Preparation and History.—Eclectic physicians prefer liquid remedies when practicable, objecting to any form of pill, tablet, or confectionary, especially of galenicals. "The points demanded to prepare a proper pill mass are, to obtain sufficient consistency that the particles may cohere together, and to have them firm enough to retain a globular form; their component parts should be such as to prevent any tendency to moldiness, or any absorption of moisture when exposed to the atmosphere. Medicines which are deliquescent should never enter into a pill mass, and efflorescent salts should be previously exposed to heat so as to fall to powder, by the removal of their water. Ingredients which have a chemical reaction upon each other should not be added together in a pill mass, unless it be desired to secure the influence of the resulting compound.
"Gum-resins and inspissated extracts are sometimes soft enough to be made into pills without addition; where any moisture is requisite, a few drops of alcohol is more proper than syrups or conserves, as it unites more readily with them, without sensibly increasing their bulk. In some instances, where alcohol will not act upon the mass, water may be substituted" (Coxe).
Substances which do not admit of being made into a pill mass by themselves, must have certain inert matters added to them, called excipients, and such excipients only should be employed as will give the proper degree of consistence and tenacity to the mass, without interfering in any way with the action of its medicinal agents or rendering the pills too large or hard. Excipients vary much in their character, according to the nature of the articles to be made into pill form; the most common are syrup, glycerin, mucilage, soap, bread-crumb, conserve of roses, water, spirit, gum, sugar, magnesia, starch, molasses, etc. The dry excipients are used to give the required firmness to extracts, confections, oils, and other fluid or soft substances, while the moist excipients are intended for dry medicines, or agents which are insoluble, and among these molasses, syrup, and conserve of roses are the most esteemed, especially when the pills are to be kept for a length of time.
The addition of too much gum Arabic or tragacanth to the pill mass, is objectionable, as it often causes the pill to become so hard as to materially modify its operation, or perhaps cause it to pass through the intestines without being dissolved. Whenever the excipient is named by the physician in his prescription, the apothecary should adopt it if practicable; but, if it be not practicable, then he must follow his own judgment. Indeed, it would always be better in prescribing extemporaneous preparations of pills, if the physician would omit the excipient, and leave it to the more practical knowledge of the apothecary to supply the appropriate excipient.
The best excipients for dry powders, as jalap, rhubarb, ipecacuanha, ginger, digitalis, conium, etc., are molasses or conserve of roses; those for resinous extracts, resins and gum-resins, are soap, proof-spirit, alkaline solutions, and sometimes mucilage; and those for the volatile oils and oleoresins, are soap, magnesia, white wax, etc. The proper selection of these, however, depends entirely upon the peculiar nature of the medicines ordered, and requires a considerable degree of practical knowledge, not expected to be possessed by the practicing physician.
The medicinal ingredients of the pill mass should be perfectly mixed and incorporated, usually combining together the active ingredients first, and afterward the excipient, and the mass should be worked in the hand, on a pill slab, or in a mortar, until it is thoroughly homogeneous. If the mass be too hard, it may not be dissolved in the juices of the stomach; if too soft, there will be difficulty in forming it into pills. The pill mass being properly formed, is now to be divided into pills; certain portions of it are, by means of a spatula, or by the pill-machine, made into long, round, slender rolls, of the desired thickness, which are then divided into pills. If the pill-machine be used, the pills are accurately divided and made globular at the same time; if the spatula be used, the pills are to be rounded by the fingers. Most apothecaries are furnished with the pill-machines, which serve to expedite the process, as well as to secure a greater degree of accuracy.
Pills containing vegetable drugs usually weigh from 1 to 5 grains; containing heavy mineral preparations, 5 to 10 grains. A larger pill than these is denominated a bolus; a very small, sugar-coated pill, a granule.
PILL-COATING.—In order to cover the taste and odor of pills many plans have been devised; formerly they were covered with gold or silver leaf, but this is a very objectionable method, as pills thus prepared frequently pass through the bowels without being dissolved. Another mode is to dip each pill in a melted solution of pure glue, but this plan is tedious and requires considerable time for the drying of the pills. Collodion has been recommended as an agent for covering pills, but as the collodion will not readily dissolve in the stomach, its employment would be improper. Sugar is frequently used, combined with gum Arabic, and sometimes starch is likewise added, the proportions of each article being the same; the pills to be dipped in a thin syrup, and then rolled in the mixture. This process is most applicable to disagreeably odorous substances, as castor, asafoetida, valerian, etc., which are completely masked by it. When the gelatin is previously colored with carmine, the pills resemble hawthorn berries.
M. Calloud treats of the subject of enveloping medicinal substances in a covering to prevent unpleasant taste, in Jour. de Pharm., Vol. XXIII, p. 301. He had recourse to the dried mucilage of flaxseed prepared with sugar. His method is: Take of flaxseed, 1 part; white sugar, 3 parts; spring water, a sufficient quantity. A thick mucilage is obtained by carefully boiling the seeds, the sugar is added, and the whole of the moisture evaporated by careful desiccation. The mixture is but slightly hygroscopic, may be reduced to fine powder, and employed for covering pills. This operation is effected extemporaneously with great facility. The pills, slightly moistened, are rolled in the mucilaginous powder, by which they are coated with a layer of the compound.
