CHAPTER XXVIII.

PILLS.

PILLS are a very convenient mode of administering medicines, the chief advantage lying in the small bulk to which the medicine is reduced and the almost complete disguise of bitter and nauseous remedies, by reason of their being swallowed without previous mastication. Pills are admirably adapted for the administration of heavy metallic substances not readily suspended in liquids, and also in cases in which the action of the medicine is to be slow, or even retarded until it reaches the lower bowels. The usual shape given to pills is that of a sphere or globe, although an ovoid shape is also sometimes used, and, in a few cases, even the lenticular shape is preferred. Their weight ranges from less than 0.06 Gm. to 0.3 Gm. (1 gr. to 5 gr.) for vegetable substances, or about 0.5 or 0.6 Gm. (8 to 10 grains) for heavy mineral compounds; if a pill exceeds this weight it is called a bolus. Boluses are occasionally made weighing 1.3 or 2.0 Gm. (20 or 30 grains) each and are often of a softer consistence than pills. Very small pills coated with sugar, are called granules.

Although of late years the extemporaneous preparation of pills has materially decreased, and in some localities has almost entirely disappeared, the operation must yet be considered one of the most important pharmaceutical manipulations, and is deserving of a lengthy discussion, because the opportunities for a practical acquaintance with the details of the work are growing less day by day, owing to the untiring efforts of manufacturers to induce physicians to specify factory-made pills on their prescriptions.

The most important step in the preparation of pills is the formation of a proper mass, which should consist of a paste, sufficiently plastic to admit of being moulded without adhering to the moulds, yet firm enough to prevent the pills from losing their original shape. Although a firm consistence should characterize every wellmade pill mass, its ready disintegration and solution in the fluids of the stomach and bowels, are of paramount importance, and it is essential to so unite the ingredients of a pill-mass that ready separation in the stomach may be assured. Plasticity is that peculiar condition in which adhesiveness and firmness are properly balanced; the former of these properties is due to a partial softness, which enables the particles of the mass to adhere to each other, thus imparting tenacity to the whole. Some substances possess this adhesiveness in themselves, but require the addition of a liquid-water or alcohol-in order to develop it; as, for instance, gums and resinous drugs. Other

substances possess no inherent adhesive properties, and, in such cases, it becomes necessary to impart tenacity to them, by the addition of some adhesive liquid or solid material; such substances are camphor, calomel, bismuth salts, some saline or vegetable powders, reduced iron and the like. Firmness in a pill-mass is as essential as adhesiveness, and, while the latter is brought about by a state of partial solution or fluidity, so, inversely, the insolubility of some particles is necessary for the required firmness. The substances added to pillmasses as adhesive or absorbent agents are known as excipients, and must be employed judiciously, so that the constituents of the mass be not modified in their action nor the bulk unnecessarily increased. After each addition, the mass should be well kneaded, which, itself having a softening influence, by reason of the heat generated, enables the operator to judge of the true condition of the mixture. Whenever possible, all constituents of a pill-mass should be reduced to very fine powder, before the addition of any excipient, as only in this condition can the homogeneity of the mass as well as the subsequent accurate division of doses be assured. Small quantities of potent remedies, such as alkaloids, narcotic extracts, toxic chemicals, etc., are preferably triturated with a little sugar of milk, before mixing them with the other ingredients, to facilitate uniform distribution.

Whenever substances are ordered in a pill-mass, in quantities which it is impossible or inconvenient to weigh accurately, as for instance, aconitine 0.001 Gm., digitalin 0.003 Gm., veratrine grain, strychnine grain, etc., a dilution of the substance should be made with sugar of milk, in such proportions that a conveniently weighable quantity shall contain the desired amount of the active ingredient. Thus, if 0.001 Gm. of any substance is wanted, carefully triturate 0.010 Gm. of the substance with 0.090 Gm. of sugar of milk (or 0.050 with 0.450 Gm. if more convenient); each 0.010 Gm. of the mixture will then contain of 0.010, or 0.001 Gm. of the medicinal

agent. If of a grain of any substance is needed, triturate grain of it with 5 grains of sugar of milk (or 1 grain with 11 grains), and each grain of the mixture will contain grain, 2 grains will contain grain, or 1 grains will contain grain of the active ingredient. In like manner any other fractional part of a centigramme or a grain may be readily obtained.

Pill-masses should always be made, according to the nature of the mass, either in iron or Wedgewood mortars, of the shape shown in Figs. 207 and 208, and the mixture should be frequently scraped down with a stiff spatula so as to bring all particles repeatedly together under the pestle. Trituration by means of a pestle is essential to produce a uniform mixture of the ingredients, and moreover it will be found that a mass can be formed in less time, with less excipient and less labor, in a mortar than on a pill-tile; very simple combinations, such as blue mass and extract of colocynth, etc., may be effected on the pill-tile, but, for all substances requiring uniform blending of fine powders, and similar cases, the use of the tile is to be condemned. Unfortunately the misuse of the pill-tile is a characteristic of many American pharmacists. One rule should be strictly observed in making every pill-mass, namely: Never use

the spatula with which the mass is scraped down for taking excipient from its container.

