Nitrofurantoin (NITRO), a well-established antibiotic for urinary tract infections, is activated by nitroreductases, a mechanism that has prompted its investigation for repurposing in breast cancer treatment, as these cancers express the nitroreductase gene.NITRO-loaded cubosomes were prepared via hot homogenization following a 2³ full factorial design. Variables examined included the drug-to-oil phase ratio (1:10 and 2:10), oil-to-aqueous phase ratio (1:10 and 1:5), and Glyceryl mono-oleate (GMO) to Poloxamer 407 (PX407) ratio (0.25:1 and 0.5:1). Eight formulations were developed and characterized for particle size, zeta potential, polydispersity index, and entrapment efficiency.Formulation S6 (1:10 drug-to-oil, 1:5 oil-to-aqueous, 0.5:1 GMO:PX407) demonstrated the highest desirability, with a particle size of 45.5 ± 1.1 nm and entrapment efficiency of 98.6 ± 1.8%, and was selected for further studies. TEM analysis confirmed its morphology. The intracellular cytotoxicity of S6 against MCF-7 breast cancer cells was assessed via MTT assay, revealing a significantly lower IC50 (83.99 ± 0.15 μg/mL) compared to free NITRO (174.54 ± 1.36 μg/mL), indicating enhanced anticancer efficacy.Nitrofurantoin-loaded cubosomes show promise for repurposing in breast cancer therapy, warranting further stability testing and in vivo evaluation.
