Ion-pair column chromatographic determination of trimethobenzamide hydrochloride in capsule and injection dosage...

An ion-pair column chromatographic method was developed for the determination of trimethobenzamide hydrochloride in capsules and injection dosage forms. Detection is by UV spectrophotometry at 261 nm. Recoveries by the Associate Referee ranged from 98.3 to 101.0% for the drug substance. Results by 5 collaborators for capsules averaged 99.1% of labeled or theoretical with coefficients of variation (CVs) of 1.81% (reproducibility) and 1.17% (repeatability); results for injections averaged 100.4% of labeled or theoretical with CVs of 1.91% (reproducibility) and 0.69% (repeatability). The method has been adopted official first action.