Spectrophotometric determination of mebeverine hydrochloride

Three simple, sensitive and reproducible visible spectrophotometric methods (A-C) for the determination of mebeverine hydrochloride (MVH) in bulk samples and pharmaceutical formulations are described. Methods A and B are based on the formation of ion-association complexes between the drug and fast green FCF (FGFCF, _max 625 nm) or bromothymol blue (BTB, _max 405 nm). Method C is based on the formation of a molecular complex between the drug and cobalt thiocyanate (CTC, _max 625 nm). Regression analysis of Beer's plots showed good correlation in the concentration ranges 2–40, 2–25 and 100–600 g/ml for methods A, B and C respectively. No interference was observed from the usually existing additives in pharmaceutical formulations and the applicability of the methods was examined by analysing tablets containing MVH. Standard deviations were typically 0.75 mg per dose (RSD: 0.25–0.5%). Recoveries were 99.0–100.2%.