Validated HPLC Determination of the Two Fixed Dose Combinations (Chlordiazepoxide Hydrochloride and Mebeverine Hydrochloride; Carvedilol and Hydrochlorothiazide) in Their Tablets

Simple, rapid, and selective RP-HPLC methods with UV detection were developed for simultaneous determination of chlordiazepoxide hydrochloride and mebeverine hydrochloride (Mixture I) and carvedilol and hydrochlorothiazide (Mixture II). The chromatographic separation in both mixtures was achieved by using an RP-C8 (octylsilyl) analytical column. For Mixture I, a mobile phase composed of acetonitrile0.05 M disodium hydrogen phosphatetriethylamine (50 + 50 + 0.2, v/v/v), pH 2.5, was used; the detector wavelength was 247 nm. For Mixture II, the mobile phase consisted of acetonitrile0.05 M disodium hydrogen phosphate (50 + 50, v/v), pH 4.0, and the detector was set at 220 nm. Quantification of the analytes was based on measuring their peak areas. Both mixtures were resolved in less than 6 min. The reliability and analytical performance of the proposed HPLC procedures were statistically validated with respect to linearity, range, precision, accuracy, selectivity, robustness, LOD, and LOQ. The linear dynamic ranges were 2.5150 and 2.5500 g/mL for chlordiazepoxide HCl and mebeverine HCl, respectively, and 0.25200 and 0.25150 g/mL for carvedilol and hydrochlorothiazide, respectively. The validated HPLC methods were successfully applied to the analysis of their commercial tablet dosage forms, for which no interfering peaks were encountered from common pharmaceutical adjuvants.

Liquid Chromatographic Determination of Clidinium Bromide and Clidinium Bromide-Chlordiazepoxide Hydrochloride Combinations in Capsules

A specific liquid chromatographic method was developed for determination of clidinium bromide and clidinium bromidechlordiazepoxide hydrochloride combinations in capsules. The procedure uses a Partisil 10 ODS-3 column and a mobile phase consisting of acetonitrile-0.3M ammonium phosphate (32 + 68) (pH = 4.3). The detection wavelength is 235 nm. Accuracy, reproducibility, and linearity were within accepted criteria. Four commercial samples of the single ingredient were tested; results compared favorably with the compendial method. Two commercial samples of the combination product were tested by the proposed method and results reported. The system was found to be free from any interferences from the 4 known related compounds of the 2 major components and Is useful as a screening procedure for 7- chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one- 4-oxide, the principal degradation product of chlordiazepoxide hydrochloride.