Physicochemical Properties of Phytopharmaceutical Preparations as Affected by Drying Methods and Carriers

Abstract

This article reports a study of the effects of the drying methods and drying carriers on system performance and physicochemical properties of spray- and spouted bed–dried phytopharmaceutical preparations from Bidens pilosa L. Colloidal silicon dioxide, β-cyclodextrin, maltodextrin dextrose equivalent (DE) 10, and microcrystalline cellulose were used as drying carriers. The dried product was characterized by the particle size and morphology, total flavonoid content, solubility, flowability, and water activity. High-performance liquid chromatography (HPLC) was used to detect four marker compounds previously reported for this plant. Spray and spouted bed drying systems were compared through energetic efficiency, product recovery, elutriation, and product accumulation. The crystalline state of the powders was assessed by X-ray diffraction. Results showed high degradation rates for total flavonoid content and marker compounds during spouted bed drying. Depending on the drying carrier added to extractive solutions, different degrees of protection from degradation were conferred, and the physical characteristics of the product were changed accordingly. The lowest flavonoid degradation (8.6%) and the higher concentration of marker compounds were obtained using β-cyclodextrin as the drying carrier. Particle size was higher when a blend of Aerosil (Evonik Degussa, Hanau, Germany) and cellulose was employed as the drying carrier. A maximum product recovery of 86.9% was achieved by spray drying and 72.9% by spouted bed drying with the Aerosil : cellulose composition.