Microsponges: A Pioneering Tool for Biomedical Applications

Microparticulate drug delivery systems have been explored across the globe due to their various advantages. In 1987, Won developed microsponge systems (Micsys), also known as solid-phase porous microspheres, having numerous interconnected voids, which serve as non-collapsible residence for bioactive compounds. A Micsys particle ranges from 5 to 300 mu m in size and shows a wide range of entrapment efficiency with desired release rates. This topical drug delivery system bestows a controlled release of bioactive compounds into the skin with reduced systemic side effects. Currently, the application fields of this promising system include oral, ocular, pulmonary, and parenteral delivery of bioactive compounds. In the present review, we summarize the updated biomedical application potential of Micsys as an effective drug-delivery vector, including an in-depth explanation of the drug-release kinetic models and drug-release mechanisms. We also discuss different techniques used to prepare a Micsys, along with their advantages and disadvantages. Moreover, in this review, we report a plethora of Micsys details, such as drug candidates and polymers, exploited in this field, along with marketed formulations, characterization methods, clinical perspectives, and patents received. This assembly of detailed literature summaries will contribute to future advances in the development of porous carriers.