Different kinds of amphiphilic block copolymers

PEG-PCL-PEG(PECL)

mPEG-PLLA(PELLA) and mPEG-PDLLA(PEDLLA)，were used to encapsulate paclitaxel to prepare nano-micelle formulation. The nano-micelles had a core-shell structure

in which paclitaxel was enveloped in the core

and the PEG shell made the micelles loaded with paclitaxel lyotropic in water. The kinetics of paclitaxel release from the micelles in phosphate buffer solution(PBS) was studied.The results showed that the diameter of the micelles affected apparently drug release rate

and micelles with low drug loaded content(DLC) would release more paclitaxel; enhancing the refresh volume of PBS facilitated drug[DK]’s release; both PECL micelle and PELLA micelle released paclitaxel in PBS under the rule of first order equation; PEDLLA micelles loaded with paclitaxel prepared by solid dispersion technology obeyed zero-order release in two stage.