Formulation Design and Evaluation of Bilayer Buccal Tablets of Granisetron Hydrochloride

Abstract:

In the present study, an attempt was made to design and evaluate bilayer buccal tablets of granisetron hydrochloride (an anti-emetic drug), in order to overcome bioavailability problems, to reduce dose dependent side effects and frequency of administration. Bilayer buccal tablets containing the drug were prepared by direct compression method using combination of polymers (such as sodium alginate, HPMC 50 cps and Carbopol 934p) and ethyl cellulose as an impermeable backing layer to release the drug in a unidirectional way toward the mucosa, thus avoiding loss of drug due to wash out by saliva. The designed tablets were evaluated for various physical and biological parameters, drug content uniformity, in-vitro drug release, short-term stability, drug- excipient interactions (FTIR). The formulation SAF with the drug matrix layer 1 composition- sodium alginate (47% w/w), Carbopol 934p (3% w/w), PVP K-30 (binder, 30% w/w) and mannitol (channeling agent, 15% w/w) was found to be promising. This optimized formulation exhibited an in vitro drug release of 94% in 8 h along with satisfactory bioadhesion o strength (4.6 gm). Short-term stability studies (40±2⁰ C/75±5% RH for 3 months) on the promising formulation indicated that there are no significant changes in drug content and in vitro dissolution characteristics (p<0.05). IR spectroscopic studies indicated that there are no drugexcipient interactions.

Key words: Granisetron hydrochloride, buccal tablets, sodium alginate, HMPC 50 cps and Carbopol 934p.