High
tumor targeting and sustained
drug concentration are key points for successful anti-
tumor therapy, however, it is a challenging task. In this work, a novel
micelle formulation of
paclitaxel (PTX) has been prepared for the purpose of prolonging the blood circulation time as well as improving the accumulation of the
drug within the
tumor tissue. PEGylated P(CL-co-LLA) (poly(ε-
caprolactone-co-L-
lactide))
micelles containing PTX were prepared by solid dispersion-sonication method with a higher
drug-loading efficiency and encapsulation ratio (28.4% and 94.7%, respectively). Pharmacokinetic study revealed that the
drug-loading
micelles exhibited a higher AUC values and a prolonged residence time of
drug in the blood circulation than those of PTX injection. As demonstrated by tissue distribution and anti-
tumor study in S180
tumor-bearing mice, the PEG-P(CL-co-LLA)/PTX
micelles displayed modified tissue distribution of PTX and increased accumulation of PTX in
tumor, therefore, resulted in anti-
tumor effects enhancement and
drug concentration in the normal tissues reduction. Furthermore, the preliminary safety tests were performed by measuring the
body weight, histopathology, blood cell counts and clinical chemistry parameters, and the results showed no subacute toxicity to hematological system, major organs or tissues in mice. Taken together, our valuation shows that PEG-P(CL-co-LLA)
micelles is a potential drug delivery system of PTX for the effective treatment of the
tumor and systematic toxicity reduction, thus, the micellar formulation can provide a useful alternative
dosage form for i.v. administration of PTX.