Abstract

FORMULATION AND EVALUATION OF COLON TARGETED DRUG DELIVERY SYSTEM OF METRONIDAZOLE USING COATED MINI TABLETS APPROACH

Nampelly Karnakar, Anil Middha and Reddy Sunil*

Abstract

The present work is mainly concentrated on designing oral tablet dosage forms of Metronidazole tablets for the treatment of the colonic inflammatory diseases. In the present work of investigation an attempt has been made to design tablet dosage formulations for colon inflammatory diseases. pH sensitive drug delivery has been chosen for the delivery of drug in the colon. The pH sensitive polymers like Eudragit S-100 and Eudragit L-100 are disintegrated at their threshold pH i.e., at pH 7 & pH 6. From the results it was concluded that TF 5 containing core tablet composition was optimized. TF5 tablets were used for the coating of all (EC1 to ECL15) coating solutions. The tablets coated with ethyl cellulose failed to retain the coating at 3 hour of media change (pH 6.8). The coat was floated on the media without disintegration. It was not sticking to the core tablet due to hydration. The tablets coated with ES11, EL13, ECS14 coating solutions were optimized. They showed the lag time of 5 hours and drug was released less than 10% at 5 hour. The single unit tablets showed better results over multiple unit tablets. This is because the multiple unit tablets got less percentage of coating than the single units. The multiple units were coated in conventional coating pan along with the single unit tablets at 15 psi of atomizing air pressure. The EC1 to EC8 coated tablets were failed to retain the coating. Hence the attempts were made to improve the EC coating with combination of ES-100 and EL-100. The tablets coated with ECS14 coating solution shows 5 hour lag time out of all EC containing formulations. This is because of 15 %TWG of EC coating (primary coating) and 5 % TWG of ES-100 (secondary coating). The outer most ES-100 layer protects the formulation from earlier peel off problem in 6.8 pH phosphate buffer.

Keywords: Eudragit S-100 and Eudragit L-100.