title: Simultaneous determination of pyridostigmine bromide, N,N-diethyl-m-toluamide, permethrin, and their metabolites in rat plasma and urine by high-performance liquid chromatography.
abstract: A rapid and simple method was developed for the separation and quantification of the anti nerve agent drug pyridostignmine bromide (PB; 3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide) its metabolite N-methyl-3-hydroxypyridinium bromide, the insect repellent DEET (N,N-diethyl-m-toluamide), its metabolites m-toluamide and m-toluic acid, the insecticide permethrin (3-(2,2-dichloro-ethenyl)-2,2-dimethylcyclopropanecarboxylic acid(3-phenoxyphenyl)methylester), and two of its metabolites m-phenoxybenzyl alcohol, and m-phenoxybenzoic acid in rat plasma and urine. The method is based on using C18 Sep-Pak cartridges for solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with reversed-phase C18 column, and gradient UV detection ranging between 208 and 230 nm. The compounds were separated using gradient of 1 to 99% acetonitrile in water (pH 3.20) at a flow-rate ranging between 0.5 and 1.7 ml/min in a period of 17 min. The retention times ranged from 5.7 to 14.5 min. The limits of detection were ranged between 20 and 100 ng/ml, while limits of quantitation were 150-200 ng/ml. Average percentage recovery of five spiked plasma samples were 51.4+/-10.6, 71.1+/-11.0, 82.3+/-6.7, 60.4+/-11.8, 63.6+/-10.1, 69.3+/-8.5, 68.3+/-12.0, 82.6+/-8.1, and from urine 55.9+/-9.8, 60.3+/-7.4, 77.9+/-9.1, 61.7+/-13.5, 68.6+/-8.9, 62.0+/-9.5, 72.9+/-9.1, and 72.1+/-8.0, for pyridostigmine bromide, DEET, permethrin, N-methyl-3-hydroxypyridinium bromide, m-toluamide, m-toluic acid, m-phenoxybenzyl alcohol and m-phenoxybenzoic acid, respectively. The relationship between peak areas and concentration was linear over the range between 100 and 5000 ng/ml. This method was applied to analyze the above chemicals and metabolites following their administration in rats.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: A W
authors.initials: AW
authors.lastname: Abu-Qare
authors.forename: M B
authors.initials: MB
authors.lastname: Abou-Donia
mesh_terms: D000818:Animals; D002138:Calibration; D002800:Cholinesterase Inhibitors / Q000097:blood / Q000378:metabolism / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003671:DEET / Q000097:blood / Q000378:metabolism* / Q000652:urine; D007302:Insect Repellents / Q000097:blood / Q000378:metabolism / Q000652:urine; D007306:Insecticides / Q000097:blood / Q000378:metabolism / Q000652:urine; D026023:Permethrin; D011722:Pyrethrins / Q000097:blood / Q000378:metabolism* / Q000652:urine; D011729:Pyridostigmine Bromide / Q000097:blood / Q000378:metabolism* / Q000652:urine; D011786:Quality Control; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards
chemical_list: D002800:Cholinesterase Inhibitors; D007302:Insect Repellents; D007306:Insecticides; D011722:Pyrethrins; D003671:DEET; D026023:Permethrin; D011729:Pyridostigmine Bromide