Effects of poloxamer 188 on the characteristics of poly(lactide-co-glycolide) nanoparticles.

ABSTRACT

We tested the effects of poloxamer 188 on the preparation and characteristics of poly(lactice-co-glycolide) (PLGA) nanoparticles containing all-trans retinoic acid (ATRA). Spherical nanoparticles incorporated ATRA were prepared by an emulsification-diffusion method increasing concentrations of poloxamer 188 decreased nanoparticle size. The endothermic peak of ATRA at 183 degrees C disappeared in the nanoparticles and X-ray diffraction measurements showed the disappearance of characteristics of ATRA suggesting the change of the crystallinity of ATRA in the nanoparticles to an amorphous state. ATRA release in vitro increased as the concentration of poloxamer increased. The mean residence time of ATRA-loaded nanoparticles after the administration of a single intravenous dose to rats was longer than that of the sodium ATRA solution. The anti-cancer activity of ATRA-loaded nanoparticles in the human leukemia-60 cell line was similar to free ATRA. Thus, PLGA/poloxamer nanoparticles can provide a sustained release preparation of ATRA.