Molecular structure activity on pharmaceutical applications of Phenacetin using spectroscopic investigation

NASA Astrophysics Data System (ADS)

Madanagopal, A.; Periandy, S.; Gayathri, P.; Ramalingam, S.; Xavier, S.

2017-01-01

The pharmaceutical compound; Phenacetin was investigated by analyzing FT-IR, FT-Raman and 1H &13C NMR spectra. The hybrid efficient computational calculations performed for computing physical and chemical parameters. The cause of pharmaceutical activity due to the substitutions; carboxylic, methyl and amine groups in appropriate positions on the pedestal compound was deeply investigated. Moreover, 13C NMR and 1H NMR chemical shifts correlated with TMS standard to explain the truth of compositional ratio of base and ligand groups. The bathochromic shift due to chromophores over the energy levels in UV-Visible region was strongly emphasized the Anti-inflammatory chemical properties. The chemical stability was pronounced by the strong kubo gap which showed the occurring of charge transformation within the molecule. The occurrence of the chemical reaction was feasibly interpreted by Gibbs free energy profile. The standard vibrational analysis stressed the active participation of composed ligand groups for the existence of the analgesic as well as antipyretic properties of the Phenacetin compound. The strong dipole interaction energy utilization for the transition among non-vanishing donor and acceptor for composition of the molecular structure was interpreted.

Thermodynamic study of the transfer of acetanilide and phenacetin from water to different organic solvents.

PubMed

Baena, Yolima; Pinzón, Jorge A; Barbosa, Helber J; Martínez, Fleming

2005-06-01

The molar (K(C)(o/w)) and rational (K(X)(o/w)) partition coefficients in the octanol/buffer, i-propyl myristate/buffer, chloroform/buffer, and cyclohexane/buffer systems were determined for acetanilide and phenacetin at 25.0, 30.0, 35.0, and 40.0 degrees C. In all cases except for cyclohexane, the K(C)(o/w) and K(X)(o/w) values were greater than unity. This demonstrates that these two drugs have predominantly lipophilic behavior. Gibbs and van't Hoff thermodynamic analyses have revealed that the transfer of these drugs from water to organic solvents is spontaneous and that it is mainly driven enthalpically for i-propyl myristate and chloroform, and entropy-driven for octanol and cyclohexane.

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation.

PubMed

Paluch, Andrew S; Parameswaran, Sreeja; Liu, Shuai; Kolavennu, Anasuya; Mobley, David L

2015-01-28

We present a general framework to predict the excess solubility of small molecular solids (such as pharmaceutical solids) in binary solvents via molecular simulation free energy calculations at infinite dilution with conventional molecular models. The present study used molecular dynamics with the General AMBER Force Field to predict the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol solvents. The simulations are able to predict the existence of solubility enhancement and the results are in good agreement with available experimental data. The accuracy of the predictions in addition to the generality of the method suggests that molecular simulations may be a valuable design tool for solvent selection in drug development processes.

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation

NASA Astrophysics Data System (ADS)

Paluch, Andrew S.; Parameswaran, Sreeja; Liu, Shuai; Kolavennu, Anasuya; Mobley, David L.

2015-01-01

We present a general framework to predict the excess solubility of small molecular solids (such as pharmaceutical solids) in binary solvents via molecular simulation free energy calculations at infinite dilution with conventional molecular models. The present study used molecular dynamics with the General AMBER Force Field to predict the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol solvents. The simulations are able to predict the existence of solubility enhancement and the results are in good agreement with available experimental data. The accuracy of the predictions in addition to the generality of the method suggests that molecular simulations may be a valuable design tool for solvent selection in drug development processes.

Studies of paracetamol/phenacetin toxicity: isolation and characterization of p-aminophenol-glutathione conjugate.

PubMed

Eyanagi, R; Hisanari, Y; Shigematsu, H

1991-06-01

1. p-Aminophenol, a minor metabolite of phenacetin, is a potent nephrotoxic agent. 2. We have examined the binding of p-aminophenol to glutathione (GSH), a model amino acid, in the presence of horseradish peroxidase, which catalyses one electron oxidation. 3. The reaction product was purified by preparative h.p.l.c., and its structure was determined by FAB mass spectrometry and 1H-n.m.r. to be a p-aminophenol-GSH conjugate. The conjugate was formed between the ortho carbon of the amino group of p-aminophenol and the SH group of GSH. 4. It was confirmed by h.p.l.c. and 1H-n.m.r. that formation of the conjugate was catalysed in vitro by rat liver microsomes and cumene hydroperoxide.

Predicting the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol mixtures via molecular simulation

PubMed Central

Paluch, Andrew S.; Parameswaran, Sreeja; Liu, Shuai; Kolavennu, Anasuya; Mobley, David L.

2015-01-01

We present a general framework to predict the excess solubility of small molecular solids (such as pharmaceutical solids) in binary solvents via molecular simulation free energy calculations at infinite dilution with conventional molecular models. The present study used molecular dynamics with the General AMBER Force Field to predict the excess solubility of acetanilide, acetaminophen, phenacetin, benzocaine, and caffeine in binary water/ethanol solvents. The simulations are able to predict the existence of solubility enhancement and the results are in good agreement with available experimental data. The accuracy of the predictions in addition to the generality of the method suggests that molecular simulations may be a valuable design tool for solvent selection in drug development processes. PMID:25637996

Do caffeine-containing analgesics promote dependence? A review and evaluation.

PubMed

Feinstein, A R; Heinemann, L A; Dalessio, D; Fox, J M; Goldstein, J; Haag, G; Ladewig, D; O'Brien, C P

2000-11-01

Debates about the suspected association between kidney disease and use of analgesics have led to concern about whether caffeine could stimulate an undesirable overuse of phenacetin-free combined analgesics. A committee was asked to critically review the pertinent literature and to suggest guides for clinical practice and for consideration of international regulatory authorities. A group of international scientists, jointly selected by the regulatory authorities of Germany, Switzerland, and Austria and the pharmaceutical industry. All invited experts evaluated relevant literature and reports and added further information and comments. Caffeine has a synergistic effectiveness with analgesics. Although caffeine has a dependence potential, the potential is low. Experimental data regarding dependence potential for caffeine alone may not correspond to the conditions in patients with pain. Withdrawal is not likely to cause stimulation or sustainment of analgesic intake. For drug-induced headache, no single or combined analgesic was consistently identified as causative, and no evidence exists for a special role of caffeine. Strong dependence behavior was observed only in patients using phenacetin-containing preparations, coformulated with antipyretics/analgesics and caffeine. This finding may have led to the impression that caffeine stimulates overuse of analgesics. Although more experimental and long-term data would be desirable to show possible mechanisms of dependence and to offer unequivocal proof of safety, the committee concluded that the available evidence does not support the claim that analgesics coformulated with caffeine, in the absence of phenacetin, stimulate or sustain overuse.

21 CFR 201.309 - Acetophenetidin (phenacetin)-containing preparations; necessary warning statement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... of the drug were in fact responsible for kidney lesions and disease. The Commissioner of Food and... statement to the following effect: “Warning—This medication may damage the kidneys when used in large...

Analysis of cocaine and its adulterants in drugs for international trafficking seized by the Brazilian Federal Police.

PubMed

Lapachinske, Silvio Fernandes; Okai, Guilherme Gonçalves; dos Santos, Ariana; de Bairros, André Valle; Yonamine, Mauricio

2015-02-01

Here, gas chromatography with nitrogen phosphorous detector (GC-NPD) method was developed and validated for the quantification of cocaine and adulterants (caffeine, 4-dimethylaminoantipyrine, levamisole, lidocaine and phenacetin) in illicit samples. The method was based on direct dilution of samples in methanol, sonication for 5 min and centrifugation. After appropriate dilution, an aliquot was injected into GC-MS in order to identify the active compounds and into GC-NPD for the analytes quantification. Bupivacaine was used as an internal standard. The method showed to be precise, accurate and linear over a range of 0.5-100% (weight/weight percentages) for all analytes, except phenacetin which showed a linear range between 2% and 100%. The method was successfully applied to 54 samples seized by the Brazilian Federal Police in the International Airport of Sao Paulo and mailing services during the year 2011. All the samples were associated with international trafficking and were apprehended while leaving the country. The purity of cocaine ranged from 16.5% to 91.4%. Cocaine was the only detected active compound in 29.6% of total samples. Among the identified cutting agents, levamisole was the most abundant (55.6% of the total samples) and relative concentrations (weight/weight percentages) ranged from 0.7% to 23%. Lidocaine, caffeine, phenacetin and 4-dimethylaminoantipyrine were also identified in these samples in minor concentrations. In contrast with what we initially hypothesized, drugs intended to international trafficking did not present high cocaine purity and most of the samples were laced with adulterants before leaving Brazil. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Case-control study on analgesics and nephropathy (SAN): protocol

PubMed Central

Heinemann, Lothar AJ; Garbe, Edeltraut; Lewis, Michael; van der Woude, Fokko; Graf, Helmut

2005-01-01

Background The association between intake of non-phenacetin-containing analgesics and the occurrence of chronic renal failure is still controversially discussed. A new epidemiologic study was planned and conducted in Germany and Austria. Methods/design The objective of the international, multicenter case-control study was to evaluate the association between end-stage renal disease (ESRD) and use of non-phenacetin-containing analgesics with particular emphasis on combined formulations. A targeted sample of 1000 new (incident) dialysis patients, aged less than 50 years, was planned to recruit between January 1, 2001 and December 31, 2004. The age limit was chosen to avoid contamination of the study population with phenacetin-containing analgesics to the extent possible. Four control subjects per ESRD case, matched by age, sex, and region were selected from the population living in the region the case came from. Lifetime exposure to analgesics and potential renal risk factors were recorded in a single face-to-face interview. A set of aids was introduced to reinforce the memory of study participants. A standardized, pre-tested interview questionnaire (participants), a medical documentation sheet (physicians in dialysis centres), a logbook for all activities (dialysis centres) were used to collect the necessary data. Quality management consisted of the standardized procedures, (re-) training and supervision of interviewers, regular checks of all incoming data for completeness and plausibility. The study is scientifically independent and governed by a international Scientific Advisory Committee that bridged the gap between the sponsoring companies and the investigators. Also other advisory groups assisted the managing committee of the study. All relevant German and Austrian nephrological associations supported the study, and the study design was carefully reviewed and approved by the Kidney Foundation of Germany. Discussion The study is expected to answer the main research question by end 2005. There is however a high potential for various biases that we tried to address with adequate measure. One limitation however cannot be overcome: The methodologically needed age-limitation of the study will make it not easy to generalize the results to age groups over 50 years. It might be suggested to repeat the study for persons over 50 years in 10 years when contamination with phenacetin use early in life is likely to be outgrown. PMID:16086834

Metabolite formation kinetics and intrinsic clearance of phenacetin, tolbutamide, alprazolam, and midazolam in adenoviral cytochrome P450-transfected HepG2 cells and comparison with hepatocytes and in vivo.

PubMed

Donato, M Teresa; Hallifax, David; Picazo, Laura; Castell, José V; Houston, J Brian; Gomez-Lechón, M José; Lahoz, Agustin

2010-09-01

Cryopreserved human hepatocytes and other in vitro systems often underpredict in vivo intrinsic clearance (CL(int)). The aim of this study was to explore the potential utility of HepG2 cells transduced with adenovirus vectors expressing a single cytochrome P450 enzyme (Ad-CYP1A2, Ad-CYP2C9, or Ad-CYP3A4) for metabolic clearance predictions. The kinetics of metabolite formation from phenacetin, tolbutamide, and alprazolam and midazolam, selected as substrates probes for CYP1A2, CYP2C9, and CYP3A4, respectively, were characterized in this in vitro system. The magnitude of the K(m) or S(50) values observed in Ad-P450 cells was similar to those found in the literature for other human liver-derived systems. For each substrate, CL(int) (or CL(max)), values from Ad-P450 systems were scaled to human hepatocytes in primary culture using the relative activity factor (RAF) approach. Scaled Ad-P450 CL(int) values were approximately 3- to 6-fold higher (for phenacetin O-deethylation, tolbutamide 4-hydroxylation, and alprazolam 4-hydroxyaltion) or lower (midazolam 1'-hydroxylation) than those reported for human cryopreserved hepatocytes in suspension. Comparison with the in vivo data reveals that Ad-P450 cells provide a favorable prediction of CL(int) for the substrates studied (in a range of 20-200% in vivo observed CL(int)). This is an improvement compared with the consistent underpredictions (<10-50% in in vivo observed CL(int)) found in cryopreserved hepatocyte studies with the same substrates. These results suggest that the Ad-P450 cell is a promising in vitro system for clearance predictions of P450-metabolized drugs.

Kinetics of aqueous chlorination of some pharmaceuticals and their elimination from water matrices.

PubMed

Acero, Juan L; Benitez, F Javier; Real, Francisco J; Roldan, Gloria

2010-07-01

Apparent rate constants for the reactions of four selected pharmaceutical compounds (metoprolol, naproxen, amoxicillin, and phenacetin) with chlorine in ultra-pure (UP) water were determined as a function of the pH. It was found that amoxicillin (in the whole pH range 3-12), and naproxen (in the low pH range 2-4) presented high reaction rates, while naproxen (in the pH range 5-9), and phenacetin and metoprolol (in the pH range 2.5-12 for phenacetin, and 3-10 for metoprolol) followed intermediate and slow reaction rates. A mechanism is proposed for the chlorination reaction, which allowed the evaluation of the intrinsic rate constants for the elementary reactions of the ionized and un-ionized species of each selected pharmaceutical with chlorine. An excellent agreement is obtained between experimental and calculated rate constants by this mechanism.The elimination of these substances in several waters (a groundwater, a surface water from a public reservoir, and two effluents from municipal wastewater treatment plants) was also investigated at neutral pH. The efficiency of the chlorination process with respect to the pharmaceuticals elimination and the formation THMs was also established. It is generally observed that the increasing presence of organic and inorganic matter in the water matrices demand more oxidant agent (chlorine), and therefore, less chlorine is available for the oxidation of these compounds. Finally, half-life times and oxidant exposures (CT) required for the removal of 99% of the four pharmaceuticals are also evaluated. These parameters are useful for the establishment of safety chlorine doses in oxidation or disinfection stages of pharmaceuticals in treatment plants.

Acute spinal cord injury changes the disposition of some, but not all drugs given intravenously.

PubMed

García-López, P; Martínez-Cruz, A; Guízar-Sahagún, G; Castañeda-Hernández, G

2007-09-01

Experimental laboratory investigations in paraplegic rats. In order to understand why acute spinal cord injury (SCI) changes the disposition of some, but not all drugs given intravenously (i.v.), pharmacokinetic parameters of drugs with different pharmacological properties were evaluated to determine the influence of SCI on physiological processes such as distribution, metabolism and excretion. Mexico City, Mexico. Rats were subjected to severe SCI (contusion) at T-9 level; pharmacokinetic studies of phenacetin, naproxen or gentamicin were performed 24 h after. These drugs were not chosen as markers because of their therapeutic properties, but because of their pharmacokinetic characteristics. Additional studies including plasma proteins, liver and renal function tests, and micro-vascular hepatic blood flow, were also performed at the same time after injury. Acute SCI significantly reduced distribution of drugs with intermediate and low binding to plasma proteins (phenacetin 30% and gentamicin 10%, respectively), but distribution did not change when naproxen - a drug highly bound to plasma proteins (99%) - was used, in absence of changes in plasma proteins. Metabolism was significantly altered only for a drug with liver blood flow - limited clearance (phenacetin) and not for a drug with liver capacity-limited clearance (naproxen). The liver function test did not change, whereas the hepatic micro-vascular blood flow significantly decreased after SCI. Renal excretion, evaluated by gentamicin clearance, was significantly reduced as a consequence of SCI, without significant changes in serum creatinine. Changes in drug disposition associated to acute SCI are complex and generalization is not possible. They are highly dependent on each drug properties as well as on the altered physiological processes. Results motivate the quest for strategies to improve disposition of selective i.v. drugs during spinal shock, in an effort to avoid therapeutic failure.

Determination of Log K[subscript ow] Values for Four Drugs

ERIC Educational Resources Information Center

Harris, Mark F.; Logan, Jennifer L.

