Microspheres: as carrieres used for novel drug delivery system

The goal of any drug delivery system is to provide a therapeutic amount of drug to the proper site in the body and then maintain the desired drug concentration. A well designed controlled drug delivery system can overcome some of problems of conventional therapy and enhance therapeutic efficacy of the given drug. There are various approaches in delivering therapeutic substance to the target site in sustained and controlled release fashion. One such approach is using microspheres as carriers for drug. Microspheres are characteristically free flowing powders consisting of proteins or synthetic polymers which are biodegradable in nature ideally having particle size less than 200m.Various synthetic and natural materials are used for the preparation of microspheres. These are prepared by methods like Single emulsion, Double emulsion, Polymerization, Phase separation coacervation, Emulsion solvent evaporation and solvent diffusion. Microspheres are having wide range of applications because of controlled and sustained release. Most important application is that it is used for targeting tumours using anticancer drugs. It is important carrier for safe and effective in vivo drug delivery.