Ritu Verma1*, Shubham Verma2, Sokindra Kumar3

ABSTRACT

Microspheres are characteristically free flowing powders having particle size ranging from 1-1000 ?m consisting of proteins or synthetic polymers. Microspheres are used in drug delivery systems which are prepared to obtain prolonged or controlled drug delivery to improve bioavailability, stability and action at the specific site to predetermined rate. Microsphere are spherical in shape so, therapeutic efficacy of microspheres containing drug depends upon their characteristics that can be altered in required terms by altering materials, methods, polymers or techniques used. These delivery systems offer numerous advantages compared to conventional dosage forms, which include improved efficacy, reduced toxicity, improved patient compliance and convenience. Microsphere can be manufactured by various type of material such as glass, polymers, and ceramic microspheres. Microspheres are various types like Bioadhesive microspheres, Magnetic microspheres, Floating microspheres, radioactive microspheres, Polymeric microspheres, Biodegradable polymeric microspheres, Synthetic polymeric microspheres and are prepared by methods like Spray Drying, Solvent Evaporation, Single emulsion technique, Double emulsion technique, Phase separation coacervation technique, Spray drying and spray congealing, Solvent extraction, Quassi emulsion solvent diffusion. Microspheres have wide range of applications because of controlled and sustained release. Keywords: microspheres, method of preparation, patents, recent advancement, marketing formulation