samples containing high levels of patulin were stored at 22 +/- 2 degrees C and 4 degrees C for 6 months after vitamins were added. Patulin was fully degraded at the end of a 6-month period in samples stored at 22 +/- 2 degrees C, on the other hand, other quality parameters diminished significantly. Without any considerable reduction on other quality parameters, applications of 1000 and 2500 mg/kg calcium-d-pantothenate resulted in reduction of patulin of 73.6 and 94.3%, respectively, however, 42.1% of patulin reduction was observed in the control sample of AJC stored for 1 month at 22 +/- 2 degrees C. Addition of thiamine hydrochloride (1000 mg/kg), pyrodoxine hydrochloride (625 or 875 mg/kg) and calcium-d-pantothenate (1000 or 2500 mg/kg) into the samples and storage at 4 degrees C for 6 months yielded 55.5 to 67.7% of patulin reduction which was only 35.8% for the control while the other quality parameters were protected adequately. PMID:12224421

  1. Fundamentals of ionic conductivity relaxation gained from study of procaine hydrochloride and procainamide hydrochloride at ambient and elevated pressure

    NASA Astrophysics Data System (ADS)

    Wojnarowska, Z.; Swiety-Pospiech, A.; Grzybowska, K.; Hawelek, L.; Paluch, M.; Ngai, K. L.

    2012-04-01

    The pharmaceuticals, procaine hydrochloride and procainamide hydrochloride, are glass-forming as well as ionically conducting materials. We have made dielectric measurements at ambient and elevated pressures to characterize the dynamics of the ion conductivity relaxation in these pharmaceuticals, and calorimetric measurements for the structural relaxation. Perhaps due to their special chemical and physical structures, novel features are found in the ionic conductivity relaxation of these pharmaceuticals. Data of conductivity relaxation in most ionic conductors when represented by the electric loss modulus usually show a single resolved peak in the electric modulus loss M″(f ) spectra. However, in procaine hydrochloride and procainamide hydrochloride we find in addition another resolved loss peak at higher frequencies over a temperature range spanning across Tg. The situation is analogous to many non-ionic glass-formers showing the presence of the structural α-relaxation together with the Johari-Goldstein (JG) β-relaxation. Naturally the analogy leads us to name the slower and faster processes resolved in procaine hydrochloride and procainamide hydrochloride as the primary α-conductivity relaxation and the secondary β-conductivity relaxation, respectively. The analogy of the β-conductivity relaxation in procaine HCl and procainamide HCl with JG β-relaxation in non-ionic glass-formers goes further by the finding that the β-conductivity is strongly related to the α-conductivity relaxation at temperatures above and below Tg. At elevated pressure but compensated by raising temperature to maintain α-conductivity relaxation time constant, the data show invariance of the ratio between the β- and the α-conductivity relaxation times to changes of thermodynamic condition. This property indicates that the β-conductivity relaxation has fundamental importance and is indispensable as the precursor of the α-conductivity relaxation, analogous to the relation found

  2. Growth and characterization of thiosemicarbazide hydrochloride: A semiorganic NLO material

    NASA Astrophysics Data System (ADS)

    Santhakumari, R.; Ramamurthi, K.; Babu, R. Ramesh; Evans, Helen Stoeckli; Bhagavannarayana, G.; Hema, R.

    2011-11-01

    Thiosemicarbazide hydrochloride (TSCHCL) was synthesized by mixing thiosemicarbazide and hydrochloride in 1:1 molar ratio in double distilled water. Single crystals of TSCHCL were grown by slow evaporation at room temperature and were characterized by single crystal X-ray diffraction study to determine the molecular structure and by FT-IR, 1H and 13C NMR spectral analyses to confirm the synthesized compound. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. The transmission spectrum of TSCHCL showed that the crystal is transparent in the wavelength range 380-1100 nm. High resolution X-ray diffractometry (HRXRD) was employed to evaluate the perfection of the grown crystal. Mechanical properties of the grown crystal were studied using Vickers microhardness test. Second harmonic generation efficiency of the powdered TSCHCL was tested using Nd:YAG laser and is ˜1.5 times that of potassium dihydrogen orthophosphate.

  3. Buspirone hydrochloride in the treatment of an atypical paraphilia.

    PubMed

    Fedoroff, J P

    1992-08-01

    A case report involving buspirone hydrochloride in the successful treatment of a patient with an atypical paraphilia and transvestic fetishism is presented. Treatment outcome was assessed by the patient's self-report as well as by retrospective examination of detailed notes about paraphilia fantasies which unknown to the therapists, had been kept by the patient. Preliminary evidence indicates that buspirone appears to effectively treat some paraphilias. PMID:1497477

  4. Tetracycline hydrochloride: A potential clinical drug for radioprotection.

    PubMed

    Alok, Amit; Chaudhury, N K

    2016-02-01

    Radiation exposure in planned scenario necessarily requires radioprotector for protection against radiation injuries in tissues and organs. A large number of potential radioprotectors have been investigated but no approved radioprotector is available. Hence, in quest for radioprotector, repurposing of clinical drug is an approach which aims at finding the radioprotective potential of known drugs so that in case of untoward accident the knowledge could be translated to drug usage. In this study, we have investigated the radical scavenging properties of tetracycline pertaining to radioprotection. Our study suggests that tetracycline hydrochloride efficiently scavenges free radicals in ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays. Hydroxyl radical scavenging assay has demonstrated its ability to scavenge gamma radiation induced free radicals by lowering the formation of malondialdehyde. Radiation causes damage to macromolecules and hence the protection offered by tetracycline hydrochloride to DNA and protein shows its radioprotective potential. Plasmid DNA relaxation study with pBR322 has shown that tetracycline hydrochloride confers dose modification factor (DMF) of 2 and 4 at 100 μM and 250 μM concentration respectively. Tetracycline hydrochloride has also protected bovine serum albumin (BSA) from radiation induced degradation. The ex vivo studies for lipid peroxidation and mitochondrial membrane potential further substantiate our findings. The whole body animal survival study has shown the drug to offer 20% protection at a lethal radiation dose of 9 Gy. This study demonstrates the radioprotective potential of the drug by providing some insight into ex vivo and in vivo efficacy. PMID:26763761

  5. [D-Ala2,D-Leu5]-enkephalin hydrochloride.

    PubMed

    Deschamps, J R; George, C; Flippen-Anderson, J L

    1996-06-15

    The title compound, L-tyrosyl-D-alanyl-glycyl-L-phenyl-alanyl-D-leucine hydrochloride (C29H40N5O7+. Cl-), co-crystallizes with 2-butanone (C4H8O). The structure determination reveals a slightly distorted type I' beta-bend conformation stabilized by one intramolecular hydrogen bond. This conformation is similar to that observed for other [Leu]-enkephalin analogues. PMID:8766899

  6. A novel kind of TSV slurry with guanidine hydrochloride

    NASA Astrophysics Data System (ADS)

    Jiao, Hong; Yuling, Liu; Baoguo, Zhang; Xinhuan, Niu; Liying, Han

    2015-10-01

    The effect of a novel alkaline TSV (through-silicon-via) slurry with guanidine hydrochloride (GH) on CMP (chemical mechanical polishing) was investigated. The novel alkaline TSV slurry was free of any inhibitors. During the polishing process, the guanidine hydrochloride serves as an effective surface-complexing agent for TSV CMP applications, the removal rate of barrier (Ti) can be chemically controlled through tuned selectivity with respect to the removal rate of copper and dielectric, which is helpful to modifying the dishing and gaining an excellent topography performance in TSV manufacturing. In this paper, we mainly studied the working mechanism of the components of slurry and the skillful application guanidine hydrochloride in the TSV slurry. Project supported by the Major National Science and Technology Special Projects (No. 2009ZX02308), the Fund Project of Hebei Provincial Department of Education, China (No. QN2014208), the Natural Science Foundation of Hebei Province, China (No. E2013202247), and Colleges and Universities Scientific research project of Hebei Province, China (No. Z2014088).

  7. Kinetic spectrophotometric determination of tramadol hydrochloride in pharmaceutical formulation.

    PubMed

    Abdellatef, Hisham E

    2002-07-31

    Two simple and sensitive kinetic methods for the determination of tramadol hydrochloride are described. The first method is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time at 20 min. The absorbance of the colored manganate ions was measured at 610 nm. The second method is based on the reaction of tramadol hydrochloride with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in presence of 0.1 M sodium bicarbonate. The spectrophotometric measurements were recorded by measuring the absorbance at 467 nm, at fixed time at 25 min on thermostated water bath at 90+/-1 degrees C. All variables affecting the development of the colour have been investigated and the conditions were optimised. The absorbance concentration plots in both methods were rectilinear over the range 5-25 and 50-250 microg ml(-1), for the first and second methods, respectively. The two methods have been applied successfully to commercial capsule and ampoule dosage form. The results obtained are compared statistically with those given by the reference spectrophotometric method. The determination of tramadol hydrochloride by the fixed concentration and rate constant methods is feasible with the calibration equations obtained, but the fixed time method proves to be more applicable. PMID:12093516

  8. High-performance liquid chromatographic determination of memantine hydrochloride in rat plasma using sensitive fluorometric derivatization.

    PubMed

    Xie, Mei-Fen; Zhou, Wei; Tong, Xin-Yi; Chen, Yi-Le; Cai, Yi; Li, Yan; Duan, Geng-Li

    2011-02-01

    In this study, we investigated a simple, sensitive and reliable liquid chromatography-fluorescence detection method for the determination of memantine hydrochloride in rat plasma which was based on derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). For the first time, FMOC-Cl was introduced into derivatization of memantine hydrochloride in rat plasma. The amino groups of memantine hydrochloride and amantadine hydrochloride (internal standard) were trapped with FMOC-Cl to form memantine hydrochloride-FMOC-Cl and amantadine hydrochloride-FMOC-Cl compositions, which can be very compatible for LC-FLD. Precipitation of plasma proteins by acetonitrile was followed by vortex mixing and centrifugation. Chromatographic separation was performed on a C(18) column (DIAMONSIL 150 × 4.6 mm, id 5 μm) with a mobile phase consisting of acetonitrile and water at a flow rate of 1.0 mL/min. The retention times of memantine hydrochloride-FMOC-Cl and amantadine hydrochloride-FMOC-Cl compositions were 23.69 and 40.27 min, respectively. Optimal conditions for the derivatization of memantine hydrochloride were also described. The limit of quantification (LOQ) was 25 ng/mL for memantine hydrochloride in plasma, the linear range was 0.025-5.0 μg/mL in plasma with a correlation coefficient (r) of 0.9999. The relative standard deviations (RSDs) of intra-day and inter-day assays were 4.46-12.19 and 5.23-11.50%, respectively. The validated method was successfully applied to the determination of memantine hydrochloride in rat plasma samples. PMID:21268245

  9. Interaction between lidocaine hydrochloride (with and without adrenaline) and various irrigants: A nuclear magnetic resonance analysis

    PubMed Central

    Vidhya, Nirmal; Karthikeyan, Balasubramanian Saravana; Velmurugan, Natanasabapathy; Abarajithan, Mohan; Nithyanandan, Sivasankaran

    2014-01-01

    Background: Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX. Materials and Methods: Samples were divided into eight experimental groups: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test. Results: In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours. Conclusion: Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound

  10. 21 CFR 524.1484d - Neomycin sulfate, hydrocortisone acetate, tetracaine hydrochloride ear ointment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., tetracaine hydrochloride ear ointment. 524.1484d Section 524.1484d Food and Drugs FOOD AND DRUG..., tetracaine hydrochloride ear ointment. (a) Specifications. The product contains 5 milligrams of neomycin... a lesser degree, chronic otitis externa in dogs and cats. In treatment of ear canker and...

  11. 21 CFR 524.1484d - Neomycin sulfate, hydrocortisone acetate, tetracaine hydrochloride ear ointment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., tetracaine hydrochloride ear ointment. 524.1484d Section 524.1484d Food and Drugs FOOD AND DRUG..., tetracaine hydrochloride ear ointment. (a) Specifications. The product contains 5 milligrams of neomycin... a lesser degree, chronic otitis externa in dogs and cats. In treatment of ear canker and...

  12. 21 CFR 524.1484d - Neomycin sulfate, hydrocortisone acetate, tetracaine hydrochloride ear ointment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., tetracaine hydrochloride ear ointment. 524.1484d Section 524.1484d Food and Drugs FOOD AND DRUG..., tetracaine hydrochloride ear ointment. (a) Specifications. The product contains 5 milligrams of neomycin... a lesser degree, chronic otitis externa in dogs and cats. In treatment of ear canker and...

  13. 21 CFR 524.1484d - Neomycin sulfate, hydrocortisone acetate, tetracaine hydrochloride ear ointment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., tetracaine hydrochloride ear ointment. 524.1484d Section 524.1484d Food and Drugs FOOD AND DRUG..., tetracaine hydrochloride ear ointment. (a) Specifications. The product contains 5 milligrams of neomycin... a lesser degree, chronic otitis externa in dogs and cats. In treatment of ear canker and...

  14. 40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Insulation Resins by Hydroxylamine Hydrochloride B Appendix B to Subpart NNN of Part 63 Protection of... NNN of Part 63—Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride 1. Scope... free-formaldehyde (FF) content such as insulation resins. It may also be suitable for other...

  15. Effects of metomindate hydrochloride and tricaine methanesulfonate on the short term cortisol response in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of metomidate hydrochloride and tricaine methanesulfonate (MS-222) on cortisol stress response of channel catfish, Ictalurus punctatus, were examined during 10 minutes of sedation. Channel catfish were assigned to three treatments: 1. Metomidate hydrochloride (12.5 mg/L), 2. MS-222 (100...

  16. 21 CFR 520.1263a - Lincomycin hydrochloride monohydrate tablets and sirup.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lincomycin hydrochloride monohydrate tablets and sirup. 520.1263a Section 520.1263a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.1263a Lincomycin hydrochloride monohydrate tablets and sirup. (a) Specifications. The...

  17. Adverse drug reaction to metoclopramide hydrochloride in a macaw with proventricular dilatation syndrome.

    PubMed

    Massey, J G

    1993-08-15

    A 4-year-old female blue and gold macaw (Ara ararauna) with a history of chronic vomiting was treated with metoclopramide hydrochloride. After the second treatment, ataxia, torticollis, and opisthotonos became evident. These signs resolved with the administration of diphenhydramine hydrochloride. Despite supportive care, the bird died several days later. Histologic lesions were suggestive of proventricular dilatation syndrome. PMID:8407511

  18. 77 FR 41411 - Determination That TOPOTECAN INJECTION (Topotecan Hydrochloride) 1 Milligram (Base)/1 Milliliter...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ....g., 72 FR 9763, March 5, 2007; 61 FR 25497, May 21, 1996), the Agency has determined that, for... Hydrochloride) 1 Milligram (Base)/1 Milliliter, 3 Milligram (Base)/3 Milliliter, 4 Milligram (Base)/4 Milliliter... TOPOTECAN INJECTION (topotecan hydrochloride) 1 milligram (mg) (base)/1 milliliter (mL), 3 mg (base)/3 mL,...

  19. 21 CFR 520.1263a - Lincomycin hydrochloride monohydrate tablets and sirup.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Lincomycin hydrochloride monohydrate tablets and sirup. 520.1263a Section 520.1263a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.1263a Lincomycin hydrochloride monohydrate tablets and sirup. (a) Specifications. The...

  20. 21 CFR 520.1263a - Lincomycin hydrochloride monohydrate tablets and sirup.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lincomycin hydrochloride monohydrate tablets and sirup. 520.1263a Section 520.1263a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.1263a Lincomycin hydrochloride monohydrate tablets and sirup. (a) Specifications. The...

  1. 21 CFR 520.1263a - Lincomycin hydrochloride monohydrate tablets and sirup.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lincomycin hydrochloride monohydrate tablets and sirup. 520.1263a Section 520.1263a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.1263a Lincomycin hydrochloride monohydrate tablets and sirup. (a) Specifications. The...

  2. 21 CFR 520.1263a - Lincomycin hydrochloride monohydrate tablets and sirup.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Lincomycin hydrochloride monohydrate tablets and sirup. 520.1263a Section 520.1263a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... § 520.1263a Lincomycin hydrochloride monohydrate tablets and sirup. (a) Specifications. The...

  3. 21 CFR 524.1662 - Oxytetracycline hydrochloride ophthalmic and topical dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride ophthalmic and topical dosage forms. 524.1662 Section 524.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662 Oxytetracycline hydrochloride ophthalmic and topical dosage forms....

  4. 21 CFR 522.1662 - Oxytetracycline hydrochloride implantation or injectable dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride implantation or injectable dosage forms. 522.1662 Section 522.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1662 Oxytetracycline hydrochloride implantation or...

  5. 78 FR 2416 - Notice of Issuance of Final Determination Concerning Rybix® (Tramadol Hydrochloride) Tablets

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ... Border Protection (``CBP'') has issued a final determination concerning the country of origin of Rybix... determination that India is the country of origin of the Rybix (tramadol hydrochloride) tablets for purposes of... the country of origin of Rybix (tramadol hydrochloride) tablets, which may be offered to the...

  6. Probing the Interaction between Acotiamide Hydrochloride and Pepsin by Multispectral Methods, Electrochemical Measurements, and Docking Studies.

