[Determination of pentoxifylline and its major metabolites in human plasma using HPLC].

The present paper describes a rapid, reliable and simple method of pentoxiphyllin in plasma. The worked-out one-step extraction with dichloromethane yields 63% recovery of pentoxiphyllin, 58% recovery of the metabolite and 54% recovery of the internal standard. The employed column with a reverse load of Spherisorb ODS, mobile phase 65% of 0.01 M KH2PO4 and 35% acetonitrile, detection at the wavelength lambda = 273 nm, makes it possible to achieve determination of pentoxiphyllin at the levels commencing with 5 ng.ml-1 of plasma. Reproducibility of determination is 6.8%, or 4.5% in the pentoxiphyllin concentrations of 50, or 100 ng.ml-1.