An enantioselective assay for (+/-)-modafinil.
Enantiomers of modafinil, (diphenylmethyl)sulphinyl-2-acetamide, were separated by an amylose tris[(S)-1-phenylethylcarbamate] chiral stationary phase, using acetonitrile: water (25:75 v/v) as mobile phase, with excellent selectivity (alpha=1.4) and resolution factors (R(s)=1.5). The assay involved a solid-phase extraction of the enantiomers of modafinil from plasma using a C(18) Cartridge. A good linear relationship was obtained in the concentration of 0.15-3 microg ml(-1) for each enantiomer. The method developed is sufficiently accurate and precise to be used for clinical samples and has a good selectivity with the two main circulating metabolites: the (diphenylmethyl)sulphinyl-2-acetic acid and (diphenylmethyl)sulphonyl-2-acetamide. The use of a polysaccharide-based column on multimodal elution was explored in developing the method.
Cass
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QB
Departamento de Química, Universidade Federal de S. Carlos, Cx. Postal 676, São Carlos, SP, Brazil. quezia@dq.ufscar.br
Kohn
C K
CK
Calafatti
S A
SA
Aboul-Enein
H Y
HY
D001559:Benzhydryl Compounds / Q000097:blood*; D000697:Central Nervous System Stimulants / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D000077408:Modafinil; D012044:Regression Analysis; D013237:Stereoisomerism
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D000077408:Modafinil