Influência de diferentes veículos na capacidade de intumescimento e ângulo de contato em hidrogéis de quitosana e xantana para liberação controlada de fármacos

Abstract

Objetivo: O objetivo deste estudo foi avaliar a influência de três diferentes veículos (água, álcool e solução 50% água + 50% álcool) na capacidade de intumescimento, e, o ângulo de contato de hidrogéis de quitosana e xantana, com foco em aplicações para carregamento e liberação controlada de fármacos. Material e Métodos: Hidrogéis de quitosana (Q) e xantana (X) foram preparados utilizando proporções de 1:1 entre os polímeros. As soluções de Q (1% m/v) e X (1% m/v) foram feitas separadamente em solução de ácido acético 1% (v/v) e água destilada, e colocadas em agitador magnético por 1 hora. A solução de Q foi transferida para uma seringa acoplada a uma bomba injetora, gotejada sobre a solução de X a 200 ml/h, com agitação mecânica a 1000 rpm. As suspensões foram transferidas para placas de petri e secas em estufa a 37 °C por 24 h. Após lavagem para remoção de resíduos, as membranas foram secas novamente por mais 24 h. Os hidrogéis foram analisados por Microscopia Eletrônica de Varredura (MEV) para avaliar a

Objective: The objective of this study was to evaluate the influence of three different vehicles (water, alcohol, and a 50% water + 50% alcohol solution) on the swelling capacity and contact angle of chitosan and xanthan hydrogels, with a focus on applications for drug loading and controlled release. Materials and Methods: Chitosan (Q) and xanthan (X) hydrogels were prepared using a 1:1 ratio between the polymers. Q solutions (1% w/v) and X solutions (1% w/v) were prepared separately in 1% (v/v) acetic acid solution and distilled water and stirred with a magnetic stirrer for 1 hour. The Q solution was transferred to a syringe connected to an injection pump, dropped into the X solution at 200 mL/h under mechanical stirring at 1000 rpm. The suspensions were transferred to Petri dishes and dried in an oven at 37 °C for 24 hours. After washing to remove residues, the membranes were dried again for an additional 24 hours. The hydrogels were analyzed by Scanning Electron Microscopy (SEM) to evaluate surface and cross-sectional morphology, as well as swelling degree in three vehicles (water, alcohol, and 50% water + 50% alcohol solution) at intervals of 1h, 2h, 4h, 8h, and 24h. Wettability was determined by the contact angle at 180, 300, and 600 seconds. All tests were performed in triplicate, and the data obtained were analyzed using descriptive and inferential statistics. Results: The hydrogels were stable and exhibited predominant characteristics of the polysaccharides used. In the swelling analysis, a statistically significant difference was observed between the groups, with the aqueous medium showing the highest degree (%) over the analyzed time, followed by the 50/50 solution and, lastly, alcohol. In the wettability analysis, the contact angle decreased over time, demonstrating the hydrophilic nature of the material. Conclusion: The results revealed a statistically significant difference in the swelling capacity among the tested vehicles, indicating that the medium in which the drug is embedded directly influences the membrane's loading efficiency, as well as the exposure time to the vehicle. Water-based media demonstrated a substantially higher loading capacity compared to alcohol-containing vehicles when applied to chitosan and xanthan (QX) hydrogels.