Design and Characterization of Sustained Release Aceclofenac Matrix Tablets Containing Tamarind Seed Polysaccharide

Sustained release formulation of Aceclofenac based on monolithic matrix technology was developed and evaluated. It is practically insoluble in water so it is suitable to develop sustained release matrix tablet using hydrophilic polymer. Aceclofenac is non-steroidal anti-inflammatory drug (NSAID) used extensively in the treatment of rheumatoid arthritis, osteoarthritis and ankylosing spondylitis. It is newer derivative of diclofenac and having less GIT complication, with short biological half-life 4 hrs, so developed formulation provides the advantages of sustained release formulations. The tamarind seed polysaccharide (TSP) was extracted from tamarind kernel powder and this polysaccharide was utilized in the formulation of matrix tablets containing Aceclofenac by wet granulation technique and evaluated for its drug release characteristics. TSP is a hydrophilic and rate controlling polymer. Granules were prepared and evaluated for loose bulk density, tapped bulk density, compressibility index and angle of repose, shows satisfactory results. Formulation was optimized on the basis of acceptable tablet properties (hardness, friability, drug content and weight variations), in vitro drug release and stability studies. All the formulations showed compliance with pharmacopieal standards. The in vitro release study of matrix tablets were carried out in phosphate buffer pH 7.4 for 12 hr. Among all the formulations, F 5 shows 98.062% better controlled release at the end of 12 hr. The results indicated that a decrease in release kinetics of the drug was observed by increasing the polymer concentration. The release data was fitted to various mathematical models such as, Higuchi, Korsmeyer-Peppas, First-order, and Zero order to evaluate the kinetics and mechanism of the drug release. The drug release of optimized formulations F-5 follows zero order kinetics and the mechanism was found to be diffusion coupled with erosion (non-Fickian diffusion/anomalous). The stability studies were carried out according to ICH guideline which indicates that the selected formulations were stable.