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 shapeless and irregular shapes for those obtained by freeze-drying. In the microbiological evaluation, all dried products remained active against the yeast Candida albicans 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.

Microencapsulação de probióticos por spray drying: avaliação da sobrevivência sob condições gastrointestinais simuladas e da viabilidade sob diferentes temperaturas de armazenamento / Microencapsulation of probiotics by spray drying: evaluation of survival in simulated gastrointestinal conditions and availability under different storage temperatures

O objetivo deste trabalho foi avaliar microcápsulas contendo Bifidobacterium animalis e Lactobacillus acidophilus, produzidas por spray drying. Ensaios de sobrevivência foram conduzidos para avaliar a resistência dos probióticos a condições gastrointestinais simuladas e a sua viabilidade durante 120 dias de armazenamento a 4ºC e 25ºC, além da análise morfológica das microcápsulas. A microencapsulação protegeu os probióticos das condições gastrointestinais simuladas, os quais permaneceram viáveis após 120 dias de armazenamento a 4ºC e 25ºC, sendo mais viáveis a 4ºC. As microcápsulas apresentaram forma esférica, com superfície contínua relativamente lisa e sem fissuras. O estudo indica que microcápsulas de B. animalis e L. acidophilus, produzidas por spray drying, sobrevivem a condições gastrointestinais simuladas e podem ser melhor armazenadas por 120 dias a 4ºC.

The aim of this study was to evaluate microcapsules containing Lactobacillus acidophilus and Bifidobacterium animalis by spray drying. Survival assays were conducted to evaluate the resistance of probiotics to simulated gastrointestinal conditions and its availability during 120 days of storage at 4°C and 25°C, besides morphological analysis of the microcapsules. Microencapsulation protected the probiotics from simulated gastrointestinal conditions, which also remained viable after 120 days of storage at 4ºC and 25ºC, but more viable at 4ºC. The microcapsules showed spherical shape with relatively smooth continuous surface without cracks. The study indicates that microcapsules of B. animalis or L. acidophilus by spray drying survive in simulated gastrointestinal conditions and can be better stored for 120 days at 4°C.