to a pilular consistence. They are called aqueous or watery, alcoholic and acetous extracts, according to the menstruum used as a solvent What are cerates? Cerates (cerata) are unctuous preparations, intended for external application, mixed with wax, spermaceti or resin, which gives them a firm consistence, and prevents them from melting at the temperature of the body. What are liniments? Liniments (linimenta) are oleaginous preparations, intended for external application with friction. What are oleates? Oleates (oleata) are solutions in oleic acid of metallic salts or alkaloids, and are applied externally. What are ointments? Ointments or unguents (unguenta) are medicaments incorporated with some fatty substance, and intended for external use. They are of the consistence of lard. What are plasters? Plasters (emplastra) are preparations spread on linen, muslin, silk or sheepskin, and are intended to adhere closely to the surface to which they are applied. What are suppositories? Suppositories (suppositoria) are made by incorporating medicinal substances with oil of theobroma, and are intended for introduction into the rectum or vagina. They are of conical form, to facilitate their insertion. What are solutions? Solutions (liquores) are preparations in which a non-volatile substance is entirely dissolved in the menstruum (usually water). What are mixtures? Mixtures (mistura) are preparations in which, by means of some viscid substance, an insoluble medicine is suspended in water. What are waters? Waters (aqua) are aqueous solutions of gaseous or volatile substances. What are infusions? Infusions (infusa) are aqueous preparations obtained by pouring hot or cold water on vegetable substances and allowing it to remain sufficiently long to extract the virtues of the drug. What are decoctions? Decoctions (decocta) are aqueous preparations obtained by boiling vegetable substances in water for a few minutes and allowing them to cool in closely-covered vessels. What are tinctures? Tinctures (tinctura) are alcoholic solutions, usually of non-volatile substances. Alcohol or diluted alcohol is generally used as a solvent, but occasionally the aromatic spirits of ammonia is employed, the product being called an ammoniated tincture. What are spirits? Spirits (spiritus) are alcoholic solutions of gaseous or volatile sub stances. What are wines? Wines (vina) are tinctures made with stronger white wine instead of alcohol. What are glycerites? Glycerites (glycerita) are medicinal substances mixed with glycerin. What are fluid extracts? Fluid extracts (extracta fluida) are liquid preparations of uniform strength, 1 c.c. of which represent 1 Gm. (about 1 minim to the grain) of the crude drug, prepared chiefly with alcohol and glycerin. What are honeys? Honeys (mellita) are medicines dissolved in honey. What are syrups? Syrups (syrupi) are composed of medicinal substances, or of flavoring ingredients in sugar and water. Simple syrup is a concentrated solution of sugar in water. What are vinegars? Vinegars (aceta) are medicinal solutions in diluted acetic acid. What are oleoresins? Oleoresins (oleoresina) are concentrated extracts consisting chiefly of the resin dissolved in the oil of the drug from which they are obtained. May medicines be prescribed in other forms than those referred to above? Medicines are often administered in capsules (small, elongated gelatine boxes with rounded ends, which dissolve readily in the stomach), granules or parvules (very minute pills), emulsions (oils or resins suspended in a mixture by means of some viscid material), enemata (liquids injected into the rectum for their local or systemic effect), or injections (liquids forced by a syringe into the mucous passages or cavities, under the skin or into a blood vessel). Inhalations of vapors may be employed for their local effect on the bronchopulmonary tract or for their influence on the system at large, and gargles may be used as sedative, astringent or disinfecting and deodorizing applications to the buccal and pharyngeal mucous membranes. Externally, poultices (simple or medicated), lotions (washes), and fomentations (hot lotions applied on flannel or cloth and allowed to remain in contact with the surface), are also often used. What weights and measures are used in prescribing and dispensing medicines ? Troy or apothecaries' weight is used in dispensing solids, while wine or apothecaries' measure is employed for liquids; occasionally the metrical system is used in prescribing. What is apothecaries' weight? In apothecaries' weight the pound is divided into ounces, drachms, scruples and grains, as follows: = 480 grains or 24 scruples or 8 drachms 1 ounce (3). 5760 grains or 288 scruples or 96 drachms or 12 ounces 1 pound (lb). The grain (gr.), drachm (3) and ounce (3) should alone be used in prescription writing. What is wine measure? In wine measure the gallon is divided into pints, flui-ounces, fluidrachms and minims, thus: 60 minims (m) = 1 flui-drachm (fz). 480 minims or 8 flui-drachms 1 flui-ounce (fZ). 1 pint (O). 7680 minims or 128 flui-drachms or 16 flui-ounces 61440 minims or 1024 flui-drachms or 128 flui-ounces or 8 pints 1 gallon (C). The minim (m), flui-drachm (f3 ), flui-ounce (f3) and, very seldom, the pint (0) are used in prescriptions. Describe the metrical system of weights. In the metrical or decimal system the gramme is multiplied or divided by ten, Greek prefixes denoting the multiplication, and Latin the subdivisions of the unit; thus: 10 milligrammes 1 centigramme. 100 milligrammes, or 10 centigrammes 1 decigramme. 1000 milligrammes, or 100 centigrammes, or 10 decigrammes 1. gramme. 10,000 milligrammes, or 1000 centigrammes, or 100 decigrammes, or 1 decagramme. 10 grammes 100,000 milligrammes, or 10,000 centigrammes, or 1000 decigrammes, or 100 grammes, or 10 decagrammes 1 hectogramme. 1,000,000 milligrammes, or 100,000 centigrammes, or 10,000 decigrammes, or 1000 grammes, or 100 decagrammes, or 10 In writing prescriptions in the metrical system, the gramme (Gm.) alone is used for both solids and fluids, the abbreviation being preceded by Arabic figures or decimals denoting the amount of the drug (e. g., 10.0 Gm.-0.02 Gm., etc.). What is a gramme ? The gramme is the weight of a cubic centimeter (c. c.) of distilled water at 4° C. (39.5° F.). What is a centimeter ? A centimeter ( of an inch) is the T of a metre (39.37 inches), which is the ten-millionth part of a quarter of a meridian of the earth (or of the distance from the pole to the equator). What relation does the metrical system of weights bear to apothecaries' weight and measure? 1 gramme = 15.5 grains; 1 decigramme (0.1 Gm.) = 1.5 grains; 1 centigramme (0.01 Gm.) = .15 (or) grain; 1 milligramme (0.001 Gm.) .015 (or) grain; 1 grain (gr.j) = .06 gramme; 1 drachm (3j) = 4.0 grammes (approximately); 1 ounce (3) 32.0 grammes (approximately). = The following table gives the value of grains in the metrical system. (The fractions have not been carried out beyond the fourth decimal point.) As the weight of a c. c. of fluid depends upon its density, 1.0 Gm. of a light liquid (e. g., alcohol) will measure more than the same weight of a heavy liquid (e. g., glycerin). Approximately, however, mj=0.06 Gm. ; f3j=4.0 Gm. (a little less), and f3j = 32.0 Gm. (a little less). The following table gives the value of minims (of water at 4° C. in vacuo) in the metrical system. For ordinary purposes these values may be used without correction. |