KINETICS OF CEPHALEXIN RELEASE FROM EUDRAGIT-HYDROXYPROPYLCELLULOSE MEMBRANES

The release of cephalexin dispersed in films composed of different rat ios of Eudragit-RS and hydroxypropylcellulose (HPC) was investigated. The results indicate that drug release from matrix follows a diffusion -controlled model, where the quantity released per unit area is propor tional to the square roof of time. The release rate was found to be pr oportional to diethylphthalate (DEP) content, drug concentration, and HPC fraction in the film. Addition of plasticizer is indispensable for the improvement of film characteristics. The aggregation of drug part icles was increased with DEP contents in film. The release rate was en hanced by adding the HPC to the rate-controlling membrane.