2014-01-01

Though many undergraduates are interested in medicine, relatively few experiments related to drug design and development are included in introductory chemistry laboratory courses. In this experiment, aqueous solutions of four different drugs (acetaminophen, caffeine, phenacetin, and sulfanilamide) are extracted using 1-octanol, a mimic of the…

21 CFR 201.309 - Acetophenetidin (phenacetin)-containing preparations; necessary warning statement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... investigation of reports of possible toxic effects and renal damage due to misuse of the drug acetophenetidin..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL LABELING Specific Labeling Requirements... Drugs, in December 1963, appointed an ad hoc Advisory Committee of Inquiry on Possible Nephrotoxicity...

Isolation of an inducible amidase from Pseudomonas acidovorans AE1.

PubMed

Alt, J; Krisch, K

1975-04-01

A bacterial strain, AEI, which hydrolysed acetanilide, was isolated from soil and identified as Pseudomonas acidovorans. Numerous amides, esters and enzyme inhibitors were tested as amidase inducers. Phenacetin was chosen as inducer for the large scale cultivation of these organisms because it was less toxic to the bacteria than acetanilide. The induction increased the enzymic activity 250-fold. In comparison, the type culture strain of P. acidovorans, ATTCCI5668, had no amidase activity which could be induced by phenacetin. Optimal growth conditions were established with respect to the concentration of carbon source and inducer so that about 10% of the extractable bacterial protein consisted of the amidase. The organisms were lysed with lysozyme in the presence of EDTA and the enzyme was isolated mainly by column chromatography procedures. A preparation form 60 g (wet wt) bacteria yielded about 100 mg highly purified amidase with a specific activity of 137 mugmol substrate hydrolysed/min/mg protien. In addition to acetanilide, the purified enzyme hydrolysed several other amides and esters. As standard substrate, p-nitroacetanilide was chosen.

Installation Restoration Program. Remedial Investigation Report. Site 1. Fire Training Area. Volk Field Air National Guard Base, Camp Douglas, WI. Volume 1

DTIC Science & Technology

1990-07-01

Nitroaniline 4-Nitroaniline N-Nitroso-di-n-butylamine N-Nitrosopiperidine Pentachlorobenzene Pentachloronitrobenzene Phenacetin 2- Picoline Pronarnide 1,2,4,5... chromium . Cu: Chemical symbol for copper. 3 DARCY’S LAW: An equation describing the flow of fluids in porous media based on the assumption that the flow

Acetaminophen/paracetamol: A history of errors, failures and false decisions.

PubMed

Brune, K; Renner, B; Tiegs, G

2015-08-01

Acetaminophen/paracetamol is the most widely used drug of the world. At the same time, it is probably one of the most dangerous compounds in medical use, causing hundreds of deaths in all industrialized countries due to acute liver failure (ALF). Publications of the last 130 years found in the usual databases were analyzed. Personal contacts existed to renowned researchers having contributed to the medical use of paracetamol and its precursors as H.U. Zollinger, S. Moeschlin, U. Dubach, J. Axelrod and others. Further information is found in earlier reviews by Eichengrün, Rodnan and Benedek, Sneader, Brune; comp. references. The history of the discovery of paracetamol starts with an error (active against worms), continues with a false assumption (paracetamol is safer than phenacetin), describes the first side-effect 'epidemy' (phenacetin nephropathy, drug-induced interstitial nephritis) and ends with the discovery of second-generation problems due to the unavoidable production of a highly toxic metabolite of paracetamol N-acetyl-p-benzoquinone imine (NAPQI) that may cause not only ALF and kidney damage but also impaired development of the fetus and the newborn child. It appears timely to reassess the risk/benefit ratio of this compound. © 2014 European Pain Federation - EFIC®

Analgesics use and ESRD in younger age: a case-control study

PubMed Central

van der Woude, Fokke J; Heinemann, Lothar AJ; Graf, Helmut; Lewis, Michael; Moehner, Sabine; Assmann, Anita; Kühl-Habich, Doerthe

2007-01-01

Background An ad hoc peer-review committee was jointly appointed by Drug Authorities and Industry in Germany, Austria and Switzerland in 1999/2000 to review the evidence for a causal relation between phenacetin-free analgesics and nephropathy. The committee found the evidence as inconclusive and requested a new case-control study of adequate design. Methods We performed a population-based case-control study with incident cases of end-stage renal disease (ESRD) under the age of 50 years and four age and sex-matched neighborhood controls in 170 dialysis centers (153 in Germany, and 17 in Austria) from January 1, 2001 to December 31, 2004. Data on lifetime medical history, risk factors, treatment, job exposure and intake of analgesics were obtained in a standardized face-to-face interview using memory aids to enhance accuracy. Study design, study performance, analysis plan, and study report were approved by an independent international advisory committee and by the Drug Authorities involved. Unconditional logistic regression analyses were performed. Results The analysis included 907 cases and 3,622 controls who had never used phenacetin-containing analgesics in their lifetime. The use of high cumulative lifetime dose (3rd tertile) of analgesics in the period up to five years before dialysis was not associated with later ESRD. Adjusted odds ratios with 95% confidence intervals were 0.8 (0.7 – 1.0) and 1.0 (0.8 – 1.3) for ever- compared with no or low use and high use compared with low use, respectively. The same results were found for all analgesics and for mono-, and combination preparations with and without caffeine. No increased risk was shown in analyses stratifying for dose and duration. Dose-response analyses showed that analgesic use was not associated with an increased risk for ESRD up to 3.5 kg cumulative lifetime dose (98 % of the cases with ESRD). While the large subgroup of users with a lifetime dose up to 0.5 kg (278 cases and 1365 controls) showed a significantly decreased risk, a tiny subgroup of extreme users with over 3.5 kg lifetime use (19 cases and 11 controls) showed a significant risk increase. The detailed evaluation of 22 cases and 19 controls with over 2.5 kg lifetime use recommended by the regulatory advisors showed an impressive excess of other conditions than analgesics triggering the evolution of ESRD in cases compared with controls. Conclusion We found no clinically meaningful evidence for an increased risk of ESRD associated with use of phenacetin-free analgesics in single or combined formulation. The apparent risk increase shown in a small subgroup with extreme lifetime dose of analgesics is most likely an indirect, non-causal association. This hypothesis, however, cannot be confirmed or refuted within our case-control study. Overall, our results lend support to the mounting evidence that phenacetin-free analgesics do not induce ESRD and that the notion of "analgesic nephropathy" needs to be re-evaluated. PMID:18053232

Formation of 4-ethoxy-4'-nitrosodiphenylamine in the reaction of the phenacetin metabolite 4-nitrosophenetol with glutathione.

PubMed

Klehr, H; Eyer, P; Schäfer, W

1987-08-01

Phenacetin, a constituent of several analgesic and antipyretic formulations has been made responsible for a variety of toxic and carcinogenic actions. 4-Nitrosophenetol, the N-oxydation product of intermediate 4-phenetidine, forms methemoglobin and binds covalently to sulfhydryl groups of proteins and glutathione. In the reaction of 4-nitrosophenetol with glutathione and other thiols an intermediate so-called "semimercaptal" is formed from which N-(thiol-S-yl)-4-phenetidine S-oxide, N-(thiol-S-yl)-4-phenetidine and 4-phenetidine derive. Besides thiol adducts, a yellow compound is formed which was isolated as a pure crystalline product (elemental analysis) and identified by FAB-MS, EI-MS, 13C-, 1H-NMR, and UV-VIS spectroscopy as 4-ethoxy-4'-nitrosodiphenylamine. This nitrosoarene is formed by an unknown mechanism from 4-nitrosophenetol and 4-phenetidine under liberation of ethanol. In human erythrocytes this compound is easily reduced to 4-amino-4'-ethoxydiphenylamine (FAB-MS, EI-MS, 13C-NMR). During the reaction of 4-nitrosophenetol with red cells only traces of 4-ethoxy-4'-nitrosodiphenylamine were formed, whereas up to 10% appeared as the reduction product 4-amino-4'-ethoxydiphenylamine. This latter compound is unstable in red cells and is metabolized further to unidentified products.

Analgesic and anti-inflammatory drug use and risk of bladder cancer: a population based case control study

PubMed Central

Fortuny, Joan; Kogevinas, Manolis; Zens, Michael S; Schned, Alan; Andrew, Angeline S; Heaney, John; Kelsey, Karl T; Karagas, Margaret R

2007-01-01

Background Use of phenacetin and other analgesic and non-steroidal anti-inflammatory drugs (NSAIDs) potentially influences bladder cancer incidence, but epidemiologic evidence is limited. Methods We analyzed data from 376 incident bladder cancer cases and 463 controls from a population-based case-control study in New Hampshire on whom regular use of analgesic drugs and NSAIDs was obtained. Odds ratios and 95% confidence intervals were computed using logistic regression with adjustment for potentially confounding factors. Separate models by tumor stage, grade and TP53 status were conducted. Results We found an elevated odds ratio (OR) associated with reported use of phenacetin-containing medications, especially with longer duration of use (OR >8 years = 3.00, 95% confidence interval (CI) = 1.4–6.5). In contrast, use of paracetamol did not relate overall to risk of bladder cancer. We also found that regular use of any NSAID was associated with a statistically significant decrease in bladder cancer risk (OR = 0.6, 95% CI = 0.4–0.9), and specifically use of aspirin. Further, the association with NSAID use was largely among invasive, high grade and TP53 positive tumors. Conclusion While these agents have been investigated in several studies, a number of questions remain regarding the effects of analgesic and NSAID use on risk of bladder cancer. PMID:17692123

Properties of pellets manufactured by wet extrusion/spheronization process using kappa-carrageenan: effect of process parameters.

PubMed

Thommes, Markus; Kleinebudde, Peter

2007-11-09

The aim of this study was to systematically evaluate the pelletization process parameters of kappa-carrageenan-containing formulations. The study dealt with the effect of 4 process parameters--screw speed, number of die holes, friction plate speed, and spheronizer temperature--on the pellet properties of shape, size, size distribution, tensile strength, and drug release. These parameters were varied systematically in a 2(4) full factorial design. In addition, 4 drugs--phenacetin, chloramphenicol, dimenhydrinate, and lidocaine hydrochloride--were investigated under constant process conditions. The most spherical pellets were achieved in a high yield by using a large number of die holes and a high spheronizer speed. There was no relevant influence of the investigated process parameters on the size distribution, mechanical stability, and drug release. The poorly soluble drugs, phenacetin and chloramphenicol, resulted in pellets with adequate shape, size, and tensile strength and a fast drug release. The salts of dimenhydrinate and lidocaine affected pellet shape, mechanical stability, and the drug release properties using an aqueous solution of pH 3 as a granulation liquid. In the case of dimenhydrinate, this was attributed to the ionic interactions with kappa-carrageenan, resulting in a stable matrix during dissolution that did not disintegrate. The effect of lidocaine is comparable to the effect of sodium ions, which suppress the gelling of carrageenan, resulting in pellets with fast disintegration and drug release characteristics. The pellet properties are affected by the process parameters and the active pharmaceutical ingredient used.

Resonance Enhanced Multi-Photon Ionization and Uv-Uv Hole-Burning Spectroscopic Studies of Jet-Cooled Acetanilide Derivatives

NASA Astrophysics Data System (ADS)

Moon, Ceol Joo; Min, Ahreum; Ahn, Ahreum; Lee, Seung Jun; Choi, Myong Yong; Kim, Seong Keun

2013-06-01

Conformational investigations and photochemistry of jet-cooled methacetine (MA) and phenacetine (PA) using one color resonant two-photon ionization (REMPI), UV-UV hole-burning and IR-dip spectroscopy are presented. MA and PA are derivatives of acetanilide, substituted by methoxyl, ethoxyl group in the para position of acetanilide, respectively. Moreover, we have investigated conformational information of the acetanilide derivatives (AAP, MA and PA)-water. In this work, we will present and discuss the solvent effects of the hydroxyl group of acetanilide derivatives in the excited state.

A Novel LC-MS-MS Method With an Effective Antioxidant for the Determination of Edaravone, a Free-Radical Scavenger in Dog Plasma and its Application to a Pharmacokinetic Study.

PubMed

Shao, Feng; Hu, Xiao-Ling; Liu, Xin; Shan, Mang-Ting

2017-07-01

The objective of this study was to investigate the stability of edaravone in dog plasma by using an added antioxidant stabilizer, with an ultimate goal of developing and validating a sensitive, reliable and robust LC-MS-MS method for determination of edaravone in plasma samples. Edaravone was unstable in plasma, but it presented a good stability performance in the plasma with sodium metabisulfite (SMB), an effective antioxidant. The blood sample was collected in the heparinized eppendorf tube containing SMB and plasma sample was deproteinized using acetonitrile containing 20 ng/mL of phenacetin (Internal standard). The chromatographic separation was performed on a Zorbax Extend-C18 analytical column (2.1 mm × 150 mm I.D., particle size 3.5 µm, Agilent Technologies, USA). The mobile phase consisted of 0.1% formic acid in water (v/v) and methanol, and gradient elution was used. The analyte detection was performed on a triple quadrupole tandem mass spectrometer equipped with positive-ion electrospray ionization by multiple reaction ion monitoring mode of the transitions at m/z [M + H]+ 175.1 → 77.1 for edaravone, and m/z [M + H]+ 180.2 → 110.0 for phenacetin. The linearity of this method was within the concentration range of 10-1000 ng/mL for edaravone in dog plasma. The lower limit of quantification was 10 ng/mL. The relative standard deviations of intra- and inter-precision were <10%. This method was successfully employed in the pharmacokinetics evaluation of edaravone in beagle dogs after intravenous administration. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Metabolic activation and nucleic acid binding of acetaminophen and related arylamine substrates by the respiratory burst of human granulocytes.

PubMed

Corbett, M D; Corbett, B R; Hannothiaux, M H; Quintana, S J

1989-01-01

Following stimulation with phorbol myristate acetate, human granulocytes were found to incorporate acetaminophen, p-phenetidine, p-aminophenol, and p-chloroaniline into cellular DNA and RNA. Phenacetin was not incorporated into nucleic acid or metabolized by such activated granulocytes. None of the substrates gave nucleic acid binding if the granulocyte cultures were not induced to undergo the respiratory burst. Additional studies on the binding of acetaminophen to DNA and RNA were made by use of both ring-14C-labeled and carbonyl-14C-labeled forms of this substrate. The finding that equivalent amounts of these two labeled acetaminophen substrates were bound to cellular DNA demonstrated that the intact acetaminophen molecule was incorporated into DNA. On the other hand, the finding that excess ring-14C-labeled acetaminophen was incorporated into cellular RNA implies partial hydrolysis of the acetaminophen substrate prior to RNA binding. Evidence was presented which strongly indicates that the nucleic acid binding of the substrates was covalent in nature. The inability of the respiratory burst to result in the binding of phenacetin to nucleic acid suggests that arylamides are not normally activated or metabolized by activated granulocytes. Acetaminophen is an exception to the recalcitrance of arylamides to such bioactivation processes because it also possesses the phenolic functional group, which, like the arylamine group, is oxidized by certain reactive oxygen species. Myeloperoxidase appears to be much more important in the binding of acetaminophen to DNA than it is in the DNA binding of arylamines in general. The role of the respiratory burst in causing the bioactivation of certain arylamines, which are not normally genotoxic via the more usual microsomal activation pathways, was extended to include certain amide substrates such as acetaminophen.

Development and validation of an HPLC-DAD method for simultaneous determination of cocaine, benzoic acid, benzoylecgonine and the main adulterants found in products based on cocaine.

