I found this on the ricola dot com website’s FAQ section:
Are all your products Kosher?
All of our bagged cough, throat and vitamin C drops sold in the US are kosher (Ricola Kosher Certificate (PDF-Download) attached). Our drops that are sold in sticks are not.
The linked PDF is a hashgacha from a Rav Avraham Yaffe-Schlesinger in Geneve, Switzerland, whom I’m not familiar with.