A Review on Mucoadhesive Microspheres in Gastroretentive Drug Delivery System

Drugs with rapid gastrointestinal absorption and short biological half-lives are quickly eliminated from systemic circulation, necessitating frequent dosing and often compromising patient compliance. Gastroretentive drug delivery systems (GRDDS) have been developed to overcome these limitations by prolonging gastric residence time, thereby improving drug bioavailability and therapeutic efficacy. Microspheres are effective particulate carriers due to their small size and high drug-loading capacity. The incorporation of mucoadhesive properties further enhances their performance by ensuring prolonged contact with the gastrointestinal mucosa, resulting in improved therapeutic outcomes, reduced dosing frequency, minimized drug loss, and better patient compliance. Mucoadhesive microspheres are particularly advantageous for drugs requiring predictable and enhanced bioavailability or intended for local gastrointestinal action. This review provides an overview of GRDDS with emphasis on mucoadhesive microspheres, discussing factors affecting mucoadhesion, commonly used polymers, underlying mechanisms and theories, preparation techniques, and evaluation parameters.