In vitro characterization and growth inhibition effect of nanostructured lipid carriers for controlled delivery of methotrexate.

The present study describes the design and characterization of nanostructured lipid carriers (NLCs) for controlled delivery of methotrexate (MTX). A series of NLCs with or without MTX were prepared using different ratios of liquid-lipid to solid-lipid and type and concentration of surfactants. The effect of different formulation parameters on the physical properties of NLCs, entrapment efficiency of MTX and in vitro drug release was evaluated. In addition, the in vitro delivery and cytotoxicity of MTX-loaded NLCs against human prostate cancer DU-145 cells and ovarian human cancer A2780 cells were investigated. Drug loading capacity, particle size and surface charge of the prepared NLCs and the in vitro MTX release were affected by the formulation parameters. In vitro growth inhibition assay using DU-145 and A2780 cancer cell lines showed that drug-free NLCs maintained cell viability while MTX-loaded NLCs inhibited the growth of both cell lines. In addition, MTX-loaded NLCs showed superior inhibitory effect on cell growth over the free drug especially in A2780 cell lines and a higher cytotoxic effect on DU-145 at higher drug concentration. The results of the current study warrant further exploration for the use NLCs as a controlled delivery system for chemotherapeutic agents.