A Comparative Study of Spray-Dried Medicinal Plant Aqueous Extracts. Drying Performance and Product Quality

GALLO, LOREANA; RAMIREZ RIGO, MARÍA VERÓNICA; PIÑA, JULIANA; VERONICA BUCALA

CHEMICAL ENGINEERING RESEARCH & DESIGN

INST CHEMICAL ENGINEERS

Año: 2015 vol. 104 p. 681 - 694

0263-8762

In the manufacture of herbal medicinal tablets, dried plant extracts are employed as the therapeuticingredient. These powders, usually obtained by spray drying, are typically hygroscopic and possess poorflow and compactability for the manufacture of tablets by direct compression (DC). Besides, spray-dryingoperating conditions and liquid feed composition are reported to be dependent on the herbal medicine.Consequently, the production of dried extracts implies long new product development times. Therefore, thegoal of this paper was to: a) provide recommendations as initial production point of herbal powders suitablefor DC by spray drying and b) study the powder properties to identify those that are affected by the extractnature. Particularly, a unique set of operating conditions was found to be appropriate to produce powders ofseven different medicinal plant extracts. In fact, all the spray-dried products showed adequate flowability,stability and compactability.Powders properties, as particle size and morphology, moisture content, hygroscopicity, flowability andcompact hardness were not a function of the type of herb. Conversely, the process yield and glass transitiontemperature, particle and bulk densities, powder composition, compact porosity, wetting and disintegrationtimes were found to be dependent on the chemical nature of the herbs.