Determining the cytotoxicity of methotrexate-loaded microemulsion on human breast, ovarian, and prostate carcinoma cell lines: a new modality for an old drug

The main objective of this study was to develop an optimal methotrexate (MTX) microemulsion (M‐MTX) and to evaluate the suppressive effect of MTX‐loaded microemulsion on human breast, ovarian, and prostate carcinoma cell lines. The microemulsion was made up of corn‐oil as the oil phase, a mixture of Cremophore EL and Span 80 as surfactants, and isopropyl alcohol as co‐surfactant and 0.1 N NaOH as the aqueous phase. MTX (0.1 mg/mL MTX ) was added into the microemulsion at the last stage. The pH of M‐MTX was adjusted to pH 8±0.1 and the physicochemical stability of the formulation was observed. The particle size distribution was measured by Zetasizer 3000 HSA. The mean droplet diameters of M‐MTX were determined as 13.3±0.1 nm (poly dispersity index=530±0.01). The antitumor effects of M‐MTX were examined on human breast (MCF‐7), ovarian (OVCAR), and prostate (DU 145) carcinoma cell lines. It was clearly demonstrated that M‐MTX had a significant cytotoxic effect on different carcinoma cell lines and the cytotoxic effect of M‐MTX was significantly more than that of commercial preparation (C‐MTX) (P