Effect of fillers and lubricants on acetylsalicylic acid release kinetics from Eudragit matrix tablets

Abstract

The effect of fillers and lubricants on the dissolution rate of acetylsalicylic acid (ASA) from matrix tablets has been evaluated. Eudragit S-100 and Eudragit L-100-55 where chosen as matrix substances. The process of drug release in vitro was studied by the modified half-change method. The dissolution data were evaluated on the basis of theoretical dissolution equations and by linear transformation of dissolution curves. Differences in release rate of ASA from matrix tablets, regarding the diluents used, appeared to be more significant when matrices contained Eudragit L-100-55 as compared to Eudragit S-100. The highest dissolution rates of ASA were observed in the presence of Lubritab as lubricant. The other lubricants used showed similar effects on the release rate of ASA. The release of ASA from samples containing Eudragit L-100-55 corresponded best to the zero-order kinetics. The best-fitted model for the ASA release from tablets prepared with Eudragit S-100 was obtained by using the Hixson-Crowell equation.