Advancement in microsphere preparation using natural polymers and recent patents.

In present study, Authors review all aspects of microsphere based novel drug delivery system; including need of natural polymers, different approaches for preparation and recent advancements. Microspheres are a novel drug delivery approach to control release of pharmacologically active ingredient as per patient needs. Natural polymers are cheap, biodegradable and have been proved safe for pharmaceutical formulation. Microspheres of naturally derived polymers have been prepared by several techniques like coacervation phase separation, emulsion polymerization, modified quasiemulsion solvent diffusion, emulsion cross-linking, thermal denaturation, emulsification solvent evaporation, spray drying and suspension polymerisation. It can be concluded from the whole patented study that due to the formation of polymeric network system, enzyme, hormones or other active moiety can be easily entrapped within the matrix. Rate of hydration and swelling of the natural polymer controls the release pattern of the drug from the matrix.