Repurposing Efavirenz for Anticancer Therapy with Curcumin Combination in Solid Lipid Nanoparticle Formulation

Background: The aim of this study was to explore the potential of repurposing the anti-HIV drug Efavirenz (EFZ) in combination with Curcumin (CUR) for cancer therapy. EFZ is an antiviral drug and selective anti-HIV drug through its Non-Nucleoside Reverse Transcriptase Inhibition (NNRTI) mechanism. The poor survival rate of many cancers has been investigated by new and alternative therapies against immortal tumors. Repurposing is the best option because it minimizes the drug development timeline and avoids phase 1 trials. Materials and Methods: The selected drugs were formulated as Solid Lipid Nanoparticles (SLNPs) via hot emulsification to enhance solubility. All the evaluated parameters for the characterization of SLNPs were within the acceptable limit. Results: Scanning electron microscopy images and nanosize of the drugs were further confirmed by -38.6 mV and 0.204 of zeta potential and polydispersity index values. SLNPs sustained the liberation of the drug for about 24 hr and the pattern of drug release followed Higuchi kinetics. CUR and EFZ combination produced significant growth arrest in MCF-7 breast cell line formulations compared to individual EFZ, CUR formulations. The combined formulation showed a significant loss of viability: only 11.63% of cell viability, CUR 13.61% of viability and EFZ 15.98% of cell viability were retained. Conclusion: The cytotoxic activity of the combined EFZ and CUR formulation was potentiated. Treatment of HIV-1-positive patients with combined EFZ and CUR formulations with different modes of action might reduce the incidence of breast cancer with fewer side effects.