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method of mixing them is by trituration in a mortar. The latter should always be employed except in the case of substances which may explode if so treated, as Potassium Chlorate with oxidizable substances. (See ante, page 457.) The Diluent best employed in powders is Sugar of Milk, on account of its hardness, its density and its comparative insolubility. A coloring agent, as Carmine in minute quantity, is a useful ingredient, enabling the eye to judge of the degree of mixing and subdivision obtained. Powders containing soluble salts, extracts, volatile oils, camphor, or any other hygroscopic or volatile substances, should be dispensed in waxed paper. For ordinary powders the plain white paper of the drug stores will answer, but a better paper for small powders is one having a high surface finish and made very thin, as the white glazed French demy. Powders are often ordered in Wafers (Cachets), to be swallowed without unfolding. The division of powders into the number of papers (Chartula) ordered, and folding them neatly, requires a considerable amount of practice. A small machine is used over which the ends of the papers are bent, in order to have them of the proper size for the box in which they are usually dispensed. If they are to be put into an envelope less exactness of folding is required, and the mechanical contrivance may be dispensed with.

SUBSTANCES Suitable to administration in the form of powders are those which are insoluble, those which would be chemically incompatible in fluid form, and certain pulverizable extracts. Those which are unsuited to this form are such as have a very nauseous taste or odor, substances of which the dose is large, those which are deliquescent, efflorescent or very volatile, and those which liquefy on mixing. A list of deliquescent and efflorescent salts is found on page 474, while the following named, though dry alone, become moist when triturated together, viz :—

Sodium Sulphate and Potassium Carbonate.
Zinc Sulphate and Lead Acetate.
Camphor and Chloral Hydrate.

Many substances cannot be powdered without the intervention of another body thus Opium requires a hard substance like Sugar of Milk or Potassium Sulphate, Camphor requires a minute quantity of Alcohol, Myrrh needs Sugar or Gum, etc. Substances, as the alkaloids and their salts, which are very active and are used in very small doses, require some inert substance to give them bulk enough for division and handling. Sugar of Milk will be found the best agent for this purpose. Prescriptions may order the ingredients for a single powder, with directions to dispense a certain number of the same composition; or they may give the quantities for the whole number of powders ordered, with instructions to divide into a certain number. The dispenser should carefully scan the prescription in order to avoid the multiplication of quantities where divi

sion is intended. The official powders are enumerated on page 439; and the following formula will serve to illustrate those generally prescribed :—

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COMPRESSED PILLS are really powders which have been compressed into pill shape by machinery. A little pressure from the blade of a spatula will restore them to powder form. (See ante, page 475.)

Triturations (Triturationes),—are powders containing minute doses of very active agents diluted with Sugar of Milk, and possessing a definite relation between the active ingredient and the diluent, namely, 1 in 10, according to the general formula of the U. S. Pharmacopoeia, which, as well as the one official trituration, is described on page 440. Sugar of Milk is employed as the diluent because of its hardness and its comparative insolubility. The first of these qualities secures the fine comminution of the active ingredient whereby the action of the medicine is increased and better distributed. Its insolubility makes it the best diluent for powders or triturations administered from a spoon or glass with fluid, as is so often done, for unlike cane sugar it is not readily dissolved and does not leave the active substance behind on the surface of the utensil. Triturations are excellent forms for the administration of powerful alkaloids, which may thus be divided with great accuracy into the minute quantities required. Mercury and its salts are especially adapted to this method of preparation, being more uniformly divided and hence more active than when administered in any other form. Triturations of mercury with sugar were commonly used in England a

hundred years ago, and triturations of many substances were employed by the Arabian physicians of the 13th century. But the subsequent adoption of these preparations by the homoeopathists produced such a prejudice against them in the ranks of the regular profession that until recently any one using them stood in danger of being stigmatized as a homœopath. Their recent recognition by the U. S. Pharmacopoeia under their proper title does away with any such implication, though it is much to be regretted that the compilers of the last revision of the British Pharmacopoeia should have shown their fear of a name by continuing 'the title "Pulvis Elaterini Compositus" to designate a preparation which in every respect is a trituration. The preparations of Pepsin daily prescribed by physicians all over the country are really sugar-ofmilk triturations of that ferment, and not pure Pepsin as many suppose. Prof. H. G. Piffard, Med. Dept. Univ. of the City of New York, in his treatise on the Materia Medica and Therapeutics of the Skin (N. Y., 1881), after detailing several microscopical examinations of pills and triturations, uses the following language:

"It is to be expected, therefore, that the protoiodide trituration will prove, ceteris paribus, more active than the pill, and such we have found it. . . . Iodides of Mercury Since we have used the triturations, however, in preference to the ordinary pills, patients more rarely complain of disagreeable sensations. We have been enabled to materially reduce the size of the dose in order to obtain the desired effect. In other words, a larger proportion of the drug is utilized for specific purposes, while but a small amount remains to give rise to local irritation. . . . . I have nothing to add to this, except that I continue to use triturations of Mercury and other substances with increasing satisfaction. Beside those mentioned I employ Calomel, Cyanide of Mercury, Black Oxide of Mercury and Corrosive Sublimate in this form."

