The Impact of Microsponge and Microsphere on Improving Oral Bioavailability of Medications: A Short Review

While many diseases require an efficient drug delivery technology that has the ability to improve bioavailability and alleviate side effects, various types of gastroretentive drug delivery systems (GRDDS) have been developed in order to overcome the obstacles, which are related to a narrow absorption window, instability, site of action, side effects, and dosing frequency. In this context, microsponge and microsphere systems depict two different types of GRDDS, aiming to provide adequate time for active ingredients to be absorbed in the stomach despite the variation in releasing mechanisms of the entrapped ingredients. For the successful designing of these systems, it is essential to optimize the characterizations of the formulated microparticles by considering physiological, pharmaceutical, and patient-related factors, which have a dramatic impact on the efficacy. Consequently, they will demonstrate different behaviors at the desired site of action, determining which systems are showing superiority compared to others. However, each microparticle system has some advantages over the others, providing more options for researchers to ease the difficulties that exist with conventional oral dosage forms. Therefore, this review aims to shed the light on critical factors that have significant impacts on microsponge and microsphere systems and addresses their advantages and disadvantages, providing an understanding of these criteria in order to optimize the drug systems.