Determination of the antiallergenic agent, trans-3-[6-(methylthio)-4-oxo-4H-quinazolin-3-yl]-2-propenoic acid, in plasma by high-performance liquid chromatography

• Published in: Journal of chromatography 1983-01, Vol.276 (2), p.329-340
• Main Authors: Pao, Joan, Puglisi, Carl V., de Silva, J.Arthur F.
• Format: Article
• Language: English
• Subjects: Analysis; Biological and medical sciences; General pharmacology; Medical sciences; Pharmacology. Drug treatments
• ISSN: 0378-4347; 0021-9673
• DOI: 10.1016/S0378-4347(00)85099-9

A rapid and selective high-performance liquid chromatogaphic (HPLC) assay was developed for the determination of the antiallergenic compound, trans-3-[6-(methylthio)-4-oxo-4H-quinazolin-3-yl]-2-propenoic aicd, [I], in plasma. They assay involves acetonitrile protein precipitation followed by the analysis of an aliquot of the protein-free fraction by reversed-phase HPLC with fluorescence detection (excitation at 245 nm, with emission greater than 418 nm). The overall recovery of [I] from plasma was 103 ± 10%. The sensitivity limit of the assay was 0.125 μl/ml of plasma. The analogous compound, trans-3-[6-[(1-methylethyl)thio-4-oxo-4H-quinazolin-3-yl]-2-propenoic acid, [II], is used as the internal standard. The assay was used to monitor the plasma concentration—time fall-off profile of [I] in the dog an in man. The stability of [I] was demostrated in dog plasma on long-term storage for up to 180 days at −17°C and −70°C.