Unlocking the potential of microsponges: A versatile andfuturistic approach to oral drug delivery

Oral administration is widely regarded as the most practical and commonly used method for delivering medications. However, drugs with short half-lives and rapid gastrointestinal absorption are swiftly cleared from the bloodstream, necessitating frequent dosing. To address these challenges, oral controlled-release formulations have been developed. Among the innovative approaches in drug delivery systems, the Microsponge Delivery System (MDS) has gained significant attention.MDS consists of highly cross-linked, porous polymeric microspheres capable of entrapping a wide range of active compounds. Polymers such as ethyl cellulose and polystyrene are commonly used in the formation of these microsponges. The resulting active microsponges can be incorporated into various formulations, including capsules, gels, and powders, offering numerous benefits. Notably, microsponges exhibit stability across a pH range of 1 to 11 and can withstand temperatures up to 130°C. It is a unique technique for controlled release formulation. They also demonstrate high entrapment efficiency,reaching 50 - 60%. The preparation of microsponges typically involves methods such as quasi-emulsion solvent diffusion and emulsion solvent diffusion. In these processes, the release rate ofdrug from the microsponges can be modulated by adjusting the drug-to-polymer ratio and the thickness of the polymer wall. Characterization of microsponge includes assessments of their particle size, morphology and surface topography, compatibility studies, resiliency and in-vitro drug release. These evaluations ensure the quality and performance of the microsponge formulations.This review highlights the advantages of microsponges over other dosage forms, along with their preparation methods, characterization, and applications.