Formulation and In Vitro Release Kinetics of Mucoadhesive Blend Gels Containing Matrine for Buccal Administration.

Enterovirus 71 (EV71) is a pathogenic factor of severe hand, foot, and mouth disease (HFMD). No vaccine or specific treatment is currently available for EV71 infection. Hence, we developed a buccal mucoadhesive gel containing matrine to protect against HFMD. Mucoadhesive gels were prepared by Carbopol 974P and were combined with Carbopol 971P, sodium carboxymethyl cellulose (CMC-Na), or hydroxypropylmethy cellulose (HPMC K100M). The formulations were characterized in terms of tensile testing and continuous flow techniques for mucoadhesion. The rheological studies and in vitro drug release characteristics were also investigated. The results showed that combinations of two polymers significantly improved mucoadhesion, especially Carbopol 974P blended with HPMC. Carbopol 974P to HPMC blend ratios of 1:1 and 2:1 induced better mucoadhesion in the tensile test and continuous flow method, respectively. The most sustained release was obtained at a Carbopol 974P to HPMC ratio of 2.5:1. A predominantly non-Fickian diffusion release mechanism was obtained. The gel containing 2.5% Carbopol 974P combined with 1% HPMC showed good mucoadhesion properties and sustained drug release.