Microneedles loaded with lipid nanocarriers for local treatment of vulvovaginal candidiasis

Vaginal yeast infections, such as vulvovaginal candidiasis (VVC), affect nearly three out of four women worldwide. Re-occurrence is frequent and requires repeated treatments with oral, antifungal medications at high doses. Prolonged treatments contribute to development of resistant fungal strains and the risk of systemic adverse effects. Vaginal drug delivery can overcome several of the disadvantages associated with oral drug administration. However, current dosage forms, such as vaginal creams and gels, are rapidly expelled from the vaginal tract and require daily dosing to assure therapeutic outcome, thus jeopardizing patient compliance. Therefore, we developed rapidly dissolving microneedle arrays for local, vaginal delivery of antifungal drugs. Clotrimazole, a poorly water-soluble antifungal agent, was formulated in lipid-based nanocarriers (LNCs) and incorporated in the tips of microneedles. The antifungal activity was then tested against the most common VVC fungal strains, C. albicans and C. glabrata, using an in vitro disk diffusion assay and an explant model from bovine vaginal tissue. Antifungal activity increased when the LNCs were incorporated in the microneedles. Notably, the LNC-loaded microneedles inhibited fungal growth at a 10-fold lower drug dose than a commercial clotrimazole cream. Finally, a device prototype was manufactured, based on an intravaginal ring with multiple microneedle arrays on its surface. Local vaginal drug delivery using such microneedle-based devices could enable more effective treatment strategies for VVC.