RESUMEN
BACKGROUND: The human papillomavirus (HPV) is responsible for over 90% of all cervical cancer cases. The use of vaginal gels is often indicated for local vaginal drug delivery. Previous studies have shown that Thymus vulgaris essential oil (TEO) exhibits anticancer properties besides antifungal and antibacterial properties. Its activity derives from a specific increase in free radicals and oxidative stress caused in cancer cells. Furthermore, mitoxantrone (MTX), an anthracenedione, and C8, an acridine orange derivative, were shown to inhibit the growth of the cervical cancer cell line HeLa. RESULTS: The results showed that TEO + C8 is the most promising formulation in terms of viscosity and osmolality properties in vaginal fluid simulant (VFS). The combined action of TEO with the compounds MTX and C8 resulted in HeLa cell viability reduction compared with the effect obtained with the individual formulations containing each one of the compounds. CONCLUSIONS: The formulation TEO + C8 holds promise in terms of cost-benefit and topical application of the active compound for the HeLa cells.