Formulation and Evaluation of S-(-)-Amlodipine Besylate and Nebivolol Hydrochloride Tablets

The objective of the present study was to develop a tablet formulation of S-(-)-amlodipine besylate chiral separation drug and nebivolol hydrochloride for better management of hypertension, while reducing or avoiding undesirable adverse effects, which are often associated with administration of a racemic mixture of amlodipine. The composition containing the optically pure S-(-)- isomer of amlodipine 2.5 mg has calcium channel blocking activity and, nebivolol hydrochloride 5 mg has beta-receptor blocking activity. The study was also carried out to design a suitable dissolution medium for S-(-) - amlodipine besylate and nebivolol hydrochloride. Amlodipine besylate and nebivolol hydrochloride had maximum solubility in pH 1.2 and thus pH 1.2 was selected as the most suitable media for S-(-) - amlodipine besylate and nebivolol hydrochloride dissolution studies. The RSD below 2% indicated insignificant batch-to-batch variation. The accelerated stability study of the optimized formulation was performed as the ICH guidelines. The results indicated no change in optical rotation of S-(-) - amlodipine besylate. Hence, combination of two drugs can be formulated into the tablet by wet granulation technique having satisfactory release profile.