Abstract
Purpose of Study: In the present study, an attempt was made to design and evaluate mucoadhesive bilayer tablets of atenolol (beta blocker), in order to overcome bioavailability problems, to reduce dose dependent side effects and frequency of administration.
Method: Bilayer buccal tablets of atenolol were prepared by direct compression method using combination of polymers (such as Sodium CMC, Sodium alginate along with Carbopol 974p and ethylcellulose as backing layer. Ten formulations were developed with varying concentrations of polymers. The designed tablets were evaluated for various physical and biological parameters like drug content uniformity, in-vitro drug release, short-term stability, drug-excipient interactions (FTIR).
Results: Among the ten formulations, the formulation FA1 containing Sodium alginate (44% w/w of matrix layer), Carbopol 974p (6% w/w of matrix layer) and mannitol (channeling agent, 14% w/w of matrix layer) was found to be promising. This formulation exhibited an in vitro drug release of 87.19 % in 8 h along with satisfactory bioadhesion strength (4.74 g). Short-term stability studies on the promising formulation indicated that there are no significant changes in drug content and in vitro dissolution characteristics (p<0.05). FTIR studies show no evidence on interaction between drug and excipients.
Conclusion: The present study proves that mucoadhesive bilayer tablets of atenolol with controlled drug release properties can be successfully prepared by direct compression method using Sodium CMC, Sodium alginate along with Carbopol 974p as mucoadhesive polymers and ethyl cellulose as backing layer. The prepared buccal tablets of atenolol were able to stay in the buccal cavity for a longer period of time, which indicates a potential use of mucoadhesive tablets of atenolol for treating blood pressure.

Key words: Mucoadhesive buccal tablet, Atenolol, Sodium CMC, Sodium alginate, Carbopol 974p Swelling index, Bioadhesive strength.