Complete Text (Part 35)

to which definite standards of strength may be fixed for plant drugs and their preparations, etc., but all details are of necessity entrusted to the Revision Committee. The Committee of Revision appointed by the decennial convention of 1880 and those appointed by the conventions of 1890 and 1900 all consisted of twenty-five members, about half of them physicians and the remainder pharmacists. The work of revising the pharmacopoeia usually occupies from two to four years, and when that work is completed, the officers of the convention make arrangements for its publication. 553. The medicinal substances included in the pharma- copoeia are those which in the judgment of the members of the Committee of Revision are of sufficient importance and sufficiently commonly employed to require that their identity, quality, purity and strength shall be regulated. But it may be said in a general way that simple drugs and substances of definite chemical composition are those entitled to a place in any pharmacopoeia, and that complex mixtures are generally excluded. The fact that a certain preparation is extensively used does not entitle it to a place in the pharma- copoeia, unless it is a rational preparation such as educated men licensed to practice medicine may consider useful. Nearly all pharmacopoeias still retain a small number of mixed nostrums which gained admission to the pharma- copoeias a long time ago, when the scientific principles along which pharmacopceial revision should proceed had not yet taken form. [One of the pharmacopoeias, for instance, still retains a preparation containing over fifty different ingredi- ents, the sole reason for its retension in that pharmacopoeia being that the preparation is still occasionally called for at PHARMACOPOEIAS 361 the drug stores by ignorant people. The presence of such compounds in any pharmacopoeia seriously detracts from its dignity and character, and it is evident that any preparation for which there is a demand may be made and sold whether it is contained in the pharmacopoeia or not. In the Ameri- can Pharmacopoeia there are forty or fifty preparations of a complex character or of doubtful utility that should be transferred to the National Formulary as unworthy of a place in the National Pharmacopoeia. These preparations include Lady Webster's dinner pills, Plummer's pills, Morrison's pills, paregoric, compound cathartic pills, Griffith's mixture, etc., all of which preparations disfigure the pages of any scientific pharmacopoeia. ] 554. As to the plant drugs contained in the pharmacopoeia, the Revision Committee is largely guided by what is known concerning the constituents found in them by chemical investigation. Any drug containing an alkaloid is necessarily a potent medicinal agent and might well be included in the pharmacopoeia, even if it is comparatively little used, whereas a plant known not to contain appreciable quantities of any of the classes of plant constituents to which medicinal value may be attributed should be excluded from the pharma- copoeia, unless other evidence of its utility is conclusive. Whenever any plant drug is introduced into the pharma- copoeia, provision should also be made for suitable prepara- tions of it, for physicians do not order crude plant drugs to be taken in substance. Such preparations as fluidextracts, tinctures, extracts and other rational pharmaceutical con- centrations or solutions are, therefore, introduced into the pharmacopoeia as the character of each drug may require. This rule has not been strictly observed in the past, for we find in the pharmacopoeia of 1890 such drugs, for instance, as wormwood and pokeberries, without any preparations of these drugs. 3G2 A CORRESPONDENCE COURSE IN" PHARMACY Iii past generations it was held that the pharmacopoeia should not recognize any new medicinal agent, but that the utility of a medicinal substance should be thoroughly demon- strated by many years of experience and observation before it could be consistently included among the official medicines. It was also held that any medicinal substance already intro- duced in the pharmacopoeia ought not to be dropped unless its use had been discontinued. However, more rational ideas prevail at present. 555. Any substance of definite chemical composition may be rationally introduced into the pharmacopoeia as soon as it is evident that it possesses physiological and medicinal effects indicating that it deserves to be tried in the practice of medicine. 556. It is no longer held that the presence of any given medicinal substance in the pharmacopoeia constitutes evidence of its value, nor is it held that the absence of any medicinal substance from the pharmacopoeia indicates that it does not deserve to be used, for it is now recognized that the func- tions of the pharmacopoeia are not to recommend or condemn medicinal agents, but simply to provide means by which their identity, purity and strength may be fixed, so that physicians may attain reasonably uniform results from their use. 557. If there were no pharmacopoeia or other means of establishing uniformity in medicinal agents, safe and scien- tific medication would be impossible. The tincture of digi- talis dispensed in one drug store should be of precisely the same potency as in another. In the pharmacopoeia of 1870 it was provided that opium in powder should contain not less than 10 per cent of morphine, but nothing was said, about the maximum amount of morphine which powdered opium may contain without rendering it unsafe. Some samples of powdered opium contain about 20 per cent of morphine. PHAKMACOPGEIAS 363 Hence under that pharmacopoeia it was possible for one pharmacist to dispense a powdered opium twice as strong as that dispensed by another pharmacist. Clearly, that phar- macopoeia failed in establishing a proper standard of strength for that drug. In 1880 the pharmacopoeia ordered that powdered opium should contain not less than 12 per cent nor more than 16 per cent of morphine, and it was, there- fore, possible while that pharmacopoeia was in force to obtain powdered opium in one drug store that was one-third stronger than the