ACTA Pharmaceutica Sciencia 2010 , Vol 52 , Num 3
FORMULATION AND EVALUATION OF COMPRESSION COATED PIROXICAM TABLETS FOR COLON SPECIFIC DRUG DELIVERY
PRABHAKAR REDDY VEERAREDDY, RAJENDRA PRASAD MANTHRİ
St. Peter’s Institute of Pharmaceutical Sciences, Warangal, Andhra Pradesh, 506 001, India The aim of the present study was to prepare and characterize compression coated piroxicam tablets using guar gum/ hydroxypropylmethylcellulose for effective delivery of drug to the colon. In vitro drug release studies were performed in the dissolution media with and without rat caecal contents. Results showed an enhanced release in rat caecal content when compared to formulation studied in dissolution media without rat caecal content, because of microbial degradation of polymer. The rate of drug release is dependent upon the coat thickness and amount of guar gum/ hydroxypropylmethylcellulose used in the formulations. Combination of guar gum and hydroxypropylmethylcellulose K4M provided better protection of the drug, showing increased release lag time and controlled release rate. The nature of the drug transport was found to be non-Fickian (super case-II). Release of drug from tablets began after a time delay as a result of hydrogel swelling/retarding effect, followed by zero-order release for most of the formulations studied. The in vitro drug release studies and in vivo X-ray studies indicated that optimized formulation was a promising system to provide targeting of piroxicam to the colon. Keywords : GUAR GUM, PIROXICAM, COLONIC DRUG DELIVERY, RAT CAECAL CONTENTS

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