Modeling and analysis of dissolution of paracetamol/Eudragit® formulations

In this work, amorphous paracetamol/Eudragit (R) formulations for four Eudragit (R) (polymeric excipients) were prepared by spray drying technique. The simultaneous dissolution kinetics of paracetamol and Eudragit (R) 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 (R) L 100-55 and Eudragit (R) E PO formulations at pH 5.0, 6.5, and 7.2. Furthermore, a controlled paracetamol dissolution was also achieved from Eudragit (R) L 100 formulations at pH 6.51 and 7.27 as well as from Eudragit (R) S 100 formulations at pH 7.27. Paracetamol dissolution rates were controlled by both paracetamol and excipient from Eudragit (R) 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. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.