M. Calloud suggests another process, applicable in certain cases, which is the use of butter of cacao as a covering for pills, where, owing to gastric irritation, the unmasked pills will cause disagreeable symptoms. The process is very simple; the prepared pills are thrown into melted butter of cacao, then removed with a perforated skimmer, and finally rolled in finely-powdered sugar, or what is better, sugar of milk. He also prepares a powder, in which the pills, previously dampened externally with water, are agitated until sufficiently coated; it is prepared by mixing a clear mucilage of tragacanth (made of tragacanth, 1 part; water, 2 parts) with sugar of milk, 20 parts; spreading this thinly upon plates, and, when thoroughly dried, pulverizing it.
Blanchard's method, as improved by Baildon, consists of using a solution of balsam of tolu, 1 drachm, in chloroform, 3 drachms. Some of this is placed in a suitable box, the pills agitated in it, then turned upon a slab, and so arranged that they do not touch each other. In about 20 minutes they are dry and non-adhesive, and present a finished appearance. It not only conceals any unpleasant taste or smell, but it prevents the pills from becoming too hard (Amer. Jour. Pharm., Vol. XXIX, p. 350).
The foregoing remarks are largely historical, and record the method of pill-coating in the apothecary shops, and may be useful still when it is desirable to coat a few pills extemporaneously. But, at present, the coating of pills is done on a large scale by manufacturing pharmacists, who supply not only simples, but compounds of every description capable of being made into pills. Two forms of pill-coating are used—sugar and gelatin—of which we prefer the latter. Sometimes admixtures of foreign bodies are employed, such as chalk or starch, and, in some cases, the pills are given a coating of shellac or rosin previous to the sugar. This is to prevent coloring of the sugar-coat, and is to be objected to because of its insoluble nature. The methods of each manufacturer are in part peculiar to himself, and are derived from his experience and skill, but all are an outgrowth of the hand-coating processes mentioned in this article.
Mr. H. C. Archibald describes the method pursued by manufacturers in sugarcoating pills and granules, in Amer. Jour. Pharm., 1867, p. 199; and, in the same journal, 1867, p. 12, Prof. E. Parrish makes known a, new process for preparing sugar-coated pills, but which is only practicable on a large scale. (For other excipients and coatings, see following pill formulae.)
PILL-DUSTING.—Several substances are used for covering pills to prevent them from adhering to each other, as powdered elm-bark, powdered orris or liquorice roots, lycopodium, carbonate of magnesium, starch, etc., and these powders are also used during the formation of the pill to prevent them from sticking to the fingers or to the apparatus on which they are made. The powders ordinarily used are liquorice, lycopodium, and elm. Carbonate of magnesium can only be used in those instances where it occasions no decomposition with one or more active constituents of the pill.
COMPRESSED PILLS.—This class of preparations is usually prepared by means of a proper instrument, by compression of the desired material, in powder, without the addition of an excipient. Powders which are not deliquescent, yet easily soluble in water, are best adapted for compressed pills. Occasionally, for the sake of rendering the substance more easily compressible, or to facilitate the removal of the pills from the mold or instrument employed, very dry materials are combined with a very little of petrolatum, sugar, cacao butter, or alcohol. These pills are generally of lenticular shape. (See Remington's and Coblentz's Prac. of Pharm.)
PRESERVATION.—Pills are much better preserved in small, loosely-stoppered glass bottles than in the common wood or pasteboard boxes, and should be dispensed in glass vials by the apothecary. As it is not always convenient to make a large amount of pill mass into pills at one time, the balance may be kept in a bladder, which should be moistened occasionally with some of the same kind of liquid the mass was made up with, or with some aromatic oil.
TABLET TRITURATES.—These are made by compressing mixtures of powders or of simple substances in powder form into discs of variable size and shape. They are open to many objections as medicinal representatives of drugs, and can not carry the values of substances which either disintegrate or evaporate on drying. For this reason, they can not correctly represent a large class of natural drugs. Tablets are easily made, and their manufacture, on a large scale, might properly become a part of the confectioner's art. In our opinion, for all plant preparations, such as extracts, gelatin-coated pills are preferable and fully as elegant. For such simples as chemicals, that do not alter by action of the air, tablets are suitable, providing they are not stamped so hard as to prevent them from dissolving. Great discrimination should be employed in the use of tablets, and if the physician is not qualified to judge of the remedy's nature, he should be very cautious concerning its use in tablet form. Sugar and other inert substances are employed in the making of tablets to give bulk to energetic bodies. In our opinion, much injury has been done by the indiscrete attempt of tablet makers to put into tablet form remedies that deteriorate or are destroyed by drying. These general remarks on tablets are offered in this place because of the fact that we have no special department for them.
Ɣ PILULAE (N. F.), Pills.—"In giving the formulas for pills, the quantities of the several ingredients required for one hundred (100) pills are given in metric weights in the first column, while the quantities required for each single pill are given in apothecaries' weight in the second column. When it is desirable to prepare a number of pills by the proportion given for the single pill, it is recommended that, upon multiplying by the number of pills required, the nearest whole number, or nearest convenient fraction, in each case, be chosen"—(Nat. Form.).
This arrangement has been altered in this work so that the figures representing the amount in each pill follow the general formula. This is done to save space.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.