Dextran-poly-ε-caprolactone micro- and nanoparticles:: preparation, characterization and tamoxifen solubilization

This work deals with new poly-epsilon-caprolactone grafted dextran copolymers (Dex-PCL) able to solubilize tamoxifen, a poorly water soluble drug. Micro- and nanoparticles with sizes ranging from 100 to 3,000 nm, composed of Dex-PCL with various Dex contents, were prepared by the nanoprecipitation technique. Structural and surface characterization by dextranase degradation in comparison with the data obtained from the NMR studies proved core-shell structure of these nanoparticles. The PCL core of the Dex-PCL nanoparticles was degraded by the Pseudomonas lipase. Encapsulation of tamoxifen in biodegradable Dex-PCL nanoparticles resulted in loadings as high as 44 wt %. In vitro release studies of tamoxifen performed in phosphate buffer containing 0.5% (w/v) sodium lauryl sulfate showed a sustained release over more than 72 h. This result confirms that most of drug was located in the core of Dex-PCL nanoparticles.