Investigation of Bakuchiol-Loaded Beads Synthesis Using Coaxial Electrospray and their Stability

Department of Industrial Chemistry, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Wongsawang, Bangsue, 10800 Bangkok, Thailand

^* Corresponding author: Nisalak.t@sci.kmutnb.ac.th

Abstract

Bakuchiol, a meroterpene derived from Psoralea corylifolia, offers diverse skin benefits but is prone to degradation under environmental stress. This study aimed to encapsulate bakuchiol in alginate-based beads using coaxial electrospray to enhance its stability. Bead formation was optimized by varying sodium alginate concentrations, core-to-shell flow rates, and applied voltage. Optimal conditions (1.0% w/v alginate; 20:40 mL/min; 1000 V) yielded spherical, well-defined beads. Fourier-transform infrared (FT-IR) spectroscopy confirmed successful encapsulation. Stability tests demonstrated that the beads maintained structural integrity and bakuchiol retention under various storage conditions over 60 days. High retention (greater than 80%) was achieved in neutral and moderately acidic pH (3, 5 and 7) solutions and under both light and dark storage, underscoring the protective role of the alginate matrix. Conversely, exposure to alkaline pH induced degradation and diffusion-related loss. These findings indicate that coaxial electrospray-based alginate beads represent a promising delivery system for stabilizing bakuchiol, supporting its future application in cosmetic formulations.