Ceratum Plumbi Subacetatis (U. S. P.)—Cerate of Lead Subacetate.
SYNONYMS: Unguentum glycerini plumbi subacetatis, Goulard's cerate, Ointment of glycerin of lead subacetate.
Preparation.—''Solution of lead subacetate, two hundred grammes (200 Gm.) [7 ozs. av., 24 grs.]; camphor cerate, eight hundred grammes (800 Gm.) [1 lb. av., 12 ozs., 96 grs.]; to make one thousand grammes (1000 Gm.) [2 lb. av., 3 ozs., 120 grs.]. Mix them thoroughly. This cerate should be freshly prepared, when wanted"—(U. S. P.).
Care should be taken, in making this cerate, that the camphor cerate be not rancid. Both the German and British Pharmacopoeias employ no fats in the preparation of this cerate, hence their greater stability. Goulard's cerate rapidly assumes a yellow color, and shortly becomes so rancid as to render it unfit for medicinal purposes.
Action and Medical Uses.—Protective and astringent. Should be cautiously used on large raw surfaces, lest lead poisoning ensue from absorption. When rancid this cerate is irritating, and should be discarded, but when freshly prepared, it forms a good dressing for blisters, excoriations, ulcers, and to suppurative parts.