MICROSPONGE-BASED DRUG DELIVERY FOR ANTI INFLAMMATORY THERAPY: FORMULATION STRATEGIES, CHARACTERIZATION, THERAPEUTIC PERFORMANCE AND TRANSLATIONAL CHALLENGES

Abstract

Microsponge drug delivery systems have been developed to overcome the limitations of conventional dosage forms through controlled drug release, improved drug stability and bioavailability, reduced adverse effects and improved patient compliance as an advanced porous polymeric carrier platform. These highly porous cross-linked microspheres with a unique three-dimensional structure have generally a diameter between 5-300 μm that allows efficient drug encapsulation and sustained site-specific release of active medicinal components. The review describes the fundamentals of microsponge formulation, major techniques of fabrication, such as quasi-emulsion solvent diffusion, liquid–liquid suspension polymerization, spray drying, and electrospinning, and the influence of polymers, such as Eudragit RS100, Eudragit RL100, ethyl cellulose, chitosan, and poly (lactic-co-glycolic acid) (PLGA) on the formulation performance. Further, it covers the characterisation methodologies, drug release processes and kinetic models of microsponge systems. The therapeutic applications for topical, oral, ophthalmic, intranasal, intravaginal and herbal drug administration have also been highlighted. Among the preparation methods used in the literature reviewed, quasi-emulsion solvent diffusion was the most frequently used method because of its simplicity, reproducibility, high encapsulation efficiency, and suitability for sustained drug release while Eudragit RS100 and ethyl cellulose were consistently identified as the preferred polymers due to their excellent controlled-release characteristics. Most applications are still topical formulations, although recent studies indicate an increasing interest in multifunctional and targeted delivery systems for a variety of therapeutic pathways. Despite significant advances in formulation development and laboratory evaluation, large-scale production, regulatory standardization, long-term stability, clinical validation and commercialization issues still pose barriers to wider pharmaceutical acceptance. Some of the emerging trends that are projected to further enhance the adaptability and clinical applicability of this delivery platform are Quality by Design (QbD), biodegradable polymers, green manufacturing technologies, smart stimulus-responsive systems and nanotechnology-integrated microsponges. In conclusion, microsponge technology is a promising next generation drug delivery system with great potential to improve therapeutic efficacy, safety and patient compliance and further multidisciplinary research is still needed for its successful translation into clinical and commercial practice.