Ethacrynic acid (Edecrin - MSD), like chlorothiazide, is the product of an intensive search for substances with affinity for sulphydryl groups - a property shown in vitro that is closely linked with clinical diuretic potency. It is an aromatic oxyacetic acid which dissolves poorly in water, well in lipids and is acidic; these properties suggest that it will bind strongly to tissue and plasma proteins.