Preparation and characterization of estradiol-loaded PLGA nanoparticles using homogenization-solvent diffusion method

estrogens and the potential of nanoparticles (NPs) have offered tremendous scope forinvestigation. Although polymeric NPs have been used as drug carriers for many activeagents, the use of appropriate polymer and method of NP preparation to overcome differentchallenges is very important.Materials and methods: Poly lactide-co-glycolide (PLGA) NPs containing estradiolvalerate were prepared by the modified spontaneous emulsification solvent diffusionmethod. Several parameters including the drug/polymer ratios in range of 2.5-10%, polyvinyl alcohol (PVA) in concentration of 0-4% as stabilizer and internal phase volume andcomposition were examined to optimize formulation. The size distribution and morphologyof the NPs, encapsulation efficacy and in vitro release profile in phosphate buffer medium(pH 7.4) during 12 hrs were then investigated.Results: The NPs prepared in this study were spherical with a relatively mono-dispersedsize distribution. By adjustment of the process parameters, the size and the drugencapsulation efficacy as well as the drug release kinetics can be optimally controlled. Themean particle size of the best formula with encapsulation efficiency of 100% was 175 ± 19,in which release profile was best fitted to Higuchi s model of release which showed thatrelease mechanism was mainly controlled by diffusion of the drug to the release medium.Conclusion: According to the size and surface properties of the prepared particles, it maybe concluded that they are a good formulation for non-parenteral routes of administration.