Design and Development of Directly Compressed Sustained Release Matrix Tablets of Aceclofenac

The objective of the present research work was to develop once-daily directly compressed sustained release matrix tablets of aceclofenac, a novel potent analgesic used in treatment of rheumatoid arthritis, alkylosing spondylitis and other acute painful conditions.

Sustained release matrix tablets of aceclofenac were prepared by direct compression using xanthan gum, guar gum and hydroxypropyl methylcellulose K4M. Microcrystalline cellulose was used as a diluent and PEG6000 used as drug release modifier. Xanthan gum and guar gum were used as matrix former. Drug and powder blends of all batches were subjected to preformulation, precompression and postcompression studies. Optimized batches of sustained release matrix tablets were subjected to stability studies.

The batches C, F3, and T4 showed sustained release of drug for 24 hours with 98.64%, 99.13%, and 95.35% respectively. In vitro dissolution kinetic study of batch C by Korsemeyer-Peppas equation shows regression coefficient, R² = 0.9748 with release exponent, n = 2.0996 that followed super case-II transport mechanism that indicates the polymer relaxation mechanism. The formulation F3 and T4 in Korsemeyer-Peppas equation showed good linearity (R² = 0.9887, 0.9728), with slope (n = 0.7205, 08635) respectively that appears to indicate the drug release mechanism is anomalous transport, which indicates both drug diffusion and polymer relaxation mechanism. It might be due to the poor aqueous solubility of aceclofenac. The Hixson-Crowell equation for C, F3 and T4 showed R²=0.9559, 0.9503 and 0.9024 respectively. No changes were observed in results of stability studies.

It is concluded that the batches C, F3 and T4 would release the entire quantity of the drug at the end of 24 hour and it can be used for the formulation of once daily sustained release matrix tablet of aceclofenac. This prolonged release of drug might be beneficial and effective for reliving pains of rheumatoid arthritis and alkylosing spondylitis.