ABSTRACT
OBJECTIVE: To study the dissolution behavior of cilnidipine tablets, evaluate the consistency of dissolution behavior between three domestic products and the original tablets, and develop a new dissolution method with discriminatory power for prescription process. METHODS: The dissolution media were hydrochloric acid solution (pH 1.2), acetate buffer (pH 4.0), phosphate buffer (pH 6.8) and water, all containing 0.4% SDS. Using original tablets as the reference preparation, the dissolution curve of the test and reference preparations was compared by the similarity factor method. Apparatus 2 was used for the new method of dissolution test, using 900 mL phosphate buffer with 0.5% SDS (pH 6.8) as the dissolutive medium,at the rate of 75 r·min-1. The dissolution solution was taken at 60 min and analyzed by HPLC. The dissolution limit was set at 70%. RESULTS: For the three domestic pharmaceutical products, only one had consistent dissolution curves in the four dissolution media with the original product from Japanese Ajinomoto Co.. The new method of dissolution test could distinguish the products manufactured by advanced technology from those by process of general level. CONCLUSION: The new dissolution method has discriminatory power for prescription process of insoluble cilnidipine tablets when using phosphate buffer (pH 6.8) as the dissolutive medium, and the quality of the product can be effectively controlled.