Development and anti-Candida evaluation of the vaginal delivery system of amphotericin B nanosuspension-loaded thermogel

Abstract

Vulvovaginal candidiasis (VVC) is a typical kind of vaginal mucosal infection. Herein, we developed a novel vaginal delivery system of amphotericin B (AmB) nanosuspension-loaded thermogel (AmB NPs/thermogel) utilising pharmaceutical technique of high-pressure homogenisation and Poloxamer P407/P188 hydrogel. The stabiliser and hydrogel materials of the formulation were tested to maintain proper sol–gel transition as well as the relative stability of the particle size of AmB nanosuspension in the thermogel. The particle size of AmB nanosuspensions in the hydrogel was ∼247 nm. Transmission electron microscopy images confirmed the round-shape morphology of AmB nanoparticles in AmB NPs/thermogel, while that of irregular morphology of merely AmB nanosuspensions without stabiliser and hydrogel materials. AmB could be sustained release for ∼12 h in vitro. In vivo drug content in the vaginal tissue was also evaluated with 87, 47, 33 and 6.7% drug remaining after 1, 3, 6 and 12 h, respectively. The in vivo anti-Candida test was conducted on candidiasis-infected mice model. In the same drug dose of 2.5 mg/kg, AmB NPs/thermogel showed better anti-Candida efficiency compared with commercial AmB effervescent tablet. This delivery system might show some insights for the vaginal formulation development of other hydrophobic antifungal drugs.

Keywords:

• Amphotericin B
• thermogel
• nanosuspension
• Poloxamer
• vulvovaginal candidiasis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [81603048, 81773908], Natural Science Foundation of Jiangsu Province [BK20160752], Fundamental Research Funds for the Central Universities [2016ZPY014] and Programme of the “333 High-Level Personnel Training Project [No. BRA2015392]” young leaders in science and technology of Jiangsu Province and Public Technology Service Center of Nano Drug Preparation and Evaluation of Jiangsu Province.