Nifedipine Gastro Retentive Drug Delivery System: Formulation, Characterization and Evaluation.

Gastro retentive floating matrix tablet provide drug delivery at the controlled rate, improve bioavailability and prolong the retention of dosage forms in gastrointestinal tract. In present study attempt has been made to develop gastroretentive floating matrix tablet of nifedipine in the management of hypertension by direct compression method using Okra gum and HPMCK4 M polymer ratio in single or in combination; Avicel PH 102 as a directly compressible material; citric acid for production of acidic microenvironment and sodium-bicarbonate as gas generating agent. Pre-compression parameters of powdered blend as well as prepared batches were studied and found within the range. Fourier-transform infrared spectroscopy of physical mixture (nifedipine, Okra gum and HPMCK4 M) suggesting no incompatibility. Formulation batch F8 floated, and remained buoyant without disintegration with swelling index value 41.23 %, released nifedipine 91.30 % about 12 h might be due to combine use of HPMC K4 M and Okra gum; showed higher correlation coefficient (r-value) followed Zero order release kinetics. DSC thermogram of F8 confirms uniform dispersion of drug in an amorphous form as endothermic peak was below 173.5°. No significant changes in physiochemical properties, drug release profile as well as drug content of optimized F8 batch when subjected to stability at 40±2° temperature with relative humidity 75±5 % for 3 mo indicating there was no degradation and change in the matrix system. [ABSTRACT FROM AUTHOR]