Abstract

CARBOPOL-HISTIDINE CONJUGATE: A NOVEL CARRIER FOR COLON SPECIFIC DRUG DELIVERY SYSTEMS

Mini Ojha*, N.V. Satheesh Madhav, Anita Singh

Abstract

Carbopol is a high molecular weight copolymer of acrylic acid crosslinked with a polyalkenyl polyether. It is an excellent thickener, suspending agent and stabilizer. The gelling property of carbopol retards the release of the drug from the dosage form in stomach upto a certain extent and makes it susceptible to degradation in the colonic environment. In order to make it perfectly colon specific, it was conjugated with the amino acid (histidine) using the azo bond. The azo conjugate of carbopol with histidine was subjected for evaluating its colon targeting property by in-vitro method using rat fecal matter. Our experimental results reveal that the carbopol-histidine conjugate showed promising colon specificity for a period of 120 minutes in a controlled manner. So it can be used as a carrier for formulating colon targeted dosage forms.

Keywords: Colon targeted delivery, azo conjugate, microflora-activated system.