Preparation of PLA or PLGA Microspheres with Estradiol the Effects of THF—adding on the Properties of MS

Aim: polylactic acid(PLA) or polylactide-co-glycolide(PLGA) was used as biodegradable and biocompatible carriers to achieve sustained release of estradial-PLGA/PLA-Microspheres(E2-PLGA/PLA-MS).THF was added in the organic phase to study its effects on the properties of MS.Methods:MS were formed by an emulsification-solvent extraction method with mixture of ethyl acetate(EtoAc) and tetraphydrofuran(THF) as the organic solvents,and then the properties and in vitro drug release behavior were examined.Results:The results indicated that the drug loading efficiency decreased when THF added.but when the ratio of EtoAc was more than 50%,there was no obvious effcet of THF ration,but the particle size increased accordingly.The carriers‘ properties and the drug contents were the main factors influencing the in vitro drug release.Conclusions:By controlling the technology and formulation,we can get sustained-release E2 biodegradable microsperes with proper particle size,drug content and low burst-release,although THF with readily solubility in water was used in the organic phase.

Preparation of PLA or PLGA Microspheres with Estradiol the Effects of THF-adding on the Properties of MS