    PubMed

    He, Jiawei; Ma, Xianglin; Wang, Qing; Huang, Yanmei; Li, Hui

    2016-07-01

    The interaction between acotiamide hydrochloride and pepsin was systematically characterized by fluorescence and electrochemical approaches. Fluorescence lifetime measurements showed that acotiamide hydrochloride quenched the intrinsic fluorescence of pepsin with a new complex formation via static mode, which was reconfirmed by cyclic voltammetry results. Both of the binding number and binding constants were calculated from differential pulse voltammetry analysis and fluorescence spectroscopy. The values obtained from the above two methods displayed a relatively high degree of consistency. Thermodynamic parameters suggested that acotiamide hydrochloride interacted with pepsin spontaneously by hydrogen bonding and van der Waals interactions. These results were consistent with the results obtained from molecular docking analysis. As revealed by synchronous fluorescence, three-dimensional fluorescence, Fourier transform infrared spectrometry, and circular dichroism spectra, acotiamide hydrochloride could affect the microenvironment and slightly change the secondary structure of pepsin. Furthermore, acotiamide hydrochloride can inhibit pepsin activity in vitro, as explained by the molecular docking. PMID:27018070

  7. Neuroprotection against vascular dementia after acupuncture combined with donepezil hydrochloride: P300 event related potential

    PubMed Central

    Liu, Qiang; Wang, Xiu-juan; Zhang, Zhe-cheng; Xue, Rong; Li, Ping; Li, Bo

    2016-01-01

    Acupuncture can be used to treat various nervous system diseases. Here, 168 vascular dementia patients were orally administered donepezil hydrochloride alone (5 mg/day, once a day for 56 days), or combined with acupuncture at Shenting (DU24), Tianzhu (BL10), Sishencong (Extra), Yintang (Extra), Renzhong (DU26), Neiguan (PC6), Shenmen (HT7), Fengchi (GB20), Wangu (GB12) and Baihui (DU20) (once a day for 56 days). Compared with donepezil hydrochloride alone, P300 event related potential latency was shorter with an increased amplitude in patients treated with donepezil hydrochloride and acupuncture. Mini-Mental State Examination score was also higher. Moreover, these differences in P300 latency were identified within different infarcted regions in patients treated with donepezil hydrochloride and acupuncture. These findings indicate that acupuncture combined with donepezil hydrochloride noticeably improves cognitive function in patients with vascular dementia, and exerts neuroprotective effects against vascular dementia. PMID:27127486

  8. Chitosan coated vancomycin hydrochloride liposomes: Characterizations and evaluation.

    PubMed

    Yang, Zhenlei; Liu, Junli; Gao, Jinhua; Chen, Shilei; Huang, Guihua

    2015-11-10

    The present work evaluated the feasibility of chitosan coated liposomes (c-Lips) for the intravenous delivery of vancomycin hydrochloride (VANH), a water-soluble antibiotic for the treatment of gram-positive bacterial infections like osteomyelitis, arthritis, endocarditis, pneumonia, etc. The objective of this research was to develop a suitable drug delivery system in vivo which could improve therapeutic efficacy and decrease side effects especially nephrotoxicity. Firstly, the vancomycin hydrochloride liposomes (VANH-Lips) were prepared by modified reverse phase evaporation method, then the chitosan wrapped vancomycin hydrochloride liposomes (c-VANH-Lips) nanosuspension was formulated by the method of electrostatic deposition. Based on the optimized results of single-factor screening experiment, the c-VANH-Lips were found to be relatively uniform in size (220.40 ± 3.56 nm) with a narrow polydispersity index (PI) (0.21 ± 0.03) and a positive zeta potential (25.7 ± 1.12 mV). The average drug entrapment efficiency (EE) and drug loading (DL) were 32.65 ± 0.59% and 2.18 ± 0.04%, respectively. The in vitro release profile of c-VANH-Lips possessed a sustained release Characterization and the release behavior was in accordance with the Weibull equation. Hemolysis experiments showed that its intravenous injection had preliminary safety. In vivo, after intravenous injection to mice, c-VANH-Lips showed a longer retention time and higher AUC values compared with the VANH injection (VANH-Inj) and VANH-Lips. In addition, biodistribution results clearly demonstrated that c-VANH-Lips preferentially decreased the drug distribution in kidney of mice after intravenous injection. These results revealed that injectable c-VANH-Lips may serve as a promising carrier for VANH to increase therapeutic efficacy on gram-positive bacterial infections and reduce nephrotoxicity, which provides significantly clinical value for long-term use of VANH. PMID:26325316

  9. Analgesic oral efficacy of tramadol hydrochloride in postoperative pain.

    PubMed

    Sunshine, A; Olson, N Z; Zighelboim, I; DeCastro, A; Minn, F L

    1992-06-01

    Tramadol hydrochloride is a synthetic opiate agonist with a plasma elimination half-life of 5 to 6 hours and peak plasma levels at about 1 1/2 hours. It derives its activity from attachment to the mu-receptor and blockage of norepinephrine reuptake. The purpose of this single-dose, double-blind, placebo-controlled study was to determine the analgesic effectiveness of an oral administration of two dose levels of tramadol hydrochloride (75 or 150 mg) compared with the combination of 650 mg acetaminophen plus 100 mg propoxyphene napsylate in 161 patients with severe postoperative pain after cesarean section. Analgesia was assessed over a 6-hour period. Treatments were compared on the basis of standard scales for pain intensity and relief and a number of derived variables based on these data. A global rating of the study medication was also used to compare treatments. The three active treatments were effective analgesics, statistically superior to placebo for many hourly and summary measures. A dose response was seen between the two tramadol doses, with the 150 mg dose providing significantly greater analgesia over the lower dose. The 75 mg dose of tramadol was generally more effective than the acetaminophen-propoxyphene combination after hour 2, and significantly so for some hourly time points, as well as for the global rating of the medication. The 150 mg dose of tramadol was significantly more effective than the acetaminophen-propoxyphene combination from hour 2 through hour 6 for the sum of pain intensity differences and total pain relief scores, as well as for the global rating of the medication. Tramadol hydrochloride at both dose levels is an effective analgesic agent and at 150 mg is statistically superior to the acetaminophen-propoxyphene combination. No serious adverse effects were observed; however, dizziness was more frequently reported with 150 mg tramadol. PMID:1351804

  10. The effects of Dalmane /flurazepam hydrochloride/ on human EEG characteristics.

    NASA Technical Reports Server (NTRS)

    Frost, J. D., Jr.; Carrie, J. R. G.; Borda, R. P.; Kellaway, P.

    1973-01-01

    Evaluation of the changes in the waking EEGs of six healthy male subjects who received 30 mg daily oral doses of flurazepam hydrochloride for two weeks. A placebo was then substituted for flurazepam for another two weeks. An increase in beta activity with a maximum in fronto-central leads was observed during the test period. A small increase in the mean wavelength of the alpha and theta activities in the central-occipital derivations was also apparent in the subjects during the period.

  11. Kinetics membrane disruption due to drug interactions of chlorpromazine hydrochloride.

    PubMed

    Nussio, Matthew R; Sykes, Matthew J; Miners, John O; Shapter, Joseph G

    2009-01-20

    Drug-membrane interactions assume considerable importance in pharmacokinetics and drug metabolism. Here, we present the interaction of chlorpromazine hydrochloride (CPZ) with supported phospholipid bilayers. It was demonstrated that CPZ binds rapidly to phospholipid bilayers, disturbing the molecular ordering of the phospholipids. These interactions were observed to follow first order kinetics, with an activation energy of approximately 420 kJ mol(-1). Time-dependent membrane disruption was also observed for the interaction with CPZ, such that holes appeared in the phospholipid bilayer after the interaction of CPZ. For this process of membrane disruption, "lag-burst" kinetics was demonstrated. PMID:19093750

  12. Application of direct crystallization for racemic compound propranolol hydrochloride.

    PubMed

    Wang, Xiujuan; Lu, Jie; Ching, Chi Bun

    2007-10-01

    The application of direct crystallization integrating with chromatography to the resolution of a racemic compound propranolol hydrochloride was studied and the crystallization progression was clearly illustrated in terms of the diagram of solubility and metastable zone widths with different enantiomeric compositions. The solubility and metastable zone widths of propranolol hydrochloride in the mixture of methanol and isopropanol were determined using an in situ Lasentec Focused Beam Reflectance Measurement (FBRM) probe. The direct crystallizations were carried out in an automatic lab reactor (Mettler Toledo LabMax) system. The optical purity of final product crystals was examined using differential scanning calorimetry (DSC), HPLC and PXRD. The crystal size distribution and morphology were analyzed using Malvern Mastersizer and Jeol SEM. It was found that optically pure crystal product could be obtained within certain safe supersaturation limit and there was no evidence of polymorph or solvate/hydrate transformation during the crystallization process. There was no selectivity of crystal growth or nucleation between the pure enantiomer and its racemate when the solution reaches the temperature lower than saturation temperature of the racemate. Hence, the critical supersaturation control of a solution was essential to obtain pure enantiomers from a partially resolved racemate. PMID:17549769

  13. The antipyretic effect of tilorone hydrochloride in the cat.

    PubMed Central

    Clark, W G; Robins, J A

    1978-01-01

    1 The antipyretic activity of tilorone hydrochloride was studied in conscious, unrestrained cats provided with implanted jugular venous catheters, third cerebral ventricular (i.c.v.) cannulae and retroperitoneal thermocouples. 2 In afebrile animals, 10 mg/kg i.v. or 1 mg i.c.v. tilorone hydrochloride did not alter body temperature, but 20 mg/kg i.v. or 2 to 5 mg i.c.v. caused hypothermia and various behavioural responses. 3 Non-hypothermogenic doses of tilorone (i.v. or i.c.v.) antagonized hyperthermic responses to leucocytic pyrogen (i.v. or i.c.v.), bacterial pyrogen (i.c.v.) and sodium arachidonate (i.c.v.) but did not antagonize prostaglandin E1 (i.c.v.). 4 These results indicate that tilorone has an antipyretic action within the central nervous system that is distinct from its hypothermogenic action. Although there is no published evidence to indicate that tilorone can inhibit prostaglandin synthesis peripherally, its ability to reduce hyperthermic responses to arachidonate suggests that it can inhibit prostaglandin synthesis within the brain. PMID:304749

  14. Intestinal Anisakiasis Treated Successfully with Prednisolone and Olopatadine Hydrochloride

    PubMed Central

    Toyoda, Hideki; Tanaka, Kyosuke

    2016-01-01

    The clinical characteristic of gastrointestinal anisakiasis is severe abdominal pain after eating raw fish. Intestinal anisakiasis is more uncommon than gastric anisakiasis. Most patients with intestinal anisakiasis need hospitalization because anisakiasis can cause intestinal obstruction, ileus, peritonitis or intestinal perforation. We report a case of intestinal anisakiasis. A 43-year-old woman presented with symptoms of intermittent abdominal pain 2 days after eating raw fish. Her brother had eaten the same food and had been suffering from gastric anisakiasis. Abdominal ultrasonography in this patient showed localized jejunal wall thickening with dilated lumen of proximal jejunum and ascites. According to the clinical course and examinations, she was diagnosed with intestinal anisakiasis. Administration of prednisolone 5 mg/day and olopatadine hydrochloride 10 mg/day improved her symptoms quickly without hospitalization. Prednisolone was administered for 10 days, and olopatadine hydrochloride was administered for a total of 6 weeks according to ultrasonographic findings. Six months after the treatment, the abdominal ultrasonography demonstrated normal findings. This case demonstrates that ultrasonography was quite useful for the diagnosis and surveillance of intestinal anisakiasis. Furthermore, treatment with corticosteroid and an antiallergic agent could be an option for patients with intestinal anisakiasis. PMID:27403099

  15. Modulation of Venlafaxine Hydrochloride Release from Press Coated Matrix Tablet

    PubMed Central

    Gohel, M. C.; Soni, C. D.; Nagori, S. A.; Sarvaiya, K. G.

    2008-01-01

    The aim of present study was to prepare novel modified release press coated tablets of venlafaxine hydrochloride. Hydroxypropylmethylcellulose K4M and hydroxypropylmethylcellulose K100M were used as release modifier in core and coat, respectively. A 32 full factorial design was adopted in the optimization study. The drug to polymer ratio in core and coat were chosen as independent variables. The drug release in the first hour and drug release rate between 1 and 12 h were chosen as dependent variables. The tablets were characterized for dimension analysis, crushing strength, friability and in vitro drug release. A check point batch, containing 1:2.6 and 1:5.4 drug to polymer in core and coat respectively, was prepared. The tablets of check point batch were subjected to in vitro drug release in dissolution media with pH 5, 7.2 and distilled water. The kinetics of drug release was best explained by Korsmeyer and Peppas model (anomalous non-Fickian diffusion). The systematic formulation approach enabled us to develop modified release venlafaxine hydrochloride tablets. PMID:20046735

  16. [Examination of effectiveness of olopatadine hydrochloride in atopic dermatitis].

    PubMed

    Shimizu, Tadamichi; Mashiko, Maki; Shimizu, Hiroshi

    2005-02-01

    Subjective/objective symptoms (itching, papula, erythema, lichenification, desquamation, scratching, erosion) and the levels of IgE, LDH, interleukin (IL) -6, thymus and activation-regulated chemokine (TARC) were compared before and after administering olopatadine hydrochloride (ALLELOCK tablets) to 17 atopic dermatitis (AD) patients. Subject/objective symptoms improved significantly after administering the agent, and the total dosage of the combined topical steroids was also significantly decreased after administration (p<0.05), although IgE, IL-6 and LDH levels did not change, TARC was significantly decreased (p<0.05). The correlation between the levels of IgE, IL-6, LDH and TARC before and after the administration was examined. There was a positive correlation between IgE and TARC (r=0.62, p<0.01) and between IL-6 and TARC (r=0.78, p<0.01). Olopatadine hydrochloride is therefore useful in improving the symptoms in AD, and TARC may be used as an indicator of the symptom improvement. PMID:15864020

  17. Butenafine hydrochloride: for the treatment of interdigital tinea pedis.

    PubMed

    Syed, T A; Maibach, H I

    2000-03-01

    Butenafine, a derivative of benzylamine with potent fungicidal activity is a new generation of antimycotic compound that has shown to be extremely effective against experimentally-induced tinea pedis in the guinea-pig, a situation that resembles synergetic pathology similar to that of tinea pedis in humans. Butenafine, (N-4-tert-butylbenzyl-N-methyl-1-naphthalenemethyl-amine hydrochloride) with a chemical structure and mode of action similar to those of the allylamines, demonstrates superior fungicidal activity in vitro against dermatophytes and superior fungistatic activity toward Candida albicans that of naftifine and terbinafine. In vitro, pharmacodynamic data has shown that the geometric mean of minimum inhibitory concentration values for butenafine were comparatively lower than those of naftifine and clotrimazole against clinical isolates for many dermatophytes. It inhibits sterol synthesis by blocking the squalene epoxidation stage in fungi. In phramacokinetic assessments butenafine achieves and maintains high concentrations and long retention time in skin, with associated anti-inflammatory activity in vivo. In controlled clinical trials when applied topically, butenafine appears to be well tolerated with a subjective mild burning sensation at the application site. There were no withdrawals from the study. Butenafine is sparingly soluble in water but readily soluble in methanol, ethanol, dichloromethane and chloroform. If incorporated properly in semisolid topical preparations, with a balanced vehicle, butenafine hydrochloride potentially exhibits as a promising alternative antimycotic agent for the treatment of tinea pedis. PMID:11249531

  18. Intestinal Anisakiasis Treated Successfully with Prednisolone and Olopatadine Hydrochloride.

    PubMed

    Toyoda, Hideki; Tanaka, Kyosuke

    2016-01-01

    The clinical characteristic of gastrointestinal anisakiasis is severe abdominal pain after eating raw fish. Intestinal anisakiasis is more uncommon than gastric anisakiasis. Most patients with intestinal anisakiasis need hospitalization because anisakiasis can cause intestinal obstruction, ileus, peritonitis or intestinal perforation. We report a case of intestinal anisakiasis. A 43-year-old woman presented with symptoms of intermittent abdominal pain 2 days after eating raw fish. Her brother had eaten the same food and had been suffering from gastric anisakiasis. Abdominal ultrasonography in this patient showed localized jejunal wall thickening with dilated lumen of proximal jejunum and ascites. According to the clinical course and examinations, she was diagnosed with intestinal anisakiasis. Administration of prednisolone 5 mg/day and olopatadine hydrochloride 10 mg/day improved her symptoms quickly without hospitalization. Prednisolone was administered for 10 days, and olopatadine hydrochloride was administered for a total of 6 weeks according to ultrasonographic findings. Six months after the treatment, the abdominal ultrasonography demonstrated normal findings. This case demonstrates that ultrasonography was quite useful for the diagnosis and surveillance of intestinal anisakiasis. Furthermore, treatment with corticosteroid and an antiallergic agent could be an option for patients with intestinal anisakiasis. PMID:27403099

  19. [Spectroscopic studies on the binding of phenazopyridine hydrochloride and bovine serum albumin].

    PubMed

    Zhou, Hong; Chen, Chang-Yun; Xie, An-Jian

    2007-09-01

    The binding of phenazopyridine hydrochloride and bovine serum albumin under physiological conditions was studied by spectroscopic method. The quenching mechanism of the fluorescence of bovine serum albumin by phenazopyridine hydrochloride was studied with fluorescence and absorption spectroscopy. The binding constant Kb and the number of binding sites n were determined at different temperatures according to Scatchard equation, and the main binding force was discussed by thermodynamic equations. The effect of the drug on bovine serum albumin conformation was also studied by using synchronous fluorescence spectroscopy. The quenching mechanism of phenazopyridine hydrochloride to bovine serum albumin is static quenching and non-radiation energy transfer. The binding constants Kb at 15, 25 and 37 degrees C are 2.47 x 10(7), 9.15 x 10(6) and 4.36 x 10(6) mol(-1) with one binding site, respectively. The thermodynamic parameters of the reaction are DeltaH = -71.2 kJ x mol(-1), and DeltaS = 124.8 J x mol(-1) x K(-1). Binding phenazopyridine hydrochloride to bovine serum albumin is a spontaneous inter-molecular interaction in which entropy increases and Gibbs free energy decreases. The binding distance r between phenazopyridine hydrochloride and bovine serum albumin is 1.61 nm according to Forster theory of non-radiation energy transfer. The binding force is electrostatic interaction. Phenazopyridine hydrochloride can be deposited and transported by serum protein in vivo. Phenazopyridine hydrochloride does affect the serum protein conformation. PMID:18051539

  20. Extractive determination of ephedrine hydrochloride and bromhexine hydrochloride in pure solutions, pharmaceutical dosage form and urine samples.

    PubMed

    Abdel-Ghani, N T; Rizk, M S; Mostafa, M

    2013-07-01

    Simple, rapid, sensitive, precise and accurate spectrophotometeric methods for the determination of ephedrine hydrochloride (E-HCl) and bromhexine hydrochloride (Br-HCl) in bulk samples, dosage form and in spiked urine samples were investigated. The methods are based on the formation of a yellow colored ion-associates due to the interaction between the examined drugs with picric acid (PA), chlorophyllin coppered trisodium salt (CLPH), alizarin red (AR) and ammonium reineckate (Rk) reagents. A buffer solution had been used and the extraction was carried out using organic solvent, the ion associates exhibit absorption maxima at 410, 410, 430 and 530 nm of (Br-HCl)with PA, CLPH, AR and Rk respectively; 410, 410, 435 and 530 of (E-HCl) with PA, CLPH, AR and Rk respectively. (E-HCl) and (Br-HCl) could be determined up to 13, 121, 120 and 160; 25, 200, 92 and 206 μg mL(-1), using PA, CLPH, AR and Rk respectively. The optimum reaction conditions for quantitative analysis were investigated. In addition, the molar absorptivity, Sandell sensitivity were determined for the investigated drug. The correlation coefficient was ≥0.995 (n=6) with a relative standard deviation (RSD) ≤1.15 for five selected concentrations of the reagents. Therefore the concentration of Br-HCl and E-HCl drugs in their pharmaceutical formulations and spiked urine samples had been determined successfully. PMID:23624039

  1. Identification and Characterization of Potential Impurities in Raloxifene Hydrochloride

    PubMed Central

    Reddy, Reguri Buchi; Goud, Thirumani Venkateshwar; Nagamani, Nagabushanam; Kumar, Nutakki Pavan; Alagudurai, Anandan; Murugan, Raman; Parthasarathy, Kannabiran; Karthikeyan, Vinayagam; Balaji, Perumal

    2012-01-01

    During the synthesis of the bulk drug Raloxifene hydrochloride, eight impurities were observed, four of which were found to be new. All of the impurities were detected using the gradient high performance liquid chromatographic (HPLC) method, whose area percentages ranged from 0.05 to 0.1%. LCMS was performed to identify the mass number of these impurities, and a systematic study was carried out to characterize them. These impurities were synthesized and characterized by spectral data, subjected to co-injection in HPLC, and were found to be matching with the impurities present in the sample. Based on their spectral data (IR, NMR, and Mass), these impurities were characterized as Raloxifene-N-Oxide [Impurity: 1]; EP impurity A [Impurity: 2]; EP impurity B [Impurity: 3]; Raloxifene Dimer [Impurity: 4]; HABT (6-Acetoxy-2-[4-hydroxyphenyl]-1-benzothiophene or 6-Hydroxy-2-[4-acetoxyphenyl]-1-benzothiophene) [Impurity: 5]; PEBE (Methyl[4-[2-(piperidin-1-yl)ethoxy

  2. Simultaneous Estimation of Nebivolol Hydrochloride and Valsartan using RP HPLC

    PubMed Central

    Kokil, S. U.; Bhatia, M. S.