PubMed

Floriani, Gisele; Gasparetto, João Cleverson; Pontarolo, Roberto; Gonçalves, Alan Guilherme

2014-02-01

Here, an HPLC-DAD method was developed and validated for simultaneous determination of cocaine, two cocaine degradation products (benzoylecgonine and benzoic acid), and the main adulterants found in products based on cocaine (caffeine, lidocaine, phenacetin, benzocaine and diltiazem). The new method was developed and validated using an XBridge C18 4.6mm×250mm, 5μm particle size column maintained at 60°C. The mobile phase consisted of a gradient of acetonitrile and ammonium formate 0.05M - pH 3.1, eluted at 1.0mL/min. The volume of injection was 10μL and the DAD detector was set at 274nm. Method validation assays demonstrated suitable sensitivity, selectivity, linearity, precision and accuracy. For selectivity assay, a MS detection system could be directly adapted to the method without the need of any change in the chromatographic conditions. The robustness study indicated that the flow rate, temperature and pH of the mobile phase are critical parameters and should not be changed considering the conditions herein determined. The new method was then successfully applied for determining cocaine, benzoylecgonine, benzoic acid, caffeine, lidocaine, phenacetin, benzocaine and diltiazem in 115 samples, seized in Brazil (2007-2012), which consisted of cocaine paste, cocaine base and salt cocaine samples. This study revealed cocaine contents that ranged from undetectable to 97.2%, with 97 samples presenting at least one of the degradation products or adulterants here evaluated. All of the studied degradation products and adulterants were observed among the seized samples, justifying the application of the method, which can be used as a screening and quantification tool in forensic analysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Research review. Interactions between environmental chemicals and drug biotransformation in man.

PubMed

Alvares, A P

1978-01-01

Many factors influence the metabolism of drugs in man. Besides genetic factors, environmental factors may play a significant role in explaining the variation observed in the rates of drug metabolism between different individuals. Intentional or unintentional exposure to environmental chemicals could enhance or inhibit the activity of hepatic mixed function oxidases that metabolise drugs and other foreign chemicals, as well as endogenous substrates such as steroid hormones. A major source of such exposure may be occupational. Exposure to the heavy metal, lead, has been shown to inhibit drug metabolism; whereas intensive exposure to chlorinated insecticides, and other halogenated hydrocarbons such as polychlorinated biphenyls, has been shown to enhance the metabolism of test drugs such as antipyrine and phenylbutazone. An intentional source of exposure to foreign chemicals is cigarette smoke. Cigarette smoke contains polycyclic hydrocarbons, which are known inducers of hepatic mixed function oxidases. A number of studies have shown that cigarette smoking can alter the pharmacological action and/or the metabolism of some drugs. Pharmacokinetic studies have shown that cigarette smoking decreases the bioavailability of phenacetin and increases dosage requirements of theophylline by enhancing their rate of metabolism. Data, which are not very conclusive, indicate that heavy marijuana use may have an inhibitory effect on metabolism of some drugs and an inducing effect on others such as theophylline. Dietary factors may also play a significant role in the regulation of drug metabolism. Charcoal broiling which introduces polycyclic hydrocarbons into foods has been shown to enhance the metabolism of the test drug, antipyrine, and of such commonly used drugs as phenacetin and theophylline. Such intentional or unintentional exposure to environmental chemicals which may alter the rates of drug metabolism in man indicates the importance of individualisation of drug therapy.

[Determination of six main components in compound theophylline tablet by convolution curve method after prior separation by column partition chromatography

NASA Technical Reports Server (NTRS)

Zhang, S. Y.; Wang, G. F.; Wu, Y. T.; Baldwin, K. M. (Principal Investigator)

1993-01-01

On a partition chromatographic column in which the support is Kieselguhr and the stationary phase is sulfuric acid solution (2 mol/L), three components of compound theophylline tablet were simultaneously eluted by chloroform and three other components were simultaneously eluted by ammonia-saturated chloroform. The two mixtures were determined by computer-aided convolution curve method separately. The corresponding average recovery and relative standard deviation of the six components were as follows: 101.6, 1.46% for caffeine; 99.7, 0.10% for phenacetin; 100.9, 1.31% for phenobarbitone; 100.2, 0.81% for theophylline; 99.9, 0.81% for theobromine and 100.8, 0.48% for aminopyrine.

Installation Restoration Program. Stage 3. Remedial Investigation/ Feasibility Study. Elmendorf Air Force Base, Alaska. Volume 5. Appendix G

DTIC Science & Technology

1990-05-01

Pentachloronitrobenzene ND mg/kg 2.5 S P henaceti n NO mg/kg 2- Picoline ND mg/kgI Pronamideh NO mg/kg 2.5I benzene ND mg/kg 2.5 2, 6-Di chi orophenol ND mg/kg 2.5 I...mg/kg 2.5 Pentachloronitrobenzene NO mg/kg 2.5 Phenaceti n ND mg/kg 2.5 2- Picoline ND mg/kg 2.5 Pronamide ND mg/kg 2.5 1 ,2,4,5-Tetrachloro benzene ND...Phenacetin ND mg/kg 2.5 2- Picoline ND mg/kg 2.5 Pronami de ND mg/kg 2.5 1,2,4,5-Tetrachlorobenzene ND mg/kg 2.5 2, 6-Di chi orophenol ND mg/kg 2.5 2-Methyl

Enthalpy-entropy compensation for the solubility of drugs in solvent mixtures: paracetamol, acetanilide, and nalidixic acid in dioxane-water.

PubMed

Bustamante, P; Romero, S; Pena, A; Escalera, B; Reillo, A

1998-12-01

In earlier work, a nonlinear enthalpy-entropy compensation was observed for the solubility of phenacetin in dioxane-water mixtures. This effect had not been earlier reported for the solubility of drugs in solvent mixtures. To gain insight into the compensation effect, the behavior of the apparent thermodynamic magnitudes for the solubility of paracetamol, acetanilide, and nalidixic acid is studied in this work. The solubility of these drugs was measured at several temperatures in dioxane-water mixtures. DSC analysis was performed on the original powders and on the solid phases after equilibration with the solvent mixture. The thermal properties of the solid phases did not show significant changes. The three drugs display a solubility maximum against the cosolvent ratio. The solubility peaks of acetanilide and nalidixic acid shift to a more polar region at the higher temperatures. Nonlinear van't Hoff plots were observed for nalidixic acid whereas acetanilide and paracetamol show linear behavior at the temperature range studied. The apparent enthalpies of solution are endothermic going through a maximum at 50% dioxane. Two different mechanisms, entropy and enthalpy, are suggested to be the driving forces that increase the solubility of the three drugs. Solubility is entropy controlled at the water-rich region (0-50% dioxane) and enthalpy controlled at the dioxane-rich region (50-100% dioxane). The enthalpy-entropy compensation analysis also suggests that two different mechanisms, dependent on cosolvent ratio, are involved in the solubility enhancement of the three drugs. The plots of deltaH versus deltaG are nonlinear, and the slope changes from positive to negative above 50% dioxane. The compensation effect for the thermodynamic magnitudes of transfer from water to the aqueous mixtures can be described by a common empirical nonlinear relationship, with the exception of paracetamol, which follows a separate linear relationship at dioxane ratios above 50%. The results corroborate earlier findings with phenacetin. The similar pattern shown by the drugs studied suggests that the nonlinear enthalpy-entropy compensation effect may be characteristic of the solubility of semipolar drugs in dioxane-water mixtures.

Aspirin and the Kidney

PubMed Central

1974-01-01

A survey of 763 patients with rheumatoid arthritis and 145 with osteoarthritis in six clinics in New Zealand showed no association between aspirin intake and a score designed to detect analgesic nephropathy. Analgesic nephropathy was diagnosed clinically in three patients taking APC (aspirin, phenacetin, and caffeine or codeine or both) and in one who took aspirin and phenylbutazone and was suspected in one who took aspirin and paracetamol. Isolated aspirin was not implicated. The study showed that most people can take large quantities of salicylates without renal injury. The findings are, however, consistent with the view that there is a risk from APC compounds taken in large quantity, but the numbers at risk in this study were small. Aspirin may have an additive effect with other analgesics in causing renal damage. An increased frequency of urinary tract symptoms in those taking analgesics requires further investigation. PMID:4821007

Osler on migraine.

PubMed

Boes, Christopher J

2015-03-01

William Osler's 1892 textbook The Principles and Practice of Medicine became the dominant medical text in the English-speaking world. Osler was labeled a therapeutic nihilist by some. The topic of migraine, including treatment, was succinctly covered in his text. The objectives of this study were to review Osler's thoughts on migraine, and outline his therapeutic recommendations. Preventively Osler mentioned bromides, iron, arsenic, nitroglycerin, and cannabis. Acutely he recommended coffee, chloroform, cannabis, antipyrin, antifebrin, phenacetin, caffeine citrate, nux vomica, or ergot. He thought cannabis was the most satisfactory remedy. Osler was not a therapeutic nihilist when it came to migraine, and his treatment recommendations were similar to other writers of his time. Osler did not draw upon his personal experience to contribute new knowledge about migraine. Regardless, given the popularity and clarity of his text, Osler's well-summarized migraine chapter had a great influence on practicing physicians.

Sorption behavior of 20 wastewater originated micropollutants in groundwater — Column experiments with pharmaceutical residues and industrial agents

NASA Astrophysics Data System (ADS)

Burke, Victoria; Treumann, Svantje; Duennbier, Uwe; Greskowiak, Janek; Massmann, Gudrun

2013-11-01

Since sorption is an essential process with regard to attenuation of organic pollutants during subsurface flow, information on the sorption properties of each pollutant are essential for assessing their environmental fate and transport behavior. In the present study, the sorption behavior of 20 wastewater originated organic micropollutants was assessed by means of sediment column experiments, since experimentally determined data for these compounds are not or sparsely represented in the literature. Compounds investigated include various psychoactive drugs, phenazone-type pharmaceuticals and β-blockers, as well as phenacetine, N-methylphenacetine, tolyltriazole and para-toluenesulfonamide. While for most of the compounds no or only a low sorption affinity was observed, an elevated tendency to sorb onto aquifer sand was obtained for the β-blockers atenolol, propranolol and metoprolol. A comparison between experimental data and data estimated based on the octanol/water partition coefficient following the QSAR approach demonstrated the limitations of the latter to predict the adsorption behavior in natural systems for the studied compounds.

Radial basis function neural networks in non-destructive determination of compound aspirin tablets on NIR spectroscopy.

PubMed

Dou, Ying; Mi, Hong; Zhao, Lingzhi; Ren, Yuqiu; Ren, Yulin

2006-09-01

The application of the second most popular artificial neural networks (ANNs), namely, the radial basis function (RBF) networks, has been developed for quantitative analysis of drugs during the last decade. In this paper, the two components (aspirin and phenacetin) were simultaneously determined in compound aspirin tablets by using near-infrared (NIR) spectroscopy and RBF networks. The total database was randomly divided into a training set (50) and a testing set (17). Different preprocessing methods (standard normal variate (SNV), multiplicative scatter correction (MSC), first-derivative and second-derivative) were applied to two sets of NIR spectra of compound aspirin tablets with different concentrations of two active components and compared each other. After that, the performance of RBF learning algorithm adopted the nearest neighbor clustering algorithm (NNCA) and the criterion for selection used a cross-validation technique. Results show that using RBF networks to quantificationally analyze tablets is reliable, and the best RBF model was obtained by first-derivative spectra.

Sorption behavior of 20 wastewater originated micropollutants in groundwater--column experiments with pharmaceutical residues and industrial agents.

PubMed

Burke, Victoria; Treumann, Svantje; Duennbier, Uwe; Greskowiak, Janek; Massmann, Gudrun

2013-11-01

Since sorption is an essential process with regard to attenuation of organic pollutants during subsurface flow, information on the sorption properties of each pollutant are essential for assessing their environmental fate and transport behavior. In the present study, the sorption behavior of 20 wastewater originated organic micropollutants was assessed by means of sediment column experiments, since experimentally determined data for these compounds are not or sparsely represented in the literature. Compounds investigated include various psychoactive drugs, phenazone-type pharmaceuticals and β-blockers, as well as phenacetine, N-methylphenacetine, tolyltriazole and para-toluenesulfonamide. While for most of the compounds no or only a low sorption affinity was observed, an elevated tendency to sorb onto aquifer sand was obtained for the β-blockers atenolol, propranolol and metoprolol. A comparison between experimental data and data estimated based on the octanol/water partition coefficient following the QSAR approach demonstrated the limitations of the latter to predict the adsorption behavior in natural systems for the studied compounds. © 2013.

Microscopic Structure and Solubility Predictions of Multifunctional Solids in Supercritical Carbon Dioxide: A Molecular Simulation Study.

PubMed

Noroozi, Javad; Paluch, Andrew S

2017-02-23

Molecular dynamics simulations were employed to both estimate the solubility of nonelectrolyte solids, such as acetanilide, acetaminophen, phenacetin, methylparaben, and lidocaine, in supercritical carbon dioxide and understand the underlying molecular-level driving forces. The solubility calculations involve the estimation of the solute's limiting activity coefficient, which may be computed using conventional staged free-energy calculations. For the case of lidocaine, wherein the infinite dilution approximation is not appropriate, we demonstrate how the activity coefficient at finite concentrations may be estimated without additional effort using the dilute solution approximation and how this may be used to further understand the solvation process. Combining with experimental pure-solid properties, namely, the normal melting point and enthalpy of fusion, solubilities were estimated. The results are in good quantitative agreement with available experimental data, suggesting that molecular simulations may be a powerful tool for understanding supercritical processes and the design of carbon dioxide-philic molecular systems. Structural analyses were performed to shed light on the microscopic details of the solvation of different functional groups by carbon dioxide and the observed solubility trends.

Methaemoglobinaemia associated with the use of cocaine and volatile nitrites as recreational drugs: a review

PubMed Central

Hunter, Laura; Gordge, Laura; Dargan, Paul I; Wood, David M

2011-01-01

Methaemoglobinaemia can cause significant tissue hypoxia, leading to severe, potentially life-threatening clinical features and/or death. Over recent years there have been increasing reports of methaemoglobinaemia related to recreational drug use. There have been 25 articles describing methaemoglobinaemia related to recreational use of volatile nitrites (poppers) and more recently, four reports of methaemoglobinaemia in association with recreational cocaine use. In this article we discuss the mechanisms by which methaemoglobinaemia occurs in relation to the use of both volatile nitrites and cocaine, and summarize the published cases of recreational drug-related methaemoglobinaemia. The volatile nitrites can cause methaemoglobinaemia directly through their activity as oxidizing agents. However, with cocaine, methaemoglobinaemia is related to adulterants such as local anaesthetics or phenacetin, rather than to the cocaine itself. Clinicians managing patients with acute recreational drug toxicity should be aware of the potential for methaemoglobinaemia in these patients, particularly in patients with cyanosis or unexplained low oxygen saturations on pulse oximetry, and ensure that appropriate and timely management is provided, including, where appropriate, the use of methylthioninium chloride (methylene blue). PMID:21352269

Determination of low intrinsic clearance in vitro: the benefit of a novel internal standard in human hepatocyte incubations.

PubMed

Zanelli, Ugo; Michna, Thomas; Petersson, Carl

2018-03-26

1. A novel method utilizing an internal standard in hepatocytes incubations has been developed and demonstrated to decrease the variability in the determination of intrinsic clearance (CL int ) in this system. The reduced variability was shown to allow differentiation of lower elimination rate constants from noise. 2. The suggested method was able to compensate for a small but systematic error (0.5 µL/min/10 6 cells) caused by an evaporation of approximately 15% of the volume during the incubation time. 3. The approach was validated using six commercial drugs (ketoprofen, tolbutamide, phenacetin, etodolac and quinidine) which were metabolized by different pathways. 4. The suggested internal standard, MSC1815677, was extensively characterized and the acquired data suggest that it fulfills the requirements of an internal standard present during the incubation. The proposed internal standard was stable during the incubation and showed a low potential to inhibit drug metabolizing enzymes and transporters. With MSC1815677 we propose a novel simple, robust and cost-effective method to address the challenges in the estimation of low clearance in hepatocyte incubations.

In vivo pharmacokinetic interaction by ethanolic extract of Gymnema sylvestre with CYP2C9 (Tolbutamide), CYP3A4 (Amlodipine) and CYP1A2 (Phenacetin) in rats.

