Emplastrum Resinae (U. S. P.)—Resin Plaster.
SYNONYMS: Adhesive plaster, Sticking plaster.
Preparation.—"Resin, in fine powder, one hundred and forty grammes (140 Gm.) (4 ozs. av., 411 grs.]; lead plaster, eight hundred grammes (800 Gm.) [1 lb. av., 12 ozs., 96 grs.]; yellow wax, sixty grammes (60 Gm.) [2 ozs. av., 5 1 grs.]; to make one thousand grammes (1000 Gm.); [2 lbs. av., 3 ozs., 120 grs.]. Melt the lead plaster and yellow wax together with a gentle heat, then add the resin, and, when it is melted, mix the mass thoroughly"—(U. S. P.).
This preparation, when spread on muslin, forms the ordinary Adhesive plaster; as age impairs its adhesiveness, fresh supplies should be obtained frequently. Sometimes powdered Castile soap is added to it, which increases its plasticity without diminishing its adhesiveness, and renders it less brittle in winter. If a small band of adhesive plaster be used as though it were paper, the writing being made on its reverse side, then warmed and placed upon a bottle, it will form an excellent label for vessels kept in cellars and damp places. In place of ink, varnish may be used, colored with vermilion, and then both ink and label resist the action of water and moisture.
Action and Medical Uses.—This plaster is more irritating, as well as more adhesive than Lead plaster. It is used in surgery to hold the edges of wounds together, to keep the dressings of ulcers, etc., in place, to make pressure upon, or give support to parts, and for the same purposes as the lead plaster. It is sufficiently irritating in its composition, without having any other stimulating agents combined with it.