Application of first-derivative UV spectrophotometry, TLC-densitometry andliquid chromatography for the simultaneous determination of mebeverine hydrochloride and sulpiride

Three methods are described for the simultaneous determination of mebeverin e hydrochloride (MB) and sulpiride (SU) in combined pharmaceutical tablets. The first method depends on first-derivative ultraviolet spectrophotometry , with zero-crossing measurement method. The first derivative amplitudes at 214.2 and 221.6 nm were selected for the assay of MB and SU, respectively. Calibration graphs follow Beer's law in the range of 10-30 and 2-8 mu g ml (-1), and the linearity was satisfactory (r = 0.9999), for MB and SU, respe ctively. The second method was based on the application of the thin layer c hromatographic separation of both drugs followed by the densitometric measu rements of their spot areas. After separation on silica gel GF254 plates, u sing ethanol: diethyl ether: triethylamine (70:30:1 v/v) as the mobile phas e, the chromatographic zones corresponding to the spots of MB and SU were s canned at 262 and 240 nm, respectively. The calibration function was establ ished in the ranges of 4-12 mu g for MB and 2-8 mu g for SU. The third meth od was an internal standard procedure based on high performance liquid chro matographic separation of the two drugs on a reversed-phase, Bondapak CN co lumn. The detection was done at 243 nm using buclizine hydrochloride as int ernal standard. All chromatographic methods showed good linearity, precisio n and reproducibility. No spectral or chromatographic interference from the tablet excipients were found. The proposed methods were successfully appli ed to the assay of commercial tablets and content uniformity test. The proc edures were rapid, simple acid suitable for quality control application. (C ) 1999 Elsevier Science B.V. All rights reserved.