Assessment of stability of a spray dried extract from the medicinal plant Bidens pilosa L.

Spray drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable phytopharmaceutical preparations. Bidens pilosa L. is a South American medicinal plant with proved antimalaric, hepatoprotector and antioxidant activities, generally linked to their secondary metabolites, flavonoids and polyacetylenes. In this work the physicochemical stability of an optimized spray dried composition from a B. pilosa extract was evaluated at three different stress storage conditions in open containers and in sealed sachets. High performance liquid chromatography was employed to monitor the concentration of three marker compounds over 12 months. Color variation of the stored samples was evaluated by using a color spectrophotometer. It was observed that the concentration of the monitored compounds of the plant decreases more drastically in samples stored in open containers. The two flavonoids monitored, rutin and hyperoside, showed lower degradation than the polyacetylene. The concentration of the markers did not change significantly at the lowest temperature. With regard to color, darker hues were observed at higher temperatures and storage times. This study showed that the storage conditions cause significant impact on stability of standardized spray dried B. pilosa extract.