Microparticles

The present investigation involves the Preparation and Characterization of etoposide loaded PCL Composite micropartices on account to control initial burst release. The prepared composite particles were characterized physicochemically for Encapsulation efficiency, Mean particle size, Release kinetic and compared with nanoparticles and simple microparticles prepared by the same double emulsion method. The major objective of the present study is to incorporate a hydrophilic drug etoposide within hydrophobic polymer poly (ε-caprolactone) for the preparation of composite micro particles to minimize initial burst release of the drug which is generally associated with micro and nanoparticles. Micro particles and nanoparticles were prepared by W/O/W emulsion solvent extraction and W/O/W solvent evaporation method respectively using different ratios of drug to polymer (0.1:1, 0.2:1 and 0.4:1). These prepared nanoparticles were further fabricated in micro particles using double emulsion method in ratio of (0.05:1, 0.1:1, 0.2:1).When PCL nanoparticles were encapsulated into the microparticles, there was a large decrease in the burst release again; this decrease is much more marked when p < 0.05. When nanoparticles formulated in to composite micropartices the burst released is suppressed only 50% of the drug was released in 8 hrs. Therefore, the advantage of encapsulating nanoparticles in microparticles (composite microparticles) has been definitely demonstrated for a hydrophilic drug.

Osteoarthritis (OA) is a group of chronic, painful, disabling condition affecting synovial joints. OA is the most common among elderly people. Approximately 80% of population above 65 years of age suffers from OA and this value reaches near to 100% with increasing age. Currently available treatments of OA provide symptomatic relief or slow the progression of disease. The oral or parenteral administration of these drugs causes serious systemic side effects leading to even withdrawal of certain drugs from market. To overcome these problems, localized IA drug delivery presents a new hope. A number of drugs have been investigated for their local effect after IA administration. A number of novel drug delivery systems are available for their own merits and demerits. This review discusses the pathophysiology of OA and formulation consideration of IA injections along with details of current and novel drug formulation for OA treatments.

  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