    2009-01-01

    In this study, a rapid, precise, accurate, specific and sensitive ion-paired reverse phase liquid chromatographic method has been developed for the simultaneous estimation of nebivolol hydrochloride and valsartan in their capsule formulation. The chromatographic method was standardized using a HIQ sil C18 column (250×4.6 mm i.d., 5 μm particle size) with UV detection at 289 nm and flow rate of 1 ml/min. The mobile phase consisting of methanol:water (80:20 v/v) with addition of 0.1 percent 1-hexanesulfonic acid monohydrate sodium salt as an ion-pairing reagent was selected. The method was validated and produced accurate and precise results for estimation of the two drugs. PMID:20336202

  3. Peganine hydrochloride dihydrate an orally active antileishmanial agent.

    PubMed

    Khaliq, Tanvir; Misra, Pragya; Gupta, Swati; Reddy, K Papi; Kant, Ruchir; Maulik, P R; Dube, Anuradha; Narender, T

    2009-05-01

    Protozoic infections caused by genus Leishmania pose an enormous public health threat in developing countries, compounded by the toxicity and resistance to current therapies. Under the aegis of our ongoing program on drug discovery and development on antileishmanial agents from plants, we carried out bioassay guided fractionation on Peganum harmala seeds which resulted in the isolation of 1 as an antileishmanial agent. 2D-NMR spectral data and single crystal X-ray crystallography data indicated 1 as peganine hydrochloride in dihydrated form. The compound 1 exhibited in-vitro activity against both extracellular promastigotes as well as intracellular amastigotes residing within murine macrophages in Leishmania donovani. Furthermore, 1 also exhibited in-vivo activity, 79.6 (+/-8.07)% against established VL in hamsters at a dose of 100mg/kgb.wt. PMID:19339182

  4. Interaction between fasudil hydrochloride and bovine serum albumin: spectroscopic study.

    PubMed

    Yu, Xianyong; Jiang, Bingfei; Xun, Caifang; Yao, Qing

    2016-06-01

    The interaction between fasudil hydrochloride (FSD) and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopy under imitated physiological conditions. The Stern-Volmer quenching model has been successfully applied and the results revealed that FSD could quench the intrinsic fluorescence of BSA effectively via static quenching. The binding constants and binding sites for the BSA-FSD system were evaluated. The corresponding thermodynamic parameters obtained at different temperatures indicated that hydrophobic force played a major role in the interaction of FSD and BSA. The distance between the donor (BSA) and the acceptor (FSD) was obtained according to fluorescence resonance energy transfer (FRET). Synchronous fluorescence spectroscopy and FT-IR spectra showed that the conformation of BSA was changed in the presence of FSD. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26554343

  5. [Photodegradation of Ciprofloxacin Hydrochloride in the Aqueous Solution Under UV].

    PubMed

    Duan, Lun-chao; Wang, Feng-he; Zhao, Bin; Chen, Ya-jun

    2016-01-15

    Effects of ciprofloxacin hydrochloride (CIP) initial concentration, Pb (NO3) 2, Cd (NO3) 2, PbCl2 and CdCl2 on the photodegradation of CIP using UV irradiation were investigated. The experiments results showed that UV irradiation could lead to effective removal of CIP, but there was no CIP degradation in dark. The photodegradation rate of CIP reduced with increasing initial concentration under UV irradiation. Pb(NO3)2 and Cd(NO3)2 (except for the experiment group of 0.006 mmol x L(-1)) could enhance CIP photodegradation, and the half-life of CIP gradually increased with increasing molar ratio between heavy metal and CIP ( with the decreasing concentration of nitrate). With increasing molar ratio (with the decreasing concentration of chlorate), PbCl2 and CdCl2 first promoted and then inhibited the CIP photodegradation. PMID:27078959

  6. Multilayer Films and Capsules of Sodium Carboxymethylcellulose and Polyhexamethylenguanidine Hydrochloride

    NASA Astrophysics Data System (ADS)

    Guzenko, Nataliia; Gabchak, Oleksandra; Pakhlov, Evgenij

    The complexation of polyhexamethylenguanidine hydrochloride (PHMG) and sodium carboxymethylcellulose (CMC) was investigated for different conditions. Mixing of equiconcentrated aqueous solutions of the polyelectrolytes was found to result in the formation of an insoluble interpolyelectrolyte complex with an overweight of carboxymethylcellulose. A step-by-step formation of stable, irreversibly adsorbed multilayer film of the polymers was demonstrated using the quartz crystal microbalance method. Unusually thick polymer shells with a large number of loops and tails of the polyanion were formed by the method of layer-by-layer self-assembly of PHMG and CMC on spherical CaCO3 particles. Hollow multilayer capsules stable in neutral media were obtained by dissolution of the inorganic matrix in EDTA solution.

  7. Stability of morphine sulphate and diamorphine hydrochloride in intrasite gel.

    PubMed

    Zeppetella, Giovambattista; Joel, Simon P; Ribeiro, Maria D C

    2005-03-01

    Several studies have reported that opioids applied topically to painful ulcers produce an analgesic effect. It is unknown whether these opioids (usually mixed with hydrogels) are stable and, if so, for how long. We investigated the stability of morphine sulphate and diamorphine hydrochloride, each mixed with intrasite gel at a concentration of 1.25 mg/mL. Samples were prepared in the laboratory and then stored in plastic containers in the dark, at room temperature, in conditions of normal day/night at room temperature, and at 4 degrees C. Aliquots were collected from each container over a 28-day period and analysed using HPLC. No known degradation products were measured in the morphine-intrasite gel mixture stored for up to 28 days, irrespective of the temperature and whether or not samples were exposed to light, suggesting that morphine remains stable. Diamorphine, breaks down to morphine and no other degradation products are measurable. PMID:15810752

  8. Determination of tetracycline hydrochloride by terahertz spectroscopy with PLSR model.

    PubMed

    Qin, Jianyuan; Xie, Lijuan; Ying, Yibin

    2015-03-01

    Antibiotic residues in agricultural and food products are of great concern to legislatures and consumers. Reliable techniques for rapid and sensitive detection of these residues are necessary to ensure food safety. In this study, tetracycline hydrochloride (TC-HCl) in powder and solution form was detected and quantified using terahertz (THz) spectroscopy. Partial least-squares regression (PLSR) was used to build calibration models. The results obtained in this study indicated that the PLSR model for powder samples was excellent and could be used for quality control. However, the PLSR model for solution samples was not robust and needed to be improved. Overall, THz spectroscopy combined with PLSR model had its potential for the rapid and non-destructive prediction of TC-HCl residue without sophisticated methods, although the accuracy was not high for solution samples which should be improved in future study. PMID:25306365

  9. Cryptolepine hydrochloride: a potent antimycobacterial alkaloid derived from Cryptolepis sanguinolenta.

    PubMed

    Gibbons, Simon; Fallah, Fatemeh; Wright, Colin W

    2003-04-01

    The activity of cryptolepine hydrochloride, a salt of the main indoloquinoline alkaloid from the West African medicinal plant Cryptolepis sanguinolenta, was assessed against the fast growing mycobacterial species Mycobacterium fortuitum, which has recently been shown to be of use in the evaluation of antitubercular drugs. The low minimum inhibitory concentration (MIC) of this compound (16 microg/mL) prompted further evaluation against other fast growing mycobacteria namely, M. phlei, M. aurum, M. smegmatis, M. bovis BCG and M. abcessus and the MICs ranged over 2-32 microg/mL for these species. The strong activity of this agent, the need for new antibiotics with activity against Mycobacterium tuberculosis, coupled with the ethnobotanical use of C. sanguinolenta extracts to treat infections, highlight the potential of the cryptolepine template for development of antimycobacterial agents. PMID:12722159

  10. Simple colorimetric method for determination of thiamine hydrochloride in pharmaceuticals.

    PubMed

    Sane, R T; Doshi, V J; Jukar, S; Joshi, S K; Sawant, S V; Pandit, U R

    1985-01-01

    A simple colorimetric method is described for the determination of thiamine hydrochloride (vitamin B1) in dosage forms. The method is based on measurement of a yellow complex formed when thiamine HCl is treated with p-methylaminophenol sulfate (Metol) under alkaline conditions. Compounds such as vitamins A, B2, B6, B12, C, D, and E, and niacinamide, citric acid, liquid glucose, calcium pantothenate, biotin, liver extract, and folic acid do not interfere in the reaction. Extracting the complex into chloroform before quantitation enhances the stability of the reaction product and removes interference of water-soluble colored constituents in syrup samples. Statistical validation shows that the method is precise and accurate. Results agree well with those obtained by other methods in the literature. PMID:3980419

  11. Stability of apomorphine hydrochloride in aqueous sodium bisulphite solutions.

    PubMed

    Ng Ying Kin, N M; Lal, S; Thavundayil, J X

    2001-10-01

    Apomorphine (Apo), a dopamine receptor agonist used extensively in clinical research, is known to be chemically unstable. The authors have used a high performance liquid chromatography (HPLC) method to study the long-term stability of pharmaceutical preparations of R(-) Apomorphine hydrochloride (ApoHCI) for parenteral use. In a concentration of 1 mg/ml, ApoHCI in aqueous solutions of sodium metabisulphite (0.125%), kept at 4 degrees and shielded from light, was found to be stable for up to six months. On the other hand, solutions of 0.1 mg/ml were found to decompose after only three weeks, showing extraneous peaks in the HPLC. However, the blue-green discoloration, characteristic of Apo degradation, was only apparent after six weeks storage. The rapidity of the HPLC method used, its reproducibility and sensitivity make it suitable for quality control studies of pharmaceutical preparations of ApoHCI intended for clinical research. PMID:11513359

  12. Development and Statistical Optimisation of Buspirone Hydrochloride Buccoadhesive Films

    PubMed Central

    Nagaich, Upendra; Chaudhary, Vandana; Nagaich, Jaya

    2014-01-01

    The aim of the present study was to prepare unidirectional buccal films of buspirone hydrochloride by solvent casting technique. Hydroxypropylmethylcellulose (HPMC K15M) and Eudragit RL-100 were used as polymers in different proportion. Polyethylene glycol 400 and sodium lauryl sulphate were used as plasticizer and permeation enhancer, respectively, in different concentration. In the formulation, total amount of polymer (X1) and percentage of HPMC K15M (X2) were kept as independent variables. Afterwards, statistically optimized process was carried out and two optimized formulations (OF1 and OF2) were developed. The observed results of optimized formulation were showed a greater degree of percentage of similarity with predicted values. The stability studies showed that there was no significant change found in physicochemical properties, in-vitro release, and ex-vivo diffusion studies. PMID:27351002

  13. Coated hydralazine hydrochloride beads for sustained release after oral administration.

    PubMed

    Mughal, M Akhlaq; Saripella, Kalyan K; Kouba, Chahinaz; Iqbal, Zafar; Neau, Steven H

    2013-09-01

    Hydralazine hydrochloride is an antihypertensive used alone or in combination with isosorbide nitrate for the treatment of congestive heart failure. Since control of blood pressure should be continuous, sustained release delivery of this drug is considered therapeutically beneficial. Core beads for oral administration of this drug were prepared by extrusion-spheronization. Using experimental design to define the coat that was applied, the core beads were coated using a fluid bed coater to different coat thickness with combinations of two commercially available products dissolved in a hydroalcoholic solvent. The coat is a film with a combination of ethylcellulose and hydroxypropylcellulose that can provide desirable release profiles. Visually spherical and rugged bead products were obtained. Two products were identified that exhibited essentially a zero order release profile following a 2-h lag time with release of greater than 70% of the drug over the next 10 h in simulated intestinal fluid. PMID:23057650

  14. Formulation and evaluation of verapamil hydrochloride loaded solid lipid microparticles.

    PubMed

    Pilaniya, U; Pilaniya, K; Chandrawanshi, H K; Gupta, N; Rajput, M S

    2011-01-01

    The present study aimed to produce verapamil hydrochloride-loaded solid lipid microparticles (SLM) by the w/o/w emulsion solvent evaporation technique, using diethyl ether as solvent phase, glyceryl monostearate as biodegradable polymer and Span 60 as surfactant. SLM of spherical shape were prepared by simple dilution of the emulsion with water. To increase the lipid load the process was conducted at 50 degrees C, and in order to reach sub-micron size, a high-shear homogenizer was used. The encapsulation efficiency of prepared SLM reached 74.29 +/- 0.76%. Particle size (98.55 +/- 1.42 microm), surface morphology (spherical) and drug loading efficiency (18.57 +/- 1.25% w/w) were investigated. And optimization of drug polymer ratio (3:1), nature and concentration of emulsion stabilizer in the external aqueous (0.1%), phase viscosity of external aqueous phase (0.5%), volume of external aqueous phase and stirring rate (1000 rpm) were detected. Analysis of microsphere content after processing showed that verapamil did not undergo any chemical modification within the micro-particles. The in-vitro release of verapamil from the microparticles was very low and an initial burst effect of 17% of the dose was observed. The slow release may help to avoid a high frequency of administration. The prepared solid lipid microparticles appear to have interesting perspectives as delivery systems for the oral administration of verapamil hydrochloride with improved half-life, improved bioavailability, and minimized local and systemic gastrointestinal disturbances of the drug. PMID:21391431

  15. 40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... in the polymeric form. The hydrolysis of these polymers is catalyzed by hydrogen ions. 2.2The resin... hydroxylamine hydrochloride will produce sufficient hydrogen ions to catalyze the depolymerization of...

  16. The effect of tramadol hydrochloride on early life stages of fish.

    PubMed

    Sehonova, Pavla; Plhalova, Lucie; Blahova, Jana; Berankova, Petra; Doubkova, Veronika; Prokes, Miroslav; Tichy, Frantisek; Vecerek, Vladimir; Svobodova, Zdenka

    2016-06-01

    The aim of this study was to perform the fish embryo acute toxicity test (FET) on zebrafish (Danio rerio) and the early-life stage toxicity test on common carp (Cyprinus carpio) with tramadol hydrochloride. The FET was performed using the method inspired by the OECD guideline 236. Newly fertilized zebrafish eggs were exposed to tramadol hydrochloride at concentrations of 10; 50; 100 and 200μg/l for a period of 144h. An embryo-larval toxicity test on C. carpio was performed according to OECD guideline 210 also with tramadol hydrochloride at concentrations 10; 50; 100 and 200μg/l for a period of 32 days. Hatching was significantly influenced in both acute and subchronic toxicity assays. Subchronic exposure also influenced early ontogeny, both morphometric and condition characteristics and caused changes in antioxidant enzyme activity. The LOEC value was found to be 10μg/l tramadol hydrochloride. PMID:27208654

  17. 78 FR 40484 - Determination That METADATE ER (Methylphenidate Hydrochloride) Extended-Release Tablet, 10...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... HUMAN SERVICES Food and Drug Administration Determination That METADATE ER (Methylphenidate... Administration (FDA) has determined that METADATE ER (methylphenidate hydrochloride (HCl)) extended-release... determination will allow FDA to approve abbreviated new drug applications (ANDAs) for methylphenidate...

  18. Sustained transdermal release of diltiazem hydrochloride through electron beam irradiated different PVA hydrogel membranes

    NASA Astrophysics Data System (ADS)

    Bhunia, Tridib; Goswami, Luna; Chattopadhyay, Dipankar; Bandyopadhyay, Abhijit

    2011-08-01

    Extremely fast release of diltiazem hydrochloride (water soluble, anti anginal drug used to treat chest pain) together with its faster erosion has been the primary problem in conventional oral therapy. It has been addressed in this paper by encapsulating the drug in electron beam irradiated various poly (vinyl alcohol) hydrogel membranes and delivering it through transdermal route. Results show excellent control over the release of diltiazem hydrochloride through these membranes subject to their physico-mechanicals.

  19. 40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrochloric acid that is liberated when hydroxylamine hydrochloride reacts with formaldehyde to form..., using the prestandardized pH meter, 1.0 N hydrochloric acid, 0.1 N hydrochloric acid, and 0.1 N sodium... hydrochloride solution, 100 grams per liter, pH adjusted to 4.00. 4.3Hydrochloric acid solution, 1.0 N and 0.1...

  20. 40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrochloric acid that is liberated when hydroxylamine hydrochloride reacts with formaldehyde to form..., using the prestandardized pH meter, 1.0 N hydrochloric acid, 0.1 N hydrochloric acid, and 0.1 N sodium... hydrochloride solution, 100 grams per liter, pH adjusted to 4.00. 4.3Hydrochloric acid solution, 1.0 N and 0.1...

  1. Benzydamine hydrochloride in prevention and management of pain in oral mucositis associated with radiation therapy

    SciTech Connect

    Epstein, J.B.; Stevenson-Moore, P.

    1986-08-01

    Benzydamine hydrochloride rinse reduced pain associated with radiation mucositis when it was used during the course of radiation therapy. Fewer patients using benzydamine rinse required systemic analgesics. All patients using benzydamine tolerated the rinse well and continued with regular rinsing throughout the course of radiation therapy. Benzydamine hydrochloride is currently undergoing clinical trials in the United States for application for approval from the Food and Drug Administration.

