Spray-dried powders improve the controlled release of antifungal tioconazole-loaded polymeric nanocapsules compared to with lyophilized products

This work aimed to obtain solid formulations from polymeric nanocapsules and nanoemulsions containing tioconazole, a broad spectrum antifungal drug. Two dehydration methods were used: spray-drying and freeze-drying, using lactose as adjuvant (10%, w/v). The liquid formulations had a mean particle size around 206 nm and 182 nm for nanocapsules and nanoemulsions, respectively; and an adequate polydispersity index. Tioconazole content was close to the theoretical amount (1.0 mg/mL). After drying, the content ranged between 98 and 102% with a mean nanometric size of the dried products after redispersion. Scanning electron microscopy showed that the particles are rounded, sphere-shaped for the dried products obtained by spray-drying, and shapelessand irregular shapes for those obtained by freeze-drying. In the microbiological evaluation, all dried products remained active against the yeast Candida albi cans when compared to the original systems. The dried products obtained by spray-drying from nanocapsules presented better control of the tioconazole release when compared to the freeze-drying products. (C) 2015 Elsevier B.V. All rights reserved.