Release of 2-aminothiazole from polymer carriers

Abstract

New dosage forms able to control drug release in the stomach have been prepared and investigated in this paper. Three different types of bonding of medicinal agent (MA) were chosen in order to examine drug release: (i) MA attached to ethylenic monomer, the polymer carrier being obtained by polymerizing this monomer; (ii) MA linked to an organic product, which possesses the same function, the molecule then being enclosed in a polymer matrix; (iii) MA dispersed in its original form into a Eudragit RL matrix. Theoretical and experimental analyses of the kinetics of controlled release of MA from polymer systems or MA carriers were conducted for the case of contact with synthetic gastric fluid (pH 1.2). The process was found to be controlled by transient diffusion of the liquid into, and MA out of the dosage form, with constant diffusivities. The data on drug release provide the opportunity for predicting quantitatively the rate of MA release from the polymer carrier or dosage forms, directly into the organism. A mathematical treatment, according to Fick's law, led to the amount of matter transferred at time t being evaluated. The present study demonstrates that it is possible to derive an expression for the rate of diffusion of MA.