Large quantities of pillmasses which cannot be conveniently handled in the mortar are best made in a special apparatus known as a pill-mixer, operated either by hand

Power machine for mixing pill-masses.

or steam-power. As a rule, these kneading machines consist of smooth iron rollers (for white pill-masses hard-wood rollers are generally

used), which revolve in opposite directions, some being so constructed that they can be heated, if necessary, by passing steam through them. The ingredients for the mass are first roughly mixed in a basin or tank and then repeatedly passed between the rollers until a uniform mixture been been produced. In Figs. 209 and 210 are shown two sizes of iron mixers for pill-masses, made by J. H. Day & Co, of Cincinnati, the smaller one having a capacity of three pounds and the larger of thirty pounds. The tanks are porcelain lined, and the corrugated rollers or mixers are galvanized. As shown in the illustrations, the machines are easily opened and taken apart for cleaning purposes. While mixing a mass the rollers turn toward each other, and while emptying, from each other. The finished mass can be easily removed by tilting the machine and at the same time causing the rollers to revolve slowly in a reverse direction.

EXCIPIENTS. It being impossible to select one single substance as an excipient suitable for all pill-masses, owing to the variable properties of drugs and the many different combinations ordered by physicians, it is essential that the pharmacist be familiar with the peculiarities of each excipient, in order to use the same intelligently and advantageously. Excipients for pill-masses may be divided into three distinct classes, as follows:

1. Those which are intended to develop adhesiveness, and hence act as solvents. To this class belong water, alcohol, diluted alcohol, glycerin, and a mixture of glycerin and water.

2. Those which are intended to impart adhesiveness; these may be fluid, semi-fluid, or solid. To this class belong syrup, glucose, honey, mucilage and syrup of acacia, mucilage of tragacanth, glycerite of starch, acacia with glucose or honey, tragacanth with glycerin, soap with water or diluted alcohol, extract of malt, confection of rose, manna and powdered elm bark mixed with tragacanth; the last named requires the addition of syrup or glycerin and water. 3. Those which are intended to act simply as absorbents of excessive moisture and, in a few cases, impart adhesiveness to the mass at the same time. To this class belong powdered liquorice root, soap and liquorice root, calcium phosphate, powdered orris root, powdered tragacanth, powdered elm bark, starch and powdered marshmallow.

The first class, solvents, are employed in many cases in which physicians have ordered vegetable powders in connection with soap or solid extracts, the latter in insufficient quantity to form a good mass. Solvents must be added to pill-masses with great care, especially when water or glycerin is used with soap or extracts; by adding the fluid in drops and working the mass well after each addition, the required consistence will soon be developed, and a firm, yet plastic mass, be obtained, while an excess of moisture causes a softening of the mass, which frequently increases, and prevents the formation of perfect pills, besides requiring the addition of absorbent powders, which add to the bulk of the mass.

The second class, adhesive excipients, are more extensively used than any other, because the majority of substances prescribed in pill form do not possess inherent adhesive properties, or at least insufficiently, for properly massing the ingredients. Mucilage and syrup of acacia are the least desirable of the class, unless the pills are for immediate use, as pills made with acacia are apt in time to become very hard; the addition of glycerin, however, obviates the difficulty. Syrup or glucose is usually preferred to water for massing vegetable powders, in the absence of soap or solid extracts. Tragacanth with glycerin can be most conveniently used in the form of a jelly, made by triturating 85 grains of powdered tragacanth with 6 fluidrachms of glycerin and 1 fluidrachm of water; it is an excellent excipient for the salts of quinine, salol, acetanilid, sodium salicylate, iodoform, calcium sulphide and also gallic and tannic acids, but for cinchonidine sulphate, or salicylate, acacia with glucose or honey is preferable. Soap with water or diluted alcohol, is the best excipient for aloes, rhubarb and the various gum-resins; it cannot, however, be used with soluble metallic salts as those of iron, lead, copper, etc., owing to the formation, by mutual decomposition, of metallic oleates, which cause the mass to crumble.

The necessary precaution regarding the use of water in conjunction with soap has already been mentioned in the preceding paragraph. Manna is very desirable for massing reduced iron or manganese dioxide, when these are prescribed alone. Extract of malt is very similar to glucose in its applicability, but can only be used for darkcolored masses. Confection of rose, at one time much esteemed as an excipient for mixtures of vegetable powder and metallic salts, has now almost gone out of use. For the valerianates of iron, quinine, or zine, no better excipient can be used than acacia and alcohol in the following proportions: Iron, quinine, or zine valerianate, 30 grs.; powdered acacia, 10 grs.; alcohol, 5 minims. Camphor and monobromated camphor can be made into very satisfactory pill-masses, by the addition of soap and oil of sweet almond or castor oil; about 1 grain of soap and 2 drops of oil will be sufficient for 12 grains of camphor.

As an excellent adhesive agent for heavy metallic salts, such as bismuth subnitrate or calomel, as well as for the scale salts of iron and troublesome combinations like capsicum, camphor and lead acetate, Mattison's excipient powder will be found very serviceable; it consists of 1 part of powdered tragacanth and 7 parts of finely powdered (No. 80) elm bark. Only a very small proportion of the powder is required, thus: 3 grains for 60 grains of bismuth subnitrate, calomel, cerium oxalate, iron by hydrogen, or equal parts of camphor and lead acetate; 6 grains of the powder for 60 grains of dried ferrous sulphate, the scale salts of iron, or equal parts of camphor and capsicum, etc. In all cases in which this excipient powder is employed, the mass should be made up rather soft with syrup, otherwise it is apt to crack or crumble while the pills are being formed