Preparation of resveratrol-loaded ethyl cellulose microspheres via foam-transfer and its application performances

Abstract

Resveratrol (Res) has been widely used in personal-care and pharmaceutical products due to its anti-oxidant, anti-inflammatory, cardioprotective and anti-cancer properties. However, the direct application of Res as functional additives have been limited due to its insolubility and instability. In this work, Res is loaded on the biodegradable ethyl cellulose (EC) carrier to prepare highly porous EC/Res microspheres via a foam-transfer method to understand the sustained release and the degradation property. The experimental results show that when the PVA concentration = 2.5 wt%, the stirring rate = 600 rpm, the oil/water (O/W) ratio = 1:2, the polymer concentration = 1:25, the heating rate = 0.33 °C/min, and the viscosity of EC = 90 ~ 110 mpa.s, the EC/Res microspheres are obtained with a yield up to 80.70 wt% and an encapsulation efficiency of 73.89% via the batch-process; the EC/Res microspheres are further produced continuously with a higher encapsulation efficiency of 90.63% with a yield of 85.58 wt%. The EC/Res microsphere reaches a cumulative release rate up to 91.97 wt% in the phosphate buffer solution (PBS) at pH = 5.0 under 45 °C for 120 h. After the EC/Res microspheres degraded in PBS (pH = 7.4) for 45 days, the hardness decreased from 12.01 ± 0.56 MPa to 4.02 ± 0.45 MPa. This work thus provides a practical solution for Res’s application as sustained release functional additives.