Stability studies of compression coated ornidazole tablets for colon specific drug delivery

In our previous study, colon targeted tablets of ornidazole were prepared with compression coating technique. Pectin was used as the coating layer and different ethyl cellulose (EC) types (EC N7, N 10 and N 100) were added to Pectin to enhance mechanical and release properties. The object of the present study was performed stability testing of these coated tablets of ornidazole in a high density polyethylene plastic bottle with/without silica gel as per ICH guidelines. For this aim, several quality-control parameters such as uniformity of weight, diameter and thickness of tablets, tablet hardness, friability, content uniformity and tablet dissolution rate are determined in stability conditions (25 +/- 2 degrees C /60 +/- 5% relative humidity and 40 +/- 2 degrees C /75 +/- 5% relative humidity). These parameters were evaluated at 0 month, 3 month, 6 month and 12 month intervals. It was concluded that the coated ornidazole tablets should be stored in a high density polyethylene plastic bottle with silica gel at controlled room temperature (25 degrees C) or below their relative humidities and the presence of desiccant in the market package was essential.