Starch (Amylum) - coating agent. In cold water insoluble in hot form a colloidal solution. Starch is applied externally (in the form of powders of oxide of zinc, talc , etc.,), inside and enema (in the form of starch paste - 1% solution) for protection of sensitive nerve endings from exposure to irritants and to slow down the intake of medicines. Cm. also Enveloping means of Powder.