Formulation and Evaluation of Controlled Porosity Osmotic Drug Delivery System of Carvedilol Phosphate

Controlled porosity osmotic tablet of carvedilol phosphate prepared and evaluated in this study. Carvedilol phosphate is very low soluble drug. So it is difficult to formulate osmotic tablet of carvedilol phosphate which gives drug release up to 24 hr at zero order. To get desired dissolution profile various formulation parameters like osmogen concentration, level of weight gain and level of pore former concentration were studied. Polysorbate 80 was added as solubilizer to increase its dissolution rate and get drug release up to 24 hr at zero order. As concentration of solubilizer increases, dissolution rate increases. Final optimized formulation was studied for effect of pH of dissolution media, agitation intensity and osmotic pressure of dissolution media. There is no effect of pH of dissolution media and agitation intensity on dissolution. There is significant effect of osmotic pressure on dissolution confirms that prepared carvedilol phosphate tablet gives drug release with osmotic mechanism.