FORMULATION and EVALUATION of some BIOADHESIVE DRUG DELIVERY SYSTEMS

Abstract

Recently, considerable attention has been focused on the use of bioadhesion for drug delivery purposes. There has been a growing interest in bioadhesive polymers as controlled-release systems for both local and systemic drugs. Buccal mucoadhesive devices represent a feasible and accessible way, which permits prolonged retention of drugs to the absorbing membrane, thus, reaching systemic circulation in a reproducible concentration. One added advantage is the avoidance of first pass effect associated with peroral route. Regarding local delivery, mucoadhesive devices ensure therapeutic drug level over prolonged period in the oral cavity. The main objectives of the thesis are the development and evaluation of mucoadhesive buccal dosage forms for the local and systemic drug delivery. PART I of the thesis focused on the design of buccal mucoadhesive tablets intended for systemic effect. Water-soluble drugs, diltiazem hydrochloride (DZ) and metoclopramide hydrochloride (MP), both suffering from extensive first pass effect, were chosen. Different types of mucoadhesive polymers including anionic (CP934,

CP940, PC, CMC Na, and pectin), cationic (chitosan) and non-ionic (HPMC) were investigated for their comparative bioadhesive force, swelling behavior, residence time and surface acidity. To optimize the bioadhesive characteristics of the tablets, polymer combinations were designed and evaluated. Results revealed that PAA derivatives showed the highest bioadhesion force, prolonged residence time and high surface acidity.