Preparation and evaluation of mebeverine hydrochloride as mucoadhesive buccal tablet for local anesthesia

Purpose: To formulate and evaluate an antispasmodic drug, mebeverine hydrochloride (Mbv-HCl), as a local anesthetic mucoadhesive buccal tablet. Methods: Mbv-HCl loaded tablets were formulated, using a direct compression technique, with varying polymer concentrations including carbopol 934P alone, carbopol 934P/hydroxypropyl methylcellulose (HPMC) mixture, or carbopol 934P/chitosan mixture. The tablets were evaluated for physicochemical characteristics, in-vitro drug release, bioadhesive strength, swelling, ex-vivo residence time, ex-vivo permeation, drug permeation through the buccal membrane of sheep, and stability. Results: The results indicate that formulation F4, which contains HPMC/carbopol 934P (3:1), showed the best in-vitro drug release profile. The release kinetics for all the formulations fitted well with Hixson- Crowell kinetic model. Bioadhesive strength, surface pH, and swelling index of F4 were 41.52, 6.36, and 231.2 %, respectively. Maximum residence time ex-vivo was exhibited by formulation F4, showing a maximum residence time of about 330 min with 80 % of Mbv-HCl permeated in 6 h ex-vivo . F4 was stable after storage for 60 days at 25 o C/60 % RH and 40 o C/75 % RH, with non-significant change ( p < 0.05) in drug content, bioadhesive strength and in vitro release. Conclusion: The optimized mucoadhesive buccal formulation is promising for delivery of Mbv-HCl, and displays high bioadhesion and adequate permeability through sheep buccal membrane to achieve a local anesthetic action. Keywords: Mebeverine hydrochloride, Buccal, Mucoadhesive tablet, Swelling index, Bioadhesive strength, Local anesthetic