Study on preparation and pharmacokinetics of rhein-loaded polylactic acid nanoparticles / 中国药学杂志

OBJECTIVE: To prepare rhein-loaded polylactic acid nanoparticles, and investigate their physicochemical properties, release behavior in vitro and pharmacokinetics in vivo in rats. METHODS: Rhein-loaded polylactic acid nanoparticles were prepared by a modified spontaneous emulsificationsolvent diffusion method with PLA as the carrier. The morphology of rhein-loaded polylactic acid nanoparticles was observed by transmission electron microscope. Mean particle size and Zeta potential were estimated by laser particle size analyzer. Entrapment efficiency and drug loading were investigated by ultracentrifugation. Drug release behavior in vitro was studied by dialysis. Using rhein aqueous suspension as control, the pharmacokinetic behavior of rhein-loaded polylactic acid nanoparticles after oral administration in rats were studied. RESULTS: The shape of rhein-loaded polylactic acid nanoparticles was spherical. The mean particle size, Zeta potential, entrapment efficiency and drug loading were (134.37 ± 3.61) nm, (-18.41 ± 0.07) mV, (60.37 ± 1.52)% and (1.32 ± 0.09)%, respectively. The profiles of release were fitted well by Higuchi equation. Results of pharmacokinetic study showed that the ρmax of rhein suspension and rhein-loaded polylactic acid nanoparticles were (5.788 ±0.15) and (11.607 ± 0.56) mg · L-1, tmax were (0.193 ±0.01) and (1.102 ±0.13) h, AUC0→t were(8.077 ±2.98) and (34.583 ±3.93) mg · h · L-1, t1/2β were (3.319 ±0.23) and (21.721 ± 6.13) h, respectively. CONCLUSION: Polylactic acid nanoparticles can effectively improve the pharmacokinetic behaviour and oral bioavailability of rhein. Copyright 2012 by the Chinese Pharmaceutical Association.

Study on Gambogic Acid-loaded Polylacticacid Nanoparticles / 中国生物工程杂志

Gambogic acid-loaded polylacticacid nanoparticles (GA-PLA-NPs) were prepared by modified emulsification solvent diffusion. The shape of nanoparticles was observed by transmission electron microscope (TEM).The size distribution and mean diameter were measured by laser particle size analyzer. The entrapment efficiency and content of drug loading were determined by Ultraviolet Spectrophotometer after ultracentrifugation. GA-PLA-NPs release behavior in vitro was carried out. The acute toxicity were carried out to study the security of GA-PLA-NPs. The preparation process adapted to the formulation was as follows: the volume ratio of the aqueous and organic was 2∶1(v/v), the surfactant concentration in aqueous was 0.5%,the drug concentration in organic was 0.1%(w/v), GA∶PLA was 1∶4(w/w). The mean diameter was 51.36nm for the nanoparticles prepared by above conditions.The entrapment efficiency and content of drug loading were 98.87 % and 13.3 %. The release behavior of drug in vitro showed an initial burst effect with subsequently a slower rate stage. The LD50 value of GA-PLA-NPs on mouse was 26.3 mg/kg. The results showed that the GA-PLA-NPs were well prepared with stable quality and high dispersion. PLA-NPs might be used as a new carrier for gambogic acid.