  2. Effects of Olopatadine Hydrochloride, a Histamine H1 Receptor Antagonist, on Histamine-Induced Skin Responses

    PubMed Central

    Hashimoto, Takashi; Ishii, Norito; Hamada, Takahiro; Dainichi, Teruki; Karashima, Tadashi; Nakama, Takekuni; Yasumoto, Shinichiro

    2010-01-01

    Effects of olopatadine hydrochloride, a histamine H1 receptor antagonist, on histamine-induced skin responses were evaluated in 10 healthy subjects in comparison with placebo, fexofenadine hydrochloride, and bepotastine besilate. Olopatadine significantly suppressed histamine-induced wheal, flare, and itch, starting 30 minutes after oral administration. Olopatadine was more effective than fexofenadine and bepotastine. None of the drugs studied impaired performance of word processing tasks. These results suggest that olopatadine can suppress skin symptoms caused by histamine soon after administration. PMID:20886023

  3. Co-Amorphous Combination of Nateglinide-Metformin Hydrochloride for Dissolution Enhancement.

    PubMed

    Wairkar, Sarika; Gaud, Ram

    2016-06-01

    The aim of the present work was to prepare a co-amorphous mixture (COAM) of Nateglinide and Metformin hydrochloride to enhance the dissolution rate of poorly soluble Nateglinide. Nateglinide (120 mg) and Metformin hydrochloride (500 mg) COAM, as a dose ratio, were prepared by ball-milling technique. COAMs were characterized for saturation solubility, amorphism and physicochemical interactions (X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR)), SEM, in vitro dissolution, and stability studies. Solubility studies revealed a sevenfold rise in solubility of Nateglinide from 0.061 to 0.423 mg/ml in dose ratio of COAM. Solid-state characterization of COAM suggested amorphization of Nateglinide after 6 h of ball milling. XRPD and DSC studies confirmed amorphism in Nateglinide, whereas FTIR elucidated hydrogen interactions (proton exchange between Nateglinide and Metformin hydrochloride). Interestingly, due to low energy of fusion, Nateglinide was completely amorphized and stabilized by Metformin hydrochloride. Consequently, in vitro drug release showed significant increase in dissolution of Nateglinide in COAM, irrespective of dissolution medium. However, little change was observed in the solubility and dissolution profile of Metformin hydrochloride, revealing small change in its crystallinity. Stability data indicated no traces of devitrification in XRPD of stability sample of COAM, and % drug release remained unaffected at accelerated storage conditions. Amorphism of Nateglinide, proton exchange with Metformin hydrochloride, and stabilization of its amorphous form have been noted in ball-milled COAM of Nateglinide-Metformin hydrochloride, revealing enhanced dissolution of Nateglinide. Thus, COAM of Nateglinide-Metformin hydrochloride system is a promising approach for combination therapy in diabetic patients. PMID:26314243

  4. Safety and efficacy of tramadol hydrochloride on treatment of premature ejaculation.

    PubMed

    Eassa, Bayoumy I; El-Shazly, Mohamed A

    2013-01-01

    Premature ejaculation (PE) is the most common sexual disorder. It affects 20%-30% of adult men; the aetiology of this condition has not yet been elucidated. The aim of this study is to evaluate the efficacy, safety, tolerability, undesirable effects and improved satisfaction with sexual intercourse with tramadol hydrochloride at different dosages for the treatment of PE. A total of 300 patients who presented with lifelong (primary) PE were included in this study. The study was performed for 28 weeks, in which placebo (starch tablet) was given for 4 weeks, and active ingredient (tramadol hydrochloride) was administered at different therapeutic dosages for 24 weeks. Patients were divided into three equal groups, each consisting of 100 patients. The first group (A) was given tramadol hydrochloride capsule 25 mg. The second group (B) was given tramadol hydrochloride capsule 50 mg. The third group (C) was given tramadol hydrochloride capsule 100 mg. All of the 300 participants included completed the study voluntarily. The age of the patients varied from 25 to 50 years. After the treatment period, the recorded data were collected for each group and analysed. The results showed a highly significant increase in the mean intravaginal ejaculatory latency time (IELT) in all groups compared to baseline data (P<0.0001). We concluded that using tramadol hydrochloride at different doses on demand for the treatment of PE is effective, safe and tolerable, with minimal undesirable effects, and approval for this indication should be sought. PMID:23103596

  5. Stability-indicating HPLC Method for Simultaneous Determination of Montelukast and Fexofenadine Hydrochloride

    PubMed Central

    Pankhaniya, Mona; Patel, Parula; Shah, J. S.

    2013-01-01

    A simple, specific, accurate, and stability-indicating reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of montelukast and fexofenadine hydrochloride, using a Lichrospher® 100, RP-18e column and a mobile phase composed of methanol:0.1% o-phosphoric acid (90:10 v/v), pH 6.8. The retention times of montelukast and fexofenadine hydrochloride were found to be 10.16 and 12.03 min, respectively. Linearity was established for montelukast and fexofenadine hydrochloride in the range of 2-10 μg/ml and 24-120 μg/ml, respectively. The percentage recoveries of montelukast and fexofenadine hydrochloride were found to be in the range of 99.09 and 99.81%, respectively. Both the drugs were subjected to acid and base hydrolysis, oxidation, photolytic, and thermal degradation conditions. The degradation products of montelukast and fexofenadine hydrochloride were well resolved from the pure drug with significant differences in their retention time values. This method can be successfully employed for simultaneous quantitative analysis of montelukast and fexofenadine hydrochloride in bulk drugs and formulations. PMID:24082344

  6. Using crystal structure prediction to rationalize the hydration propensities of substituted adamantane hydrochloride salts.

    PubMed

    Mohamed, Sharmarke; Karothu, Durga Prasad; Naumov, Panče

    2016-08-01

    The crystal energy landscapes of the salts of two rigid pharmaceutically active molecules reveal that the experimental structure of amantadine hydrochloride is the most stable structure with the majority of low-energy structures adopting a chain hydrogen-bond motif and packings that do not have solvent accessible voids. By contrast, memantine hydrochloride which differs in the substitution of two methyl groups on the adamantane ring has a crystal energy landscape where all structures within 10 kJ mol(-1) of the global minimum have solvent-accessible voids ranging from 3 to 14% of the unit-cell volume including the lattice energy minimum that was calculated after removing water from the hydrated memantine hydrochloride salt structure. The success in using crystal structure prediction (CSP) to rationalize the different hydration propensities of these substituted adamantane hydrochloride salts allowed us to extend the model to predict under blind test conditions the experimental crystal structures of the previously uncharacterized 1-(methylamino)adamantane base and its corresponding hydrochloride salt. Although the crystal structure of 1-(methylamino)adamantane was correctly predicted as the second ranked structure on the static lattice energy landscape, the crystallization of a Z' = 3 structure of 1-(methylamino)adamantane hydrochloride reveals the limits of applying CSP when the contents of the crystallographic asymmetric unit are unknown. PMID:27484376

  7. Safety and efficacy of tramadol hydrochloride on treatment of premature ejaculation

    PubMed Central

    Eassa, Bayoumy I; El-Shazly, Mohamed A

    2013-01-01

    Premature ejaculation (PE) is the most common sexual disorder. It affects 20%–30% of adult men; the aetiology of this condition has not yet been elucidated. The aim of this study is to evaluate the efficacy, safety, tolerability, undesirable effects and improved satisfaction with sexual intercourse with tramadol hydrochloride at different dosages for the treatment of PE. A total of 300 patients who presented with lifelong (primary) PE were included in this study. The study was performed for 28 weeks, in which placebo (starch tablet) was given for 4 weeks, and active ingredient (tramadol hydrochloride) was administered at different therapeutic dosages for 24 weeks. Patients were divided into three equal groups, each consisting of 100 patients. The first group (A) was given tramadol hydrochloride capsule 25 mg. The second group (B) was given tramadol hydrochloride capsule 50 mg. The third group (C) was given tramadol hydrochloride capsule 100 mg. All of the 300 participants included completed the study voluntarily. The age of the patients varied from 25 to 50 years. After the treatment period, the recorded data were collected for each group and analysed. The results showed a highly significant increase in the mean intravaginal ejaculatory latency time (IELT) in all groups compared to baseline data (P<0.0001). We concluded that using tramadol hydrochloride at different doses on demand for the treatment of PE is effective, safe and tolerable, with minimal undesirable effects, and approval for this indication should be sought. PMID:23103596

  8. Increased Mortality in Groups of Cattle Administered the β-Adrenergic Agonists Ractopamine Hydrochloride and Zilpaterol Hydrochloride

    PubMed Central

    Loneragan, Guy H.; Thomson, Daniel U.; Scott, H. Morgan

    2014-01-01

    The United States Food and Drug Administration (FDA) approved two β-adrenergic agonists (βAA) for in-feed administration to cattle fed in confinement for human consumption. Anecdotal reports have generated concern that administration of βAA might be associated with an increased incidence of cattle deaths. Our objectives, therefore, were to a) quantify the association between βAA administration and mortality in feedlot cattle, and b) explore those variables that may confound or modify this association. Three datasets were acquired for analysis: one included information from randomized and controlled clinical trials of the βAA ractopamine hydrochloride, while the other two were observational data on zilpaterol hydrochloride administration to large numbers of cattle housed, fed, and cared for using routine commercial production practices in the U.S. Various population and time at-risk models were developed to explore potential βAA relationships with mortality, as well as the extent of confounding and effect modification. Measures of effect were relatively consistent across datasets and models in that the cumulative risk and incidence rate of death was 75 to 90% greater in animals administered the βAA compared to contemporaneous controls. During the exposure period, 40 to 50% of deaths among groups administered the βAA were attributed to administration of the drug. None of the available covariates meaningfully confounded the relationship between βAA and increased mortality. Only month of slaughter, presumably a proxy for climate, consistently modified the effect in that the biological association was generally greatest during the warmer months of the year. While death is a rare event in feedlot cattle, the data reported herein provide compelling evidence that mortality is nevertheless increased in response to administration of FDA-approved βAA and represents a heretofore unquantified adverse drug event. PMID:24621596

  9. Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride.

    PubMed

    Başkan, M Halim; Aydın, Murat

    2013-08-01

    The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3ĊHCOOC2H5, -CH2ĊHCOOH and -CH2ĊHCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed. PMID:23680512

  10. Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride

    NASA Astrophysics Data System (ADS)

    Başkan, M. Halim; Aydın, Murat

    2013-08-01

    The electron paramagnetic resonance (EPR) of gamma irradiated powders of DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride were investigated at room temperature. The observed paramagnetic species were attributed to the CH3ĊHCOOC2H5, -CH2ĊHCOOH and -CH2ĊHCOOCH3 radicals, respectively. Hyperfine structure constants and g-values were determined for these three radicals. Some spectroscopic properties and suggestions concerning the possible structure of the radicals were also discussed.

  11. The solid state structure and reactivity of NbCl(5) x (N,N'-dicyclohexylurea) in solution: evidence for co-ordinated urea dehydration to the relevant carbodiimide.

    PubMed

    Aresta, Michele; Dibenedetto, Angela; Stufano, Paolo; Aresta, Brunella Maria; Maggi, Sabino; Pápai, Imre; Rokob, Tibor András; Gabriele, Bartolo

    2010-08-14

    NbCl(5) x (N,N'-dicyclohexylurea) 1a owns a distorted octahedral structure due to intramolecular NH...Cl bonding. The unit cell contains four units which are intermolecularly NH...Cl and NH...N bonded. An extended intramolecular network of H-bonding (N-H...Cl, CH...Cl, CH...N) causes the 3D self assembling of the units. Upon addition of base, the HCl release from 1a is observed with the transfer to Nb of the O-atom of the carbonylic function of the starting urea which is converted into the relevant carbodiimide CyN=C=NCy 4. The latter is quantitatively released by adding an excess of NEt(3) at 308 K (py and DBU are less efficient) with formation of the known NbOCl(3)(NEt(3))(2), isolated in quantitative yield. Increasing the temperature leads to a loss in selectivity as the formed DCC undergoes further reactions. At 350 K, the isocyanate CyN=C=O has been isolated in 60% yield besides a mixture of Nb-complexes. DFT calculations have been coupled to IR and NMR experiments for characterizing possible reaction intermediates and the behaviour of 1a. Several other MCl(x) species (ScCl(3), YCl(3), LaCl(3), TiCl(4), TaCl(5), AlCl(3), SnCl(4)) have been shown to be able to co-ordinate DCU but not all of them promote the conversion of urea into DCC. PMID:20544121

  12. The carboxyl modifier 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide (EDC) inhibits half of the high-affinity Mn-binding site in photosystem II membrane fragments

    SciTech Connect

    Preston, C.; Seibert, M. )

    1991-10-08

    The diphenylcarbazide (DPC)/Mn{sup 2+} assay was used to assess the amount of the high-affinity Mn-binding site in manganese-depleted photosystem II (PS II) membrane fragments from spinach and Scenedesmus obliquus. The assay mechanism at high DPC concentration was shown to involve noncompetitive inhibition of only half of the control level of DPC donation to PS II by micromolar concentrations of Mn at pH 6.5. At low DPC concentration both DPC and Mn{sup 2+} donate to PS II additively. Treatment with the carboxyl amino acid modifier 1-ethyl-3-(3(dimethylamino) propyl) carbodiimide (EDC) inhibited half of the high affinity Mn-binding site in spinach and Scenedesmus WT PS II membranes and all of the available site in Scenedesmus LF-1 mutant PS II membranes. A similar EDC concentration dependence was observed in all cases. This protection was specific for Mn{sup 2+}; six other divalent cations were ineffective. The authors conclude that EDC modifies that half of the high-affinity Mn-binding site that is insensitive to the histidine modifier diethyl pyrocarbonate (DEPC) and directly affects ligands that bind Mn. The effects of EDC and DEPC that influence the high-affinity site are mutually exclusive and are specific to the lumenal side of the PS II membrane. They suggest that carboxyl residues on reaction center proteins are associated with half of the high-affinity Mn-binding site in PS II and are involved along with histidine residues in binding Mn functional in the O{sub 2}-evolving process.

  13. Microneedle-assisted delivery of verapamil hydrochloride and amlodipine besylate.

    PubMed

    Kaur, Monika; Ita, Kevin B; Popova, Inna E; Parikh, Sanjai J; Bair, Daniel A

    2014-02-01

    The aim of this project was to study the effect of stainless steel solid microneedles and microneedle rollers on percutaneous penetration of verapamil hydrochloride and amlodipine besylate. Verapamil, 2-(3,4-dimethooxyphenyl)-5-[2-(3,4 dimethoxyphenyl)ethyl-methyl-amino]-2-propan-2-yl-pentanenitrile is a calcium channel blocker agent that regulates high blood pressure by decreasing myocardial contractilty, heart rate and impulse conduction. Amlodipine, (R, S)-2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-1, 4-dihydropyridine, is a calcium channel blocker that is used for the management of hypertension and ischemic heart disease. Passive penetration of verapamil and amlodipine across the skin is low. In vitro studies were performed with microneedle-treated porcine ear skin using vertical static Franz diffusion cells (PermeGear, Hellertown, PA, USA). The receiver chamber contained 5ml of PBS (pH7.4) and was constantly maintained at 37°C temperature with a water circulation jacket. The diffusion area of the skin was 1.77cm(2). The donor compartment was loaded with 1ml of the solution containing 2.5mg/ml of amlodipine besylate. The donor chamber was covered with parafilm to avoid evaporation. Passive diffusion across untreated porcine skin served as control. Aliquots were taken every 2h for 12h and analyzed by liquid chromatography-mass spectrometry. Transcutaneous flux of verapamil increased significantly from 8.75μg/cm(2)/h to 49.96μg/cm(2)/h across microneedle-roller treated porcine skin. Percutaneous flux of amlodipine besylate following the use of stainless steel microneedles was 22.39μg/cm(2)/h. Passive flux for the drug was 1.57μg/cm(2)/h. This enhancement of amlodipine flux was statistically significant. Transdermal flux of amlodipine with microneedle roller was 1.05μg/cm(2)/h in comparison with passive diffusion flux of 0.19μg/cm(2)/h. The difference in flux values was also statistically significant. Stainless

  14. Stability-indicating HPTLC determination of ambroxol hydrochloride in bulk drug and pharmaceutical dosage form.

    PubMed

    Jain, P S

    2010-01-01

    A simple, selective, precise, and stability-indicating high-performance thin-layer chromatographic (HPTLC) method for the analysis of ambroxol hydrochloride both as a bulk drug and in formulations was developed and validated. The method employed HPTLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of methanol-triethylamine (4:6 v/v). The system was found to give a compact spot for ambroxol hydrochloride (R(f) value of 0.53 +/- 0.02). Densitometric analysis of ambroxol hydrochloride was carried out in the absorbance mode at 254 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r(2) = 0.9966 +/- 0.0013 with respect to peak area in the concentration range 100-1000 ng/spot. The mean value +/- standard deviation of slope and intercept were 164.85 +/- 0.72 and 1168.3 +/- 8.26 with respect to peak area. The method was validated for precision, recovery, and robustness. The limits of detection and quantitation were 10 and 30 ng/spot, respectively. Ambroxol hydrochloride was subjected to oxidation and thermal degradation. The drug undergoes degradation under oxidation and heat conditions. This indicates that the drug is susceptible to oxidation and heat. Statistical analysis proves that the method is repeatable, selective, and accurate for the estimation of said drug. Stability indicating of new chemical entities is an important part for the drug development of ambroxol hydrochloride and for its estimation in plasma and other biological fluids; the novel Statistical analysis proves that the method is repeatable and selective for the analysis of ambroxol hydrochloride as bulk drug and in pharmaceutical formulations. The proposed developed HPTLC method can be applied for identification and quantitative determination of ambroxol hydrochloride in bulk drug and dosage forms. This work is to determine the purity of the drug available from the various sources by detecting

  15. Efficacy of landiolol hydrochloride for atrial fibrillation after open heart surgery.

    PubMed

    Nishi, Hiroyuki; Sakaguchi, Taichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Saito, Shunsuke; Ueno, Takayoshi; Kuratani, Toru; Sawa, Yoshiki

    2013-07-01

    It is important to establish effective treatment for postoperative atrial fibrillation (AF), the most common complication after cardiac surgery. We evaluated the efficacy and safety of landiolol hydrochloride for rhythm conversion in patients with postoperative AF. Among 134 patients who developed new-onset AF after open heart surgery between 2007 and 2009, 69 patients who received landiolol hydrochloride for treatment of postoperative AF were enrolled. The AF conversion rate, the percentage of patients with 20 % reduction of the ventricular rate, and the factors related to successful treatment were evaluated. Then, the landiolol group was compared with 65 patients who had postoperative AF and did not receive landiolol hydrochloride. Landiolol hydrochloride was the first-line treatment in 46 patients and the only therapy in 26 patients. Reversion to sinus rhythm was achieved in 51 patients, while the conversion rate in patients without landiolol hydrochloride was only 56.8 % (p < 0.05). A 20 % reduction of the ventricular rate was achieved more frequently in the landiolol group. Although landiolol hydrochloride was highly effective in patients who had undergone off-pump coronary artery bypass grafting, patients with cardiopulmonary bypass did not respond as well. The heart rate was reduced from 130 ± 26 to 81 ± 12 (p < 0.05) after landiolol administration, while blood pressure did not decrease significantly. Landiolol hydrochloride was effective for conversion of postoperative AF. This ultra-short-acting β-blocker is a safe first-line treatment for postoperative AF after open heart surgery, and is most effective in patients who have undergone off-pump coronary artery bypass grafting. PMID:22661097

  16. A Double-Blind, Placebo-Controlled Trial of Dexmethylphenidate Hydrochloride and D,l-Threo-Methylphenidate Hydrochloride in Children with Attention-Deficit-Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Wigal, Sharon; Swanson, James M.; Feifel, David; Sangal, R. Bart; Elia, Josephine; Casat, Charles D.; Zeldis, Jerome B.; Conners, C. Keith

    2004-01-01

    Objective: To evaluate the efficacy and safety of dexmethylphenidate hydrochloride (d-MPH, Focalin[TM]) for the treatment of attention-deficit/hyperactivity disorder (ADHD) and to test an a priori hypothesis that d-MPH would have a longer duration of action than d,l-threo-methylphenidate (d,l-MPH). Method: This was a randomized, double-blind study…

  17. Development and validation of a HPLC method for the determination of buprenorphine hydrochloride, naloxone hydrochloride and noroxymorphone in a tablet formulation.

