Gupta Khemchand, Singhvi I, Kale V, Avari JG, Agrawal Neeraj
The major objective of this study was to use pectin (high methoxylated) in combination with guar gum to control the burst effect by promoting gelation and also to examine the release pattern of guar-pectin matrices. Guar gum has long been used to prepare matrix tablets. But its uncontrolled rate of hydration and initial slow gelling results into undesirable burst effect. Various combination of drug: polymer ratios were tried, out of which the ratio 1:2 yielded best results. The ratio of gaur: pectin in the polymer blend which gave best results was found to be 1:1.The effects of various diluents on the drug release were also determined at the same polymer level. The matrix tablet were prepared by wet granulation method using distilled water, were subjected to physical characterization and in vitro release studies. Release kinetics was evaluated by using USP apparatus type II at 100 rpm in 900 ml of acidic dissolution medium ( pH 1.2) for two hours, followed by 900 ml phosphate buffer dissolution medium (pH 6.8).The in-vitro drug release study revealed that (batch F3) combining pectin with guar gum sustained the drug release for 10 hours (87.54±2.36% release). Fitting the in-vitro drug release data to Korsmeyer-Peppas equation indicated that diffusion along with erosion could be the mechanism of drug release. At the same polymer level the order of release fell in the following manner lactose, avicel pH 101, starch and Emcompress®. It was concluded from the study that guar-pectin binary polymeric matrix system is an interesting alternative for preparing sustained release tablets.
