A PROMISING APPROACH TO PROVIDE APPROPRIATE COLON TARGET DRUG DELIVERY SYSTEMS OF METRONIDAZOLE: DEVELOPMENT AND EVALUATION

Abstract

The aim of present study was to develop colon targeted system for Metronidazole using guar gum and xanthan gum. Tablet matrices containing 10–60% of tablet weight of guar gum (F1–F6) were prepared by direct compression and subjected to in vitro release studies to explore their sustained release in the colon. Various release retarding synthetic and natural polymers, namely, hydrogenated castor oil, hydroxypropyl methyl cellulose, xanthan gum, and ethyl cellulose, Eudragit RL 100, were incorporated to modify the drug release rate from the guar gum matrix tablets. Matrix tablets were enteric coated with hydroxypropyl methyl cellulose phthalate as an enteric polymer. Various synthetic and natural polymers were incorporated to F6 to modify the drug release rate. Different 15 matrix tablet formulations (F6–F20) were enteric coated with hydroxypropyl methyl cellulose phthalate. The in-vitro drug release study was undertaken at 37±0.5°C in 0.1N HCl for 2 h; followed by pH 7.4 phosphate buffer (3h) finally in, simulated colonic fluid pH 6.8 phosphate buffer 20 h. The formulation F6, F13 and F20 showed promising sustained release results having median dissolution time (MDT) values: 8.25, 7.97, and 7.64, respectively. When studies were continued in colonic fluids, matrix tablets released almost 100% drug. whereas, Metronidazole enteric  formulations did not release drug in stomach and small intestine, but delivered drug to the colon resulting in slow absorption of the drug and making drug available for local action in the colon.

Keywords:  Colon Target Delivery, Guar gum, Metronidazole, Enteric coated, Tablet Matrices