Is working in a pharmacy that purchases tranquilizers and mood enhancers in quantities exceeding the permitted limits considered unlawful (haram)?

A medicine whose large quantity intoxicates, then a small quantity of it is unlawful (haram). Its sale, purchase, and use are forbidden. The money generated from its sale is unlawful. It is permissible to work for a seller of these medicines provided that one does not participate in their sale. However, it is preferable to leave working for him because his money is mixed (with unlawful earnings) and as a form of deterrence and disapproval against him.