Cleaning validation for herbal extract

Dear Forum Professionals,

I have to perform cleaning validation for herbal extracts (API) process. I have experienced cleaning validation for finished drug product, but herbal extracts are very new to me.

The process is very simple. Natural sourced herbal plant will be extracted with ethyl alcohol, filtered, and concentrated to make viscous extract. The process equipment is multi-use with other products. I’ve tried to find some good resources to describe cleaning validation for herbal extract, but I couldn’t. My concern is as below.

Firstly, product grouping is an issue. If solubility data and/or toxicity data will be available, then the product grouping is much easier, but the information is absence.

Secondly, how to establish acceptance criteria? There is no dose information, as well LD50 toxicity data. In this case, what am I supposed to do?

Thirdly, what analytical method will be utilized? Herbal extract has very low level of active ingredient (approximately 2%). Is the analytical method specific for active ingredient?

I have completely no idea of this work. Please advise me to the right direction.

Thanks in advance,

HJ