Stabilized micelle structure nanoparticles were prepared using Pluronic F127 and poly(butylcyanoacrylate) (PBCA). To increase the drug loading of nanoparticles, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was additionally included into the nanoparticle composition. The poorly soluble anticancer drug 10-hydroxycamptothecin (HCPT) was used as a model drug and incorporated into nanoparticles. The results obtained from FT-IR and DSC confirmed that HCPT was molecularly dispersed in nanoparticles and no chemical reaction occurred. The size of the nanoparticles measured by DLS demonstrated that the size distribution was narrow and the average diameter was less than 200 nm. The morphology of the nanoparticles observed by TEM indicated that the nanoparticles exhibited a smooth surface and distinct spherical shape. In vitro release experiments indicated that the HCPT-loaded nanoparticles showed sustained release profiles. The results of a drug loading test revealed that adding TPGS could increase the drug loading. The drug loading of stabilized micelle structure nanoparticles with 70% of TPGS was about 0.0425 +/- 0.0011% w/w compared to 0.0254 +/- 0.0008% w/w found for the nanoparticles without TPGS. The results of CMC value tests showed that the CMC values of the stabilized nanoparticles were approximately 10-fold lower than those of the nonstabilized micelles (from 2.0 x 10(-5) to 2.5 x 10(-4) M). Cytotoxicity tests showed that the cytotoxicity of HCPT-loaded nanoparticles against cancer cells in vitro was remarkably higher than that of free drugs. 10-Hydroxycamptothecin-loaded nanoparticles may serve as a stable delivery system for poorly soluble HCPT. (C) 2009 Elsevier Inc. All rights reserved.