Formulation and in vitro evaluation of once daily sustained release formulation of aceclofenac

Purpose: The objective of the study was to develop matrix tablets for oral controlled release of aceclofenac using ethyl cellulose, guar gum and various grades of cellulose polymers.
Methods: Possible drug-excipient interaction was evaluated by high performance liquid chromatography (HPLC) and Fourier infrared spectroscopy (FTIR). The tablets prepared were assessed for their physicochemical, in vitro drug release at pH1.2, 4.5, 6.8 and 7.5 and stability characteristics. Comparison with a ′once daily′ commercial aceclofenac product was made in the in vitro studies.
Results: There was no interaction between aceclofenac and the polymers used as excipients. Furthermore, the physicochemical properties of the tablets were satisfactory. The release profile of one of the formulated aceclofenac tablets (F7), which contained hydroxypropyl methyl cellulose (HPMC K4M), was statistically similar (p < 0.05) to that of the commercial aceclofenac brand in all the dissolution media. The formulated products ware stable and showed no changes in physical appearance, drug content, or dissolution pattern after storage at 40 ^o C /75 %RH for 6 months.
Conclusion: The results indicate that it is feasible to achieve a stable ′once daily′ sustained release aceclofenac tablet formulation by using HPMC K4M of 4000cps viscosity grade as matrix material.

Keywords
Aceclofenac, Sustained release, Matrix tablets, Cellulose polymers, Stability studies