Plasma determination of the novel anticonvulsant D,L-3-hydroxy-3-ethyl-3-phenylpropionamide and preliminary pharmacokinetic studies in the rat.
A sensitive gas chromatographic method with flame ionization detection was developed for the analysis in plasma of the novel anticonvulsant D,L-3-hydroxy-3-ethyl-3-phenylpropionamide (HEPP), using D,L-2-hydroxy-2-ethyl-2-phenylacetamide as the internal standard. HEPP was extracted from alkalinized plasma into dichloromethane and quantified after derivatization with bis(trimethylsilyl)-trifluoroacetamide: Standard curves were linear from 0.5 to 50 and from 2 to 100 micrograms/ml of plasma, using 1.5 and 5 micrograms of the internal standard, respectively. The lower limit of detection at a signal-to-noise ratio of 3 standard deviations was 0.33 micrograms/ml of sample. The sensitivity, accuracy and reproducibility of the method were shown to be satisfactory for pharmacokinetic studies of HEPP. After intraperitoneal administration of 50 mg/kg to Wistar rats, the principal kinetic parameters were: absorption half-life = 0.04 h; volume of distribution = 1.32 l/kg; clearance = 4.40 ml/min; peak concentration = 50 micrograms/ml; peak time = 0.25 h; mean residence time = 4.55 h.
Gomez
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Departamento de Farmacología y Toxicología, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Mexico City, Mexico.
Lehmann
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D000818:Animals; D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002849:Chromatography, Gas / Q000379:methods*; D005410:Flame Ionization; D007274:Injections, Intraperitoneal; D008297:Male; D010666:Phenylpropionates / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
D000927:Anticonvulsants; D010666:Phenylpropionates; C067697:beta-hydroxy-beta-ethyl-phenylpropionamide