PREPARATION AND EVALUATION OF MUCOADHESIVE NANOPARTICLE OF AN ANTIHYPERTENSIVE AGENT

Diltiazem HCl (DTZ) is an antihypertensive agent that antagonizes the action of beta-1 receptor. DTZ when given orally is well absorbed from the gastrointestinal tract and is subject to an extensive first-pass effect. DTZ undergoes extensive metabolism in which only 2% to 4% of the unchanged drug appears in the urine. Drugs which induce or inhibit hepatic microsomal enzymes may alter DTZ disposition. It has been reported that the absolute bioavailability of DTZ when given orally is 30-40%. The biological half-life of DTZ is 4-6 hour and the main site of absorption is proximal small intestine.The reduced bioavailability of DTZ may be because of transportation of dosage form from the region of absorption window to site where it is less absorbed. Therefore there was a need to increase gastroretention time of dosage form so that drug would be available at the site of absorption and results in improved bioavailability. A mucoadhesive nanoparticle delivery system was envisioned for DTZ as such a system when administered would adhere on the gastric mucosa for a prolong period of time and the drug would be available at the main site of absorption i.e. proximal small intestine resulting in enhanced bioavailability.