Formulation and evaluation of colon targeted drug delivery system

Abstract

The main objective of the present study was to develop colon targeted drug delivery systems for Nitrofurantoin using guar gum as a carrier. Matrix tablets containing various proportions of guar gum were prepared by wet granulation technique using starch paste as a binder. The in-vitro drug release study was undertaken at 37±0.5°C in 0.1N Hcl for 2 hr; followed by pH 7.4 phosphate buffer (3hr) finally in simulated colonic fluid pH 6.8 phosphate buffer containing 4% w/v rat ceacal content for 10 hr. It was found that 10.04% drug is released in first 5hr from F4 (GG-20%), where as the other matrix tablets released 20-30% of Nitrofurantoin in physiological environment of stomach and small intestine. When studies were continued in colonic fluids, matrix tablets released almost 100% drug. The results of the study show that matrix tablets containing 20% of guar gum are most likely to provide targeting of Nitrofurantoin in the colon.