Design And Evaluation Of Mucoadhesive Controlled Release Oral Tablets Of Glipizide
Matrix tablets of glipizide were formulated using two mucoadhesive polymers namely sodium carboxymethylcellulose and hydroxypropylmethylcellulose and with and without ethylcellulose and the tablets were evaluated. Tablets formulated employing sodium carboxymethylcellulose or hydroxypropylmethylcellulose and with ethylcellulose provided slow release of glipizide over a period of 12 h and were found suitable for maintenance portion of oral controlled release tablets. Glipizlde release from these tablets was diffusion controlled and followed zero order kinetics after a lag time of 1 h and up t o 90 per cent release. The matrix tablets exhibited good mucoadhesion in the small intestine for 10 h as evaluated by X-ray studies. Two layered tablet formulations, designed with an immediately releasing layer consisting of glipizide and a super disintegrant (Ac-Di-Sol) and a slow releasing matrix consisting of glipizide in sodium carboxymethylcellulose or hydroxypropylmethylcellulose and ethylcellulose as second layer, gave release close to the theoretical sustained release needed for glipizide based on its pharmacokinetic parameters.