Abstract

DESIGN AND DEVELOPMENT OF ORAL COLON TARGETED DRUG DELIVERY SYSTEM OF DEXAMETHASONE

*S. RAWAT¹, S. JAIN², A. JAIN²

Abstract

Inflammatory bowel disease (IBD) afflicts approximately four million people across the world, usually before the age of 40. It describes two major chronic, non-specific inflammatory disorders of the gastro-intestinal (GI) tract, ulcerative colitis (UC) and Crohn’s disease (CD), the causes of which remain unknown. UC is usually limited to the colon and rectum. The colon and rectum are parts of the body’s digestive system which remove nutrients from food and stores waste until it passes out of the body. The present study was aimed at developing dexamethasone matrix tablets by direct compression technique. The compatibility of drug, polymer and excipients were determined by I.R. spectroscopy analysis. For precompression evaluation, the powder mix was subjected to micrometric evaluation (bulk density and Carr’s Index) and drug content uniformity to check the mixing uniformity, after which matrix tablets containing various proportion of guar gum ranging from 40 to 80% of guar gum and immediate release (reference formulation) containing 5% sodium starch glycollate (superdisintegrant at 5% level) were prepared, and subjected to thickness, diameter, weight variation, hardness, friability and drug content uniformity. After these studies the matrix tablets containing 40 to 60% were subjected to in-vitro release studies in 0.1N HCl (2h), pH 7.4 Sorensen’s phosphate buffer (3h) and simulated colonic fluids (rat caecal content medium at 4% w/v level after 7 days of enzyme induction), than potential formulations (containing guar gum 50% and 60% as carrier) were subjected to scanning electron microscopy (SEM) to examine the surface topography, texture of the formulations, morphology of fractured or sectioned surfaces and to analyze the surface of polymeric drug delivery systems that provided important information about the porosity of the device and swelling changes in the matrix of the formulations by subjecting the formulations to SEM in dry state. At the end short term stability studies were carried out at 370C/60% RH and 500C/75% RH for a specific time period up to 30 days for selected formulation (containing guar gum 50% and 60% as carrier) and were analyzed for the physical evaluation like appearance (color) and hardness and chemical evaluation like determination of drug content and drug polymer compatibility.

Keywords: Inflammatory bowel disease, Matrix tablets, Direct compression, Colonic release, Scanning electron microscopy.