The Development of Novel Ganoderic-Acid-Encapsulated Nanodispersions Using the Combination of Ultrasonic Cavitation and Solvent Evaporation through Response Surface Optimization

Abstract

Ganoderic Acid (GA), a major bioactive compound isolated from the East Asian medicinal mushroom Ganoderma tsugae, is traditionally believed to have significant medicinal properties. GA is poorly soluble in water, which poses several challenges in terms of its formulation. In this study, Ganoderma tsugae extracts obtained through ethanol extraction were encapsulated in nanodispersions via ultrasonic cavitation and solvent evaporation to increase their bioavailability. The preparation route was thoroughly analyzed using Response Surface Methodology (RSM) to determine the interactions between the variables. Based on the results, the Hydrophilic–Lipophilic Balance (HLB) and the evaporation temperature significantly influenced the resulting particle size. In the optimized nanodispersions, GA was incorporated into a hydrophobic core with a particle size no greater than 200 nm and a very narrow particle distribution (namely, a polydispersity index of 0.289). Due to the high negative zeta potential (−45.9 mV), a very slow particle growth rate of 0.239% over short-term storage (14 days) was achieved. In addition, the zeta average remained virtually unchanged for 14 days at room temperature in solutions at different pH levels. In summary, this paper provides the first-ever demonstration that ultrasound cavitation in conjunction with solvent evaporation can be used to generate GA nanodispersions.