Preparation and Study of Oral Galenic Forms by Dispersing into Eudragit/Matrix a Polyacryloyl-Acetylsalicylic Anhyride

Abstract

Oral galenic forms able to control the drug release in stomach are prepared and studied in this paper. A branched polymer is dispersed in a biocompatible polymer as Eudragit. A Polyanhydride is chosen for this branched polymer and it is obtained by reacting the anhydride with the drug and then polymerizing this branched monomer. The process of release of drug is studied by using in vitro tests with synthetic gastric liquid. The process is proved to be controlled by transient diffusion of the liquid into and the drug out of the galenic form, with contant diffusivities. A simple mathematical model is thus able to describe both these matter transfers. Moreover, the branched pulymer itself exhibits a retardancy in the release of drug which is also controlled by diffusion. This retardancy can be of interest, especially in case of accident when the galenic form is broken in the patient's mouth and chewed.