Formulation Development of Atenolol Bilayer Tablets and Their In-vitro Characterization

B. Venkateswara Reddy*, N. Gangadhar, K. Navaneetha
Department of Industrial Pharmacy, St.Paul’s College of Pharmacy, Turkayamjal (V), Hayathnagar (M), R.R.Dist-501510.

A B S T R A C T
The objective of this study was to develop an optimized bilayer floating tablet (BFT) containing atenolol. The BFT contains two layers, an immediate release layer having the conventional dose of atenolol along with superdisintegrants, which help in quick release of drug and a sustained release layer possessing the remaining amount of atenolol. Atenolol is released from the floating sustained release layer for a prolonged period of time. Independent variables studied were, the drug: total polymer ratio, hydroxy propyl methylcellulose (HPMC): Carbopol 974P ratio and gas generating agent, Sodium bicarbonate content. DSC and FTIR studies were carried out to determine the compatibility between the drug and the various excipients. Studies revealed that there is no incompatibility. Total of 8 formulations have been prepared by changing the composition of SR layer. The prepared bilayer tablets were evaluated for various quality control tests like hardness, thickness, weight variation, floating lag time and total buoyancy time. The floating lag time was in the range of 4– 75sec and they remained buoyant for 24 hours. The formulation F6 is considered as the optimized formulation as 50% of drug is released in 1hour and the remaining drug is released in a controlled manner and the drug release at the end of 12hours was found to be 90.124%. The drug release was controlled by both swelling and diffusion. There was no significant change in the formulation after subjecting to accelerated stability studies for a period of 3months.
Keywords: Bilayer Floating tablet, Atenolol, Carbopol, HPMC, Accelerated stability studies.