SUSTAINED RELEASE MICROPARTICLES: A REVIEW

  Controlled release of drug from micrometrics is of the particular therapeutic importance for oral medication in patients. There are various approaches in delivering a therapeutic substance to the target site in a sustained controlled release fashion. One such approach is using microparticles as carriers for drugs. The idea behind a controlled drug delivery system is to incorporate the drug within a polymeric carrier that controls the release rate of the drug. Various processes, such as diffusion, erosion, and/or swelling can be involved in the control of the overall drug release rate, resulting in a broad spectrum of possible release profiles. Solvent evaporation and extraction based processes are required for the preparation of microparticles. The microparticles show lower percentage compressibility but good flowability, hence a capsule dosage form was thought to be suitable. The microparticle formulation was optimized with respect to size distribution and increased drug loading. The microparticles was physically evaluated with respect to bulk density, angle of repose, and percent compressibility, drug content, swelling study and in-vitro release study. Polyvinyl alcohol is proposed as a polymer to be used for the present controlled release formulation development. The intent of the paper is to highlight the potential of microparticles as a vital dosage form in novel drug delivery.   Key words: Microparticles, Sustain release, Solvent evaporation, Release profile, Therapeutic range, Compressibility