The effect of preparation variables on the poly (D,L-lactide-co-glycolide) (PLGA) microparticles by modified emulsification diffusion method / Asmirah Md Redzuan

Poly (D,L-lactide-co-glycolide) (PLGA) is the most commonly used biodegradable polymer in microparticles and nanoparticles. The PLGA microparticles were commonly prepared by technique of evaporation but less with diffusion method. The aim of this study was to prepare and determine the effect of preparation variables on PLGA microparticles by the modified emulsification diffusion method. The preparation method consists of emulsifying a solution of polymer and an aqueous phase containing stabilizer, previously saturated, followed by adding excess water. The concept of this method used a binary mixture, dichloromethane (DCM) and acetone (ACE) as polymer solvents and using of PY A as stabilizer. Influence of process variables such two particular variables that are PY A concentration (0.1 %, 0.5%, 1.0%, 2.0% and 3.0% w/v) and homogenizer speed (1000, 3000, 5000, 7000 and 9000 rpm) were studied. The discrete powder of PLGA microparticles was obtained by freeze drying. The mean particle size, particle size distribution and the morphology of the PLGA microparticles were evaluated. The results were clarified that both parameters, PY A concentration and homogenizer speed had influenced on the mean particle size and particle distribution of PLGA microparticles. As the PY A concentration and/or homogenizer speed increase, the mean particle sizes of PLGA microparticles were decreased. The prepared PLGA microparticles with different homogenizer speed were in unimodally dispersed particles with mean particle size of about range from 7 µm to 45 µm, whereas those prepared with different PY A concentration exhibited bimodal distribution with mean particle size of about range from 9 µm to 52 µm. The micrograph from scanning electron (SEM) revealed the surface of PLGA microparticles was not smooth and the particle size distribution was not good.