Formulation and Evaluation of Bilayered Tablets of Nifedipine as Immediate Release and Atenolol as Sustained Released Tablet

Objective: The objective of the present study was to develop Bilayered tablets of Nifedipine and atenolol. Bilayered tablet contains two layers. We can formulate first layer into immediate release and second layer into sustained release for desired action. Nifedipine have half-life 2hrs make the drug suitable for immediate release. Atenolol have half-life 6-7hrs make the drug suitable for sustained release. Methods: In this formulation using super disintegrants for immediate release, acacia and ethyl cellulose as polymers for sustained release. Tablets were prepared by wet granulation method. In this study Bilayered tablets of Nifedipine and Atenolol tablets were evaluated for weight variation, hardness, thickness, drug content and In-vitro studies. Results: Bi-layer tablet is suitable for sequential release of two drugs in combination, separate to incompatible substances and also for immediate release as initial dose and sustained release as maintenance dose. In Immediate release formulation, IR-F-3 formulation gives 98% release within 15min. For sustained effect SR-F-3, SR-F-1 gives 98% release within 8-9hrs. SR-F-2 gives 99% release within 10-11hrs for a longer period of time. Conclusion: The combination of IF-3 and SR-F-2 suitable for formulation. This formulation is used for Bilayered tablet to combine with sustained released tablet. The evaluation parameters were estimated.