This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Sensible and Chemical Properties. The solution is a colourless liquid, of a sweetish and astringent taste, of the sp. gr. 1.267 as prepared by the U. S. process, and of an alkaline reaction. Exposed to the air, it absorbs carbonic acid, forming the carbonate of lead, which is deposited at the bottom and on the sides of the vessel. Its constituents are known by the same tests as those of the neutral acetate, from which it is distinguished by forming a heavy white precipitate with solution of gum arabic, which is not affected by that salt, and by being more copiously precipitated by carbonic acid.
Incompatibles. These are the same as those of the neutral acetate, with the addition of pure gum arabic, and certain mucilages, as those of sassafras pith and flaxseed, which are strongly precipitated by the diacetate, while, though in some degree affected by the neutral salt, they are scarcely sufficiently so to be incompatible with it. Gum mezquite, brought into notice some years since by Dr. Shumard, as a product of New Mexico, though strongly resembling gum arabic in many of its properties, does not, according to Professor Procter, yield a precipitate with the solution of subacetate of lead.
This solution has all the effects on the system of the other preparations of lead, but in this country and Great Britain is seldom if ever given internally. In France, it has been prescribed by M. Boudin, with some success, in the vomiting of epidemic cholera.
Its local effects are the same as those of the acetate, but probably somewhat more intense. In France, it is much employed for all the purposes for which the acetate is used locally with us; for example, as a collyrium in ophthalmia; as an injection in morbid discharges from the nostrils and ear; as a mouth-wash and gargle in different forms of angina and stomatitis; as an enema in chronic mucoid or purulent discharges from the rectum, with or without ulceration; and as a topical remedy in leucorrhoea and gonorrhoea. I have long been in the habit of using acetate of lead, by injection, in cases of acute dysentery affecting especially the rectum. M. Barthez has successfully used the solution of the subacetate in the same way; and the practice has been extended to acute diarrhoea and epidemic cholera, with satisfactory results. Vast quantities were injected, largely diluted with warm water, without any unpleasant constitutional effect; the liquid producing its local impression upon the mucous membrane, but not being retained long enough to be largely absorbed. M. Barthez administered at first somewhat more than a drachm in 100 times its weight of water; but afterwards increased the quantity to one, two, and even three ounces in one injection, without poisonous effects.* (Trousseau et Pidoux).
In this country, the use of the solution of subacetate of lead is confined chiefly to superficial inflammations, either of the skin, the subcutaneous cellular tissue, the lymphatic glands, the tendons and aponeuroses, or the more superficial vessels, whether absorbents or veins. In the inflammation of sprains, bruises, wounds, etc.; in the more inflammatory states of certain cutaneous eruptions, as erythema, erysipelas, eesema, herpes, and impetigo; in burns, blisters, and excoriations; and in various ulcerative affections attended with irritation, inflammation, excessive secretory discharge, or hemorrhage; it may be used as an antiphlogistic, astringent, anodyne, or haemostatic. For the purposes above mentioned, the preparation is usually employed very much diluted, as in the form of the officinal diluted solution.
In France, it has recently been recommended, in very strong solution, in mercurial salivation; not less than a sixth, or an eighth part being used in the mouth-water or gargle employed; and a preparation of equal strength is recommended in leucorrhoeal discharges, especially connected with superficial ulceration of the neck of the uterus, being applied by means of a sponge or roll of linen saturated with the liquid.
* The sp. gr. of the present French preparation is 1.32, while that of the U. S. Pharm. is 1.267; so that the former is considerably stronger than the latter.
Great success has been claimed, in the treatment of the inflammation and fungous growth connected with inverted nail, for the solution of subacetate of lead, applied by separating the nail from the flesh, and every hour, two, or three hours, dropping into the vacant space two or three drops of the liquid; the parts in the mean time being covered with a pledget of raw cotton wet with the same liquid, and the cotton changed every day.
The following are preparations of the solution now under consideration.
This dilute solution, usually called lead water, is at present made by adding three fluidrachms of the strong solution to a pint of water. The carbonic acid in the water causes some turbidness in the diluted preparation, which does not, however, interfere with its virtues. The strength of the diluted solution may often be much increased with advantage; and from half a fluidounce to a fluidounce may be employed to each pint, with perfect impunity, when the cuticle is unbroken. Local paralysis is stated in the books to have resulted from its use; and, though this must be extremely rare, as I have never witnessed nor heard of a well-authenticated case of it, still some caution should be exercised in applying the solution to abraded surfaces. It may be applied by means of linen cloths, or in the form of the cold poultice, as the solution of acetate of lead.
This consists of the solution of subacetate of lead, incorporated with wax, olive oil, and a very little camphor. It is an excellent preparation, admirably calculated to produce the local effects of lead, in cases in which the cuticle is wanting. Irritable, inflamed, and painful ulcers are often relieved by it; while by its astringency it favours desiccation in those which are copiously suppurating, and disposes the loose and flabby to take on the healing process. In blisters, burns or scalds, chilblains, intertrigo and other forms of superficial abrasion or excoriation, herpetic, ecze-matous, and impetiginous eruptions with serous or puruloid discharge, and a similar condition in lichen agrius and other cutaneous affections, it is one of the best applications that can be made. I know nothing equal to it as a dressing for blisters indisposed to heal. In many instances, and particularly in the one last mentioned, it may be combined at first with an equal weight of simple cerate. The caution should always be observed not to employ it in a rancid state, in which it becomes irritant. Hence it should be made with perfectly sweet oil, and used as fresh as possible. It is sometimes combined with opium, or calomel, or both, as an application in skin diseases of a local character.
This was made, according to the Pharmacopoeia of 1850, by boiling the solution of subacetate of lead with soap, and, after due evaporation, adding wax and olive oil. The process yielded a fine white cerate, capable of being spread by a knife upon linen or muslin. The present Pharmacopoeia prepares it by melting lead plaster with wax, and adding olive oil to the mixture. Soap cerate is a mild sedative and desiccant preparation, applicable to similar purposes with the preceding, and employed in scrofulous swellings, and other external inflammations.