Development of emulgel formulation for vaginal candidiasis: Pharmaceutical characterization, in vitro and in vivo evaluation

Abstract The aim of the investigation was to develop nanoemulsion (NE) based emulgel of Mentha essential oil (MEO: potent antifungal property) to ensure enriched and extended therapeutic effectiveness against various species of Candida and vaginal candidiasis. NE was prepared and optimized using central composite design. pH-triggered crosslinking of NE in carbopol 940 matrix (emulgel) was achieved by triethanolamine. Emulgel was evaluated for in vitro (against Candida spp.) and in vivo (efficacy in Swiss albino female mice infected by installing 4 × 10 7  cfu/ml of Candida albicans ) activity against the standard control and simple gel of MEO. NE droplets were observed to be spherical and uniform in size (178.087 ± 0.834 nm). Zeta potential and polydispersibility index (PDI) were measured using a diffraction light scattering technique and was found to be 31.56 ± 1.987 mV and 0.176, respectively. Emulgel demonstrated a significantly broader zone of growth inhibition than simple gel (gel of coarse emulsion) when studied against Candida spp. In vivo colony counts of C. albicans in the case of emulgel were observed to be significantly lesser in number (165 cfu/ml) than simple gel (380 cfu/ml). Texture and viscosity of emulgel were measured using a texture analyser and Brookfield viscometer, respectively and were found to be reasonably acceptable for mucosal administration. Texture parameters of emulgel were consistent over 90 days (prolonged stability). Encapsulation of MEO in NE followed by crosslinking in cellulosic polymer ensures reduced volatility and improved effectiveness against candidiasis like condition.