PubMed

Vaghela, Madhuri; Sahu, Niteshkumar; Kharkar, Prashant; Pandita, Nancy

2017-12-25

Gymnema sylvestre (GS) is a medicinal herb used for diabetes mellitus (DM). Herbs are gaining popularity as medicines in DM for its safety purpose. The aim of the present study was to evaluate in vivo pharmacokinetic (PK) interaction between allopathic drugs tolbutamide (TOLBU), amlodipine (AMLO), and phenacetin (PHENA) at low (L) and high (H) doses with ethanolic extract (EL) from GS. EL was extracted and subjected to TLC, total triterpenoid content (19.76 ± 0.02 W/W) and sterol content (0.1837 ± 0.0046 W/W) estimation followed by identification of phytoconstituents using HRLC-MS and GC-MS. PK interaction study with CYP2C9, CYP3A4 and CYP1A2 enzymes were assessed using TOLBU, AMLO and PHENA respectively to index cytochrome (CYP) mediated interaction in rats after concomitant administration of EL extract (400 mg/kg) from GS for 7 days. The rats were divided into four groups for each PK study where, group I and II were positive control for low and high dose of test drugs (CYP substrates) while group II and IV were orally administered EL. The PK study result of PHENA indicated that area under the plasma concentration-time curve (AUC 0-24 ) was significantly (P < 0.0001) increased by 1.4 (L) and 1.3-fold (H), plasma concentration (C max ) was significantly (P < 0.001) increased by 1.6 (L) and 1.4-fold (H). Whereas for TOLBU; clearance rate (CL) was significantly (P < 0.0001) decreased by 2.4 (L) and 2.3-fold (H), C max, was significantly (P < 0.001) decreased by 26.5% (L) and 50.4% (H) and AUC 0-24 was significantly (P < 0.0001) decreased by 59.8% (L) and 57.5% (H). Thus, EL is seen to be interacting with CYP1A2 by inhibiting its metabolic activity. HRLC-MS and GC-MS helped identify the presence of gymnemic acid (GA), triterpenoids and steroids in EL which could be the reason for PK interaction of CYP1A2 and CYP2C9. Also, in silico structure based site of metabolism study showed Fe accessibility and intrinsic activity for GA-IV, GA-VI, GA-VII and GA-X with CYP2C9. PK parameters of AMLO were not significantly affected by pre-treatment of EL. Thereby our findings indicate that co-administration of GS with drugs that are metabolized by CYP2C9 and CYP1A2 could lead to potential HDI. Copyright © 2017. Published by Elsevier B.V.

Metabolism of proposed nerve agent pretreatment, pyridostigmine bromide. Final report, December 1995-December 1996

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

Leo, K.U.

A reverse phase High Pressure Liquid Chromatography (HPLC) method was developed to separate pyridostigmine bromide from four potential metabolites. Using male and female microsomes from both rat and human, our data suggest that pyridostigmine bromide is not metabolized by the human live microsomes or DNA expressed human CYP-450s via direct observation of no metabolites being formed for incubations up to 90 minutes. Indirect evidence that pyridostigmine metabolism is not via the major human hepatic CYP-450s involved in drug metabolism, 1A2, 2C9, 2E1, 2D6, and 3A4, was observed by failure to inhibit these isozymes while co-incubated with substrates specific for thosemore » isozymes at concentrations of 2-3 times Km. The following CYP-450 substrates were co-incubated with pyridostigmine: phenacetin, tolbutamide, chlorzoxazone, bufuralol, and testosterone. Using unlabelled and 14C-pyridostigmine, metabolite formation was not observed in both male and female rat and human subcellular fractions, specifically cytosol and S9, or under conditions favoring human FMO activity (pH 8.3). These findings indicate the metabolism of pyridostigmine bromide is unlikely to be under any component of sexual dimorphism.« less

[Effect of oligosaccharide esters and polygalaxanthone Ill from Polygala tenuifolia willd towards cytochrome P450].

PubMed

Li, Zhao-liang; Dong, Xian-zhe; Wang, Dong-xiao; Dong, Rui-hua; Guo, Ting-ting; Sun, Yan; Liu, Ping

2014-11-01

Five compounds (tenuifoliside C, tenuifoliside D, telephiose A, telephiose C and polygalaxanthone III) from polygala tenuifolia wild were incubated together with CYP probe substrate in human liver microsomes to investigate the inhibitory effect towards CYP450 enzyme. Phenacetin (CYP1A2), coumarin (CYP2A6), paclitaxel (CYP2C8), diclofenac (CYP2C9), S-mepheriytoin (CYP2C19), dextromethorphan (CYP2D6), chlorzoxazone (CYP2E1), midazolam (CYP3A) were selected as the isoforfn specific substrate. And the formation of paracetamol, 7-hydroxycoumarin, 6alpha-hydroxy paclitaxel, 4'-hydroxydiclofenac, dextrorphan, 6-hydroxychlorzoxazone, 1'-hydroxymidazolam, 4'-hydroxymephenytoin were detected respectively to measure the effect towards CYP450 by high-pressure liquid chromatography (HPLC). The result shows that five compounds from polygala tenuifolia willd significantly inhibit chlorzoxazone 6-hydroxylation catalyzed by CYP2E1, while showed no effect towards CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A. And IC50 value was 38.73, 54.14, 61.77, 62.22, 50.56 micromol x L(-1), respectively.

Raman spectra of crystalline secondary amides

NASA Astrophysics Data System (ADS)

Kolesov, Boris A.

2017-05-01

We present a Raman-spectroscopic study of secondary amides (acetanilide, methacetin, phenacetine, orthorhombic and monoclinic polymorphs of paracetamol) as well as simple amides formanilide and benzanilide. The study was carried out on single crystals and in the temperature range of 5-300 K. The series of compounds with the same molecular fragment - acetamide group - can serve as a model system to study the interrelation between this group and the properties of the intermolecular "peptide-type" NH ⋯ Odbnd C hydrogen bonds. For all of the "acetamide family" of the compounds, similar changes in the Raman spectra were observed upon cooling of the samples: emergence of new Amide I(-) and Amide I(+) bands, which are red and blue shifted, respectively, from the conventional Amide-I band by around of 5-10 cm- 1. Corresponding changes in the same temperature range were observed for the Nsbnd H out-of-plane bending (Amide V) and Nsbnd H stretching vibrations of the Nsbnd H ⋯ Odbnd C hydrogen bond. All of the spectral changes observed upon cooling of the samples can be presumed to result from a delocalization of the Amide-I and Nsbnd H modes and appearance of dynamical (Davydov's) splitting at low temperature.

Electron attachment to antipyretics: Possible implications of their metabolic pathways

NASA Astrophysics Data System (ADS)

Pshenichnyuk, Stanislav A.; Modelli, Alberto

2012-06-01

The empty-level structures and formation of negative ion states via resonance attachment of low-energy (0-15 eV) electrons into vacant molecular orbitals in a series of non-steroidal anti-inflammatory drugs (NSAIDs), namely aspirin, paracetamol, phenacetin, and ibuprofen, were investigated in vacuo by electron transmission and dissociative electron attachment (DEA) spectroscopies, with the aim to model the behavior of these antipyretic agents under reductive conditions in vivo. The experimental findings are interpreted with the support of density functional theory calculations. The negative and neutral fragments formed by DEA in the gas phase display similarities with the main metabolites of these commonly used NSAIDs generated in vivo by the action of cytochrome P450 enzymes, as well as with several known active agents. It is concluded that xenobiotic molecules which possess pronounced electron-accepting properties could in principle follow metabolic pathways which parallel the gas-phase dissociative decay channels observed in the DEA spectra at incident electron energies below 1 eV. Unwanted side effects as, e.g., hepatoxicity or carcinogenicity produced by the NSAIDs under study in human organism are discussed within the "free radical model" framework, reported earlier to describe the toxic action of the well-known model toxicant carbon tetrachloride.

Risk factors for bladder cancer in a cohort exposed to aromatic amines

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

Schulte, P.A.; Ringen, K.; Hemstreet, G.P.

1986-11-01

Occupational and nonoccupational risk factors for bladder cancer were analyzed in a cohort of 1385 workers with known exposure to a potent bladder carcinogen, beta-naphthylamine. Bladder cancer was approximately seven times (95% confidence interval (CI) = 3.9, 12.4) more likely in exposed rather than nonexposed individuals, yet, otherwise, the groups were generally similar in other exogenous or hereditary risk factors. A total of 13 cases of bladder cancer were identified. After the first year of a screening program involving 380 members of the cohort, 9 of the 13 cases of bladder cancer and 36 persons with atypical bladder cytology, histology,more » or pathology were compared with 335 noncases for distributions of different variables. Occupational variables were significant in a multivariate model that controlled for age, cigarette smoking history, and source of drinking water. The estimated odds ratio for the association for bladder cancer and the duration of employment, when controlling of these other variables, is 4.3 (95% CI = 1.8, 10.3). In addition to the occupational factors, age was significant in the multivariate analysis. Other potential risk factors, such as consumption of coffee or artificial sweeteners, use of phenacetin, or decreased use of vitamin A were not found to be significantly different in cases and noncases.« less

Molecular characterization of a novel bacterial aryl acylamidase belonging to the amidase signature enzyme family.

PubMed

Ko, Hyeok-Jin; Lee, Eun Woo; Bang, Won-Gi; Lee, Cheol-Koo; Kim, Kyoung Heon; Choi, In-Geol

2010-05-01

In seeking aryl acylamidase (EC 3.5.1.13) acting on an amide bond in p-acetaminophenol (Tylenol), we identified a novel gene encoding 496 residues of a protein. The gene revealed a conserved amidase signature region with a canonical catalytic triad. The gene was expressed in E. coli and characterized for its biochemical properties. The optimum pH and temperature for the activity on p-acetaminophenol were 10 and 37 degrees C, respectively. The half-life of enzyme activity at 37 degrees C was 192 h and 90% of its activity remained after 3 h incubation at 40 degrees C. Divalent metals was found to inhibit the activity of enzyme. The K (m) values for various aryl acylamides such as 4-nitroacetanilide, p-acetaminophenol, phenacetin, 4-chloroacetanilide and acetanilide were 0.10, 0.32, 0.83, 1.9 and 19 mM, respectively. The reverse reaction activity (amide synthesis) was also examined using various chain lengths (C(1) approximately C(4) and C(10)) of carboxylic donors and aniline as substrates. These kinetic parameters and substrate specificity in forward and reverse reaction indicated that the aryl acylamidase in this study has a preference for aryl substrate having polar functional groups and hydrophobic carboxylic donors.

Determination of antazoline hydrochloride in rat plasma and excreta by reversed-phase ion-pair chromatography and its application to pharmacokinetics.

PubMed

Wang, Rui; Chu, Yanle; Li, Xiaotian; Wan, Baoluo; Yu, Tong; Wang, Linxi; Hao, Lianqi; Guo, Maowen

2013-12-01

A reversed-phase ion pair chromatography method with liquid-liquid extraction analytical method was developed and validated for the determination of antazoline hydrochloride in plasma and excreta of rat. The aim of our study was to characterize the preclinical pharmacokinetics and excretion profiles of antazoline hydrochloride in rats after intravenous injection at the dose of 10 mg/kg. Plasma and excreta samples were extracted with ethyl acetate, and phenacetin was used as the internal standard. The result showed that the method is suitable for the quantification of antazoline hydrochloride in plasma and excreta samples. Analysis of accuracy (90.89-112.33%), imprecision (<7.1%) and recovery (>82.5%) showed adequate values. After a single intravenous administration at 10 mg/kg to rats, plasma concentration profile showed a relative fast elimination proceeding with a terminal elimination half-life of 3.53 h. Approximately 61.8 and 14.2% of the administered dose were recovered in urine and bile after 72 and 24 h post-dosing respectively; 5.9% of the administered dose was recovered in feces after 72 h post-dosing. The above results show that the major elimination route is urinary excretion. Copyright © 2013 John Wiley & Sons, Ltd.

Thin layer chromatography coupled to paper spray ionization mass spectrometry for cocaine and its adulterants analysis.

PubMed

De Carvalho, Thays C; Tosato, Flavia; Souza, Lindamara M; Santos, Heloa; Merlo, Bianca B; Ortiz, Rafael S; Rodrigues, Rayza R T; Filgueiras, Paulo R; França, Hildegardo S; Augusti, Rodinei; Romão, Wanderson; Vaz, Boniek G

2016-05-01

Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0μgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A highly sensitive LC-MS/MS method for the determination of S-citalopram in rat plasma: application to a pharmacokinetic study in rats.

PubMed

Suresh, P S; Giri, Sanjeev; Husain, Raghib; Mullangi, Ramesh

2010-10-01

A highly sensitive, rapid assay method has been developed and validated for the estimation of S-citalopram (S-CPM) in rat plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive-ion mode. The assay procedure involves a simple liquid-liquid extraction of S-CPM and phenacetin (internal standard, IS) from rat plasma with t-butyl methyl ether. Chromatographic separation was operated with 0.2% formic acid:acetonitrile (20:80, v/v) at a flow rate of 0.50 mL/min on a Symmetry Shield RP(18) column with a total run time of 3.0 min. The MS/MS ion transitions monitored were 325.26 → 109.10 for S-CPM and 180.10 → 110.10 for IS. Method validation and pre-clinical sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.5 ng/mL and the linearity was observed from 0.5 to 5000 ng/mL. The intra- and inter-day precisions were in the range of 1.14-5.56 and 0.25-12.3%, respectively. This novel method has been applied to a pharmacokinetic study and to estimate brain-to-plasma ratio of S-CPM in rats. Copyright © 2010 John Wiley & Sons, Ltd.

Differences in cytochrome p450-mediated pharmacokinetics between chinese and caucasian populations predicted by mechanistic physiologically based pharmacokinetic modelling.

PubMed

Barter, Zoe E; Tucker, Geoffrey T; Rowland-Yeo, Karen

2013-12-01

International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines emphasize the need for better understanding of the influence of ethnicity on drug response to minimize duplication of clinical studies, thereby expediting drug approval. We have developed a Chinese database for the prediction of differences in the population kinetics of drugs mainly metabolized by cytochromes P450 (CYPs) relative to Caucasian populations. Such predictions should help to inform the need for duplication of in vivo pharmacokinetic studies in the two ethnic groups and the design of such studies. Demographic and physiological data for Chinese, along with information on CYP abundances and the frequencies of associated genetic polymorphisms in Chinese, were collated from literature sources and incorporated within the Simcyp Population-based Simulator(®) (v11.1). Default Simcyp parameter values for a virtual Caucasian population and for model compounds metabolized principally by specific CYPs were used as the point of reference. The drugs and the main CYPs involved in their metabolism were phenacetin (CYP1A2), desipramine (CYP2D6), tolbutamide (CYP2C9), omeprazole (CYP2C19), and alprazolam and midazolam (CYP3A). Hydroxy bupropion formation was used as a more sensitive marker of CYP2B6 activity than bupropion kinetics. Observed plasma drug concentration-time profiles and pharmacokinetic parameters after oral and, where possible, intravenous dosing were obtained from published in vivo studies in both Chinese and Caucasian subjects. Virtual subjects generated within Simcyp were matched to the subjects used in the in vivo studies with respect to age, sex, dosage and, where possible, CYP phenotype frequency. Predicted and observed plasma drug concentrations and weight-normalized clearances were compared between the ethnic groups. Significant differences were identified between Chinese and Caucasian populations in the frequency of CYP2C19 poor metabolizers (PMs) [Chinese 13 %; Caucasian 2.4 %], CYP2D6 PMs and intermediate metabolizers (IMs) [Chinese PMs 0.3 %, IMs 39 %; Caucasian PMs 8 %, IMs <1 %], the hepatic abundance of CYP2C19 (mean values: Chinese 8 pmol/mg; Caucasian 14 pmol/mg) and liver weight (mean values: Chinese 1198 g; Caucasian 1603 g). The observed plasma drug concentration-time profiles and weight-normalized clearances were predicted with reasonable accuracy (100 % within twofold; 89 % within 1.5-fold) in both ethnic groups. The predicted phenacetin, tolbutamide, omeprazole, desipramine, midazolam (intravenous), midazolam (oral), alprazolam (intravenous) and alprazolam (oral) clearances were 36, 25, 51, 43, 24, 17, 21 and 22 % lower, respectively, in Chinese than in Caucasians; the observed clearances were 28, 2, 75, 42, 19, 62, 20 and 21 % lower, respectively. Predicted and observed formation of hydroxy bupropion was lower in Caucasians than in Chinese (6 and 20 %, respectively). Differences between ethnic groups were less after normalization for body weight. The results of this study indicate the value of simulation based on mechanistic physiologically based pharmacokinetic modelling (PBPK) in anticipating the likely extent of any differences in the kinetics of CYP substrates in Chinese and Caucasian populations arising from demographic, physiological and genetic differences.

