If you hover over drop down menus in the rpg maker, it often gives you a tool tip at what that effect does.
Element Rate decides how much damage a character takes from that element, including physical.
I assume you mean the Sp-Parameter for physical damage? The tip in this case is less helpful, but I believe in this case it increases/decreases the physical damage a character does to others.
If you put "pharmacology rpg maker mv" in google, you get the answer immediately: "Increased effects of item-based healing. This does not apply to status removal items (remedy/antidote) but does apply to HP/MP/TP items."
(Source: https://www.reddit.com/r/RPGMaker/comments/3f8wtz/pharmacology/ )