    PubMed

    Mostafavi, Ali; Abedi, Ghazaleh; Jamshidi, Ahmad; Afzali, Daryoush; Talebi, Mohammad

    2009-02-15

    A simple isocratic reversed-phase high-performance liquid chromatographic method (RP-HPLC) was developed for the simultaneous determination of buprenorphine hydrochloride, naloxone hydrochloride dihydrate and its major impurity, noroxymorphone, in pharmaceutical tablets. The chromatographic separation was achieved with 10 mmol L(-1) potassium phosphate buffer adjusted to pH 6.0 with orthophosphoric acid and acetonitrile (17:83, v/v) as mobile phase, a C-18 column, Perfectsil Target ODS3 (150 mm x 4.6mm i.d., 5 microm) kept at 35 degrees C and UV detection at 210 nm. The compounds were eluted isocratically at a flow rate of 1.0 mL min(-1). The average retention times for naloxone, noroxymorphone and buprenorphine were 2.4, 3.8 and 8.1 min, respectively. The method was validated according to the ICH guidelines. The validation characteristics included accuracy, precision, linearity, range, specificity, limit of quantitation and robustness. The calibration curves were linear (r>0.996) over the concentration range 0.22-220 microg mL(-1) for buprenorphine hydrochloride and 0.1-100 microg mL(-1) for naloxone hydrochloride dihydrate and noroxymorphone. The recoveries for all three compounds were above 96%. No spectral or chromatographic interferences from the tablet excipients were found. This method is rapid and simple, does not require any sample preparation and is suitable for routine quality control analyses. PMID:19084658

  18. Trans-ungual delivery of itraconazole hydrochloride by iontophoresis.

    PubMed

    Kushwaha, Avadhesh; Jacob, Melissa; Shiva Kumar, H N; Hiremath, Shobharani; Aradhya, Sacchidanand; Repka, Michael A; Murthy, S Narasimha

    2015-01-01

    Itraconazole (ITR) is a potent antifungal drug. However, poor aqueous solubility limits its permeation ability across the human nail plate. Therefore, in this project, ITR was converted to hydrochloride salt (ITR-HCl) to improve its solubility and to render it amenable to iontophoresis. ITR-HCl was characterized by spectroscopic methods and antifungal efficacy was evaluated in comparison to the base. In vitro and ex vivo transport studies (passive and iontophoresis) were carried out across the porcine hoof membrane and excised human cadaver toe using two different protocols; continuous delivery of drug for 24 h and pulsed delivery of drug for 3 days (8 h/day). The antifungal efficacy of ITR-HCL was comparable to ITR. Iontophoresis was found to be more effective than passive mode of delivery of ITR-HCL. In both iontophoresis as well as passive mode of delivery, the pulsed protocol resulted in more ungual and trans-ungual delivery of drug than continuous protocol. ITR-HCL could be delivered into and across the nail plate by iontophoresis. Human cadaver toe appears to be a good model to investigate the ungual delivery of drugs. PMID:25482587

  19. Stability of revex, nalmefene hydrochloride injection, in injectable solutions.

    PubMed

    Murthy, S S; Brittain, H G

    1996-11-01

    The short-term stability of Revex, nalmefene hydrochloride injection, was determined in a number of diluents commonly employed for intravenous use. An HPLC method was used to follow the potency of the diluted solutions, and was fully validated for its intended concentration range prior to its use. Dilutions of Revex were prepared separately in 0.9% sodium chloride injection, 0.45% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.45% sodium chloride injection, lactated Ringer's injection, 5% dextrose and lactated Ringer's injection and 5% sodium hydrogencarbonate injection. Each admixture was stored at 4 degrees C, room temperature (21 degrees C) and 40 degrees C, with samples being tested after storage at each temperature for 0, 24, 48 and 72 h. Defining stability as the retention of at least 95% of the initial drug concentration at the end of the storage period, it was concluded that the diluted solutions of Revex were uniformly stable for up to 72 h in all of the injectable solutions maintained at either 4, 21 or 40 degrees C. PMID:8933423

  20. [Pharmacokinetics of naltrexone hydrochloride and naltrexone glucuronide in the dog].

    PubMed

    Li, H; Zhao, S F; Wang, N; Ge, Z H

    1996-01-01

    Pharmacokinetics of naltrexone hydrochloride (NTX) and naltrexone glucuronide was studied in the dog using HPLC-electrochemical detection with naloxone as internal standard. After iv 5 mg or po 10 mg NTX, the plasma concentration-time curves of NTX were found to fit to a two-compartment model and a single compartment with first-order absorption. The elimination half-lives of NTX were 78 +/- 6 min and 74 +/- 6 min, respectively. Although NTX could be absorbed rapidly in the dog after po administration, the plasma concentration of the parent drug was very low and its absolute bioavailability was 15.8%. The experiments showed that the major metabolite of NTX in dog plasma was beta-glucuronidase-hydrolyzable conjugate. Dosing NTX intravenously and orally, the plasma levels of the conjugate were 1.3 and 23 times as high as that of the parent drug, the elimination half-lives of the glucuronide from plasma were 3.4 h and 12.6 h, respectively. The results indicate that NTX is subjected to a marked first-pass effect in the dog after oral administration. PMID:9208648

  1. Preliminary Toxicological Report of Metformin Hydrochloride Loaded Polymeric Nanoparticles

    PubMed Central

    Lekshmi, Unnikrishnan Meenakshi Dhana; Reddy, Pully Neelakanta

    2012-01-01

    Nanosized materials have tremendous application in every field of human activity, with a lot of economic benefit increasing nanoparticle research and use. There are number of nanosized products already available commercially and many others are in queue. Therefore, there is a pressing need for careful consideration of benefits and side effects of the use of nanoparticles in medicine. This research work aims at providing a balanced update of this exciting potentially toxicological effect of manufactured Metformin hydrochloride loaded polymeric nanoparticles. To assess the toxicities systematically on the functions of various tissues and organs in rats, the rats were fed with the manufactured polymeric nanoparticles for a period of 30 days repeated oral administration. Variation in the protein, carbohydrate and fat metabolic profile of the rat exposed to nanoparticles were studied by hematobiochemical and pathology profiles. The haemolytic potential of these nanoparticles were determined by means of an in vitro haemolysis assay. All formulations showed haemolytic effect less than 5%. The study revealed that Metformin loaded PMMA and PLGA polymeric nanoparticle did not produce any toxicity. PMID:23293465

  2. Release kinetics of papaverine hydrochloride from tablets with different excipients.

    PubMed

    Kasperek, Regina; Polski, Andrzej; Zimmer, Łukasz; Poleszak, Ewa

    2014-09-01

    The influence of excipients on the disintegration times of tablets and the release of papaverine hydrochloride (PAP) from tablets were studied. Ten different formulations of tablets with PAP were prepared by direct powder compression. Different binders, disintegrants, fillers, and lubricants were used as excipients. The release of PAP was carried out in the paddle apparatus using 0.1 N HCl as a dissolution medium. The results of the disintegration times of tablets showed that six formulations can be classified as fast dissolving tablets (FDT). FDT formulations contained Avicel PH 101, Avicel PH 102, mannitol, (3-lactose, PVP K 10, gelatinized starch (CPharmGel), Prosolv Easy Tab, Prosolv SMCC 90, magnesium stearate, and the addition of disintegrants such as AcDiSol and Kollidon CL. Drug release kinetics were estimated by the zero- and first-order, Higuchi release rate, and Korsmeyer-Peppas models. Two formulations of the tablets containing PVP (K10) (10%), CPharmGel (10% and 25%), and Prosolv Easy Tab (44% and 60%) without the addition of a disintegrant were well-fitted to the kinetics models such as the Higuchi and zero-order, which are suitable for controlled- or sustained-release. PMID:25853076

  3. Kinetics of degradation of imidapril hydrochloride in finished dosage formulations.

    PubMed

    Stanisz, Beata; Regulska, Katarzyna

    2013-01-01

    This study investigates the impact of relative air humidity and temperature on the stability of imidapril hydrochloride (IMD) tablets. For this purpose the forced degradation test was used and the following environmental conditions were employed: RH = 76.4% and the temperature range of 313 - 333 K. For the determination of IMD content in the analyzed samples a reversed-phase high performance liquid chromatography (RP-HPLC) technique was used. Three series of tablets were prepared: whole-blistered tablets, whole-bare tablets and halved-bare tablets, in order to analyze the influence of different in-home storage habits on IMD tablets' quality. In the course of the study, the degradation of IMD was observed in each series of tablets. The kinetic mechanisms and the thermodynamic parameters of these reactions were established. It was evidenced that halved IMD tablets stored without immediate packaging retain their quality only for 12 days while tablets stored according to label recommendations are stable for 513 days. PMID:23923397

  4. Cinchocaine hydrochloride determination by atomic absorption spectrometry and spectrophotometry.

    PubMed

    Abdel-Ghani, Nour T; Youssef, Ahmed F A; Awady, Mohamed A

    2005-05-01

    Two sensitive spectrophotometric and atomic absorption spectrometric procedures have been developed for determination of cinchocaine hydrochloride (Cin.Cl) in pure form and in pharmaceutical formulation. The spectrophotometric method was based on formation of an insoluble colored ion-associate between the cited drug and tetrathiocyanatocobaltate (CoTC) or hexathiocyanatochromate (CrTC) which dissolved and extracted in an organic solvent. The optimal experimental conditions for quantitative extraction such as pH, concentration of the reagents and solvent were studied. Toluene and iso-butyl alcohol proved to be the most suitable solvents for quantitative extraction of Cin-CoTC and Cin-CrTC ion-associates with maximum absorbance at 620 and 555 nm, respectively. The optimum concentration ranges, molar absorptivities, Ringbom ranges and Sandell sensitivities were also evaluated. The atomic absorption spectrometric method is based on measuring of the excess cobalt or chromium in the aqueous solution, after precipitation of the drug, at 240.7 and 357.9 nm, respectively. Linear application ranges, characteristic masses and detection limits were 57.99-361.9, 50.40 and 4.22 microg ml(-1) of Cin.Cl, in case of CoTC, while 37.99-379.9, 18.94 and 0.81 microg ml(-1) in case of CrTC. PMID:15910814

  5. Conformation and interactions of dopamine hydrochloride in solution

    SciTech Connect

    Callear, Samantha K.; Imberti, Silvia; Johnston, Andrew; McLain, Sylvia E.

    2015-01-07

    The aqueous solution of dopamine hydrochloride has been investigated using neutron and X-ray total scattering data together with Monte-Carlo based modelling using Empirical Potential Structure Refinement. The conformation of the protonated dopamine molecule is presented and the results compared to the conformations found in crystal structures, dopamine-complexed protein crystal structures and predicted from theoretical calculations and pharmacophoric models. It is found that protonated dopamine adopts a range of conformations in solution, highlighting the low rotational energy barrier between different conformations, with the preferred conformation being trans-perpendicular. The interactions between each of the species present (protonated dopamine molecules, water molecules, and chloride anions) have been determined and are discussed with reference to interactions observed in similar systems both in the liquid and crystalline state, and predicted from theoretical calculations. The expected strong hydrogen bonds between the strong hydrogen bond donors and acceptors are observed, together with evidence of weaker CH hydrogen bonds and π interactions also playing a significant role in determining the arrangement of adjacent molecules.

  6. Echocardiographic reference values in healthy cats sedated with ketamine hydrochloride.

    PubMed

    Fox, P R; Bond, B R; Peterson, M E

    1985-07-01

    An M-mode echocardiographic examination was performed in a consistent manner in 30 clinically healthy cats under light ketamine hydrochloride sedation. There was a significant linear relationship between increasing body size and increasing cardiac dimensions for several echocardiographic values. Positive correlation existed between body weight and body surface area with aortic root, left ventricular caudal wall thickness (LVCW), interventricular septal thickness (IVS), IVS/LVCW, and mean velocity of circumferential fiber shortening (Vcf); there was a negative correlation between body weight and body surface area with left ventricular ejection time (LVET). Body surface area also correlated positively with percentage of ventricular minor axis dimensional change (% delta D). Positive correlations were recorded between left ventricular end-diastolic dimension (LVEDD) and left ventricular endsystolic dimension (LVESD), LVESD and LVET, LVCW and IVS, LVET (calculated by LVCW motion) and LVET (calculated by aortic valve motion), % delta D and Vcf, heart rate and Vcf, and Vcf (calculated using aortic valve motion to compute LVET) and Vcf (using LVCW motion to compute LVET). There were negative correlations between LVEDD and % delta D, LVEDD and Vcf, LVESD and Vcf, LVET and Vcf, LVET and heart rate, LVET and % delta D. Significant differences were recorded between means of echocardiographic reference values generated in this and other studies, except for LVESD. PMID:4026030

  7. Preliminary toxicological report of metformin hydrochloride loaded polymeric nanoparticles.

    PubMed

    Lekshmi, Unnikrishnan Meenakshi Dhana; Reddy, Pully Neelakanta

    2012-09-01

    Nanosized materials have tremendous application in every field of human activity, with a lot of economic benefit increasing nanoparticle research and use. There are number of nanosized products already available commercially and many others are in queue. Therefore, there is a pressing need for careful consideration of benefits and side effects of the use of nanoparticles in medicine. This research work aims at providing a balanced update of this exciting potentially toxicological effect of manufactured Metformin hydrochloride loaded polymeric nanoparticles. To assess the toxicities systematically on the functions of various tissues and organs in rats, the rats were fed with the manufactured polymeric nanoparticles for a period of 30 days repeated oral administration. Variation in the protein, carbohydrate and fat metabolic profile of the rat exposed to nanoparticles were studied by hematobiochemical and pathology profiles. The haemolytic potential of these nanoparticles were determined by means of an in vitro haemolysis assay. All formulations showed haemolytic effect less than 5%. The study revealed that Metformin loaded PMMA and PLGA polymeric nanoparticle did not produce any toxicity. PMID:23293465

  8. [Effect of flunarizine hydrochloride on striatal D-2 dopamine receptors].

    PubMed

    Ogawa, N; Asanuma, M; Takayama, H; Sato, H; Nukina, I

    1990-11-01

    Flunarizine hydrochloride (FZ) is used to improve cerebral circulation and possesses Ca antagonistic effects. In recent years, this drug has been reported to induce parkinsonism and depressive symptoms as side effects, particularly in the elderly. Effects of FZ on dopamine receptors of the rat striatum were studied by radiolabeled receptor assay to clarify the mechanism of onset of parkinsonism in response to FZ. FZ was found to directly and competitively affect D-2 receptors without affecting D-1 receptors. Furthermore, the effect of FZ on D-2 receptors was found to be antagonistic based on the finding that the displacement curve for FZ in the binding of [3H]spiperone to D-2 receptors remained unchanged even after the addition of GppNHp. The effect of FZ on the D-2 receptors in aged rats was more marked than that in young-adult rats. In addition, the tertiary structures of FZ and the anti-schizophrenic agents, pimozide and haloperidol, were examined using computer graphics. FZ was found to have a tertiary structure highly analogous to pimozide and haloperidol, and FZ also had an alkyl structure linking a fluorophenyl group and a nitrogen atom, believed to be particularly necessary for the binding of anti-schizophrenic agents to D-2 receptors. These results may contribute to clarifying the mechanism of onset of parkinsonism in response to FZ, especially in the elderly. PMID:2150791

  9. Adsorption behavior of epirubicin hydrochloride on carboxylated carbon nanotubes.

    PubMed

    Chen, Zhe; Pierre, Dramou; He, Hua; Tan, Shuhua; Pham-Huy, Chuong; Hong, Hao; Huang, Jilong

    2011-02-28

    The aim of this study was to understand the interaction between carboxylated carbon nanotubes (c-CNTs) and anticancer agents and evaluate the drug-loading ability of c-CNTs. We prepared carboxylated multi-walled carbon nanotubes (c-MWNTs) with nitric acid treatment, then evaluated the adsorption ability of c-MWNTs as adsorbents for loading of the anticancer drug, epirubicin hydrochloride (EPI), and investigated the adsorption behavior of EPI on c-MWNTs. Unmodified multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) were included as comparative adsorbents. The results showed that carbon nanotubes were able to form supramolecular complexes with EPI via π-π stacking and possessed favorable loading properties as drug carriers. The Freundilich adsorption model was successfully employed to describe the adsorption process. Because of the high surface area and hydrogen bonding, c-MWNTs' adsorption efficiency was the highest and the most stable and their drug-loading capacity was superior to that of MWNTs. With the increase of pH, the adsorption capacity of EPI on the c-MWNTs increased. Low-temperature facilitated the adsorption. More rapid EPI adsorption rate and higher drug-loading ability were observed from c-MWNTs with smaller diameter. Moreover, the adsorption kinetics of EPI on c-MWNTs could be well depicted by using the pseudo-second-order kinetic model. PMID:21145959

  10. Release Kinetics of Papaverine Hydrochloride from Tablets with Different Excipients

    PubMed Central

    Kasperek, Regina; Polski, Andrzej; Zimmer, Łukasz; Poleszak, Ewa

    2014-01-01

    Abstract The influence of excipients on the disintegration times of tablets and the release of papaverine hydrochloride (PAP) from tablets were studied. Ten different formulations of tablets with PAP were prepared by direct powder compression. Different binders, disintegrants, fillers, and lubricants were used as excipients. The release of PAP was carried out in the paddle apparatus using 0.1 N HCl as a dissolution medium. The results of the disintegration times of tablets showed that six formulations can be classified as fast dissolving tablets (FDT). FDT formulations contained Avicel PH 101, Avicel PH 102, mannitol, (3-lactose, PVP K 10, gelatinized starch (CPharmGel), Prosolv Easy Tab, Prosolv SMCC 90, magnesium stearate, and the addition of disintegrants such as AcDiSol and Kollidon CL. Drug release kinetics were estimated by the zero- and first-order, Higuchi release rate, and Korsmeyer-Peppas models. Two formulations of the tablets containing PVP (K10) (10%), CPharmGel (10% and 25%), and Prosolv Easy Tab (44% and 60%) without the addition of a disintegrant were well-fitted to the kinetics models such as the Higuchi and zero-order, which are suitable for controlled- or sustained-release. PMID:25853076

  11. In vitro effects of Pilocarpus microphyllus extracts and pilocarpine hydrochloride on Rhipicephalus (Boophilus) microplus.

