抄録
In vitro release of ketotifen from transdermal systems made of silicone pressure sensitive adhesive matrices (PSA) containing crystalline ketotifen (PSA-Crystalline) or that containing amorphous ketotifen (PSA-Amorphous) was analyzed based on two types of mathematical models. Higuchi’s model which assumes an infinite drug dissolution rate in the matrices well described the release from PSA-Amorphous. On the other hand, Higuchi’s model overestimated the release from PSA-Crystalline and the deviation was significantly diminished by incorporating a dissolution control term in the model. This analysis suggested that the ketotifen release from PSA-Amorphous is almost entirely diffusion-controlled, while that from PSA-Crystalline is controlled by both diffusion and dissolution processes.
