Carreadores lipídicos nanoestruturados contendo anfotericina B: desenvolvimento, avaliação das propriedades farmacêuticas e estabilidade sob acondicionamento

Abstract

The solid lipid nanoparticles were developed in the 1990s and a new generation of this system group has been studied in recent years: the nanostructured lipid carriers (NLC). This nanostructure can improve the vectorization of drugs such as amphotericin B (AmB). Therefore, this study aimed to develop a NLC containing AmB and to evaluate their physicochemical and pharmaceutical properties. Initially, preformulation studies were carried out in order to estimate the AmB solubility in different liquids lipids and the conditions for processing the samples. NLCs formulated with sesame oil exhibited better results. Moreover, an experimental design was used to determine the components concentration within the formulation. The combination of solid/liquid lipid at the 7:3(w/w) ratio and surfactant at 3%(w/v) concentration was further used. The physicochemical stability of the formulations was determined based on the particle size, the polydispersity index (PdI), the zeta potential and the AmB recovery rate. After production, NLC and AmB-NLC was presented as translucent nanodispersions, white and yellow, respectively. These samples were analyzed for up to 60 days, when instability was observed. Thus, the lyophilization process was used to increase their stability. Among the studied cryoprotectants, maltose showed better results at the concentration of 10% and after 48 hours of lyophilization. Then, the particles were analyzed over 360 days in accordance with the tests previously described. The lyophilized particles presented higher particle size, smaller PdI and constant zeta potential. The lyophilizates were obtained as white (Liof-NLC) and yellow (Liof-AmB-NLC), easily redispersible powders. The Liof-AmB-NLC presented drug loading rates above 90% during the analysis time. The differential scanning calorimetry and the X-ray diffraction results exhibited the state of crystallinity of the particles. The in vitro release profile was assessed 24 hours after the preparation of the NLC and the best model for fitting the data was Baker-Lonsdale. Thus, the NLC developed and analyzed in this work can be an alternative for the treatment of diseases that have AmB as its therapeutic choice.