A validated LC-MS/MS assay for simultaneous quantification of methotrexate and tofacitinib in rat plasma: application to a pharmacokinetic study.

PubMed

Sharma, Kuldeep; Giri, Kalpeshkumar; Dhiman, Vinay; Dixit, Abhishek; Zainuddin, Mohd; Mullangi, Ramesh

2015-05-01

A highly sensitive, specific and rapid LC-ESI-MS/MS method has been developed and validated for simultaneous quantification of methotrexate (MTX) and tofacitinib (TFB) in rat plasma (50 μL) using phenacetin as an internal standard (IS), as per the US Food and Drug Administration guidelines. After a solid-phase extraction procedure, the separation of the analytes and IS was performed on a Chromolith RP₁₈e column using an isocratic mobile phase of 5 m m ammonium acetate (pH 5.0) and acetonitrile at a ratio of 25:75 (v/v) using flow-gradient with a total run time of 3.5 min. The detection was performed in multiple reaction monitoring mode, using the transitions of m/z 455.2 → 308.3, m/z 313.2 → 149.2 and m/z 180.3 → 110.2 for MTX, TFB and IS, respectively. The calibration curves were linear over the range of 0.49-91.0 and 0.40-74.4 ng/mL for MTX and TFB, respectively. The intra- and interday accuracy and precision values for MTX and TFB were <15% at low quality control (QC), medium QC and high QC and <20% at lower limit of quantification. The validated assay was applied to derive the pharmacokinetic parameters for MTX and TFB post-dosing of MTX and TFB orally and intravenously to rats. Copyright © 2014 John Wiley & Sons, Ltd.

The Alzheimer Pandemic: Is Paracetamol to Blame?

PubMed Central

Jones, Günther Robert Norman

2013-01-01

Historical Background: The clinical recognition of a form of dementia closely resembling Alzheimer's disease dates from around 1800. The role of analgesics derived from coal-tar in the spread of the pandemic is traced in terms of the introduction of phenacetin (PN) in 1887; its nephrotoxicity; the observation of lesions characteristic of the disease by Fischer and Alzheimer; the discovery of paracetamol (PA) as the major metabolite of PN; the linking of kidney injury and dementia with high PN usage; and the failure of PN replacement by PA to halt and reverse the exponential, inexorable rise in the incidence of Alzheimer-type dementia. Fischer observed his first case before Alzheimer; it is proposed to rename the syndrome Fischer-Alzheimer disease (F-AD). Disease development: PA-metabolising enzymes are localised in the synaptic areas of the frontal cortex and hippocampus, where F-AD lesions arise. The initiating chemical lesions in liver poisoning comprise covalent binding of a highly reactive product of PA metabolism to proteins; similar events are believed to occur in brain, where alterations in the antigenic profiles of cerebral proteins activate the microglia. β-Amyloid forms, and, like PA itself, induces nitric oxide synthase. Peroxynitrite modifies cerebral proteins by nitrating tyrosine residues, further challenging the microglia and exacerbating the amyloid cascade. Spontaneous reinnervation, N-acetyl cysteine administration and tyrosine supplementation may attenuate the early stages of F-AD development. Conclusion: F-AD is primarily a man-made condition with PA as its principal risk factor. PMID:24350947

High-throughput, 384-well, LC-MS/MS CYP inhibition assay using automation, cassette-analysis technique, and streamlined data analysis.

PubMed

Halladay, Jason S; Delarosa, Erlie Marie; Tran, Daniel; Wang, Leslie; Wong, Susan; Khojasteh, S Cyrus

2011-08-01

Here we describe a high capacity and high-throughput, automated, 384-well CYP inhibition assay using well-known HLM-based MS probes. We provide consistently robust IC(50) values at the lead optimization stage of the drug discovery process. Our method uses the Agilent Technologies/Velocity11 BioCel 1200 system, timesaving techniques for sample analysis, and streamlined data processing steps. For each experiment, we generate IC(50) values for up to 344 compounds and positive controls for five major CYP isoforms (probe substrate): CYP1A2 (phenacetin), CYP2C9 ((S)-warfarin), CYP2C19 ((S)-mephenytoin), CYP2D6 (dextromethorphan), and CYP3A4/5 (testosterone and midazolam). Each compound is incubated separately at four concentrations with each CYP probe substrate under the optimized incubation condition. Each incubation is quenched with acetonitrile containing the deuterated internal standard of the respective metabolite for each probe substrate. To minimize the number of samples to be analyzed by LC-MS/MS and reduce the amount of valuable MS runtime, we utilize timesaving techniques of cassette analysis (pooling the incubation samples at the end of each CYP probe incubation into one) and column switching (reducing the amount of MS runtime). Here we also report on the comparison of IC(50) results for five major CYP isoforms using our method compared to values reported in the literature.

[Effect of Gegen Qinlian decoction on hepatic cytochrome CYP450 isozymes in rats by HPLC-MS/MS].

PubMed

Liu, Zi-hua; An, Rui; Zhang, Yi-zhu; Gu, Qing-qing; You, Li-sha; Wang, Xin-hong

2015-08-01

To study the effect of Gegen Qinlian decoction and its major effective components on five hepatic microsomal CYP450 isozymes in rats. The in vitro hepatic microsomal incubation technique was used to co-culture Gegen Qinlian decoction and its major effective components together with each probe substrate. HPLC-MS/MS was used to establish the analytical method for metabolites of the five isoform probe substrates of CYP450 isozymes, detect the linearity among micoromal protein concentration, incubation time and metabolite formation amount. And HPLC-MS/MS was applied to determine the formation rate (V) of corresponding metabolites (acetaminophen, 4-OH-chlorzoxazone, dextrophan, 6-OH-chlorzoxazone and 6β-hydroxytestosterone) specific probe substrates of the five isoform probe substrates of CYP450 isozymes (phenacetin, polbutamide, dextromethorphan, chlorzoxazone, testosterone), in order to determine the activity of each isozyme. The result showed good linearity among acetaminophen, 4-OH-tolbutamide, dextrophan, 6-OH-chlorzoxazone and 6β-hydroxytestosterone, satisfactory precision, stability and average recovery, suggesting the method was feasible. The optimized in vitro microsomal incubation conditions conformed to the requirements in the guideline of drug-drug interaction. Gegen Qinlian decoction showed different degrees of inhibitor effect on 5 CYP450 isoforms (CYP1A2, CYP2C11, CYP2D2, CYP2E1, CYP3A1/2). Its major effective component berberine could inhibit each CYP450 isoform at high concentrations (except for CYP1A2, CYP3A1/2).

A robust LC-MS/MS method for the determination of pidotimod in different biological matrixes and its application to in vivo and in vitro pharmacokinetic studies.

PubMed

Wang, Guangji; Wang, Qian; Rao, Tai; Shen, Boyu; Kang, Dian; Shao, Yuhao; Xiao, Jingcheng; Chen, Huimin; Liang, Yan

2016-06-15

Pidotimod, (R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, was frequently used to treat children with recurrent respiratory infections. Preclinical pharmacokinetics of pidotimod was still rarely reported to date. Herein, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine pidotimod in rat plasma, tissue homogenate and Caco-2 cells. In this process, phenacetin was chosen as the internal standard due to its similarity in chromatographic and mass spectrographic characteristics with pidotimod. The plasma calibration curves were established within the concentration range of 0.01-10.00μg/mL, and similar linear curves were built using tissue homogenate and Caco-2 cells. The calibration curves for all biological samples showed good linearity (r>0.99) over the concentration ranges tested. The intra- and inter-day precision (RSD, %) values were below 15% and accuracy (RE, %) was ranged from -15% to 15% at all quality control levels. For plasma, tissue homogenate and Caco-2 cells, no obvious matrix effect was found, and the average recoveries were all above 75%. Thus, the method demonstrated excellent accuracy, precision and robustness for high throughput applications, and was then successfully applied to the studies of absorption in rat plasma, distribution in rat tissues and intracellular uptake characteristics in Caco-2 cells for pidotimod. Copyright © 2016 Elsevier B.V. All rights reserved.

Crystals and tablets in the Spanish ecstasy market 2000-2014: Are they the same or different in terms of purity and adulteration?

PubMed

Vidal Giné, Claudio; Ventura Vilamala, Mireia; Fornís Espinosa, Iván; Gil Lladanosa, Cristina; Calzada Álvarez, Nú; Fitó Fruitós, Ariadna; Rodríguez Rodríguez, Joan; Domíngo Salvany, Antonia; de la Torre Fornell, Rafael

2016-06-01

Although 3,4-methylenedioxymethamphetamine (MDMA) has a long history in recreational settings, research on its composition (purity and adulteration) has focused only on tablets even though crystal format is readily available for users. Drug specimens collected between January 2000 and December 2014 were analyzed at Energy Control's facilities. All samples were voluntarily provided by drug users. Sample identification was made with thin layer chromatography and gas chromatography coupled to mass spectrometry, and quantification with ultraviolet spectrophotometry (only in unadulterated samples). Between January 2000 and December 2014, 6200 samples purchased as ecstasy by their users were analyzed. Crystals were the most frequent format (60.6%) followed by tablets (38.8%). During the study period, the proportion of samples containing only MDMA was higher in crystals than in tablets. Compared with tablets, adulterated crystal samples contained the same number of adulterants but more combinations of different substances. Although caffeine was commonly detected as adulterant both in crystals and tablets, other substances such as phenacetin, lidocaine, dextrometorphan or methamphetamine were detected almost exclusively in crystal samples. The amount of MDMA in crystal samples remained stable unlike tablets for which a huge increase in MDMA dose was observed since 2010. Crystal samples of ecstasy showed clear differences compared to ecstasy tablets and this must be taken into account both in research and harm reduction. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Simultaneous determination of tetrahydropalmatine, protopine, and palmatine in rat plasma by LC-ESI-MS and its application to a pharmacokinetic study.

PubMed

Ma, Hongda; Wang, Yongjun; Guo, Tao; He, Zhonggui; Chang, Xinyu; Pu, Xiaohui

2009-02-20

A sensitive and specific liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method has been developed and validated for the simultaneous quantification of tetrahydropalmatine, protopine and palmatine in rat plasma using phenacetin as the internal standard (IS). Two hundred microliters plasma samples were extracted by dichloromethane under a strong basic condition. The analytes were separated by a C18 column and detected with a single quadrupole mass spectrometer. The used mobile phase was acetonitrile-water (40:60, v/v) containing 5mM ammonium acetate and 0.2% glacial acetic acid. Detection was carried out by positive electrospray ionization in selected ion reaction (SIR) mode at m/z 356.6 for tetrahydropalmatine, 354.6 for protopine, 352.6 for palmatine and 180.4 for the IS, respectively. The method was validated over the concentration range of 1.00-500ngmL(-1) and the lower limit of quantification (LLOQ) was 1.00ngmL(-1) for all three analytes. The intra- and inter-day precision values were less than 9% relative standard deviation (R.S.D.), and the relative error ranged from -7.4 to 4.8%. The extraction recoveries were on average 91.42% for tetrahydropalmatine, 84.75% for protopine, 57.26% for palmatine, and 83.18% for IS. The validated method was successfully applied to a pharmacokinetic study of tetrahydropalmatine, protopine and palmatine in rats after oral administration of Rhizoma Corydalis Decumbentis extract.

A simple assay for the simultaneous determination of human plasma albendazole and albendazole sulfoxide levels by high performance liquid chromatography in tandem mass spectrometry with solid-phase extraction.

PubMed

Wojnicz, Aneta; Cabaleiro-Ocampo, Teresa; Román-Martínez, Manuel; Ochoa-Mazarro, Dolores; Abad-Santos, Francisco; Ruiz-Nuño, Ana

2013-11-15

A simple, reproducible and fast (4 min chromatogram) method of liquid chromatography in tandem with mass spectrometry (LC/MS-MS) was developed to determine simultaneously the plasma levels of albendazole (ABZ) and its metabolite albendazole sulfoxide (ABZOX) for pharmacokinetic and clinical analysis. Each plasma sample was extracted by solid phase extraction (SPE) using phenacetin as internal standard (IS). The extracted sample was eluted with a Zorbax XDB-CN column using an isocratic method. The mobile phase consisting of water with 1% acetic acid (40%, A) and MeOH (60%, B), was used at a flow rate of 1 mL/min. ABZ and ABZOX were detected and identified by mass spectrometry with electrospray ionization (ESI) in the positive ion and multiple-reaction monitoring (MRM) mode. The method was linear in the range of 5-1000 ng/mL for ABZ and 10-1500 ng/mL (full validation) or 10-5000 ng/mL (partial validation) for ABZOX, with 5 and 10 ng/mL lower limit of quantification (LLOQ) for ABZ and ABZOX, respectively. The tests of accuracy and precision, matrix effect, extraction recovery and stability of the samples for both ABZ and ABZOX did not deviate more than 20% for the LLOQ and no more than 15% for other quality controls (QCs), according to regulatory agencies. © 2013.

Adulteration Practices of Psychoactive Illicit Drugs: An Updated Review.

PubMed

Solimini, Renata; Rotolo, Maria C; Pellegrini, Manuela; Minutillo, Adele; Pacifici, Roberta; Busardò, Francesco P; Zaami, Simona

2017-01-01

Powdery drugs such as cocaine and heroin are frequently adulterated or diluted predominantly to obtain more doses and to increase the drug dealer's profits, but also to enhance, to modify or to oppose drug effects. The aim of this report is to provide an overview of the recent scientific literature on medicines as well as on new psychoactive substances, used as cutting agents (i.e. pharmacologically active adulterants) and on the related adverse health effects on consumers, possibly due to the synergistic effect of the adulterants laced with substances of abuse. A literature search up to January 2017 was performed on MEDLINE, Scopus and Web of Science and reports and documents of international agencies or institutions were also searched. Pharmacologically active substances such as: paracetamol, caffeine, dextromethorphan, clenbuterol for heroin; levamisole, phenacetine, lidocaine, hydroxyzine and diltiazem for cocaine; caffeine and phentermine for amphetamine, have been identified over the years. Furthermore, since cocaine and morphine (this latter as a precursor of heroin) are both extracted from natural products, some impurities and minor alkaloids can be present in the final preparation. In this context, it is worth considering that new psychoactive substances are also used as cutting agents. The wide availability of illicit psychotropic drugs is the most serious hazard threatening consumers. Indeed emergency departments are often responsible in evaluating damages caused not only by the base substance, but also by other eventual compounds added to mimic or antagonize drug effects or simply dilute the drug amount, with a possible harmful synergic toxic action. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Inhibitory Mechanisms of Human CYPs by Three Alkaloids Isolated from Traditional Chinese Herbs.

PubMed

Zhao, Yong; Hellum, Bent Håvard; Liang, Aihua; Nilsen, Odd Georg

2015-06-01

The three purified herbal compounds tetrahydropalmatine (Tet), neferine and berberine (Ber) were explored in vitro for basic inhibition mechanisms towards recombinant human CYP1A2, CYP2D6 and CYP3A4 metabolic activities. Phenacetin, dextromethorphan and testosterone, respectively, were used as CYP1A2, CYP2D6 and CYP3A4 substrates, and their metabolites were determined by validated HPLC methodologies. Positive inhibition controls were used. Mechanism-based (irreversible) inhibition was assessed by time-dependent and nicotinamide adenine dinucleotide phosphate-dependent and reversible inhibition by Lineweaver-Burk plot assessments. Inhibition mechanisms were also assessed by computerized interaction prediction by using the Discovery Studio CDOCKER software (Accelrys, San Diego, CA, USA). Tetrahydropalmatine showed a mechanism-based inhibition of both CYP1A2 and CYP2D6, and Ber of CYP2D6. Neferine and Ber both showed a nonmechanistic inhibition of CYP1A2. All compounds showed a similar and significant mechanism-based inhibition of CYP3A4. Tetrahydropalmatine and Ber demonstrated both reversible and irreversible inhibition of CYP2D6 and CYP3A4. Tetrahydropalmatine and Ber displayed H-bond and several Pi-bond connections with specific amino acid residues of CYP1A2, CYP2D6 and CYP3A4, giving further knowledge to the identified reversible and irreversible herb-drug interactions. Tetrahydropalmatine and Ber should be considered for herb-drug interactions in clinical therapy until relevant clinical studies are available. Copyright © 2015 John Wiley & Sons, Ltd.