powdered opium dispensed in another drug store. In 1890 the Eevision Committee introduced in the pharma- copoeia our present standard of morphine strength for powdered opium, which provides that the drug shall contain not less than 13 nor more than 15 per cent, but clearly the most proper standardization of powdered opium would be one requiring an absolutely fixed percentage of morphine, above or below which no deviation should be permitted, since it is as easy to enforce such a rigid and uniform standard as it is to enforce variable standards, for, in order to fix the morphine strength of opium in any manner, the opium must first be assayed, after which poorer and richer opiums are mixed until the average complies with the pharmacopoeial requirements. Then the product can quite easily be made to have an absolutely fixed morphine strength. The Phar- macopoeia of 1900 makes the strength of opium from 12 to 12^ per cent of morphine. 558. With reference to tests for purity, absolute freedom from all impurities is not insisted upon, unless necessary, because small amounts of other substances may be present in medicinal agents without impairing their medicinal value, and in such cases the purity tests are so framed as to insure satisfactory results without imposing hypercritical standards which cannot be attained without great difficulty. 559. The essential distinctive features of the text of the 364 A CORRESPONDENCE COURSE IN PHARMACY pharmacopoeia are as follows : The titles, the definitions of the titles, the descriptions, the identity tests, the purity tests, the potency tests or quantitative tests, the working formulas, the directions for the preservation of the medicinal substances, the general directions, and the tables. 560. The titles of the medicinal substances in the pharma- copoeia are of two kinds — the Latinic title and the technical English title. The Latinic title is not Latin, except in a minority of cases ; it is simply Latinic in form. The reason for retaining at this day in the pharmacopoeia Latinic titles for the medicinal substances is the ease with which scientific technical titles can be constructed having a Latinic form, and the great difficulty which is encountered in the effort to construct scientific technical titles of any other kind. The Latinic titles are in most cases arbitrarily coined words, and their meaning is specific and fixed. In many pharmacopoeias the Latinic titles of plant drugs are their only technical titles, for the other titles of the plant drugs are merely the popular names current among the people. A great change has been made in the American Pharmacopoeia in this respect. Our pharmacopoeia formerly employed such titles as "deadly nightshade," "dandelion," "foxglove" and "German chamomile." It now substitutes for those names the technical titles belladonna, taraxacum, digitalis and matricaria. Much remains to be done, how- ever, to complete this commendable reform. There seems to be no good reason why in pharmacy and medicine we should not substitute the technical titles myristica for nutmeg, viburnum prunifolium for black haw (just as we have sub- stituted viburnum opulus for cramp bark), ulmus for elm, galla for nutgall, coccus for cochineal, allium for garlic, etc. The technical titles of plant drugs are usually the genus names of the plants from which the drugs are derived. In some cases they are old genus names now discarded by PHAKMACOPCEIAS 365 botanists, and in other cases they are species names now or formerly in use. The title of rhubarb is rheum, which is the botanical genus name of the plant yielding the root called rhubarb. The Latinic title of sweet flag is calamus, which is the species name of the plant acorus calamus, which yields the drug. But in some cases the Latinic titles have no connection with the botanical names; they are arbitrarily adopted and purely pharmaceutical titles. The word bucliu is used as a Latinic title and also as the English technical title for one of our much used drugs, but buchu is the name employed by the Hottentots to designate the drug. Tragacantha is the Latinic title of the gum which in English we call traga- canth, but the word tragacantha is not a botanical title. In some pharmacopoeias the Latinic titles of the plant drugs are generally made up of two words, one indicating the botanical source of the drug and the other the plant- organ or plant-part employed. For instance, the title of rhubarb is in such a pharmacopoeia rhei radix, which trans- lated into English means the root of rheum, whereas in the American Pharmacopoeia rhubarb is given the Latinic title rheum, which is considered sufficient, because the root is the only part of rheum that is medicinally employed. But when two different organs of the same plant are separately employed as drugs it is, of course, necessary that the pharmacopoeia should distinguish between them in the titles. Thus, our pharmacopoeia gives belladonna root the title belladonna radix and belladonna leaves the title belladonna? folia. In cases where two or more different species of the same plant genus furnish drugs, the genus name is, of course, insufficient to designate each drug. In such cases, the species name is used together with the genus name. The Latinic title of peppermint is therefore mentha piperita, and the title of spearmint mentha viridis. 3G6 A CORRESPONDENCE COURSE IN PHARMACY In naming Indian cannabis, which consists of the flowering tops of cannabis sativa grown in the East Indies, it is neces- sary to call it Cannabis Indica, because cannabis sativa grown in other countries does not constitute the drug. Sometimes the botanical titles of plants yielding drugs are modified in their endings to "transform them into specific titles for the drugs. The botanical title of the almond tree is primus amygdalus, but the seed or almond is called amygdala. In the British Pharmacopoeia the title for cloves is caryopliyllum, derived from the old botanical name "caryophyllus. " The titles of pharmaceutical preparations are generally made up of two words, one indicating the character of the preparation and the other giving the name of the drug of which the preparation is made. Tincture of rhubarb is, for instance, called tinctura rliei, and the extract of rhubarb, extractum rhei. [The next chapter of this book will be devoted to Pharmaceutical Nomenclature.] After giving the Latinic title and then the English technical title, the pharmacopoeia next names in brackets any very common or recently used English name or names. In speaking of gum arabic, the pharmacopoeia, for instance, puts the text as follows : ACAOIA Acacia [Gum Arabic] In this case it will be seen that the Latinic title and the English title are identical, as is the case with very many of the drugs of the pharmacopoeia. 