Abstract
According to the 8th Hungarian Pharmacopoeia, propylene glycol can be chosen as solvent over ethyl alcohol for use in food supplements, therefore, the concentration of flavonoids and polyphenols in medicinal plants is measured using propylene glycol extracts. Samples of seven products, used in veterinary medicine, known to be rich in polyphenols and flavonoids were chosen to verify the usefulness of propylene glycol as extraction solvent. The polyphenol measurements were carried out using the Folin-Ciocâlteu method and the total flavonoid content was established using the modified method from the 10th Romanian Pharmacopoeia, Cynarae folium monograph. Propylene glycol/water mixture (70%/30%), used as extraction solvent for medicinal plants rich in flavonoids and polyphenols, proved to be useful for extraction of these valuable active substances and correlates with the known amounts stated previously to be present in these vegetable materials. Results were in correlation with literature data, concentrations ranged between 0.05 and 0.07 mg/ml (immediately after preparation), 0.02 and 0.08 mg/ml (within six months following preparation) in case of flavonoids and 2.44 and 3.80 mg/ml (immediately after preparation), 1.20 and 2.18 mg/ml (within six months following preparation) in case of polyphenols.