Formulation, optimization and evaluation of bilayered tablets of amlodipine besilate as immediate release and metoprolol succinate as sustained release.

ABSTRACT

The purpose of the study was to develop a bilayer tablet of Amlodipine besilate (IR) and Metoprolol succinate (SR) having different release pattern, which is indicated for the management of hypertension. The study was planned in three stages. In the first stage six batches (A1, A2, A3, A4, A5 and A6) of immediate release tables of Amlodipine besilate was prepared by direct compression method using sodium starch glycolate and pre-gelatinised starch as super disintegrant. In the second stage, six batches(M1, M2, M3, M4, M5, M6) of Metoprolol succinate sustained release part was prepared using HPMC polymers as rate retardant. Preformulation studies were performed prior to compression. In the third stage compressed bilayer tablets were evaluated for weight variation, dimension, hardness, friability, drug content, and disintegration time and invitro drug release using RP-HPLC. DSC studies revealed no disturbances in the principle peaks of pure drugs Metoprolol succinate and Amlodipine besilate and it confirms the integrity and compatibility of pure drugs with their excipients. The stability studies were performed for optimised batch for three months and it showed acceptable results.