<span>A cold medicine should be soluble in the water, as it needs to be transpored throughout your body. This allows better absorption of the drug, by the system. Water-soluble drugs stay in the blood and the fluid surrounding it, and acts there and also gets circulated into the body, easily.</span>
Producing toxins is the answer
I don’t think you’re looking for a part but I believe you’re looking for blood, more specifically the red blood cells