Electrohydrodynamic methods applied for the co-encapsulation of polyphenols and vitamins in pullulan microstructures

Recently, electrospun micro/nanostructures attracted a lot of attention and have shown to have a significant potential for drug delivery. This work focuses on the application of pullulan to prepare different micro/nanostructures. When pullulan is used on the submicron-to-nanoscale dimension, it demonstrates to have some advantages for biomedical, pharmaceutical, and engineering applications. Two different biomolecules were used as models for polyphenols and vitamins encapsulation, Epigallocatechin-3-gallate (EGCG) and vitamin B12, respectively. So, the current work aims to develop pullulan microstructures containing EGCG, Vitamin B12 and the combination of both (EGCG+VitB12) using Electrohydrodynamic techniques (EHD). The encapsulation was performed for different concentrations of pullulan (10–20% w/v) containing 1% w/w of active compound, resulting in the production of micro/nanoparticles, fibers, or mixture of them. Through the evaluation of the release profiles, it was concluded that the longest releases are associated with the structures loaded with EGCG+VitB12 and with highest pullulan concentration (20% w/v). The experimental release profiles were evaluated using different kinetic models, and the results indicated that the Weibull model was the most appropriate. High encapsulation efficiencies were obtained for all samples (>82.4%). It was also concluded that co-encapsulated compounds had very similar release profiles and the main release mechanism was associated with the Fickian diffusion transport.