The influence of granulating solvents on drug release from tablets containing grewia gum

The influence of granulating solvents on release of indomethacin from tablets containing grewia gum was evaluated. The tablets were prepared by either wet granulation or direct compression. The experimental design was based on a 3x5 factorial design. The drug/gum ratio was varied at three levels, 2:1, 1:1 and 1:2. At each of these levels, the solvent effects were examined at five levels namely, 100% water, 75% water and 25% ethanol, 50% each of water and ethanol, 25% water and 75%. These were compared with a fifth level which is a matrix tablet prepared by direct compression without any solvent. The dissolution rates of the tablets were determined using a rotating paddle dissolution apparatus. The cumulative percent of drug dissolved from the three matrix tablets are not significantly different (p>0.05). Although no rank correlation was observed among the tablets prepared with 100%, 75% and 50% water, drug release from the tablets prepared with 25% water are significantly lower than the other wet granulated tablets, but higher than the matrix tablets. The granulating solvent influenced the release of drug which increased with increase in the water content.