Encapsulation of complex extracts in beta-cyclodextrin: an application to propolis ethanolic extract.
Propolis ethanolic extracts (PE) are rather complicated mixtures of bioactive compounds belonging to several chemical classes. The potential use of beta-cyclodextrin (beta-CD) cavity for the incorporation of specific PE components, aiming to increase their solubility in water, was studied in a Greek propolis, which was rich in polyphenols and terpenes. The PE/beta-CD inclusion complexes were prepared by sonication of PE suspensions in aqueous solutions of beta-CD, followed by filtration and freeze-drying. The aqueous solubility of PE in the presence of beta-CD was studied by the construction of solubility diagrams and by determining the fraction of PE constituents that was dissolved in water. Encapsulation efficiencies were found to be higher (9.4-23.3%) for relatively small aromatic molecules like cinnamic and benzoic acid derivatives and lower for terpenic acids (5.0-6.7%), anthraquinones (3.6-8.4%) and flavonoids (4.0-10.7%). The respective in vitro solubilities in simulated gastric fluid followed an opposite trend, being lower for the relatively small aromatic molecules. It is concluded that the encapsulation in beta-CD may increase the solubility of PE constituents in a manner related to their structure, while the amount of substances released will depend both on their chemical properties and on their relative abundance in the matrix.
Kalogeropoulos
Nick
N
Department of Nutrition & Dietetics, Harokopio University, Kallithea, Athens, Greece.
Konteles
Spyros
S
Mourtzinos
Ioannis
I
Troullidou
Elena
E
Chiou
Antonia
A
Karathanos
Vaios T
VT
D002152:Calorimetry, Differential Scanning; D004339:Drug Compounding; D000431:Ethanol / Q000737:chemistry*; D005612:Freeze Drying; D008401:Gas Chromatography-Mass Spectrometry; D011429:Propolis / Q000737:chemistry*; D012995:Solubility; D047392:beta-Cyclodextrins / Q000737:chemistry*
D047392:beta-Cyclodextrins; D000431:Ethanol; D011429:Propolis; C031215:betadex