Polymeric microcapsules have attracted a great deal of interest because of their application in different fields such as pharmaceutical field. Biodegradable microcapsules are used to encapsulate different types of drugs and bioactive compounds which can be released upon injected in the body in a controlled and sustained manner. Besides, if targeting molecules (i.e. antibodies) are attached to the microcapsules, they can be directed to the targeting place in the body (i.e. Cancer cells) achieving targeting drug delivery and reducing the side effects associated with oral drug administration (i.e. chemotherapy, which affects normal and infected cells). The current study aims to investigate the effect of the type of polymer on the drug release behavior and kinetics from the microcapsules. Three different types of biodegradable-biocompatible polymers; poly-caprolactone (PCL), poly-L-lactide (PLLA) and poly-DL-lactide(PDLLA) and their blends were used for preparation of the microcapsules.
The biodegradable microcapsules were prepared by Pre-mix membrane emulsification method. In this method, a polymer solution consists of biodegradable polymer /solvent (dichloromethane) /Drug (Carvedilol) were mixed with continuous phase that consists of non-solvent (water) and surfactant polyvinyl alcohol (PVA) to get primary (premix) emulsion which has large and non-uniform droplet size. This premix emulsions was then passed through the pores of glass fiber membrane several passes to obtain microcapsules with small and uniform size distribution .The microcapsules were placed in a dialysis membrane then immersed in phosphate buffer solution with PH=7.4 and the drug release behavior was monitored by recording the absorbance during specific time intervals using UV-spectrophotometer.