A validated high-performance liquid chromatographic method for the determination of moclobemide and its two metabolites in human plasma and application to pharmacokinetic studies.

PubMed

Plenis, Alina; Chmielewska, Aleksandra; Konieczna, Lucyna; Lamparczyk, Henryk

2007-09-01

A rapid and sensitive reversed-phase high-performance liquid chromatographic method (RP-HPLC) with ultraviolet detection has been developed for the determination of moclobemide and its metabolites, p-chloro-N-(-2-morpholinoethyl)benzamide N'-oxide (Ro 12-5637) and p-chloro-N-[2-(3-oxomorpholino)ethyl]-benzamide (Ro 12-8095), in human plasma. The assay was performed after single liquid-liquid extraction with dichloromethane at alkaline pH using phenacetin as the internal standard. Chromatographic separation was performed on a C(18) column using a mixture of acetonitrile and water (25:75, v/v), adjusted to pH 2.7 with ortho-phosphoric acid, as mobile phase. Spectrophotometric detection was performed at 239 nm. The method has been validated for accuracy, precision, selectivity, linearity, recovery and stability. The quantification limit for moclobemide and Ro 12-8095 was 10 ng/mL, and for Ro 12-5637 was 30 ng/mL. Linearity of the method was confirmed for the range 20-2500 ng/mL for moclobemide (r = 0.9998), 20-1750 ng/mL for Ro 12-8095 (r = 0.9996) and 30-350 ng/mL for Ro 12-5637 (r = 0.9991). Moreover, within-day and between-day precisions and accuracies of the method were established. The described method was successfully applied in pharmacokinetic studies of parent drug and its two metabolites after a single oral administration of 150 mg of moclobemide to 20 healthy volunteers. Copyright (c) 2007 John Wiley & Sons, Ltd.

Early drug discovery and the rise of pharmaceutical chemistry.

PubMed

Jones, Alan Wayne

2011-06-01

Studies in the field of forensic pharmacology and toxicology would not be complete without some knowledge of the history of drug discovery, the various personalities involved, and the events leading to the development and introduction of new therapeutic agents. The first medicinal drugs came from natural sources and existed in the form of herbs, plants, roots, vines and fungi. Until the mid-nineteenth century nature's pharmaceuticals were all that were available to relieve man's pain and suffering. The first synthetic drug, chloral hydrate, was discovered in 1869 and introduced as a sedative-hypnotic; it is still available today in some countries. The first pharmaceutical companies were spin-offs from the textiles and synthetic dye industry and owe much to the rich source of organic chemicals derived from the distillation of coal (coal-tar). The first analgesics and antipyretics, exemplified by phenacetin and acetanilide, were simple chemical derivatives of aniline and p-nitrophenol, both of which were byproducts from coal-tar. An extract from the bark of the white willow tree had been used for centuries to treat various fevers and inflammation. The active principle in white willow, salicin or salicylic acid, had a bitter taste and irritated the gastric mucosa, but a simple chemical modification was much more palatable. This was acetylsalicylic acid, better known as Aspirin®, the first blockbuster drug. At the start of the twentieth century, the first of the barbiturate family of drugs entered the pharmacopoeia and the rest, as they say, is history. Copyright © 2011 John Wiley & Sons, Ltd.

FIXED DOSE COMBINATIONS WITH SELECTIVE BETA-BLOCKERS: QUANTITATIVE DETERMINATION IN BIOLOGICAL FLUIDS.

PubMed

Mahu, Ştefania Corina; Hăncianu, Monica; Agoroaei, Luminiţa; Grigoriu, Ioana Cezara; Strugaru, Anca Monica; Butnaru, Elena

2015-01-01

Hypertension is one of the most common causes of death, a complex and incompletely controlled disease for millions of patients. Metoprolol, bisoprolol, nebivolol and atenolol are selective beta-blockers frequently used in the management of arterial hypertension, alone or in fixed combination with other substances. This study presents the most used analytical methods for simultaneous determination in biological fluids of fixed combinations containing selective beta-blockers. Articles in Pub-Med, Science Direct and Wiley Journals databases published between years 2004-2014 were reviewed. Methods such as liquid chromatography--mass spectrometry--mass spectrometry (LC-MS/MS), high performance liquid chromatography (HPLC) or high performance liquid chromatography--mass spectrometry (HPLC-MS) were used for determination of fixed combination with beta-blockers in human plasma, rat plasma and human breast milk. LC-MS/MS method was used for simultaneous determination of fixed combinations of metoprolol with simvastatin, hydrochlorothiazide or ramipril, combinations of nebivolol and valsartan, or atenolol and amlodipine. Biological samples were processed by protein precipitation techniques or by liquid-liquid extraction. For the determination of fixed dose combinations of felodipine and metoprolol in rat plasma liquid chromatography--electrospray ionization--mass spectrometry (LC-ESI-MS/MS) was applied, using phenacetin as internal standard. HPLC-MS method was applied for the determination of bisoprolol and hydrochlorothiazide in human plasma. For the determination of atenolol and chlorthalidone from human breast milk and human plasma the HPLC method was used. The analytical methods were validated according to the specialized guidelines, and were applied to biological samples, thing that confirms the permanent concern of researchers in this field.

Sensitive LC-MS/MS Method for the Simultaneous Determination of Bendamustine and its Active Metabolite, γ-Hydroxybendamustine in Small Volume Mice and Dog Plasma and its Application to a Pharmacokinetic Study in Mice and Dogs.

PubMed

Chandrashekar, Devaraj V; Suresh, Ponnayyan S; Kumar, Rajnish; Bhamidipati, Ravi Kanth; Mullangi, Ramesh; Richter, Wolfgang; Srinivas, Nuggehally R

2017-09-01

A highly sensitive, specific and rapid LC-ESI-MS/MS method has been developed and validated for the simultaneous quantification of bendamustine (BM) and γ-hydroxybendamustine (HBM) in small volume (20 µL) mice and dog plasma using phenacetin as an internal standard (IS) as per regulatory guidelines. Both the analytes and IS were extracted from mice and dog plasma using a liquid-liquid extraction method. Chromatography was achieved on Atlantis dC 18 column using an isocratic mobile phase (0.2% formic acid:acetonitrile, 25:75) at a flow rate of 0.40 mL/min. The total chromatographic run time was 3.0 min and the elution of BM, HBM and IS occurred at ~1.2, 1.2 and 2.0 min, respectively. A linear response function was established 0.11-518 ng/mL for both the analytes in mice and dog plasma. The intra- and inter-day accuracy and precisions were in the range of 3.46-12.9 and 3.63-8.23%; 1.15-9.00 and 7.86-9.49% for BM and HBM, respectively in mice plasma and 2.15-6.49 and 1.73-13.1%; 4.35-13.9 and 4.33-10.5% for BM and HBM, respectively in dog plasma. This novel method has been applied to a pharmacokinetic study in mice and dogs. © Georg Thieme Verlag KG Stuttgart · New York.

Tobacco use, occupation, coffee, various nutrients, and bladder cancer.

PubMed

Howe, G R; Burch, J D; Miller, A B; Cook, G M; Esteve, J; Morrison, B; Gordon, P; Chambers, L W; Fodor, G; Winsor, G M

1980-04-01

In a Canadian population-based case-control study of 480 males and 152 female case-control pairs, the relative risk for development of bladder cancer for ever used versus never used cigarettes was 3.9 for males and 2.4 for females, with a dose-response relationship in both sexes. A reduced risk was associated with the use of filter cigarettes compared to nonfilter cigarettes. After control for cigarette usage, a significant risk was noted for male pipe smokers. For male ex-smokers the risk after 15 years of no smoking was less than one-half that of current male smokers. Bladder cancer risk was found for workers in the chemical, rubber, photographic, petroleum, medical, and food processing industries among males and for workers occupationally exposed to dust or fumes among both sexes. Bladder cancer risk was elevated for males consuming all types of coffee, regular coffee, and instant coffee and for females consuming instant coffee, but no dose-response relationship was found. Risk was found for males consuming water from nonpublic supples but not for females. No risk was observed in males or females consuming nitrate-containing foods, beverages other than coffee, or fiddlehead greens. Hair dye usage in females and phenacetin usage in males and females carried no risk. Divergent findings by area for aspirin suggested that an overall association was not causal. Reevaluation of the data on artificial sweeteners confirmed a significant bladder cancer risk in males and a dose-response relationship. The cumulated population attributable risk for bladder cancer was 90% for males from cigarette smoking, industrial exposure, and exposure to nonpublic water supplies and 29% for females from cigarette smoking, industrial exposure, and instant coffee consumption.

Oxidative stress/reactive metabolite gene expression signature in rat liver detects idiosyncratic hepatotoxicants

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

Leone, Angelique; Nie, Alex; Brandon Parker, J.

Previously we reported a gene expression signature in rat liver for detecting a specific type of oxidative stress (OS) related to reactive metabolites (RM). High doses of the drugs disulfiram, ethinyl estradiol and nimesulide were used with another dozen paradigm OS/RM compounds, and three other drugs flutamide, phenacetin and sulindac were identified by this signature. In a second study, antiepileptic drugs were compared for covalent binding and their effects on OS/RM; felbamate, carbamazepine, and phenobarbital produced robust OS/RM gene expression. In the present study, liver RNA samples from drug-treated rats from more recent experiments were examined for statistical fit tomore » the OS/RM signature. Of all 97 drugs examined, in addition to the nine drugs noted above, 19 more were identified as OS/RM-producing compounds—chlorpromazine, clozapine, cyproterone acetate, dantrolene, dipyridamole, glibenclamide, isoniazid, ketoconazole, methapyrilene, naltrexone, nifedipine, sulfamethoxazole, tamoxifen, coumarin, ritonavir, amitriptyline, valproic acid, enalapril, and chloramphenicol. Importantly, all of the OS/RM drugs listed above have been linked to idiosyncratic hepatotoxicity, excepting chloramphenicol, which does not have a package label for hepatotoxicity, but does have a black box warning for idiosyncratic bone marrow suppression. Most of these drugs are not acutely toxic in the rat. The OS/RM signature should be useful to avoid idiosyncratic hepatotoxicity of drug candidates. - Highlights: • 28 of 97 drugs gave a positive OS/RM gene expression signature in rat liver. • The specificity of the signature for human idiosyncratic hepatotoxicants was 98%. • The sensitivity of the signature for human idiosyncratic hepatotoxicants was 75%. • The signature can help eliminate hepatotoxicants from drug development.« less

Pathway-Targeted Pharmacogenomics of CYP1A2 in Human Liver

PubMed Central

Klein, Kathrin; Winter, Stefan; Turpeinen, Miia; Schwab, Matthias; Zanger, Ulrich M.

2010-01-01

The human drug metabolizing cytochrome P450 (CYP) 1A2, is one of the major P450 isoforms contributing by about 5–20% to the hepatic P450 pool and catalyzing oxidative biotransformation of up to 10% of clinically relevant drugs including clozapine and caffeine. CYP1A2 activity is interindividually highly variable and although twin studies have suggested a high heritability, underlying genetic factors are still unknown. Here we adopted a pathway-oriented approach using a large human liver bank (n = 150) to elucidate whether variants in candidate genes of constitutive, ligand-inducible, and pathophysiological inhibitory regulatory pathways may explain different hepatic CYP1A2 phenotypes. Samples were phenotyped for phenacetin O-deethylase activity, and the expression of CYP1A2 protein and mRNA was determined. CYP1A2 expression and function was increased in smokers and decreased in patients with inflammation and cholestasis. Of 169 SNPs in 17 candidate genes including the CYP1A locus, 136 non-redundant SNPs with minor allele frequency >5% were analyzed by univariate and multivariate methods. A total of 13 strong significant associations were identified, of which 10 SNPs in the ARNT, AhRR, HNF1α, IL1β, SRC-1, and VDR genes showed consistent changes for at least two phenotypes by univariate analysis. Multivariate linear modeling indicated that the polymorphisms and non-genetic factors together explained 42, 38, and 33% of CYP1A2 variation at activity, protein and mRNA levels, respectively. In conclusion, we identified novel trans-associations between regulatory genes and hepatic CYP1A2 function and expression, but additional genetic factors must be assumed to explain the full extent of CYP1A2 heritability. PMID:21918647

The pharmaceutical industry and the German National Socialist Regime: I.G. Farben and pharmacological research.

PubMed

López-Muñoz, F; García-García, P; Alamo, C

2009-02-01

Before the National Socialist party came to power, the German pharmaceutical industry constituted an international reference as far as the development of new medicines was concerned, having been responsible for synthetic analgesics (phenacetin, phenazones, acetylsalicylic acid), arsphenamine, barbiturates and sulfonamides. The year 1925 saw the founding of I.G. Farben (Interessen-Gemeinschaft Farbenindustrie AG), a conglomerate of companies that would monopolize the country's chemical production and come to own all its major pharmaceutical industries. During the World War II, I.G. Farben participated in numerous operations associated with the criminal activities of the Nazi executive, including the use of slave labour in plants built close to concentration camps, such as that at Auschwitz. With regard to medical and pharmacological research projects, I.G. Farben became involved in experimental programmes using patients from the Nazi regime's euthanasia programmes and healthy subjects recruited without their consent from concentration camps, on whom various pharmacological substances were tested, including sulfamide and arsenical derivatives and other preparations whose composition is not precisely known (B-1012, B-1034, 3382 or Rutenol, 3582 or Acridine), generally in relation to the treatment of infectious diseases, such as typhus, erysipelas, scarlet fever or paratyphoid diarrhoea. Furthermore, I.G. Farben played a decisive role in the German army's chemical warfare programme, contributing to the development of the first two neurotoxic substances, later known as 'nerve agents', tabun and sarin. Some of these activities came to light as a result of the one the famous Nuremberg Trials in 1947, which saw 24 executives and scientists from I.G. Farben brought to justice for, among other offences, the use of slave labour in the concentration camps and forced experimentation with drugs on prisoners.

A role for cytochrome b5 in the in vivo disposition of anti-cancer and cytochrome P450 probe drugs in mice

PubMed Central

Henderson, Colin J.; McLaughlin, Lesley A.; Finn, Robert D.; Ronseaux, Sebastien; Kapelyukh, Yury; Wolf, C. Roland

2014-01-01

The role of microsomal cytochrome b5 (Cyb5) in defining the rate of drug metabolism and disposition has been intensely debated for several decades. Recently we described mouse models involving the hepatic or global deletion of Cyb5, demonstrating its central role in in vivo drug disposition. We have now used the cytochrome b5 complete null (BCN) model to determine the role of Cyb5 in the metabolism of ten pharmaceuticals metabolised by a range of cytochrome P450s, including five anti-cancer drugs, in vivo and in vitro. The extent to which metabolism was significantly affected by the absence of Cyb5 was substrate-dependent, with AUC increased (75-245%), and clearance decreased (35-72%), for phenacetin, metoprolol and chlorzoxazone. Tolbutamide disposition was not significantly altered by Cyb5 deletion, while for midazolam clearance was decreased by 66%. The absence of Cyb5 had no effect on gefitinib and paclitaxel disposition, while significant changes in the in vivo pharmacokinetics of cyclophosphamide were measured (Cmax and terminal half-life increased 55% and 40%, respectively), tamoxifen (AUClast and Cmax increased 370% and 233%, respectively) and anastrozole (AUC and terminal half-life increased 125% and 62%, respectively; clearance down 80%). These data from provide strong evidence that both hepatic and extra-hepatic Cyb5 levels are an important determinant of in vivo drug disposition catalysed by a range of cytochrome P450s, including currently-prescribed anti-cancer agents, and that individuality in Cyb5 expression could be a significant determinant in rates of drug disposition in man. PMID:24115751

A survey of adulterants used to cut cocaine in samples seized in the Espírito Santo State by GC-MS allied to chemometric tools.

