823FORMULATION & CHARACTERIZATION OF TAMARIND GUM BASED COLON TARGETED MATRIX TABLETS Ornidazole (ORN), a nitroimidazole derivative is used in the treatment of bacterial vaginosis, amoebiasis, and infections due to anaerobic bacteria. These drugs are highly soluble in acidic media and precipitates in alkaline media thereby losing its solubility. The site of absorption of Ornidazole is in the whole GI tract and has a long half life of 13 hr. Hence we attempted to develop colon targeted matrix tablet of Ornidazole using natural polymers like tamarind gum, pectin and locust bean gum as a carrier in various concentrations (3%, 4% and 5%). The physicochemical compatibility of the drug and the polymers was studied by infrared spectroscopy and differential scanning calorimetry. The results suggested no physicochemical incompatibility between the drug and the polymers. The matrix tablets were prepared by wet granulation method and all the formulations (F1 to F9) were evaluated for pharmacopoeial requirements such as hardness, friability, thickness, weight variation etc. In- Vitro drug release study was performed in 1.2 Ph for 2 hrs, for next 3 hrs in 7.4 ph and rest of the time was followed by 6.8 ph in phosphate buffer. In-Vitro drug release study of tamarind gum based formulation (F1) revealed that tablets formulated with natural polysaccharides i.e. Tamarind gum have enough potential to target the drug in the colon due to its ph sensitive characterization. The mechanism of drug release was found to be nonfickian diffusion- ayancipt@gmail.comResearch1112020Ornidazole, Tamarind gum, Matrix tablet, Colon targeted drug deliveryKar Banhishikha,Kar Ayan KumarDepartment of Pharmaceutics, Calcutta Institute of Pharmaceutical Technology & AHS, Banitabla, Uluberia, Howrah – 711316, West Bengal,Department of Pharmaceutics, Calcutta Institute of Pharmaceutical Technology & AHS, Banitabla, Uluberia, Howrah – 711316, West Bengal