Determination of pentoxifylline in serum by high-performance thin-layer chromatography

An analytical method to study the bioavailability of newly developed pentoxifylline sustained-release tablets has been developed and assessed in experiments on dogs. For the isolation of pentoxifylline and its metabolites from serum solid—liquid extraction was applied by involving the internal standard probe. HPTLC plates with a preconcentration zone were used for separation of the analysed substances, using chloroform—methanol (95:5, v/v). Quantification was by densitometric detection. The detector response was linear in the concentration range investigated for pentoxifylline: 0.02–1.5 μg ml −1 of serum.