Application of quality by design paradigm in the design of muco-adhesive extended release film for oral ulcer

The present study deals with the formulation of mucoadhesive bilayered buccal film of lidocaine hydrochloride and benzydamine hydrochloride for treatment of oral ulcers (aphthous stomatitis). Eudragit-RLPO and Ethyl cellulose were used as film forming polymers and low viscosity grade hydroxyl propyl cellulose as a mucoadhesive agent. Solvent casting method was adopted for film formation. The film was evaluated for content uniformity, tensile strength, folding endurance, swelling, mucoadhesive strength, ex vivo mucoadhesive time and in vitro drug release. The films were characterized for DSC and FTIR. The film showed acceptable film properties and muco-adhesion. The formulation showed predictive drug release, i.e. 80 in 2, 4 and 6 h respectively. In-vitro drug release study revealed that a combination of Eudragit and Ethyl cellulose was required for better control of the drug release. The DSC and FTIR study confirmed drug-drug and drug–excipient compatibility. Keywords: Bilayer film, Eudragit-RLPO, Ethyl cellulose, Muco-adhesion, Extended drug release.