Upadhye Shashikant Sudarshan

The microspheres are also called as micro-particles. To overcome some of the problems of conventional therapy and enhance the therapeutic efficacy of a given drug they are designed. At the target tissue the drug should deliver in an optimal amount in the right period of time with the minimum side effect & maximum therapeutic effect, to get the desired effect. The microspheres received much attention not only for the prolonged release but also for targeting of the anticancer drugs to the tumour. The microsphere are spherical microparticles & are used where predictable & consistent particle surface area is important. . The microspheres has the drug located centrally within the particle where it is encased within the unique polymeric membrane. This review focuses on types, materials used, different methods of preparation, evaluation & applications of microspheres.

The drug delivery through the skin to achieve a systemic as well as local effect of a drug is known as Transdermal drug delivery system. Its main advantage includes controlled drug release with minimum side effects, improved bioavailability and many more. The human skin is readily accessible surface for drug delivery. For penetration of drug through the skin the stratum corneum is the main barrier. So to avoid the stratum corneum and to increase the flux through the skin membrane different techniques of penetration enhancement are used.  This review mainly represents different factors affecting Transdermal bioavailability, technologies for developing Transdermal drug delivery system, different evaluation tests for Transdermal patches, different methods of preparation of TDDS, recent techniques for enhancing Transdermal drug delivery system.