PubMed

de Souza, Lindamara M; Rodrigues, Rayza R T; Santos, Heloá; Costa, Helber B; Merlo, Bianca B; Filgueiras, Paulo R; Poppi, Ronei J; Vaz, Boniek G; Romão, Wanderson

2016-03-01

Cocaine is a stimulant drug of the central nervous system (CNS) extracted from the leaves of Erytroxylum coca. It is defined as a tropane alkaloid containing 1R-(exo,exo)-3-(benzoyloxy)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylic acid methyl esther. However, despite its defined composition, a wide variety of chemical additives are present in cocaine found in the illicit market, such as benzocaine, lidocaine, caffeine, procaine and phenacetin. In this work, 512 cocaine samples seized by the Civil Police of Espirito Santo state (PC-ES, Brazil) were analyzed by gas chromatography mass spectrometry (GC-MS) allied to principal component analysis (PCA) in order to classify the samples as a function of seizure year (2008, 2009, 2010, 2011 and 2012) and location (metropolitan, north, south and central). The cocaine content (wt.%) and its adulterants were also estimated. Analyzing the samples seized between 2008 and 2011, three sample sets are clearly grouped according to the degree of adulteration with caffeine and lidocaine: 100-50 wt.% of cocaine; 50-20 wt.% of cocaine; and 20-80 wt.% of lidocaine and 60-80 wt.% of caffeine, simultaneously. The last group is formed by samples seized between 2008 and 2009, which proves the higher degree of adulteration during this period. In 2012, higher cocaine content was observed for the 191 analyzed samples than in samples from previous years. The PCA data also suggests that the metropolitan region samples had a higher degree of adulteration than the state countryside samples. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Scutellarin inhibits cytochrome P450 isoenzyme 1A2 (CYP1A2) in rats.

PubMed

Jian, Tun-Yu; He, Jian-Chang; He, Gong-Hao; Feng, En-Fu; Li, Hong-Liang; Bai, Min; Xu, Gui-Li

2012-08-01

Scutellarin is the most important flavone glycoside in the herbal drug Erigeron breviscapus (Vant.) Hand.-Mazz. It is used frequently in the clinic to treat ischemic vascular diseases in China. However, the direct relationship between scutellarin and cytochrome P450 (CYP450) is unclear. The present study investigated the in vitro and in vivo effects of scutellarin on cytochrome P450 1A2 (CYP 1A2) metabolism. According to in vitro experiments, scutellarin (10-250 µM) decreased the formation of 4-acetamidophenol in a concentration-dependent manner, with an IC₅₀ value of 108.20 ± 0.657 µM. Furthermore, scutellarin exhibited a weak mixed-type inhibition against the activity of CYP1A2 in rat liver microsomes, with a K(i) value of 95.2 µM. Whereas in whole animal studies, scutellarin treatment for 7 days (at 5, 15, 30 mg/kg, i.p.) decreased the clearance (CL), and increased the T(1/2) (at 15, 30 mg/kg, i.p.), it did not affect the V(d) of phenacetin. Scutellarin treatment (at 5, 15, 30 mg/kg, i.p.) increased the AUC(0-∞) by 14.3%, 67.3% and 159.2%, respectively. Scutellarin at 30 mg/kg also weakly inhibited CYP1A2 activity, in accordance with our in vitro study. Thus, the results indicate that CYP1A2 is inhibited directly, but weakly, by scutellarin in vivo, and provide useful information on the safe and effective use of scutellarin in clinical practice. Copyright © 2012 John Wiley & Sons, Ltd.

Wavenumber selection method to determine the concentration of cocaine and adulterants in cocaine samples.

PubMed

Kahmann, A; Anzanello, M J; Fogliatto, F S; Marcelo, M C A; Ferrão, M F; Ortiz, R S; Mariotti, K C

2018-04-15

Street cocaine is typically altered with several compounds that increase its harmful health-related side effects, most notably depression, convulsions, and severe damages to the cardiovascular system, lungs, and brain. Thus, determining the concentration of cocaine and adulterants in seized drug samples is important from both health and forensic perspectives. Although FTIR has been widely used to identify the fingerprint and concentration of chemical compounds, spectroscopy datasets are usually comprised of thousands of highly correlated wavenumbers which, when used as predictors in regression models, tend to undermine the predictive performance of multivariate techniques. In this paper, we propose an FTIR wavenumber selection method aimed at identifying FTIR spectra intervals that best predict the concentration of cocaine and adulterants (e.g. caffeine, phenacetin, levamisole, and lidocaine) in cocaine samples. For that matter, the Mutual Information measure is integrated into a Quadratic Programming problem with the objective of minimizing the probability of retaining redundant wavenumbers, while maximizing the relationship between retained wavenumbers and compounds' concentrations. Optimization outputs guide the order of inclusion of wavenumbers in a predictive model, using a forward-based wavenumber selection method. After the inclusion of each wavenumber, parameters of three alternative regression models are estimated, and each model's prediction error is assessed through the Mean Average Error (MAE) measure; the recommended subset of retained wavenumbers is the one that minimizes the prediction error with maximum parsimony. Using our propositions in a dataset of 115 cocaine samples we obtained a best prediction model with average MAE of 0.0502 while retaining only 2.29% of the original wavenumbers, increasing the predictive precision by 0.0359 when compared to a model using the complete set of wavenumbers as predictors. Copyright © 2018 Elsevier B.V. All rights reserved.

Modulation of P450 enzymes by Cuban natural products rich in polyphenolic compounds in rat hepatocytes.

PubMed

Rodeiro, I; Donato, M T; Lahoz, A; González-Lavaut, J A; Laguna, A; Castell, J V; Delgado, R; Gómez-Lechón, M J

2008-03-10

This paper reports cytotoxic effects and changes in the P450 system after exposing rat hepatocytes to four polyphenol-rich products widely used in Cuban traditional medicine (Mangifera indica L. (MSBE), Thalassia testudinum (Tt), Erythroxylum minutifolium and confusum extracts). Effects of mangiferin, the main polyphenol in MSBE, were also evaluated. Cytotoxicity was assayed by the MTT test after exposure of cells to the products (50-1000 microg/mL) for 24 or 72 h. The results showed that 500 microg/mL MSBE was moderately cytotoxic after 72 h, while mangiferin was not. Marked reductions in cell viability were produced by Erythroxylum extracts at concentrations > or = 200 microg/mL, whereas only moderate effects were induced by 1000 microg/mL Tt. Seven specific P450 activities were evaluated after 48 h exposure of cells to the products. MSBE reduced phenacetin O-deethylation (POD; CYP1A2) activity in a concentration-dependent manner (IC(50)=190 microg/mL). No decreases were observed in other activities. In contrast, mangiferin produced reductions in five P450 activities: IC(50) values of 132, 194, >200, 151 and 137 microg/ml for POD (CYP1A2), midazolam 1'-hydroxylation (M1OH; CYP3A1), diclofenac 4'-hydroxylation (D4OH; CYP2C6), S-mephenytoin 4'-hydroxylation (SM4OH), and chlorzoxazone 6-hydroxyaltion (C6OH; CYP2E1), respectively. E. minutifolium, E. confusum and Tt extracts produced small reductions in SM4OH and C6OH activities, but no significant changes were noted in the other P450 activities. On the other hand, all the products increased the benzyloxyresorufin O-debenzylation (BROD; CYP2B1) activity, with MSBE, mangiferin or E. minutifolium showing the highest effects (about 2-fold over control). Our results showed in vitro effects of these natural products on P450 systems, possibly leading to potential metabolic-based interactions.

The cutting of cocaine and heroin: A critical review.

PubMed

Broséus, Julian; Gentile, Natacha; Esseiva, Pierre

2016-05-01

The illicit drug cutting represents a complex problem that requires the sharing of knowledge from addiction studies, toxicology, criminology and criminalistics. Therefore, cutting is not well known by the forensic community. Thus, this review aims at deciphering the different aspects of cutting, by gathering information mainly from criminology and criminalistics. It tackles essentially specificities of cocaine and heroin cutting. The article presents the detected cutting agents (adulterants and diluents), their evolution in time and space and the analytical methodology implemented by forensic laboratories. Furthermore, it discusses when, in the history of the illicit drug, cutting may take place. Moreover, researches studying how much cutting occurs in the country of destination are analysed. Lastly, the reasons for cutting are addressed. According to the literature, adulterants are added during production of the illicit drug or at a relatively high level of its distribution chain (e.g. before the product arrives in the country of destination or just after its importation in the latter). Their addition seems hardly justified by the only desire to increase profits or to harm consumers' health. Instead, adulteration would be performed to enhance or to mimic the illicit drug effects or to facilitate administration of the drug. Nowadays, caffeine, diltiazem, hydroxyzine, levamisole, lidocaïne and phenacetin are frequently detected in cocaine specimens, while paracetamol and caffeine are almost exclusively identified in heroin specimens. This may reveal differences in the respective structures of production and/or distribution of cocaine and heroin. As the relevant information about cutting is spread across different scientific fields, a close collaboration should be set up to collect essential and unified data to improve knowledge and provide information for monitoring, control and harm reduction purposes. More research, on several areas of investigation, should be carried out to gather relevant information. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Polysaccharide peptides from Coriolus versicolor competitively inhibit model cytochrome P450 enzyme probe substrates metabolism in human liver microsomes.

PubMed

Yeung, John H K; Or, Penelope M Y

2012-03-15

Polysaccharide peptide (PSP), isolated from COV-1 strain of Coriolus versicolor, is commonly used as an adjunct in cancer chemotherapy or health supplement in China. Previous studies have shown that PSP decreased antipyrine clearance and inhibited rat CYP2C11-mediated tolbutamide 4-hydroxylation and in human CYP2C9. In this study, the effects of the water extractable fraction of PSP on the metabolism of model CYP1A2, CYP2D6, CYP2E1 and CYP3A4 probe substrates were investigated in pooled human liver microsomes. PSP (1.25-20μM) dose-dependently decreased CYP1A2-mediated metabolism of phenacetin to paracetamol (IC(50) 19.7μM) and CYP3A4-mediated metabolism of testosterone to 6β-hydroxytestosterone (IC(20) 7.06μM). Enzyme kinetics studies showed the inhibition of CYP1A2 activity was competitive and concentration-dependent (K(i)=18.4μM). Inhibition of testosterone to 6β-hydroxytestosterone was also competitive and concentration-dependent (K(i)=31.8μM). Metabolism of dextromethorphan to dextrorphan (CYP2D6-mediated) and chlorzoxazone to 6-hydroxychlorzoxazone (CYP2E1-mediated) was only minimally inhibited by PSP, with IC(20) values at 15.6μM and 11.9μM, respectively. This study demonstrated that PSP competitively inhibited the CYP1A2- and CYP3A4-mediated metabolism of model probe substrates in human liver microsomes in vitro. The relatively high K(i) values for CYP1A2 and CYP3A4 would suggest a low potential for PSP to cause herb-drug interaction related to these CYP isoforms. Copyright © 2011 Elsevier GmbH. All rights reserved.

Reverse-phase liquid chromatography with electrospray ionization/mass spectrometry for the quantification of pseudoephedrine in human plasma and application to a bioequivalence study.

PubMed

Kim, Jin-Ki; Jee, Jun-Pil; Park, Jeong-Sook; Kim, Hyung Tae; Kim, Chong-Kook

2011-01-01

A sensitive and selective reverse-phase liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) method was developed and validated to quantify pseudoephedrine (CAS 90-82-4) in human plasma. Phenacetin was used as the internal standard (I.S.). Sample preparation was performed with a deproteinization step using acetonitrile. Pseudoephedrine and I.S. were successfully separated using gradient elution with 0.5% trifluoroacetic acid (TFA) in water and 0.5% TFA in methanol at a flow-rate of 0.2 mL/min. Detection was performed on a single quadrupole mass spectrometer by a selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The ESI source was set at positive ionization mode. The ion signals of m/z 166.3 and 180.2 were measured for the protonated molecular ions of pseudoephedrine and I.S., respectively. The lower limit of quantification (LLOQ) of pseudoephedrine in human plasma was 10 ng/mL and good linearity was observed in the range of concentrations 10-500 ng/mL (R2 = 1). The intra-day accuracy of the drug containing plasma samples was more than 97.60% with a precision of 3.99-11.82%. The inter-day accuracy was 99.36% or more, with a precision of 7.65-18.42%. By using this analytical method, the bioequivalence study of the pseudoephedrine preparation was performed and evaluated by statistical analysis of the log transformed mean ratios of pharmacokinetic parameters. All the results fulfilled the standard criteria of bioequivalence, being within the 80-125% range which is required by the Korea FDA, US FDA, and EMEA to conclude bioequivalence. Consequently, the developed reverse-phase LC-ESI-MS method was successfully applied to bioequivalence studies of pseudoephedrine in healthy male volunteers.

Metabolic capabilities of cytochrome P450 enzymes in Chinese liver microsomes compared with those in Caucasian liver microsomes

PubMed Central

Yang, Junling; He, Minxia M; Niu, Wei; Wrighton, Steven A; Li, Li; Liu, Yang; Li, Chuan

2012-01-01

AIM The most common causes of variability in drug response include differences in drug metabolism, especially when the hepatic cytochrome P450 (CYP) enzymes are involved. The current study was conducted to assess the differences in CYP activities in human liver microsomes (HLM) of Chinese or Caucasian origin. METHODS The metabolic capabilities of CYP enzymes in 30 Chinese liver microsomal samples were compared with those of 30 Caucasian samples utilizing enzyme kinetics. Phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, amodiaquine N-desethylation, diclofenac 4′-hydroxylation (S)-mephenytoin 4′-hydroxylation, dextromethorphan O-demethylation, chlorzoxazone 6-hydroxylation and midazolam 1′-hydroxylation/testosterone 6β-hydroxylation were used as probes for activities of CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A, respectively. Mann-Whitney U test was used to assess the differences. RESULTS The samples of the two ethnic groups were not significantly different in cytochrome-b5 concentrations but were significantly different in total CYP concentrations and NADPH-P450 reductase activity (P < 0.05). Significant ethnic differences in intrinsic clearance were observed for CYP1A2, CYP2C9, CYP2C19 and CYP2E1; the median values of the Chinese group were 54, 58, 26, and 35% of the corresponding values of the Caucasian group, respectively. These differences were associated with differences in Michaelis constant or maximum velocity. Despite negligible difference in intrinsic clearance, the Michaelis constant of CYP2B6 appeared to have a significant ethnic difference. No ethnic difference was observed for CYP2A6, CYP2C8, CYP2D6 and CYP3A. CONCLUSIONS These data extend our knowledge on the ethnic differences in CYP enzymes and will have implications for drug discovery and drug therapy for patients from different ethnic origins. PMID:21815912

Human liver microsomal cytochrome P-450 enzymes involved in the bioactivation of procarcinogens detected by umu gene response in Salmonella typhimurium TA 1535/pSK1002.

PubMed

Shimada, T; Iwasaki, M; Martin, M V; Guengerich, F P

1989-06-15

A total of 57 procarcinogens was examined for induction of umu gene response in the chimeric plasmid pSK1002, carried in Salmonella typhimurium TA 1535, after incubation with a series of human liver microsomal preparations which had been selected on the basis of characteristic levels of individual cytochrome P-450 (P-450) enzymes. The 18 most active compounds were selected and further analyzed using the umu gene response and correlative studies with a larger number of microsomal preparations, enzyme reconstitution studies involving purified enzymes, immunochemical inhibition, and patterns of stimulation and inhibition of catalytic activity by 7,8-benzoflavone. The results collectively indicate that 16 of these 18 most potent genotoxins examined are activated primarily either by P-450NF (the nifedipine oxidase) or P-450PA (the phenacetin O-deethylase). P-450NF appears to be the major enzyme involved in the bioactivation of aflatoxin B1, aflatoxin G1, sterigmatocystin, trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene, 6-aminochrysene, and tris-(2,3-dibromopropyl)phosphate in human liver. P-450PA appears to be the major enzyme involved in the bioactivation of 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,5-dimethylimidazo[4, 5-f]quinoline, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-aminoanthracene, 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole, 2-aminofluorene, 2-acetylaminofluorene, 4-aminobiphenyl, 3-amino-1-methyl-5H-pyrido[4,3-b] indole, and 2-aminodipyrido[1,2-a:3',2'-d]imidazole. More than one enzyme appears to contribute significantly to the bioactivation of the other two compounds examined, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole and 6-nitrochrysene. The literature suggests that the two human liver P-450s involved in activation of these 16 procarcinogens are highly inducible by barbiturates, macrolide antibodies, and certain steroids (P-450NF) and by smoking and ingestion of charcoal-containing food (P-450PA); noninvasive assays are available to monitor the function of both P-450NF and P-450PA.

