Production of encapsulated quercetin particles using supercritical fluid technologies

Abstract

Quercetin is an antioxidant compound with highly promising pharmacological properties against a wide variety of diseases. A major limitation for the clinical application of quercetin is its low bioavailability, due to its low solubility in water. In this work, quercetin is microencapsulated in a surfactant material with the objective of increasing its bioavailability. For this, quercetin is first treated using Supercritical Fluid Extraction of Emulsions in order to precipitate it in nanometric scale in an aqueous suspension, and then this suspension is further treated by Particles from Gas Saturated Solutions (PGSS)-drying technology, to obtain quercetin loaded dried particles in micrometric scale. Soy-bean lecithin and Pluronic L64® are used as surfactant and encapsulating materials. Mircoencapsulation of quercetin by lyophilisation of SFEE-produced aqueous suspensions is also studied in order to compare it with the results of PGSS-drying. Samples are characterized considering encapsulation efficiency, antioxidant activity and Franz-cell measurements of transdermal diffusion of encapsulated quercetin product as assessment of its bioavailability. It is observed that samples encapsulated by SFEE and PGSS-drying are more homogeneous and less crystalline than samples obtained by lyophilisation, which results in a higher transdermal diffusivity.