Hi,

Antimicrobial Activities of European Propolis Collected from Various Geographic Origins Alone and in Combination with Antibiotics

You have to dry under low heat otherwise the effectiveness of the extract can be compromised. If you have access to a fume cupboard/chamber you can put in the extract and turn on the fan for several days. If you still have some liquid present thereafter, it might be the oily component of the extract.

As my view, you got the problem on drying by using rotary evaporator, didn't you ? if yes, of course, there is difficult being full drying. As my experience, you should move your matter from rotary evaporator remaining lesser solvent. For full drying, you could use nitrogen.

I hope, I answer your question, good luck

Dear Badria Al-Battashy

please refer this article

Phytochemical analysis and antioxidant potential of the crude extract of Allium oschaninii scape

Article Phytochemical analysis and antioxidant potential of the crud...

Hello, Badria Al-Battashy

perhaps, this article may help you Article Bioanalytical HPLC method of Piper Betle L. for quantifying ...