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 bromide-chlordiazepoxide 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.