Drug Release Kinetics and Stability Studies of Tablets of Tramadol HCl Microspheres

The objectives of study were the development of new formulations of Tramadol HCl (TmH) microspheres and their evaluation primarily for kinetics and stability. Microspheres of different polymer concentration M-1 (1:1), M-2 ( 1 :2) and M-3 (1:3) were developed and compressed into tablets i.e., T-1, T-2 and T-3, respectively. Zero order, First order, Higuchi. Hixson-Crowell and Korsmeyer-Peppas kinetic models were applied to assess the mechanism and pattern of drug release. Higuchi model was found to be the best among all models. The chemical and physical stability of TmH formulation was studied using FTIR. Thermal analysis, X-ray diffraction and dissolution tests. In-vitro analysis showed that tablets of ratio T-2 released the drug over 12hrs and the release profile was comparable with that of reference tablet, Tramal (R) SR. The effect of different storage temperatures on the physicochemical stability of T-2 was insignificant (p > 0.05).