    PubMed

    Castro, Karina Neoob de Carvalho; Lima, David Fernandes; Wolschick, Dolores; Andrade, Ivanilza Moreira de; Santos, Raimunda Cardoso Dos; Santos, Francisco José de Seixas Dos; Veras, Leiz Maria Costa; Costa-Júnior, Lívio Martins

    2016-06-01

    The aim of this study was to assess the activity of aqueous (AE) and ethanolic extracts (EE) and pilocarpine hydrochloride, which were extracted and isolated from Pilocarpus microphyllus (Jaborandi), respectively, on Rhipicephalus (Boophilus) microplus. High performance liquid chromatography (HPLC) was performed to quantify these compounds. Larval packet and adult immersion tests were conducted with different concentrations. Five AE and EE concentrations, ranging from 6.2 to 100.0 mg mL-1, and six concentrations of pilocarpine hydrochloride, ranging from 0.7 to 24.0 mg mL-1, were tested. The lethal concentration (LC50) of each extract for larvae and engorged females was calculated through Probit analysis. The concentration of pilocarpine hydrochloride obtained from the EE and the AE was 1.3 and 0.3% (m/m), respectively. Pilocarpine hydrochloride presented the highest acaricidal activity on larvae (LC50 2.6 mg mL-1) and engorged females (LC50 11.8 mg mL-1) of R.(B.) microplus, followed by the EE which presented LC50 of 56.4 and 15.9 mg mL-1, for larvae and engorged females, respectively. Such results indicate that pilocarpine hydrochloride has acaricidal activity, and may be the primary compound responsible for this activity by P. microphyllus EE. PMID:27276670

  12. In vitro effects of Pilocarpus microphyllus extracts and pilocarpine hydrochloride on Rhipicephalus (Boophilus) microplus.

    PubMed

    Castro, Karina Neoob de Carvalho; Lima, David Fernandes; Wolschick, Dolores; Andrade, Ivanilza Moreira de; Santos, Raimunda Cardoso Dos; Santos, Francisco José de Seixas Dos; Veras, Leiz Maria Costa; Costa-Júnior, Lívio Martins

    2016-06-01

    The aim of this study was to assess the activity of aqueous (AE) and ethanolic extracts (EE) and pilocarpine hydrochloride, which were extracted and isolated from Pilocarpus microphyllus (Jaborandi), respectively, on Rhipicephalus (Boophilus) microplus. High performance liquid chromatography (HPLC) was performed to quantify these compounds. Larval packet and adult immersion tests were conducted with different concentrations. Five AE and EE concentrations, ranging from 6.2 to 100.0 mg mL-1, and six concentrations of pilocarpine hydrochloride, ranging from 0.7 to 24.0 mg mL-1, were tested. The lethal concentration (LC50) of each extract for larvae and engorged females was calculated through Probit analysis. The concentration of pilocarpine hydrochloride obtained from the EE and the AE was 1.3 and 0.3% (m/m), respectively. Pilocarpine hydrochloride presented the highest acaricidal activity on larvae (LC50 2.6 mg mL-1) and engorged females (LC50 11.8 mg mL-1) of R.(B.) microplus, followed by the EE which presented LC50 of 56.4 and 15.9 mg mL-1, for larvae and engorged females, respectively. Such results indicate that pilocarpine hydrochloride has acaricidal activity, and may be the primary compound responsible for this activity by P. microphyllus EE. PMID:27334829

  13. Design and development of polyethylene oxide based matrix tablets for verapamil hydrochloride.

    PubMed

    Vidyadhara, S; Sasidhar, R L C; Nagaraju, R

    2013-03-01

    In the present investigation an attempt has been made to increase therapeutic efficacy, reduced frequency of administration and improved patient compliance by developing controlled release matrix tablets of verapamil hydrochloride. Verapamil hydrochloride was formulated as oral controlled release matrix tablets by using the polyethylene oxides (Polyox WSR 303). The aim of this study was to investigate the influence of polymer level and type of fillers namely lactose (soluble filler), swellable filler (starch 1500), microcrystalline cellulose and dibasic calcium phosphate (insoluble fillers) on the release rate and mechanism of release for verapamil hydrochloride from matrix tablets prepared by direct compression process. Higher polymeric content in the matrix decreased the release rate of drug. On the other hand, replacement of lactose with anhydrous dibasic calcium phosphate and microcrystalline cellulose has significantly retarded the release rate of verapamil hydrochloride. Biopharmaceutical evaluation of satisfactory formulations were also carried out on New Zealand rabbits and parameters such as maximum plasma concentration, time to reach peak plasma concentration, area under the plasma concentration time curve(0-t) and area under first moment curve(0-t) were determined. In vivo pharmacokinetic study proves that the verapamil hydrochloride from matrix tablets showed prolonged release and were be able to sustain the therapeutic effect up to 24 h. PMID:24019567

  14. HPLC study on the stability of bendamustine hydrochloride immobilized onto polyphosphoesters.

    PubMed

    Pencheva, Ivanka; Bogomilova, Anita; Koseva, Neli; Obreshkova, Danka; Troev, Kolio

    2008-12-01

    Novel water soluble polymer complexes of bendamustine hydrochloride, a bifunctional alkylating agent with antimetabolic and cytotoxic activity, were developed using biodegradable polymer carriers-poly(oxyethylene H-phosphonate), poly(methyloxyethylene phosphate) and poly(hydroxyoxyethylene phosphate). Bendamustine hydrochloride was immobilized onto polyphosphoesters via covalent, ionic and hydrogen bonding. The structure of the complexes formed was elucidated by (1)H, (13)C, (31)P NMR and FT-IR spectroscopy. The chemical stability of bendamustine hydrochloride in the novel complexes was studied by HPLC analysis based on a validated method with appointed analytical parameters such as specificity, repeatability, limit of quantitation, limit of detection and linearity. The results from the HPLC indicate that in neutral (pH 7) and alkaline (pH 9) media bendamustine hydrochloride in the polymer complexes is more stable than the pure bendamustine hydrochloride. The enhanced stability of the immobilized drug is explained with the drug interaction with the polymer carriers or their degradation products. PMID:18926656

  15. 40 CFR 721.1025 - Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine, 2-chloro-6-methyl-. 721.1025 Section 721... Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine,...

  16. 40 CFR 721.1025 - Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine, 2-chloro-6-methyl-. 721.1025 Section 721... Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine,...

  17. Pharmacokinetics of hydromorphone hydrochloride after intravenous and intramuscular administration of a single dose to American kestrels (Falco sparverius)

    USGS Publications Warehouse

    Guzman, David Sanchez-Migallon; KuKanich, Butch; Drazenovich, Tracy L.; Olsen, Glenn H.; Paul-Murphy, Joanne R.

    2014-01-01

    Results indicated hydromorphone hydrochloride had high bioavailability and rapid elimination after IM administration, with a short terminal half-life, rapid plasma clearance, and large volume of distribution in American kestrels. Further studies regarding the effects of other doses, other administration routes, constantrate infusions, and slow release formulations on the pharmacokinetics of hydromorphone hydrochloride and its metabolites in American kestrels may be indicated.

  18. Identification of impurities and statistical classification of methamphetamine hydrochloride drugs seized in the China

    PubMed Central

    Zhang, Jian Xin; Zhang, Da Ming; Han, Xu Guang

    2008-01-01

    A total of 48 methamphetamine hydrochloride samples from eight seizures were analyzed using gas chromatography–mass spectrometry (GC–MS) and a flame ionization detector (GC–FID). Major impurities detected include 1,2-dimethyl-3-phenylaziridine, Ephedrine/pseudoephedrine, 1,3-dimethyl-2-phenylnaphthalene, 1-benzyl-3-methylnaphthalene. These data are suggestive of ephedrine/pseudoephedrine as the main precursor of the methamphetamine hydrochloride samples seized during 2006–2007. Additionally the presence of 1,3-dimethyl-2-phenylnaphthalene, 1-benzyl-3-methylnaphthalene is indicative that six seizures were synthesized via the more specific ephedrine/hydriodic acid/red phosphorus method. In addition, five impurities were found for the first time in methamphetamine hydrochloride samples. Seventeen impurity peaks were selected from the GC–FID chromatograms. The peak areas of the selected peaks were then grouped for cluster analysis. PMID:19008060

  19. Photoacoustic imaging to detect rat brain activation after cocaine hydrochloride injection

    NASA Astrophysics Data System (ADS)

    Jo, Janggun; Yang, Xinmai

    2011-03-01

    Photoacoustic imaging (PAI) was employed to detect small animal brain activation after the administration of cocaine hydrochloride. Sprague Dawley rats were injected with different concentrations (2.5, 3.0, and 5.0 mg per kg body) of cocaine hydrochloride in saline solution through tail veins. The brain functional response to the injection was monitored by photoacoustic tomography (PAT) system with horizontal scanning of cerebral cortex of rat brain. Photoacoustic microscopy (PAM) was also used for coronal view images. The modified PAT system used multiple ultrasonic detectors to reduce the scanning time and maintain a good signal-to-noise ratio (SNR). The measured photoacoustic signal changes confirmed that cocaine hydrochloride injection excited high blood volume in brain. This result shows PAI can be used to monitor drug abuse-induced brain activation.

  20. Thermal Analysis Investigation of Dapoxetine and Vardenafil Hydrochlorides using Molecular Orbital Calculations

    PubMed Central

    Attia, Ali Kamal; Souaya, Eglal R.; Soliman, Ethar A.

    2015-01-01

    Purpose: Thermal analysis techniques have been used to study the thermal behavior of dapoxetine and vardenafil hydrochlorides and confirmed using semi-empirical molecular orbital calculations. Methods: Thermogravimetric analysis, derivative thermogravimetry, differential thermal analysis and differential scanning calorimetry were used to determine the thermal behavior and purity of the drugs under investigation. Thermodynamic parameters such as activation energy, enthalpy, entropy and Gibbs free energy were calculated. Results: Thermal behavior of DAP and VAR were confirmed using by semi-empirical molecular orbital calculations. The purity values were found to be 99.97% and 99.95% for dapoxetine and vardenafil hydrochlorides, respectively. The purity of dapoxetine and vardenafil hydrochlorides is similar to that found by reported methods according to DSC data. Conclusion: Thermal analysis justifies its application in quality control of pharmaceutical compounds due to its simplicity, sensitivity and low operational costs. PMID:26819925

  1. Impurity profiling of methamphetamine hydrochloride drugs seized in the Philippines.

    PubMed

    Dayrit, Fabian M; Dumlao, Morphy C

    2004-08-11

    Methamphetamine hydrochloride is one of the most widely used illicit drugs in the Philippines. In this study, we describe the application of cluster analysis of trace impurities in the profiling of the seized methamphetamine drug samples. Thirty milligrams of a homogenized drug sample were dissolved in 1 mL of pH 10.5 buffer solution and extracted with ethyl acetate containing three internal standards. The trace impurities were identified using gas chromatography-mass spectrometry (GC-MS) and quantified by gas chromatography with a flame ionization detector (GC-FID). Following previously reported methodologies, 30 impurity peaks were selected from the GC-FID chromatograms. The peak areas and retention times were referenced to the internal standards. The peak areas of the selected peaks were then grouped for cluster analysis. In order to check for consistency of clustering, two further cluster analyses were performed using 40 and 50 impurity peaks. Changes in clustering were observed in going from 30 to 40 impurity peaks, while analyses using 40 and 50 impurity peaks gave similar results. Thus, for the seized drug samples used in this study, cluster analysis using at least 40 impurity peaks showed better consistency of clustering as compared to analysis using 30 peaks only. Ten of the impurity peaks were identified, of which four were identified for the first time in methamphetamine drug samples. These are p-bromotoluene, N-benzyl amphetamine, N-ethyl amphetamine, and N-ethyl methamphetamine. The presence of phenyl-2-propanone (P2P), N,N-dimethyl amphetamine, and N-formyl amphetamine is indicative that these casework samples were synthesized using the Leuckart method. PMID:15240018

  2. Effect of penehyclidine hydrochloride on heart rate variability in hysteroscopy

    PubMed Central

    LIU, XIAO-BO; PAN, SHU; YANG, XI-GE; LI, ZHI-WEN; SUN, QING-SHAN; ZHAO, ZHUANG; MA, HAI-CHUN; CUI, CHENG-RI

    2015-01-01

    In order to evaluate the effect of different doses of penehyclidine hydrochloride (penehyclidine) on heart rate (HR) and HR variability (HRV) in hysteroscopy, 180 patients (American Society of Anesthesiologists grade I–II) were randomized equally to three groups: 0.5 mg penehyclidine and intravenous anesthesia (group I), 1.0 mg penehyclidine and intravenous anesthesia (group II) and saddle anesthesia combined with intravenous anesthesia (control group). HR and HRV, including total power (TP), low-frequency power (LF), high-frequency power (HF) and the LF to HF ratio (LF/HF), were recorded prior and subsequent to the induction of anesthesia (T0 and T1, respectively), following the start of surgery (T2) and following completion of surgery (T3). HR was lower at T2 than at T0 in the control patients, but no differences were observed in groups I and II. The HR at T2 was increased in group II compared with that in group I. TP in group II was significantly higher compared with that in group I at T2. At T1 and at T2, the LF and HF values were lower in group I than those in the controls. Patients in group II also had higher LF and HF at T2 than patients in group I. The HF was higher at T2 than that at T0 in the controls; however, the HF and LF did not change significantly within groups I and II. No significant differences were observed in the LF/HF ratio among the three groups. At a dose of 0.5 mg, penehyclidine stabilized HRV and did not alter the autonomic nervous modulation of HR. A penehyclidine dose of 1.0 mg may be superior to a dose of 0.5 mg in maintaining HR, but is less effective at balancing sympathetic and parasympathetic activity. PMID:26170932

  3. Retinal toxicity of chloroquine hydrochloride administered by intraperitoneal injection.

    PubMed

    Gaynes, Bruce Ira; Torczynski, Elise; Varro, Zoltan; Grostern, Richard; Perlman, Jay

    2008-10-01

    Chloroquine is quinolone derivative known to exert dose-related retinal toxicity, albeit in a variable manner. It is thought that variability in the presentation of chloroquine retinopathy may be the result of perturbations in drug bioavailability subsequent to oral ingestion. In order to better understand the ramifications of bioavailability on the development of retinal injury subsequent to chloroquine use, this study investigated the relationship between retinal injury and chloroquine administration via intraperitoneal rather than oral administration. Four-week-old C57/6J mice underwent daily intraperitoneal injection of 10 mg kg(-1) chloroquine hydrochloride for a total of 62 days. Following treatment, tissue was fixed in preparation for analysis by light and transmission electron microscopy. Treated animals demonstrated marked abnormality of the outer retinal layers described as complete loss of the outer plexiform layer as well as photoreceptors and photoreceptor nuclei. The retinal pigmented epithelium demonstrated focal atrophy, loss of nuclei and pigment irregularity. Findings in the inner retina were notable for the loss of Müller cells and the presence of membranous cytoplasmic bodies. Retinae of control animals were entirely normal. In contrast to previous studies in the murine model examining chloroquine retinopathy subsequent to oral administration, this study suggests that intraperitoneal chloroquine administration facilitates retinal toxicity, presumably due to heightened drug absorption and bioavailability. It is posited that an increased rate of drug accumulation within the retina leads to an enhanced lysosomotrophic drug effect due to inability of the lysosome to compensate for chloroquine-induced elevation in pH through re-acidification of the intra-lysosomal content. PMID:18484088

  4. Determination of phenformin hydrochloride employing a sensitive fluorescent probe.

    PubMed

    Shi, Lin; Xie, Jian-Hong; Du, Li-Ming; Chang, Yin-Xia; Wu, Hao

    2016-06-01

    A complexation of non-fluorescent phenformin hydrochloride (PFH) with cucurbit [7]uril (CB [7]) in aqueous solution was investigated using the fluorescent probe of palmatine (PAL) coupled with CB [7]. The fluorescent probe of CB [7]-PAL exhibited strong fluorescence in aqueous solution, which was quenched gradually with the increase of PFH. This effect is observed because when PFH was added to the host-guest system of CB [7]-PAL, PFH and PAL competed to occupy the CB [7] cavity. Portions of the PAL molecule were expelled from the CB [7] cavity owing to the introduction of PFH. Based on the significant quenching of the supramolecular complex fluorescence intensity, a fluorescence method of high sensitivity and selectivity was developed to determine PFH with good precision and accuracy for the first time. The linear range of the method was 0.005-1.9μgmL(-1) with a detection limit of 0.003μgmL(-1). In this work, association constants (K) of PFH with CB [7] were also determined. KCB [7]-PFH=(2.52±0.05)×10(5)Lmol(-1). The ability of PFH to bind with CB [7] is stronger than that of PAL. The results of a density functional theory calculation authenticated that the moiety of PFH was embedded in the hydrophobic cavity of CB [7] tightly, and the nitrogen atom is located in the vicinity of a carbonyl-laced portal in the energy-minimized structure. The molecular modelling of the interaction between PFH and CB [7] was also confirmed by (1)H NMR spectra (Bruker 600MHz). PMID:26994318

  5. Potentiometric sensor for the high throughput determination of tetramisole hydrochloride.

    PubMed

    Gupta, Vinod Kumar; Singh, Ashok Kumar; Gupta, Barkha

    2007-08-01

    The electrochemical response characteristics of poly(vinyl)chloride (PVC) based membrane sensors for determination of tetramisole hydrochloride (TmCl) is described. The membranes of these electrodes consist of tetramisole-tetraphenyl borate (Tm-TPB), chlorophenyl borate (Tm-ClPB), and phosphotungstate (Tm(3)-PT) ion associations dispersed in a PVC matrix with dibutylpthalate as a plasticizer. The electrodes were fully characterized in terms of composition, life span, usable pH range, and working concentration range and ionic strength. The electrodes showed Nernstian response over the concentration ranges of 7.4 x 10(-7) to 1.0 x 10(-2) M, 1.7 x 10(-6) to 1.0 x 10(-2) M, and 5.6 x 10(-6) to 1.0 x 10(-2) M TmCl, respectively, and were applied to the potentiometric determination of tetramisole ion in pure solutions and pharmaceutical preparations. The potentiometric determination was also used in the determination of tetramisole in pharmaceutical preparations in four batches of different expiration dates. The electrodes exhibited good selectivity for TmCl with respect to a large number of excipients such as inorganic cations, organic cations, amino acids, and sugars. The solubility product of the ion-pair and the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductometrically. The new potentiometric method offers the advantages of high-throughput determination, simplicity, accuracy, automation feasibility, and applicability to turbid and colored sample solutions. PMID:17979641

  6. Determination of phenformin hydrochloride employing a sensitive fluorescent probe

    NASA Astrophysics Data System (ADS)

    Shi, Lin; Xie, Jian-Hong; Du, Li-Ming; Chang, Yin-xia; Wu, Hao

    2016-06-01

    A complexation of non-fluorescent phenformin hydrochloride (PFH) with cucurbit [7]uril (CB [7]) in aqueous solution was investigated using the fluorescent probe of palmatine (PAL) coupled with CB [7]. The fluorescent probe of CB [7]-PAL exhibited strong fluorescence in aqueous solution, which was quenched gradually with the increase of PFH. This effect is observed because when PFH was added to the host-guest system of CB [7]-PAL, PFH and PAL competed to occupy the CB [7] cavity. Portions of the PAL molecule were expelled from the CB [7] cavity owing to the introduction of PFH. Based on the significant quenching of the supramolecular complex fluorescence intensity, a fluorescence method of high sensitivity and selectivity was developed to determine PFH with good precision and accuracy for the first time. The linear range of the method was 0.005-1.9 μg mL- 1 with a detection limit of 0.003 μg mL- 1. In this work, association constants (K) of PFH with CB [7] were also determined. KCB [7]-PFH = (2.52 ± 0.05) × 105 L mol- 1. The ability of PFH to bind with CB [7] is stronger than that of PAL. The results of a density functional theory calculation authenticated that the moiety of PFH was embedded in the hydrophobic cavity of CB [7] tightly, and the nitrogen atom is located in the vicinity of a carbonyl-laced portal in the energy-minimized structure. The molecular modelling of the interaction between PFH and CB [7] was also confirmed by 1H NMR spectra (Bruker 600 MHz).

