Not quite. Patents can be for individual chemicals, but can also be for combinations of substances. But to get the patent, the chemical (or combination of materials) must be new, and not obvious. So a well-known combination, such as in ayurveda medicine, cannot be patented because it is not new.
If we formulate a new compound drug of Unani Medicine(By mixing two or more ingredients such as Curcuma, Neem etc) which is not available anywhere (not in any classical book of unani medicine). This type of formulation is based on our own experiences then what is your opinion.
Then there is a good chance it can be patented as long as no-one else has tried using the formulation before (prior use, rather than prior publication)