HMPC-Based Matrix Tablets Of Atenolol And Cisapirde : Effect Of Viscosity Of Polymer And Drug Solubility On In Vitro Release
Matrix tablets of cisapride and atenolol were prepared with varying proportions of hydroxypropylmethylcellulose of different viscosity grades viz; E15, E4M, K4M and K15M (15,4000, 4000 and 15 000 cps at 2% aqueous solution, respectively), alone and in combinations by wet granulation technique. The prepared tablets were evaluated for uniformities of weight, thickness, drug content and diameter, hardness and tensile strength, friability and disintegration time. The in vitro release kinetics of the matrix tablets were studied using USP XXI apparatus with distilled water as the dissolution medium. The tablet properties complied with the official limits. The efficiency of viscosity grades of hydroxypropylmethylcellulose in sustaining the release was observed to be in the following order E15>E4M>K4M>K15M. As the solubility of drug increases from cisapride to atenolol, an increase in the release rate was observed. The release of cisapride and atenolol from their respective tablets followed predominantly diffusion controlled mechanism, based on Higuchi's model. The study also indicated that the amount of drug released decreased with an increase in the polymer concentration (from 10, 20 to 30%).The combination of the different viscosity grades did not provide any additional advantage.