The quinoidine of commerce ought never to be used in medicine unless purified.
From such liquors it is precipitated in an impure state by an alkali, and brought into commerce under the name of quinoidine.
Dr de Vrij, for instance, found sometimes more than 20% of quinidine in some samples of quinoidine of commerce.
quinoidine qui·noi·dine (kwĭ-noi'dēn', -dĭn)
A brownish-black mixture of alkaloids remaining after extraction of crystalline alkaloids from cinchona bark, used as a quinine substitute.