Formulation and Evaluation of Aluminium Ion (Al+3) Cross-Linked Carboxymethyl Guar Gum Matrix Tablets For Colon Delivery

ABOUT AUTHOR
Vishram Yadav*, Rahul Dev, Pravin Gupta
Sir Madanlal Institute of Pharmacy, Alampur Hauz Etawah-206001 U.P.
*E-mail: vishrampy@gmail.com

Abstract
Targeting of drugs to the colon by the oral route could be achieved by different approaches including matrix and coated systems, for which the drug release is controlled by the gastrointestinal pH, transit times and intestinal flora. The method by which the drug release will be triggered by the colonic flora appears to be more interesting with regard to the selectivity. Metronidazole is only used antibiotics which can be used in colonic diseases. Matrix tablets were prepared by mixtures of Pectin and Guar gum, in which Metronidazole was selected as model drug. Six Matrix (F-I to VI) and coated (F VII to XII) tablet formulations of Metronidazole were prepared by different mixtures of pectin and guar gum then coated with Eudragit RS 100, for coated tablets. The results of drug release studies, performed according to the USP paddle method by using 0.1N hydrochloric acid for 2 hrs, pH 7.4 phosphate buffer for 3 hrs and pH 6.8 phosphate buffer for 24 hrs. And In vitro dissolution study for metronidazole tablets in Rat cecal content were performed. Matrix tablets of guar gum with metronidazole in the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 83%, 63% and 55% respectively. Pectin in the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 100%, 95% and 82% respectively. Coated tablets of guar gum with metronidazole in the ratio the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 96%, 60% and 52% respectively. Pectin in the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 97%, 99% and 95% respectively. All these batches in first two hours i.e. pH 1.2 hydrochloric acid shows very neglible release, then it showed slight increase in pH 7.4 Phosphate Buffer. Drug release up to 5 hours but it showed high and fast increase in drug release from 6th hour in pH 6.8 Phosphate buffer, as it enters in colonic pH. So natural polymers are most cheap and suitable for colonic drug delivery.