Technical modification of the Balb/c 3T3 cell transformation assay: the use of serum-reduced medium to optimise the practicability of the protocol.

PubMed

Hayashi, Kumiko; Sasaki, Kiyoshi; Asada, Shin; Tsuchiya, Toshiyuki; Hayashi, Makoto; Yoshimura, Isao; Tanaka, Noriho; Umeda, Makoto

2008-12-01

The two-stage Balb/c 3T3 model of cell transformation can mimic the two-stage carcinogenicity bioassay, and has been recognised as a screening method for detecting potential tumour initiators and promoters. A technical modification to the original protocol (which involved the use of M10F medium, consisting of MEM plus 10% fetal bovine serum [FBS]) has been previously proposed, in order to increase its efficacy, namely: the introduction of enriched, serum-reduced medium (DF2F medium, comprising DMEM/F12 plus 2% FBS and other supplements). The aim of this study was to further modify the protocol, so as to attain higher practicability for the assay. The protocol was further optimised by: a) reducing the number of plates required, through the use of larger plates; b) reducing the cost of the assay by retaining the reduced serum concentration and by using 2microg/ml insulin, rather than the more-complex insulin-transferrin-ethanolamine-sodium selenite (ITES) supplement (i.e. DF2F2I medium); and c) extending the culture period from 24-25 days to 31-32 days, resulting in clearer foci (the number of medium changes did not increase, as less-frequent medium changes were performed during the extended culture period). Growth curve construction revealed that variations in the saturation densities of the parental Balb/c 3T3 cell line and its three transformed clones were highest when M10F medium was replaced with DF2F2I medium just before cells reached confluence. We applied this newly-optimised protocol to the assessment of: a) the tumour initiating activity of 3-methylcholanthrene (MCA), N-methyl-N'-nitro-N-nitrosoguanidine, mitomycin C, methylmethane sulphonate, CdCl(2) and phenacetin, combining a post-treatment of 100ng/ml 12-O-tetradecanoylphorbol-13-acetate at the promotion stage; and b) the tumour promoting activity of insulin, lithocholic acid, CdCl(2) and phenobarbital, with pre-treatment of 0.2microg/ml MCA at the initiation stage. In the present study, only phenobarbital was negative when tested by using the modified protocol. 2008 FRAME.

Simultaneous Determination of Vinpocetine and its Major Active Metabolite Apovincaminic Acid in Rats by UPLC-MS/MS and its Application to the Brain Tissue Distribution Study.

PubMed

Wang, Manman; Wang, Lijuan; Sun, Jinghan; Zhang, Lili; Zhao, Longshan; Xiong, Zhili

2018-03-01

A specific, rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for simultaneous determination of vinpocetine (VP) and its active metabolite, apovincaminic acid (AVA) in rat brain regions, such as hypothalamus, striatum, cortex, cerebellum and hippocampus. Phenacetin was used as internal standard (IS). Brain tissue samples were precipitated protein by using 500 μL methanol. The separation was achieved on a Waters ACQUITY UPLC BEH C18 column (100 mm × 2.1 mm, 1.7 μm), using a methanol-water gradient elution at the flow rate of 0.20 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode via positive electrospray ionization source (ESI). The quantification was operated using the transitions of m/z 351 → m/z 280 for VP, m/z 323 → m/z 280 for AVA and m/z 180 → m/z 110 for IS, respectively. The calibration curve was linear in concentration range from 0.100 to 60.0 ng/mL for VP and 0.103 to 6.18 ng/mL for AVA. The intra-day and inter-day precision (relative standard deviation, RSD) values were within 11.8%, the accuracy (relative error, RE) was from -1.7% to 3.0% for VP and 2.7% to 9.5% for AVA at all the three concentration levels of quality-control (QC) samples. The improved UPLC-MS/MS method was specific, rapid and sensitive, which was further successfully applied to simultaneous determination of VP and AVA in different rat brain regions after intragastric administration of 4 mg/kg VP. It was indicated that VP could be eliminated quickly in brain, while the elimination of AVA was slow and it could be maintained for more than 12 h in brain. Moreover, it was found that the contents of VP and AVA were much higher in the hypothalamus, striatum and cortex than those in the cerebellum and hippocampus, which verified the distribution characteristics of VP and AVA in different brain regions from the point of quantitation in rats.

Evidence on unusual way of cocaine smuggling: cocaine-polymethyl methacrylate (PMMA) solid solution--study of clandestine laboratory samples.

PubMed

Gostic, T; Klemenc, S

2007-07-04

An abandoned clandestine laboratory was seized in Slovenia. All confiscated exhibits were analysed in a forensic laboratory, where the following analytical methods were applied: capillary gas chromatography coupled with mass spectrometry (GC-MS) combined also by solid-phase micro extraction (SPME) and pyrolysis (Py) technique, Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy with energy dispersive X-ray detector (SEM-EDX). The most interesting analytical findings can be summarised as follows: at the crime scene some plastic pieces, which contained cocaine dissolved (as solid solution) in polymethyl methacrylate-plexiglass (PMMA), were found. The highest cocaine concentration measured in the plastic sample was about 15% by weight. Two larger lumps of material (12 and 3 kg) were composed mainly of PMMA and CaCO3 and contained only 0.4 and 0.5% of cocaine, respectively. As for the low cocaine concentration, we assume that those two lumps of material represent discarded waste product--residue after the isolation of cocaine from plastic. Higher quantities of pure solvents (41 l) and solvent mixtures (87 l) were seized. We identified three types of pure solvents (acetone, gasoline and benzine) and two different types of solvent mixtures (benzine/acetone and gasoline/acetone). The total seized volume (87 l) of solvent mixtures holds approximately 395 g of solid residue formed mainly of PMMA and cocaine. Obviously solvent mixtures were used for isolation of cocaine from the plastic. Small quantities of relatively pure cocaine base were identified on different objects. There were two cotton sheets, most probably used for filtration. One sheet had traces of cocaine base (76% purity) on the surface, while cocaine in hydrochloride form (96%) was identified on the other sheet. GC-MS analyses of micro traces isolated from analytical balances showed the presence of cocaine and some common adulterants: phenacetine, lidocaine and procaine. A cocaine sample compressed in the shape of block was also seized. The above analytical findings inferred us to the conclusion that the illicit laboratory was used for the isolation of cocaine from PMMA resin. Further more, analyses confirm that not only isolation but also further manipulation of cocaine, i.e. adulteration/dilution, as well as the formation of cocaine blocks took place in the house. The information obtained through analyses also allowed us to make some hypotheses about possible multistage isolation procedure.

Activation of amino-alpha-carboline, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and a copper phthalocyanine cellulose extract of cigarette smoke condensate by cytochrome P-450 enzymes in rat and human liver microsomes.

PubMed

Shimada, T; Guengerich, F P

1991-10-01

The ability of cigarette smoke condensate to induce a genotoxic response has been measured in liver microsomal and reconstituted monooxygenase systems containing rat and human cytochrome P-450 (P-450) enzymes, as determined by umu gene expression in Salmonella typhimurium TA1535/pSK1002. The reactivities of amino-alpha-carboline and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), two compounds known to be present at considerable levels in cigarette smoke condensate, were also determined and compared with regard to genotoxicity. Amino-alpha-carboline and PhIP are activated principally by P-450 1A2 enzymes in human and rat liver microsomes: (a) activation of both compounds was catalyzed efficiently by liver microsomes prepared from rats treated with 5,6-benzoflavone, isosafrole, or the commercial polychlorinated biphenyl mixture Aroclor 1254, and the activities could be considerably inhibited by antibodies raised against P-450 1A1 or 1A2; (b) the rates of activation of these compounds were correlated with the amount of human P-450 1A2 and of phenacetin O-deethylation activity in different human liver microsomal preparations, and these activities were inhibited by anti-P-450 1A2; (c) reconstituted enzyme systems containing P-450 1A enzymes isolated from rats and humans showed the highest rates of activation of amino-alpha-carboline and PhIP. In rat liver microsomes PhIP may also be activated by P-450 3A enzymes; activity was induced in rats treated with pregnenolone 16 alpha-carbonitrile and was inhibited by anti-human P-450 3A4. However, in humans the contribution of P-450 3A enzymes could be excluded as judged by the very low effects of anti-P-450 3A4 on the microsomal activities and poor correlation with P-450 3A4-catalyzed activities in various liver samples. Cigarette smoke condensate strongly inhibited the activation of several potent procarcinogens by human liver microsomes, particularly the reactions catalyzed by P-450 1A2, but was not so inhibitory of the activation reactions catalyzed by P-450 3A4 and of P-450 2D6-catalyzed bufuralol 1'-hydroxylation. Genotoxic components of the cigarette smoke condensate were extracted by using copper phthalocyanine cellulose (blue cotton). Genotoxicity of this extract was observed only after activation by P-450, and the inhibition of P-450 1A2 activities by these extracts was slight.(ABSTRACT TRUNCATED AT 400 WORDS)

[Early achievements of the Danish pharmaceutical industry--8. Lundbeck].

PubMed

Grevsen, Jørgen V; Kirkegaard, Hanne; Kruse, Edith; Kruse, Poul R

2016-01-01

The article series provides a written and pictorial account of the Danish pharmaceutical industry's products from their introduction until about 1950. Part 8 deals with products from Lundbeck. Lundbeck which today is known as a considerable international pharmaceutical company could in 2015 celebrate its 100 years' jubilee. Among the early Danish medicinal companies H. Lundbeck & Co. is in many ways an exception as the company was not originally established as a pharmaceutical company. Not until several years after the foundation the company began to import foreign ready-made medicinal products and later-on to manufacture these medicinal products in own factory and even later to do research and development of own innovative products. When Lundbeck was established in 1915 several Danish medicinal companies, not only the well-known such as Alfred Benzon and Løvens kemiske Fabrik (LEO Pharma), but also Skelskør Frugtplantage, Ferrin and Ferraton, had emerged due to the respective enterprising pharmacy owners who had expanded their traditional pharmacy business and even with commercial success. Other medicinal companies, such as C.R. Evers & Co., Leerbeck & Holms kemiske Fabriker, Chr. F. Petri, Erslevs kemiske Laboratorium, Edward Jacobsen, Th. Fallesen-Schmidt, and yet other companies which were named after the founder had all been established by pharmacists with the primary intention to manufacture and sell medicinal products. Also for the limited companies Medicinalco, Ferrosan, Pharmacia, and GEA the primary task was to manufacture and sell medicinal products, and also in these companies pharmacists were involved in the foundation. Not until 1924, fully 9 years after the foundation, Lundbeck started to be interested in medicinal products and initiated import and sale of foreign medicinal products manufactured by a.o. German and French companies which had not established their own sales companies in Denmark. Almost all contemporary Danish manufacturers of medicinal products could exclusively determine own proprietary names of the articles and could themselves make their own homogeneous and easily recognisable design, a.o. by frequent use of prefixes as Afa, Asa, Gea, Ido, Leo, and Meco which associated to for instance the company name. However, it goes without saying that Lundbeck had to market the articles in commission according to the different contracts with their partners. Consequently their range of products appeared heterogeneously. The international financial crisis and the consequent unemployment in the 1920s and 1930s had in Denmark a.o. resulted in national regulation in order to complicate import of ready-made goods and thus support the domestic manufacture of such articles. This was one of the reasons why Lundbeck decided to initiate its own manufacture of medicinal products in Denmark instead of continuing only with the import business which had been obstructed by the authorities. This article does not mention all Lundbeck's medicinal products which were marketed in Denmark until 1955 where a new Pharmacy Act came into force though undoubtedly a lot of interest can be written about all of them. The products mentioned in this article have been carefully selected, not only because they are representative for Lundbeck's development during the first decades, but also because the Danish Collection of the History of Pharmacy has acquired consumer packages of many of the articles. Several of these packages include patient information leaflets with an instruction for use and/or other information, and especially these leaflets represent a source material which has not previously been given much attention. It does not appear from the available source material whether these earliest medicinal products from Lundbeck were assembled in Danish packages on the production sites, or whether they were repacked in Copenhagen. It is not unlikely that the assembling originally was finalized abroad, and that instructions for the production of packaging material with Danish text were supplied by Lundbeck to the respective manufacturers. However, it is not unlikely either that the currency restrictions which were made after 1932 encouraged Lundbeck, where possible, first of all to import raw materials and bulk products and then manufacture the finished products in Valby. This was the case with Anusol, which Lundbeck certainly emphazised in the advertisement. It has to be pointed out that at that time there were no legal requirements regarding dating, neither of the user instructions nor of advertisements. Thus it is not due to mistakes or omissions made by Lundbeck that these materials are undated. The user instructions which Lundbeck had inserted in the packages were made and distributed at a time where no legal restrictions were in force neither regarding form nor content of such. The user instructions for products marketed after 1932 had probably been presented to the Pharmacopoeia Commission as this was statutory. It is, however, uncertain whether the Commission has dealt with the contents and the look of the user instructions. The most important task of the Commission was besides of the work with maintaining the Pharmacopoeia to look after the economic interests of the pharmacies so that only new drug substances could be marketed by the pharmaceutical industry, cf. below. In order to find out whether, and if so to which extent, the Pharmacopoeia Commission has been occupied in evaluating the informative and promoting printed matters of the industry, would require studies of the unprinted files of the Commission, and that is outside the scope of this article. At that time it was not against the law to inform in a user instruction that in case of a longer period of treatment, it would be more economical for the patient to buy a larger package. If you look at these patient information leaflets with today's eyes in the light of the present detailed, comprehensive and rigid regulations which the EU Commission has stated regarding patient information leaflets, you will find that Lundbeck's patient information leaflets were both simple and easy to read. On a free sample of Gelonida meant for the prescribing physician Lundbeck stated, besides of indication, dosage and warnings, also that the article was "Manufactured in Denmark". At that time it was not required to print information of production sites on packaging materials, however, it was not unusual to use this sales promoting claim in times of unemployment. In 1949 the original packaging material for Beatin was modified because certain text elements, the therapeutic indications were removed as it appeared that they since 1933 had violated the Pharmacy Act against advertisements for medicinal products aimed at the public. The packaging material for Beatin is a model example of the possibilities to combine practical information about the use of a medicinal product with sales claims in a reliable way. The above text modification and thus the legalisation of the packaging material took place upon request from the company as the violation of the advertising rules of the Pharmacy Act apparently had not resulted in any legal problems. Studies of unpublished files from the National Board of Health may possibly explain the background of this sequence of events, however, that is outside the scope of this article. The paragraph of the Pharmacy Act of 1932, stating that a medicinal product containing a common commodity as the active ingredient could not be marketed as a proprietary medicinal product, was meant to protect the pharmacies against the increasing competition from the industry. At first the paragraph did put a strain on the industry which from then on either had to manufacture own originator products or to copy other originator products without breaking patents. In the long run it has probably caused that not only Lundbeck, but also other Danish pharmaceutical companies became research-oriented and thus have been able to develop a relatively large number of originator products. In this context a product like Lucamid can hardly be regarded as an example of such a compulsory development of an originator product, an acetylsalicylic acid analogue. There were already such products on the market, but the wish to develop a better active ingredient has probably been bigger. From the three first editions of The Tariff of Medicines from 1935, 1937 and 1939 respectively it appears how Lundbeck's business within the area of medicines developed during the last half of the 1930s. In 1935 Lundbeck had placed 36 different medicinal products on the market, and all of them were in-licensing products. 4 years later, in 1939 Lundbeck had placed 40 different medicinal products on the market, and the number of in-licensing products had been reduced to 18 and 22 products were Lundbeck products. However, the increased focus on the development of own new medicinal products as Epicutan and Klianyl did not stop the in-licensing activities. Varex which Lundbeck brought on the market in 1942 came from a German pharmaceutical company with which Lundbeck had not previously collaborated. In Denmark Lundbeck had the intention to market 4 of Goedecke's 6 different medicinal products which all had Gelonida as part of the proprietary name. However, only one of these products got a longer life and with a simplified name, namely Gelonida. The fixed combination with three compounds of acetylsalicylic acid, phenacetin and codeine was without doubt effective, however, already at the end of the 1950s concern was raised about the safety of phenacetin. The Card Index of Medicines is a primary source of knowledge of how Lundbeck marketed the earliest medicinal products to the prescribing physicians. (ABSTRACT TRUNCATED)