ABSTRACT
Objective: The objective of the present study was to develop “once daily” extended release tablets of tramadol (100 mg) by wet granulation using hydrophilic polymer like hydroxy propyl methyl cellulose K100M,K15M and polyethylene oxide (PEO). Methods: The tramadol matrix tablets were prepared by using different polymers like hydroxy propyl methyl cellulose (HPMC K15M and K100M), polyethylene oxide (PEO) as the nontoxic and easily available suitable matrix system. The extended release tablets of tramadol (400 mg) were prepared wet granulation technique. Different pre compression and post compression were performed. In vitro dissolution tests were performed and percentage drug release was calculated. The fourier-transform infrared spectroscopy (FTIR) studies conducted on pure drug tramadol and the optimize formulation (T6). Different release models like zero order, first order, higuchi and Korsemeyer-Peppas were applied to in vitro drug release data in order to evaluate the drug release mechanisms and kinetics. Results: Pre compression and post compression parameters satisfied with pharmacopeia specifications. The In vitro release studies were performed using USP type II apparatus showed that optimized formulation T6 consisting of polyethylene oxide (PEO) with 25 mg of the polymer was found to extended release of tramadol over a period of 24h. The optimized formulation T6 followed the zero order kinetics as correlation coefficient (r2) values are higher than that of first-order release kinetics. In order to understand the complex mechanism of drug release from the optimized formulation T6 matrix system, the in vitro release rate were fitted to Korsemeyer-Peppas model and the release exponent value (n) obtained was 0.82105 exhibited anomalous (non fickian) diffusion mechanism. Conclusion: The present study shows that polyethylene oxide was found to play a great role in controlling release of tramadol from the matrix system. Accordingly it can be concluded that the formulation is robust in the performance is less likely to be affected by the various factors studied.