OBJECTIVE To prepare nanostructured lipid carriers(NLCs) of plumbagin(PLB) modified with mannose(Man), investigate the in vitro drug release pattern, and conduct in vitro cytotoxicity experiments and preliminary pharmacological studies.

METHODS PLB-NLCs were prepared using the ethanol injection method, and then PLB-Man-NLCs were obtained by combining single-factor screening with Box-Behnken design-response surface methodology. The in vitro release pattern of PLB-Man-NLCs was evaluated using dialysis method and fitted with the optimal equation. NIH3T3 cells were used forotoxicity and cell proliferation inhibition experiments.

RESULTS The optimal formulation of PLB-Man-NLCs was as follows: drug-to-lip ratio of 1∶10, liquid-to-solid lipid ratio of 1∶3.85, and PLB concentration of 0.49 mg·mL⁻¹. PLB-Man-NLCs spherical or quasi-spherical shape with a particle size of (175.66±3.29)nm a Zeta potential of (−42.81±2.44)mV. The encapsulation efficiency and drug loading were (85.89±0.75)% and (5.69±0.07)%, respectively. The release curve of PLB-Man-NLCs was best fitted the Weibull equation. PLB-Man-NLCs reduced the toxicity of PLB to NIH3T3 cells and inhibited TGF-β1 induced fibroblast proliferation.

CONCLUSION PLB-Man-NLCs are successfully prepared, which the solubility and in vitro release of PLB. The experimental results provide a solid theoretical basis for further formulation development.