A promising nystatin nanocapsular hydrogel as an antifungal polymeric carrier for the treatment of topical candidiasis

The objective of the present work was the development and evaluation of nystatin (Nys) nanocapsular hydrogel, as an attractive dosage form for treatment of topical candidiasis. The nanocapsular dispersions were prepared using the nanoprecipitation method. The influence of formulation factors, namely, polycaprolactone (PCL) concentration (0.25, o.5% w/w) as well as that of squalene (2.5, 5% w/w) and span 60 (Sp60) (0.5, 1% w/w) was investigated on the various physicochemical properties of the produced formulations. The results revealed the significance of the studied factors which were optimized and the nanocapsular formulation; Nys-NC6 composed of 0.25% w/w PCL, 5% w/w squalene and 1% w/w Sp60 showed the most favorable attributes. Nys-NC6 exhibited high encapsulation efficiency (86.09 +/- 0.28%), small mean diameter (254 +/- 6.81 nm), low poly-dispersity index (0.23 +/- 3.03) and high negative zeta potential (-48 +/- 2.00 mV). After incorporation into Carbopol gel, the in vivo antifungal efficacy of Nys-NC6 hydrogel was studied against Candida albicans using infected rat model. At the end of the treatment period, Nys-NC6 hydrogel showed a superior antifungal effect compared to Nys hydrogel and the market product with a significant reduction of the fungal count and eradication of the Candidal infection. The obtained results were further supported by the confocal microscopy and histopathological photomicrographs confirming the antifungal efficacy of the tested formulation. The current findings suggested that nystatin nanocapsular hydrogel represent a successful approach for the treatment of topical candidiasis.