Preparation and in vitro evaluation of a new terbinafine hydrochloride bioadhesive film-forming gel

The aim of this study was to conduct the preparation and pharmaceutical characterization of a new type of terbinafine hydrochloride bioadhesive film-forming gel. The viscosity of the gel of(13 299±51)mPa ·s, pH of 3. 50±0. 50, and the shearing viscosity of(196±4)g/cm² was found. This new gel turned out to be a layer of solid film on the application site in a very short time. The remaining solid ratio of the resulting film was estimated to be(50. 74±2. 81)%; the tensile strength was(1. 17±0. 21)MPa; and the breaking elongation was(21. 42±3. 24)%. In vitro release behavior of terbinafine hydrochloride from the film was investigated according to the paddle over disk method in ChP2010. Terbinafine hydrochloride released continuously for 10 h from the film. Improved Franz type diffusion cells were used in vitro transdermal studies by the application of excised minipigs skins. No penetration of drug into the receptor medium across the skin existed and so it could imply the safety for local application. It was found that(93. 05±5. 66)% of drug stayed on the skin surface while(1. 15±0. 85)% entered into the skin, which was beneficial for the treatment of superficial skin fungal infection.