Development and Characterization of Nisin Nanoparticles as Potential Alternative for the Recurrent Vaginal Candidiasis Treatment.

The aim of this work was the development and characterization of nisin-loaded nanoparticles and the evaluation of its potential antifungal activity. Candidiasis is a fungal infection caused by Candida sp. considered as one of the major public health problem currently. The discovery of antifungal agents that present a reduced or null resistance of Candida sp. and the development of more efficient drug release mechanisms are necessary for the improvement of candidiasis treatment. Nisin, a bacteriocin commercially available for more than 50 years, exhibits antibacterial action in food products with potential antifungal activity. Among several alternatives used to modulate antifungal activity of bacteriocins, polymeric nanoparticles have received great attention due to an effective drug release control and reduction of therapeutic dose, besides the minimization of adverse effects by the preferential accumulation in specific tissues. The nisin nanoparticles were prepared by double emulsification and solvent evaporation methods. Nanoparticles were characterized by dynamic light scattering, zeta potential, Fourier transform infrared, X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy. Antifungal activity was accessed by pour plate method and cell counting using Candida albicans strains. The in vitro release profile and in vitro permeation studies were performed using dialysis bag method and pig vaginal mucosa in Franz diffusion cell, respectively. The results revealed nisin nanoparticles (300 nm) with spherical shape and high loading efficiency (93.88 ± 3.26%). In vitro test results suggest a promising application of these nanosystems as a prophylactic agent in recurrent vulvovaginal candidiasis and other gynecological diseases.

Preparation and Evaluation of Chitosan Submicroparticles Containing Pilocarpine for Glaucoma Therapy.

The objective of the present study was to optimize the preparation of chitosan submicroparticles and to assess whether they enhanced ocular permeation of pilocarpine. Submicroparticles were produced by spray drying and characterized to determine process yield, encapsulation efficiency, morphology, size distribution, drug-polymeric matrix interaction, porcine sclera permeation as well as ocular irritancy and drug retention. Quantification of pilocarpine using High Performance Liquid Chromatography was found to be selective, linear, precise, accurate and robust. The spray drying method proved to be simple and reproducibly produced particles with satisfactory yields, thus showing potential for industrial scale applications. The pilocarpine-loaded chitosan particles exhibited adequate morphological characteristics as well as high encapsulation efficiency. The particles produced were on a submicrometric scale and compatible with intraocular administration. In pilocarpine-loaded particles, the interaction between pilocarpine and chitosan polymeric matrix resulted in delayed release of the drug, attributed to formation of a reservoir system. The best fit for drug release was obtained using the Higuchi equation. The chitosan submicroparticles enhanced the permeation effect and increased the passage of pilocarpine through porcine sclera and also demonstrated low irritancy potential. Therefore, the particles produced can be considered a promising system for the ocular delivery of pilocarpine.