The following examples will illustrate the mode in which Triturations. may be prescribed:

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Suppositories (Suppositoria), -are small, conical, medicated bodies intended for introduction into the rectum, uterus, or urethra (bougies), occasionally into the vagina. No official suppositories are enumerated, but a general formula is prescribed by the Pharmacopoeia for their preparation (see ante, page 440). The basis is usually Cacao-butter, but for those intended for the urethra or uterus a mixture of Gelatin and Glycerin

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is considered the best excipient, being firmer and more plastic than cacao-butter, and more easily handled. Hollow cones of cacao-butter, or some composition resembling it, are kept in the shops, and will be used by the average druggist in filling prescriptions for rectal suppositories unless prohibited, as they save him considerable labor; the active drug being simply placed in the centre of the cone which is then sealed with a plug fitting in its base. These contrivances are by no means so efficient as the regular suppository, in which the medicinal agent is thoroughly incorporated with the excipient, for the former smear the rectum with a quantity of melted grease before the active portion of the preparation is permitted to come in contact with its walls. The agents used in suppositories are chiefly extracts and alkaloids; some few powders, and a few metallic salts are occasionally employed. Those for the adult rectum should contain from 15 to 30 grains of the excipient, for the vagina a drachm of cacao-butter is the average quantity. Those for the uterus and urethra are made of cylindrical instead of conical form, and about the diameter of a No. 9 catheter.

The methods of compounding suppositories are two, viz. :-that by the use of moulds (the official method), and that by hand. The former process is described on page 440, but many prefer the hand method, which is as follows: The medicament is mixed with finely shaved Cacaobutter by the aid of a spatula on a board or tile lightly dusted with Lycopodium or Starch. After a smooth and uniform mixture is thus obtained, the mass may be rolled into cylindrical form, cut into the required sizes and with the spatula given the required shape. When dispensed, they should be placed in a powder-box, between layers of


Bougies or Pencils, as urethral and uterine suppositories are often termed, may be prepared by melting together White Gelatin 3, Glycerin. 1, and Distilled Water 1 part by weight, then adding the medicament, and drawing the mass into a glass tube previously oiled inside. When cold the bougie may be pushed out and cut into suitable lengths.

The Br. Pharmacopoeia describes 8 official suppositories, as follows, viz. :

Suppositoria Acidi Carbolici cum Sapone,-Carbolic Acid, 12 grains; Curd Soap, in powder, 180 grains; Glycerin of Starch, 40 grains; to make 12 suppositories, each containing I grain of Carbolic Acid.

Suppositoria Acidi Tannici,-Tannic Acid, 36 grains; Oil of Theobroma, 144 grains; to make 12 suppositories, each containit g 3 grains of Tannic Acid.

Suppositoria Acidi Tannici cum Sapone, lannic Acid, 36 grains; Glycerin of Starch, 30 grains; Curd Soap, in powder, 100 grains; Starch, in powder, q. s.; to make 12 suppositories, each containing 3 grains of Tannic Acid.

Suppositoria Hydrargyri,-Mercurial Ointment, 60 grains; Oil of Theobroma, 120 grains; to make 12 suppositories, each containing 5 grains of Mercurial Ointment.

Suppositoria Iodoformi,―lodoform, 36 grains; Oil of Theobroma, 144 grains; to make 12 suppositories, each containing 3 grains of Iodoform.

Suppositoria Morphina,--Morphine Hydrochlorate, 6 grains; Oil of Theobroma, 174 grains; to make 12 suppositories, each containing grain of the Morphine salt.

Suppositoria Morphine cum Sapone,-Morphine Hydrochlorate, 6 grains; Glycerin of Starch, 30 grains; Curd Soap, in powder, 100 grains; Starch, q. s. to make 12 suppositories, each containing 1⁄2 grain of the Morphine salt.

Suppositoria Plumbi Composita,-Acetate of Lead, 36 grains; Opium, in powder, 12 grains; Oil of Theobroma, 132 grains; to make 12 suppositories, each containing 3 grains of Lead Acetate and I grain of Opium.

Suppositories and Bougies may be prescribed in the manner illustrated by the following formula:

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Ointments (Unguenta) and Cerates (Cerata),-are frequently ordered on extemporaneous formulæ, though the 34 official preparations of these classes (see ante, pages 440, 441) would seem to give the physician a sufficiently wide field for selection. The basis used is usually either the official Ceratum or Unguentum, but Petrolatum, Lard, Lead Plaster with a fixed oil, etc., may be used. Lard is probably the best basis for all ointments, as it softens the skin better than any other similar substance. Its disadvantage is that it soon becomes rancid, so that preparations made with it must be quickly used. Cerates only differ from ointments in their firmer consistence, melting at temperatures above 104° F., while the latter melt below the ordinary temperature of the body. Oleates are described fully on page 72.

The process of compounding an ointment or a cerate is sufficiently simple, being generally a mere matter of triturating the ingredients together in a mortar, or of their incorporation on a slab by means of a spatula. Rarely will melting be required in the compounding of extemporaneous ointments. When extracts, powders or gritty substances are ordered, the ingredients should be first pulverized into a fine powder, then triturated with a small quantity of the basis into a smooth, impalpable paste; the

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