ABSTRACT
Terbutaline sulfate hydrophilic matrix tablets were prepared using different hydrophilic matrix forming polymers. Cellulosic polymers used were hydroxypropylmethyl cellulose [HPMC] 15 cps, 100 cps and 4000 cps. Other polymers were sodium alginate and xanthan gum each used in concentrations of 7, 14, and 28%. Combinations of HPMC with pectin were also used for the preparation of terbutaline sulfate hydrophilic matrix tablets. In vitro evaluation of the prepared tablets was performed by the determination of the hardness, friability and release profiles. Release of the prepared formulations was performed using USP Dissolution Tester Apparatus II. Results showed that terbutaline sulfate hydrophilic matrix tablets prepared using different polymers controlled the release of the water-soluble drug over an extended period of time. The release of terbutaline from tablets prepared using hydroxypropylmethyl cellulose of different viscosity grades showed marked decrease with the increase of the viscosity grade used, where after 8 hours 94.7%, 54.7% and 49.5% of the drug was released using HPMC 15 cps, HPMC 100 cps and HPMC 4000 cps, respectively. For tablets prepared using xanthan gum, increasing the concentration of xanthan gum showed a decrease in release of terbutaline sulfate, where increasing the concentration from 7% to 28% showed a decrease in release from 91.5% to 69.1% after 8 hours. Hydrophilic matrix tablets prepared using sodium alginate did not offer the desired control over drug release. Binary mixtures of hydroxypropylmethyl cellulose and pectin in different ratios optimized the release profile of terbutaline sulfate. It was found that increasing the ratio of pectin resulted in an increase in the release rate of the drug. Optimum release profile was achieved when the hydrophilic matrix tablet was prepared using HPMC 100cps and pectin in ratio of 4:1. Kinetic analysis of the release data showed that ideal zero order release was achieved for tablets prepared using this binary mixture