HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY OF DILAZEP IN PLASMA AFTER SOLID-PHASE EXTRACTION

A new, simple and accurate high-performance liquid chromatography meth od is presented for measuring dilazep in plasma, using a reversed-phas e technique and UV absorption at 267 nm. Dilazep and papaverine (the i nternal standard) added to plasma were successfully isolated using a s olid-phase extraction procedure (CN cartridges). The method was linear between 2.5-12.5 mu g ml(-1). Over the tested concentration range the intra-day coefficient of variation for replicate analyses of plasma r anged from 2.38 to 5.27% (the day-to-day CV ranged from 2.52 to 7.99%) . The detection limit for the analysis of dilazep in plasma was 50 ng with 20 mu l injection. (C) 1997 Elsevier Science B.V.