title: Preparation of PLLA/PLGA microparticles using solution enhanced dispersion by supercritical fluids (SEDS).
abstract: In this work, poly(L-lactic acid)/poly(lactide-co-glycolide) (PLLA/PLGA) microparticles were prepared using the technique of solution-enhanced dispersion by supercritical fluids (SEDS). For comparison, separate PLLA and PLGA microparticles were also produced by the same SEDS process. The produced microparticles were characterized by scanning electron microscopy, laser particle size analyzer, X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, and gas chromatography. Results indicate that PLLA/PLGA microparticles possess sphere-like shapes with smooth surfaces. The mean particle size of PLLA/PLGA microparticles ranges from 1.76 to 2.15 microm, depending on the feeding ratio of PLLA to PLGA used in the SEDS process. The crystallinity of PLLA/PLGA microparticles decreases after the SEDS processing, so that the produced microparticles are in an amorphous state. Pure PLGA was hard to precipitate in small, fine microparticle form without the presence of PLLA. A model drug, paclitaxel, was encapsulated into PLLA/PLGA microparticles by the same SEDS process, and the in vitro release rate of paclitaxel from these PLLA/PLGA composites could be modulated by variation of the mixing ratio PLLA:PLGA. The prepared microparticles have negligible residual organic solvent. Drug-loaded PLLA/PLGA microparticles produced by SEDS have potential as an advanced colloidal suspension for pharmaceutical applications.
authors.affiliation: College of Materials Science and Engineering, Sichuan University, Chengdu, Sichuan 610064, China.
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Kang
authors.forename: Guangfu
authors.initials: G
authors.lastname: Yin
authors.forename: Ping
authors.initials: P
authors.lastname: Ouyang
authors.forename: Zhongbing
authors.initials: Z
authors.lastname: Huang
authors.forename: Yadong
authors.initials: Y
authors.lastname: Yao
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liao
authors.forename: Aizheng
authors.initials: A
authors.lastname: Chen
authors.forename: Ximing
authors.initials: X
authors.lastname: Pu