  7. Vibrational spectra of ketamine hydrochloride and 3, 4-methylenedioxymethamphetamine in terahertz range

    NASA Astrophysics Data System (ADS)

    Wang, Guangqin; Shen, Jingling; Jia, Yan

    2007-07-01

    The terahertz spectrum of ketamine hydrochloride at room temperature, in the range of 0.2-2.6THz, has been measured by terahertz time-domain spectroscopy (TDS). Full-geometry optimizations and frequency calculations using the density functional theory (DFT) are also applied to predict the absorption spectra of ketamine hydrochloride and 3, 4-methylenedioxymethamphetamine (MDMA). The results of the simulation show qualitative agreement with the experimental data especially for MDMA, and the observed spectra features are assigned based on the DFT calculation. The results suggest that use of the terahertz TDS technique can be an effective method for the detection and inspection of illicit drugs.

  8. [Effect of crystallinity on the rate of solution of oxytetracycline hydrochloride].

    PubMed

    Grakovskaia, L K; Nesterova, L Ia

    1982-11-01

    The crystal structure of 2 forms of oxytetracycline hydrochloride prepared with the method of crystallization from various solvents was studied. It was shown that these forms were 2 polymorphic modifications of the antibiotic with different crystal structures. The modification prepared with the method of crystallization from methanol was characterized by better dissolution in water. Its dissolution rate constant was 3 times as higher which makes this crystalline modification of oxytetracycline hydrochloride preferable for preparation of the antibiotic pharmaceutical forms with high bioavailability levels. PMID:7181463

  9. A validated HPTLC method for estimation of moxifloxacin hydrochloride in tablets.

    PubMed

    Dhillon, Vandana; Chaudhary, Alok Kumar

    2010-10-01

    A simple HPTLC method having high accuracy, precision and reproducibility was developed for the routine estimation of moxifloxacin hydrochloride in the tablets available in market and was validated for various parameters according to ICH guidelines. moxifloxacin hydrochloride was estimated at 292 nm by densitometry using Silica gel 60 F254 as stationary phase and a premix of methylene chloride: methanol: strong ammonia solution and acetonitrile (10:10:5:10) as mobile phase. Method was found linear in a range of 9-54 nanograms with a correlation coefficient >0.99. The regression equation was: AUC = 65.57 × (Amount in nanograms) + 163 (r(2) = 0.9908). PMID:23781417

  10. Comparative effects of zilpaterol hydrochloride and ractopamine hydrochloride on live performance and carcass characteristics of calf-fed Holstein steers.

    PubMed

    Brown, T R; Sexten, A K; Lawrence, T E; Miller, M F; Thomas, C L; Yates, D A; Hutcheson, J P; Hodgen, J M; Brooks, J C

    2014-09-01

    Holstein steers (n = 2,275) were assigned to 1 of 3 treatments: 1) a control diet containing no β-agonists, 2) a diet that contained zilpaterol hydrochloride (ZH; 8.3 mg/kg [100% DM basis]) for 20 d with a 3-d withdrawal period before harvest, and 3) a diet that contained ractopamine hydrochloride (RH; 30.1 mg/kg [100% DM basis]) for 28 d before harvest. No differences (P ≥ 0.18) were detected between treatments for initial BW, BW at d 28, or DMI. Final BW, BW gain for the last 28 d, total BW gain, ADG for the last 28 d, and overall ADG were greater (P < 0.05) for steers fed ZH or RH than for steers fed the control diet. Additionally, G:F for the last 28 d and G:F for the entire trial was increased (P < 0.02) for steers fed ZH (0.147, 0.147) or RH (0.153, 0.151) compared to steers fed the control diet (0.134, 0.143), respectively. Steers fed ZH or RH had HCW that were 15.5 and 8.2 kg heavier (P ≤ 0.01) and LM areas that were 7.1 and 2.3 cm(2) larger (P < 0.01) than control cattle. Steers fed ZH also had dressed carcass yields that were 1.3% to 1.5% greater and USDA calculated yield grades that were decreased 0.16 to 0.23 units compared to RH and control steers. No differences (P ≥ 0.39) were found between treatments for marbling score, fat thickness, and percentage KPH. Steers fed ZH had an increased (P ≤ 0.04) percentage of yield grade 1 and 2 carcasses (15.1, 55.0) and a reduced (P ≤ 0.02) percentage of yield grade 3 carcasses (27.1) compared with those fed RH (10.5, 49.1, 36.1) or the control diet (9.0, 47.4, 36.4), respectively. Additionally, ZH-fed steers had a decreased (P ≤ 0.04) percentage of yield grade 4 and 5 carcasses (2.8) compared with steers fed the control diet (6.9). Steers fed ZH had an increased (P ≤ 0.01) percentage of USDA Select grading carcass (31.0%) and a decreased (P ≤ 0.01) percentage of USDA Choice grading carcasses (65.0%) compared with steers fed RH (25.8%, 70.2%) and no β-agonist (24.8%, 72.0%), respectively. Feeding

  11. Dexmethylphenidate--Novartis/Celgene. Focalin, D-MPH, D-methylphenidate hydrochloride, D-methylphenidate, dexmethylphenidate, dexmethylphenidate hydrochloride.

    PubMed

    2002-01-01

    Celgene has developed a chirally pure form of methylphenidate (Ritalin), called dexmethylphenidate [d-methylphenidate, d-methylphenidate hydrochloride, d-MPH; Focalin]. The drug has been launched in the USA and is undergoing registration in Canada for the treatment of children with attention-deficit hyperactivity disorder (ADHD). Dexmethylphenidate is the single isomer version of racemic methylphenidate (Ritalin), which contains the active d isomer of Ritalin. Dexmethylphenidate acts via the inhibition of reuptake of norepinephrine and dopamine. Research is ongoing to further clarify the mode of therapeutic action in ADHD. Dexmethylphenidate was developed with the aim of reducing drug load, adverse events and drug interactions. Dexmethylphenidate provides effective management of attention-deficit hyperactivity disorder at half the dose of Ritalin. In April 2000, worldwide rights (excluding Canada) to dexmethylphenidate were granted to Novartis. Celgene has also granted Novartis rights to all related intellectual properties and patents. Novartis will fund all remaining development and marketing expenses required for regulatory approval and commercialisation of dexmethylphenidate. Crystaal Corporation, the marketing division of Biovail Corporation International, has exclusive Canadian marketing rights for all formulations of dexmethylphenidate. Novartis launched dexmethylphenidate (Focalin) in the USA during Q1 2002. It is available as a D-shaped tablet (2.5, 5 and 10 mg doses). Novartis had planned to use the tradename Ritadex, however the FDA recommended an alternative name due to potential prescribing errors with Ritalin. The finalized tradename to be used is Focalin. In July 2001, a new drug submission was filed with Canada's Therapeutic Products Programme for dexmethylphenidate in the treatment of attention-deficit disorder and attention-deficit hyperactivity disorder. Novartis is also developing an extended-release version of chirally pure dexmethylphenidate

  12. An evaluation of the influence of medetomidine hydrochloride and atipamezole hydrochloride on the arrhythmogenic dose of epinephrine in dogs during halothane anesthesia.

    PubMed Central

    Pettifer, G R; Dyson, D H; McDonell, W N

    1996-01-01

    Alterations in the arrhythmogenic dose of epinephrine (ADE) were determined following administration of medetomidine hydrochloride (750 micrograms/M2) and a saline placebo, or medetomidine hydrochloride (750 micrograms/M2), followed by specific medetomidine reversal agent, atipamezole hydrochloride (50 micrograms/kg) 20 min later, in halothane-anesthetized dogs (n = 6). ADE determinations were made prior to the administration of either treatment, 20 min and 4 h following medetomidine/saline or medetomidine/atipamezole administration. Epinephrine was infused for 3 min at increasing dose rates (2.5 and 5.0 micrograms/kg/min) until the arrhythmia criterion (4 or more intermittent or continuous premature ventricular contractions) was reached. The interinfusion interval was 20 min. There were no significant differences in the amount of epinephrine required to reach the arrhythmia criterion following the administration of either treatment. In addition, the ADE at each determination was not different between treatment groups. In this study, the administration of medetomidine to halothane-anesthetized dogs did not alter their arrhythmogenic response to infused epinephrine. PMID:8825986

  13. Unfolding and inactivation of cutinases by AOT and guanidine hydrochloride.

    PubMed

    Ternström, Tomas; Svendsen, Allan; Akke, Mikael; Adlercreutz, Patrick

    2005-04-15

    We present a comparative analysis of the unfolding and inactivation of three cutinases in the presence of guanidine hydrochloride (GdnHCl) and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). Previous investigations have focused on the cutinase from Fusarium solani pisi (FsC). In addition to FsC, the present study includes the cutinase from Humicola insolens (HiC) and a mutant variant of HiC (muHiC) with increased activity and decreased surfactant sensitivity. Equilibrium and time-resolved denaturation by AOT were studied in aqueous solution and reverse micelles, and were compared with GdnHCl denaturation. The far-UV CD and fluorescence denaturation profiles obtained in the aqueous solutions of the two denaturants coincide for all three cutinases, indicating that unfolding is a co-operative two-state process under these conditions. In reverse micelles, the cutinases unfold with mono-exponential rates, again indicating a two-state process. The free energy of denaturation in water was calculated by linear extrapolation of equilibrium data, yielding very similar values for the three cutinases with averages of -11.6 kcal mol(-1) and -2.6 kcal mol(-1) for GdnHCl and AOT, respectively. Hence, the AOT denatured state (D(AOT)) is less destabilised than the GdnHCl denatured state (D(GdnHCl)), relative to the native state in water. Far-UV CD spectroscopy revealed that D(AOT) retains some secondary structure, while D(GdnHCl) is essentially unstructured. Similarly, fluorescence data suggest that D(AOT) is more compact than D(GdnHCl). Activity measurements reveal that both D(AOT) and D(GdnHCl) are practically inactive (catalytic activity <1% of that of the native enzyme). The fluorescence spectrum of D(AOT) in reverse micelles did not differ significantly from that observed in aqueous AOT. NMR studies of D(AOT) in reverse micelles indicated that the structure is characteristic of a molten globule, consistent with the CD and fluorescence data. PMID:15752695

  14. Performance of finishing beef steers in response to anabolic implant dose and zilpaterol hydrochloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    British × Continental steers (n = 168; 7 pens/treatment; initial BW = 362 kg) were used to evaluate the dose of trenbolone acetate (TBA) and estradiol-17ß (E2) and feeding of zilpaterol hydrochloride (ZH) on performance and carcass characteristics. A randomized complete block design was used with a ...

  15. Performance of finishing beef steers in response to anabolic implant and zilpaterol hydrochloride supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objectives were to evaluate the dose/payout pattern of trenbolone acetate (TBA) and estradiol-17b (E2) implants and feeding of zilpaterol hydrochloride (ZH) on performance and carcass characteristics of finishing beef steers. A randomized complete block design was used with a 3 × 2 factorial arr...

  16. 78 FR 38053 - Determination That OPANA ER (Oxymorphone Hydrochloride) Drug Products Covered by New Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ...The Food and Drug Administration (FDA) has determined that OPANA ER (oxymorphone hydrochloride (HCl)) Extended-Release Tablet products approved under new drug application (NDA) 21-610 were not withdrawn from sale for reasons of safety or effectiveness. This determination means that FDA will not begin procedures to withdraw approval of abbreviated new drug applications (ANDAs) that refer to......

  17. Interaction of heparin sodium and dopamine hydrochloride in admixtures studied by microcalorimetry.

    PubMed

    Pereira-Rosario, R; Utamura, T; Perrin, J H

    1988-06-01

    Microcalorimetry was used to investigate the interaction between dopamine hydrochloride and heparin sodium in 5% dextrose injection and in 0.9% sodium chloride injection. Heat of reaction (in microjoules) was measured by flow calorimetry for the following combinations of solutions: dopamine hydrochloride solution and heparin sodium solution prepared from powdered forms of the drugs in water; solutions of the powdered drugs in 5% dextrose injection; solutions of the powdered drugs in 0.9% sodium chloride injection; solutions prepared in 5% dextrose injection from commercial dopamine hydrochloride injection and commercial heparin sodium injection; and solutions prepared in 0.9% sodium chloride injection from the commercial drug injections. Mixing the solutions of the powdered drugs in water caused heat to be evolved, as did mixing the solutions of the powdered drugs diluted with 5% dextrose injection and the commercial injections diluted with 5% dextrose injection. The interactions of the two drugs were believed to be ionic, based on the exothermic nature of the reaction. No heat of reaction was measurable when sodium chloride was used as the diluent. Based on this preliminary investigation, admixtures containing heparin sodium and dopamine hydrochloride should be mixed in 0.9% sodium chloride injection to minimize the risk of interaction between the two drugs. PMID:3414704

  18. Quantitative HPLC Analysis of a Psychotherapeutic Medication: Simultaneous Determination of Amitriptyline Hydrochloride and Perphenazine

    NASA Astrophysics Data System (ADS)

    Ferguson, Glenda K.

    1998-12-01

    A quantitative high-performance liquid chromatography (HPLC) laboratory experiment which entails the isocratic separation and simultaneous determination of the two active components of a commercial antipsychotic tablet has been developed. The prescription formulation used in this experiment contains amitriptyline hydrochloride (a tricyclic antidepressant) and perphenazine (a tranquilizer). Our experiment makes use of a straightforward HPLC separation on a cyanopropyl-packed column with an acetonitrile:methanol:aqueous monopotassium phosphate mobile phase pumped at a flow rate of 2.0 mL/min. Analytes are detected by UV absorbance at 215 nm. These conditions yield highly symmetrical and well-resolved peaks in less than 5 min after the injection of a mixture. In the experiment, students are given amitriptyline hydrochloride-perphenazine tablets without the manufacturer's labeled composition claim and a stock solution mixture with known concentrations of amitriptyline hydrochloride and perphenazine. They prepare four standards and a pharmaceutical sample of unknown concentration, assay each solution in quadruplicate, and plot average peak areas of the concentrations of the known solutions in the construction of a standard curve. From the mathematical relationships that result, the average masses of amitriptyline hydrochloride and perphenazine in the prescription tablet are determined. Finally, the standard deviations of the mean masses are calculated. The entire laboratory procedure and statistical data analysis can be completed in a single 3-hour period.

  19. 40 CFR Appendix B to Subpart Nnn... - Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Free Formaldehyde Analysis of Insulation Resins by Hydroxylamine Hydrochloride B Appendix B to Subpart NNN of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR...

  20. 40 CFR 721.5775 - Phenol, 5-amino-2,4-dicholoro-, hydrochloride.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenol, 5-amino-2,4-dicholoro... Specific Chemical Substances § 721.5775 Phenol, 5-amino-2,4-dicholoro-, hydrochloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  1. Enhancing the Effectiveness of Relaxation--Thermal Biofeedback Training with Propranolol Hydrochloride.

    ERIC Educational Resources Information Center

    Holroyd, Kenneth A.; And Others

    1995-01-01

    Evaluated the ability of propranolol hydrochloride to enhance results achieved with relaxation-biofeedback training. Results suggest that concomitant propranolol therapy (CPT) significantly enhanced the effectiveness of relaxation-biofeedback training. CPT also yielded larger reductions in analgesic use and greater improvements in quality-of-life…

  2. 21 CFR 520.2345h - Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets. 520.2345h Section 520.2345h Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2345h...

  3. 21 CFR 520.2345g - Tetracycline hydrochloride and sodium novobiocin tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride and sodium novobiocin tablets. 520.2345g Section 520.2345g Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2345g Tetracycline...

  4. 75 FR 14444 - Determination That DIDREX (Benzphetamine Hydrochloride) Tablets, 25 Milligrams, Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ...The Food and Drug Administration (FDA) has determined that DIDREX (benzphetamine hydrochloride (HCl)) Tablets, 25 milligrams (mg), were not withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for benzphetamine HCl 25 mg tablets, if all other legal and regulatory requirements are...

  5. 40 CFR 721.5775 - Phenol, 5-amino-2,4-dicholoro-, hydrochloride.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenol, 5-amino-2,4-dicholoro... Specific Chemical Substances § 721.5775 Phenol, 5-amino-2,4-dicholoro-, hydrochloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  6. HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR 2,4-DIMETHYLANILINE AND 2,4-DIMETHYLANILINE HYDROCHLORIDE

    EPA Science Inventory

    The Health and Environmental Effects Profile for 2-4-Dimethylaniline and 2,4-Dimethylaniline Hydrochloride was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to pr...

  7. The effects of zilpaterol hydrochloride and shade on blood metabolites of finishing beef steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of feeding zilpaterol hydrochloride (ZH) and shade were evaluated on blood metabolites and lung score in finishing beef steers. Cattle were fed 0 or 8.33 mg/kg ZH for 21 d with a 3- or 4-d withdrawal before harvest and were housed in open or shaded pens. Blood samples and lung scores w...

  8. 21 CFR 524.1662b - Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Oxytetracycline hydrochloride, polymyxin B sulfate ophthalmic ointment. 524.1662b Section 524.1662b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS...

  9. 77 FR 7583 - Determination That WILPO (phentermine hydrochloride) Tablets, 8 Milligrams, Was Not Withdrawn...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... amendments include what is now section 505(j)(7) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 355(j... suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines... HUMAN SERVICES Food and Drug Administration Determination That WILPO (phentermine hydrochloride)...

  10. A Parent Guide To Understanding the Effects of Ritalin (Methylphenidate Hydrochloride).

    ERIC Educational Resources Information Center

    Villegas, Orlando; And Others

    This guide provides information to help parents decide whether their child with attention deficit hyperactivity disorder (ADHD) should take methylphenidate hydrochloride (Ritalin). Information is provided in a question-and-answer format on various concerns, including: the meaning of ADHD, whether Ritalin is overprescribed, when this medication is…

  11. Effects of zilpaterol hydrochloride on blood gas, electrolyte balance, and pH in feedlot cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to examine the effects of zilpaterol hydrochloride (ZH) on blood gas, electrolyte balance and pH in feedlot cattle. Black-hided steers and heifers (n=96) were sourced from a commercial feedlot and transported to the Texas Tech University Beef Center in New Deal, TX. C...

