Modeling and analysis of dissolution of paracetamol/Eudragit® formulations


In this work, amorphous paracetamol/Eudragit® formulations for four Eudragit® (polymeric excipients) were prepared by spray drying technique. The simultaneous dissolution kinetics of paracetamol and Eudragit® from these formulations were measured as function of pH in vitro using a rotating disk system (USP II). Paracetamol dissolution mechanisms were analyzed by comparing the dissolution rates of paracetamol and excipient. It was found that a controlled paracetamol dissolution was achieved from Eudragit® L 100-55 and Eudragit® E PO formulations at pH 5.0, 6.5, and 7.2. Furthermore, a controlled paracetamol dissolution was also achieved from Eudragit® L 100 formulations at pH 6.51 and 7.27 as well as from Eudragit® S 100 formulations at pH 7.27. Paracetamol dissolution rates were controlled by both paracetamol and excipient from Eudragit® L 100 and S 100 formulations at other pH values. Moreover, a chemical-potential-gradient model combined with PC-SAFT was used to model the dissolution kinetics of PARA from these formulations in good accordance with the experimental data.