561. After the titles and common names of crude drugs and chemicals, we find next the definition of the title. The definitions of plant drugs are very brief. They state what part of the plant constitutes the drug, the name of the PHARMACOPOEIAS 367 plant itself, and the botanical family to which it belongs. The definition of the title althcea is : "The dried root of Altlma officinalis , Linne (Fam. Malvaceae)." Aloe Socotrina is defined as, "The inspissated juice of the leaves of Aloe Perryi, Baker, Aloe vera (Linne), Webb, Aloe Chinensis, Baker, or other species of Aloe (Fam. Liliacem)." The definition of Cambogia^is, "A gum-resin obtained from Garcinia Han- burii, Hooker filius (Fam. Guttiferw)." The definition of Eucalyptus is, "The leaves of Eucalyptus globulus, Labil- lardiere (Fam. Myrtacea), collected from the older parts of the tree. " That of Frangula is, "The dried bark of Rhamnus Frangula, Linne (Fam. JZhamnaceai), collected at least one year before being used." The definitions of chemical compounds are their molecular formulas, but these are sometimes supplemented by additional notes when the molecular formulas are not sufficiently definitive. Under the title of Hyoscyamine Hydrobromate, the molecular formula is given, but as hyoscyamine and atropine have the same molecular formula, it is necessary to add the statement that hyoscyamine hydrobromate is the hydrobromate of an alkaloid obtained from hyoscyamus. Definitions are not given of the titles of pharmaceutical preparations, because the title itself and the directions given for making the preparation render a definition unnecessary. 562. After the definitions, the pharmacopoeia gives neces- sary technical descriptions. These descriptions are framed in accordance with a general plan. They begin with the description of the most striking external features of the substances named, such as size, shape and color, afterwards mentioning such features and properties as require closer examination, as, for instance, the internal structure, odor and taste, solubility in common solvents, and specific weight, etc. Whenever practicable and useful, the pharmacopoeia also calls attention to certain common signs of inferiority, 3G8 A CORRESPONDENCE COURSE IN PHARMACY and directs that drugs possessing certain stated evidences of unfitness shall not be used. The following description of colchicum seed will serve to illustrate the general style : "Subglobular, about 2 mm. in diameter, very slightly pointed at the hilum; externally reddish-brown, finely pitted; internally whitish; tough and of almost bony hardness; nearly inodorous; taste bitter and somewhat acrid." The student will see that the descriptions are amplifications of definitions and are necessary to the intelligent selection of good drugs. When the pharmacopoeia directs that leaves of the second year's growth constitute the drug, the first year's leaves must, of course, not be used. When the drug is to consist of the inner bark, the outer bark must be separated from it, and the inner bark must not be accompanied by any of the wood. When root-bark is ordered, stem-bark should not accompany it, nor should the whole root be used. Flowering tops should not be made to include the whole plant, and when the drug is defined and described as consist- ing of leaves, stems and stalks must be removed. Eoots and rhizomes must be free from adhering dirt, etc. A drug which has the fresh, natural color belonging to it when well cured and preserved, and which possesses in a high degree and unaltered the peculiar odor and taste which characterize it, will generally be found of satisfactory medicinal quality; but a drug which is discolored or the odor or taste of which is impaired cannot be of good quality. Some of the drugs imported from distant parts of the world are found to require thorough garbling before they are fit for use. By garbling is meant the removal from a drug of admixtures, impurities, decayed portions, and other things that do not belong to it, under the pharmacopoeial definitions and descriptions. Occasionally these admixtures and im- purities amount to a considerable proportion; 20 per cent of PHAKMACOPCEIAS 369 sand is not uncommon in asafetida, and more than 20 per cent of stems and stalks, legumes and other admixtures in Alexandrian senna. The following description of morphine sulphate will serve as an example of descriptions of organic chemical com- pounds: "White, feathery, acicular crystals of a silky luster; odor- less and having a bitter taste ; permanent in the air. "Soluble at 15° C. in 21 parts of water and in 702 parts of alcohol, in 0.75 part of boiling water, and in 144 parts of boiling alcohol ; almost insoluble in ether. "When heated for some time at 100° 0., the salt loses three molecules (7.12 per cent) of water of crystallization; the remaining two molecules (4.75 per cent) are gradually expelled by raising the temperature to 130° C. At 255° 0. the salt melts and upon ignition it is consumed, leaving no residue. "The salt is neutral to litmus paper." In reading this description, the student will observe how the various properties and behavior of the compound are mentioned in the order in which they may be most readily determined. To find the solubilities of substances, practical trials would be necessary, if the solubilities are to be employed as means of identification. The effects of various degrees of temperature must, of course, also be determined experi- mentally, and the reaction of a substance upon test paper ascertained by actual