Linimentum Saponis Camphoratum.—Camphorated Soap Liniment.
Preparation.—Take of common white soap, 2 ounces; camphor, 1 ounce; oil of rosemary, 3 drachms; oil of Origanum, 2 drachms; aqua ammoniae (U. S. P.), 1 ounce; alcohol, 1 ½ pints. Place the soap in the alcohol and digest on a sand-bath; when the soap is dissolved, add the ammonia, oils, and camphor; agitate until they are dissolved, and immediately pour into wide-mouthed vials. When cold, this liniment becomes of a semi-solid consistence.
This liniment assumes an appearance of solidity, which is owing to its formation with a soap made with animal oil, instead of one with vegetable or olive oil. It is yellowish-white, translucent, and becomes fluid at the temperature of the body. Before cooling it is usually placed in 2 or 4-ounce vials with wide mouths, and is known by the name of Opodeldoc. The Opodeldoc of the U. S. P. (1850) was prepared by digesting, on a sand-bath, common soap (sliced), 3 ounces, in alcohol, 1 pint. When dissolved, add camphor, 1 ounce; oils of rosemary and origanum, each, 1 fluid drachm. Pour into wide-mouthed bottles. There are other formulas for opodeldoc. The National Formulary directs:
LINIMENTUM SAPONATO-CAMPHORATUM (N. F.), Camphorated soap liniment, Opodeldoc, Solid opodeldoc: "White castile soap, dried and powdered, seventy-five grammes (75 Gm.) [2 ozs. av., 284 grs.]; camphor, twenty-five grammes (25 Gill.) [386 grs.]; alcohol, nine hundred and fifty cubic centimeters (950 Cc.) [32 fl℥, 59♏]; oil of thyme, three cubic centimeters (3 Cc.) [49♏]; oil of rosemary, six cubic centimeters (6 Cc.) [97♏]; stronger water of ammonia ( U. S. P.), fifty cubic centimeters (50 Cc.) [1 fl℥, 332♏]. Introduce the castile soap, camphor, and alcohol, into a flask or suitable bottle, and apply a gentle heat until solution is effected, taking care that no loss of alcohol be incurred by evaporation. Filter the liquid, while hot, into another flask or bottle; warm again, if necessary, to render the contents liquid, add the oils and stronger water of ammonia, and when the whole has been thoroughly mixed, pour it into small dry vials, which should have been previously warmed, and should immediately be corked and cooled. Note.—The quantity above given is usually divided into from 18 to 20 vials. Solid opodeldoc is directed by the German Pharmacopoeia to be prepared with soap made from animal fats; but pure, white castile soap may be used, provided it has been previously deprived of water. The stronger water of ammonia should be of the full strength prescribed by the U. S. P."—(Nat. Form.).
Action and Medical Uses.—Camphorated soap liniment is an excellent anodyne embrocation in all local pains, rheumatism, contusions, sprains, sore throat, etc.