  12. Evaluation of objective and subjective mobility variables in feedlot cattle supplemented with zilpaterol hydrochloride

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to examine the effects of zilpaterol hydrochloride (ZH) on mobility in feedlot cattle. Black-hided steers and heifers (n=96) were sourced from a commercial feedlot and transported to the Texas Tech University Beef Center in New Deal, TX. Cattle were weighed and scan...

  13. Improved compressibility, flowability, dissolution and bioavailability of pioglitazone hydrochloride by emulsion solvent diffusion with additives.

    PubMed

    Patil, S V; Pawar, A P; Sahoo, S K

    2012-03-01

    Spherical agglomerates of pioglitazone hydrochloride were prepared by the emulsion solvent diffusion method with additives (polyethylene glycol 6000, polyvinyl pyrrolidone, beta cyclodextrin, eudragit RS100, low acyl gellan gum and xanthan gum) using methanol, chloroform and water as a good solvent, bridging liquid and poor solvent respectively. Prepared agglomerates were evaluated for compressibility, solubility, dissolution rate and bioavailability, and characterized by SEM, XRPD, DSC and FTIR spectroscopy. Particle size, flowability, compactibility, packability, solubility, dissolution rate and bioavailability of plain agglomerates and agglomerates with additives (except with polyvinyl pyrrolidone) were advantageously improved compared with raw crystalline pioglitazone hydrochloride. These improved properties for direct compression were due to their large-spherical shape and enhanced fragmentation during compaction, together with increased tensile strength and reduced elastic recovery of the compacts. XRPD and DSC studies indicated polymorphic transition of pioglitazone hydrochloride from form II to I during recrystallization but this was not associated with any chemical transition, as indicated by FTIR spectra, well supported by stability studies. Thus spherical crystallization by the emulsion solvent diffusion method with selected additives is a satisfactory method for direct tableting of pioglitazone hydrochloride giving improved bioavailability. PMID:22530302

  14. 21 CFR 524.1484f - Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops. 524.1484f Section 524.1484f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...-susceptible organisms and/or allergy. In otitis externa, 2 to 6 drops may be placed in the external ear...

  15. 21 CFR 524.1484f - Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops. 524.1484f Section 524.1484f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...-susceptible organisms and/or allergy. In otitis externa, 2 to 6 drops may be placed in the external ear...

  16. 21 CFR 524.1484c - Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment. 524.1484c Section 524.1484c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS §...

  17. 21 CFR 524.1484f - Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops. 524.1484f Section 524.1484f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...-susceptible organisms and/or allergy. In otitis externa, 2 to 6 drops may be placed in the external ear...

  18. 21 CFR 524.1484c - Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment. 524.1484c Section 524.1484c Food and Drugs FOOD AND DRUG ADMINISTRATION... observe animals being treated for evidence of hypersensitivity or allergy to the drug. If such signs...

  19. 21 CFR 524.1484c - Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment. 524.1484c Section 524.1484c Food and Drugs FOOD AND DRUG ADMINISTRATION... observe animals being treated for evidence of hypersensitivity or allergy to the drug. If such signs...

  20. 21 CFR 524.1484c - Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Neomycin sulfate, isoflupredone acetate, tetracaine hydrochloride ointment. 524.1484c Section 524.1484c Food and Drugs FOOD AND DRUG ADMINISTRATION... observe animals being treated for evidence of hypersensitivity or allergy to the drug. If such signs...

  1. 21 CFR 524.1484f - Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate, prednisolone acetate, tetracaine hydrochloride eardrops. 524.1484f Section 524.1484f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS...

  2. 76 FR 20685 - Determination That NOVANTRONE (Mitoxantrone Hydrochloride) Injection, Equivalent to 25 Milligrams...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ...) Injection, Equivalent to 25 Milligrams Base/12.5 Milliliter and Equivalent to 30 Milligrams Base/15... NOVANTRONE (mitoxantrone hydrochloride) Injection, equivalent to (EQ) 25 milligrams (mg) base/12.5 milliliters (mL) and EQ 30 mg base/15 mL, was not withdrawn from sale for reasons of safety or...

  3. Fate and transport of the ß-adrenergic agonist ractopamine hydrochloride in soil-water systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The feed additive ractopamine hydrochloride was fortified at four concentrations into batch vials containing soils that differed in both biological activity and organic matter (OM). Sampling of the liquid layer for 14 d demonstrated that ractopamine rapidly dissipated from the liquid layer. Less t...

  4. 77 FR 53892 - Determination That ALOXI (Palonosetron Hydrochloride) Capsules, 0.5 Milligram (Base), Were Not...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ...The Food and Drug Administration (FDA) has determined that ALOXI (palonosetron hydrochloride (HCl)) Capsules, 0.5 milligram (mg) (base), were not withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for palonosetron HCl capsules, 0.5 mg (base), if all other legal and regulatory requirements are...

  5. 40 CFR 721.5775 - Phenol, 5-amino-2,4-dicholoro-, hydrochloride.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenol, 5-amino-2,4-dicholoro... Specific Chemical Substances § 721.5775 Phenol, 5-amino-2,4-dicholoro-, hydrochloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  6. 40 CFR 721.5775 - Phenol, 5-amino-2,4-dicholoro-, hydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenol, 5-amino-2,4-dicholoro... Specific Chemical Substances § 721.5775 Phenol, 5-amino-2,4-dicholoro-, hydrochloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  7. 40 CFR 721.5775 - Phenol, 5-amino-2,4-dicholoro-, hydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenol, 5-amino-2,4-dicholoro... Specific Chemical Substances § 721.5775 Phenol, 5-amino-2,4-dicholoro-, hydrochloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  8. Simultaneous HPLC Determination of Butenafine Hydrochloride and Betamethasone in a Cream Formulation

    PubMed Central

    Ankam, R.; Mukkanti, K.; Durgaprasad, S.; Khan, M.

    2009-01-01

    A fast, specific, accurate and precise reverse phase high performance liquid chromatographic method was developed for the simultaneous determination of butenafine hydrochloride and betamethasone in cream formulation. The determination was carried out on licrocart licrosphere RP-select B (250×4.6 mm, 5 μ) column in isocratic mode, the mobile phase consisting of 50 mM ammonium acetate buffer and acetonitrile in the ratio of 60:40, adjusted to pH 4.5 ± 0.1 with glacial acetic acid. The flow rate was 2.0 ml/min and eluent was monitored at 254 nm. The retention times of butenafine hydrochloride and betamethasone were 4.70 min and 7.76 min, respectively, and the resolution factor was greater than 4.0. Linearity of butenafine hydrochloride and betamethasone were in the range of 100-300 μg/ml and 5-15 μg/ml, respectively. The proposed method is also found to be precise and robust for the simultaneous determination of butenafine hydrochloride and betamethasone in cream formulation. PMID:20502575

  9. Simultaneous HPLC determination of butenafine hydrochloride and betamethasone in a cream formulation.

    PubMed

    Ankam, R; Mukkanti, K; Durgaprasad, S; Khan, M

    2009-09-01

    A fast, specific, accurate and precise reverse phase high performance liquid chromatographic method was developed for the simultaneous determination of butenafine hydrochloride and betamethasone in cream formulation. The determination was carried out on licrocart licrosphere RP-select B (250x4.6 mm, 5 mu) column in isocratic mode, the mobile phase consisting of 50 mM ammonium acetate buffer and acetonitrile in the ratio of 60:40, adjusted to pH 4.5 +/- 0.1 with glacial acetic acid. The flow rate was 2.0 ml/min and eluent was monitored at 254 nm. The retention times of butenafine hydrochloride and betamethasone were 4.70 min and 7.76 min, respectively, and the resolution factor was greater than 4.0. Linearity of butenafine hydrochloride and betamethasone were in the range of 100-300 mug/ml and 5-15 mug/ml, respectively. The proposed method is also found to be precise and robust for the simultaneous determination of butenafine hydrochloride and betamethasone in cream formulation. PMID:20502575

  10. EPR study of free-radical structure and conformation in pyridoxine hydrochloride single crystal

    NASA Astrophysics Data System (ADS)

    Masiakowski, Jerzy T.; Krzyminiewski, Ryszard; Pietrzak, Jerzy

    1985-05-01

    Numerical analysis of experimental EPR spectra of γ-irradiated single crystals of pyridoxine hydrochloride (vitamin B 6) allowed determination of the structure of the radical formed. Six hyperfine couplings were distinguished. The geometrical model of the radical was found to be in good agreement with the geometry expected from the crystal structure. Semi-empirical INDO and CNDO calculations were performed.

  11. 21 CFR 520.1242c - Levamisole hydrochloride and piperazine dihydrochloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... an aqueous solution which contains in each fluid ounce 0.36 gram of levamisole hydrochloride and piperazine dihydrochloride equivalent to 3.98 grams of piperazine base. (2) The drug is a soluble powder which when reconstituted with water contains in each fluid ounce 0.45 gram of levamisole...

  12. 21 CFR 520.1242c - Levamisole hydrochloride and piperazine dihydrochloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... an aqueous solution which contains in each fluid ounce 0.36 gram of levamisole hydrochloride and piperazine dihydrochloride equivalent to 3.98 grams of piperazine base. (2) The drug is a soluble powder which when reconstituted with water contains in each fluid ounce 0.45 gram of levamisole...

  13. Kinetic spectrophotometric methods for the determination of dothiepin hydrochloride in bulk and in drug formulation.

    PubMed

    Taha, Elham A

    2003-08-01

    Two simple and sensitive kinetic methods for the determination of dothiepin hydrochloride are described. The first method is based on kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time of 25 min. The absorbance of the colored manganate ions is measured at 610 nm. The second method is based on the reaction of dothiepin hydrochloride with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in the presence of 0.1 mol L(-1) sodium bicarbonate. Spectrophotometric measurement was achieved by recording the absorbance at 470 nm for a fixed time of 60 min. All variables affecting the development of the color were investigated and the conditions were optimized. Plots of absorbance against concentration in both procedures were rectilinear over the ranges 4-24 and 50-250 microg mL(-1), with mean recoveries 99.33+/-0.42 and 99.88+/-0.53, respectively. The proposed methods were successfully applied for the determination of dothiepin hydrochloride in bulk powder and in capsule dosage form. The results obtained were found to agree statistically with those given by the non-aqueous B.P. method. Furthermore the methods were validated according to USP guidelines and also assessed by applying the standard addition technique. The determination of dothiepin hydrochloride by the fixed concentration method is feasible with the calibration equations obtained, but the fixed time method proves to be more applicable. PMID:12856096

  14. 21 CFR 520.2345h - Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets. 520.2345h Section 520.2345h Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2345h...

  15. 21 CFR 520.2345g - Tetracycline hydrochloride and sodium novobiocin tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Tetracycline hydrochloride and sodium novobiocin tablets. 520.2345g Section 520.2345g Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2345g Tetracycline...

  16. A randomized, crossover design study of sevelamer carbonate powder and sevelamer hydrochloride tablets in chronic kidney disease patients on haemodialysis

    PubMed Central

    Fan, Stanley; Ross, Calum; Mitra, Sandip; Kalra, Philip; Heaton, Jeremy; Hunter, John; Plone, Melissa; Pritchard, Nick

    2009-01-01

    Background. Sevelamer carbonate is an improved, buffered form of sevelamer hydrochloride developed for the treatment of hyperphosphataemia in CKD patients. Sevelamer carbonate formulated as a powder for oral suspension presents a novel, patient-friendly alternative to tablet phosphate binders. This study compared the safety and efficacy of sevelamer carbonate powder with sevelamer hydrochloride tablets in CKD patients on haemodialysis. Methods. This was a multi-centre, open-label, randomized, crossover design study. Thirty-one haemodialysis patients were randomly assigned to either sevelamer carbonate powder or sevelamer hydrochloride tablets for 4 weeks followed by a crossover to the other regimen for an additional 4 weeks. Results. The mean serum phosphorus was 1.6 ± 0.5 mmol/L (5.0 ± 1.5 mg/dL) during sevelamer carbonate powder treatment and 1.7 ± 0.4 mmol/L (5.2 ± 1.1 mg/dL) during sevelamer hydrochloride tablet treatment. Sevelamer carbonate powder and sevelamer hydrochloride tablets are equivalent in controlling serum phosphorus; the geometric least square mean ratio was 0.95 (90% CI 0.87–1.03). No statistically significant or clinically meaningful differences were observed in calcium × phosphorus product and lipid levels between sevelamer carbonate powder and sevelamer hydrochloride tablets. Serum bicarbonate levels increased 2.7 ± 3.7 mmol/L (2.7 ± 3.7 mEq/L) during sevelamer carbonate treatment. No statistically significant change in bicarbonate was observed during sevelamer hydrochloride treatment. Sevelamer carbonate powder and sevelamer hydrochloride were well tolerated during this study. Conclusions. Sevelamer carbonate powder and sevelamer hydrochloride tablets are equivalent in controlling serum phosphorus and well tolerated in CKD patients on haemodialysis. Bicarbonate levels improved only during sevelamer carbonate treatment. Sevelamer carbonate powder should provide a welcomed new option for the treatment of hyperphosphataemia for CKD

  17. Heat-induced reshaping and coarsening of metal nanoparticle-graphene oxide hybrids

    NASA Astrophysics Data System (ADS)

    Pan, Hanqing

    coalesce or undergo reshaping at a lower temperature. Nanoparticle- and nanorod-graphene oxide hybrid materials were also used to study the effect of covalent and non-covalent interactions between gold nanoparticles or nanorods and graphene oxide during coarsening or reshaping, respectively. Non-covalent interactions were studied by directly adding graphene oxide to aqueous solutions containing water-soluble metal nanoparticles or nanorods, and covalent interactions were achieved by the self-assembly of the same nanoparticles onto thiolated graphene oxide that was prepared by coupling L-cystine using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). When nanoparticles and nanorods are attached to graphene oxide through additional -covalent bonds, they are more strongly immobilized and therefore would undergo less coalescence and slower reshaping upon heating.

  18. In vitro and in vivo genotoxicity assessment of the dopamine receptor antagonist molindone hydrochloride.

    PubMed

    Krishna, Gopala; Gopalakrishnan, Gopa; Goel, Saryu

    2016-05-01

    Molindone hydrochloride is a dihydroindolone neuroleptic with dopamine D2 and D5 receptor antagonist activity. As an integral component of its preclinical safety evaluation, molindone hydrochloride was evaluated in a series of in vitro and in vivo genetic toxicology assays. In the bacterial reverse gene mutation assays employing four Salmonella tester strains (TA98, TA100, TA1535, and TA1537) and the E. coli tester strain WP2uvrA, molindone hydrochloride was negative in all strains, except TA100, in which it induced a positive response (up to 3-fold) in the presence of rat liver S9. With human S9, a small (2-fold), but nonreproducible, increase in revertants was observed in TA100 at the highest concentration of molindone tested (5,000 µg/plate). The mutagenicity was completely abrogated by the addition of glutathione and UDP-glucuronic acid to rat liver S9, suggesting detoxification of the mutagenic metabolite(s) by Phase II conjugation reactions, pathways commonly operational in humans. Molindone hydrochloride did not induce chromosomal aberrations in human lymphocyte cultures, did not elicit a positive response in a rat bone marrow micronucleus test for clastogencity/aneugenicity, and did not give a positive response in the rat liver comet assay for DNA damage. Collectively, the weight of evidence from these studies, combined with a large margin of safety and efficient detoxification through Phase II conjugation supports the interpretation that molindone hydrochloride does not pose a genotoxic risk to humans at the anticipated clinical dose levels. Environ. Mol. Mutagen. 57:288-298, 2016. © 2016 Wiley Periodicals, Inc. PMID:27040600

  19. Optimization of mesoporous carbons for efficient adsorption of berberine hydrochloride from aqueous solutions.

    PubMed

    Li, Yin; Fu, Jie; Deng, Shuguang; Lu, Xiuyang

    2014-06-15

    Sixteen mesoporous carbon adsorbents were synthesized by varying the ratio of soft to hard templates in order to optimize the pore textural properties of these adsorbents. The mesoporous carbon adsorbents have a high BET specific surface area (1590.3-2193.5 m(2)/g), large pore volume (1.72-2.56 cm(3)/g), and uniform pore size distribution with a median pore diameter ranging from 3.51 nm to 4.52 nm. It was observed that pore textural properties of the carbon adsorbents critically depend on the molar ratio of carbon sources to templates, and the hard template plays a more important role than the soft template in manipulating the pore textures. Adsorption isotherms of berberine hydrochloride at 303 K were measured to evaluate the adsorption efficacy of these adsorbents. The adsorption of berberine hydrochloride from aqueous solutions on the sixteen mesoporous carbon adsorbents synthesized in this work is very efficient, and the adsorption equilibrium capacities on all samples are more than double the adsorption capacities of berberine hydrochloride of the benchmark adsorbents (polymer resins and spherical activated carbons) at similar conditions. It was observed from the adsorption experiments that the equilibrium adsorption amounts of berberine hydrochloride are strongly correlated with the BET specific surface area and pore volume of the adsorbents. The adsorbent with the highest BET of 2193.5 m(2)/g displayed the largest adsorption capacity of 574 mg/g at an equilibrium concentration of 0.10mg/mL of berberine hydrochloride in an aqueous solution. PMID:24767505

  20. Stability studies of lincomycin hydrochloride in aqueous solution and intravenous infusion fluids

    PubMed Central

    Czarniak, Petra; Boddy, Michael; Sunderland, Bruce; Hughes, Jeff D

    2016-01-01

    Purpose The purpose of this study was to evaluate the chemical stability of Lincocin® (lincomycin hydrochloride) in commonly used intravenous fluids at room temperature (25°C), at accelerated-degradation temperatures and in selected buffer solutions. Materials and methods The stability of Lincocin® injection (containing lincomycin 600 mg/2 mL as the hydrochloride) stored at 25°C±0.1°C in sodium lactate (Hartmann’s), 0.9% sodium chloride, 5% glucose, and 10% glucose solutions was investigated over 31 days. Forced degradation of Lincocin® in hydrochloric acid, sodium hydroxide, and hydrogen peroxide was performed at 60°C. The effect of pH on the degradation rate of lincomycin hydrochloride stored at 80°C was determined. Results Lincomycin hydrochloride w as found to maintain its shelf life at 25°C in sodium lactate (Hartmann’s) solution, 0.9% sodium chloride solution, 5% glucose solution, and 10% glucose solution, with less than 5% lincomycin degradation occurring in all intravenous solutions over a 31-day period. Lincomycin hydrochloride showed less rapid degradation at 60°C in acid than in basic solution, but degraded rapidly in hydrogen peroxide. At all pH values tested, lincomycin followed first-order kinetics. It had the greatest stability near pH 4 when stored at 80°C (calculated shelf life of 4.59 days), and was least stable at pH 2 (calculated shelf life of 0.38 days). Conclusion Lincocin® injection was chemically found to have a shelf life of at least 31 days at 25°C when added to sodium lactate (Hartmann’s) solution, 0.9% sodium chloride solution, 5% glucose solution, and 10% glucose solution. Solutions prepared at approximately pH 4 are likely to have optimum stability. PMID:27022242