Consistency Evaluation of the Dissolution of Generic and Original Preparations of Cobamamide Capsules

OBJECTIVE To establish the dissolution test method of cobamamide capsules and evaluate its consistency with the original preparation in vitro. METHODS The dissolution of cobamamide capsules was determined by HPLC. The methodology was verified. Water, hydrochloric acid solution(pH 1.2), acetate buffer(pH 4.5) and phosphate buffer(pH 6.8) were used as dissolution medium, the volume of dissolution medium was 500 mL, basket method, rotating speed was 50 r·min⁻¹. The dissolution curves of cobamamide capsules generic and the original drug were measured, respectively. And the in vitro dissolution consistency was compared. RESULTS The linear relationship between mass concentration and peak area of cobamamide was good within a range(r≥0.999). The injection precision, solution stability and repeatability test results meet the requirements(RSD was all <2%). The average recoveries of cobamamide capsules were 98.6%, 99.6%, 99.3% and 101.2% in four kinds of medium, with RSD of 1.2%, 0.9%, 1.5% and 1.8%(n=9), respectively. In four kinds of medium, within 15 min the cumulative dissolution rate was >85%, which was consistent with the dissolution curve of the original preparation. CONCLUSION This method can be used to test the dissolution of cobamamide capsules. The dissolution in vitro of three batches of cobamamide capsules are similar to that of the original preparation, which can be used as a method to evaluate the consistency in vitro.