Determination of pentoxifylline and its major metabolites in microbial extracts by thin-layer and high-performance liquid chromatography.

Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) methods have been developed for the determination of the xanthine drug, pentoxifylline, and three of its metabolites (a secondary alcohol and two carboxylic acids) in microbial extracts. The methods require initial extraction of acidified media with dichloromethane 2-propanol (4:1). Extracts are submitted to TLC development on silica gel G layers using three solvents and HPLC development on an C18 column using methanol-phosphoric acid (0.02 M, pH 5) (3:7) as mobile phase. All systems provide good separations of the drug and its metabolites. Quantitative analyses of pentoxifylline and its metabolites by HPLC were accurate and precise. The HPLC method was applied to studies of the metabolism of pentoxifylline by two microorganisms.