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Charles Field Mason.

A complete handbook for the sanitary troops of the U. S. army and navy and national guard and naval militia online

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of water. Used externally and as an emetic.
Dose as an emetic : i Gm.

Zingiberis Fluidextractum (Fluidextract of Ginger).

Dose : i Cc.



CHAPTER II

PHARMACY

Pharmacy is the art of preparing medicines for administration.

Official Pharmacy deals with the processes and preparation of the
Pharmacopoeia.

Extemporaneous Pharmacy describes the methods of preparing
and dispensing physicians' prescriptions.

A Pharmacopoeia is an official list of drugs and their preparation
recognized by the medical profession of a certain country; such
drugs and methods are known as official.

A Dispensatory is a private treatise on official and other drugs.

The National Formulary is a book containing numerous useful
formulas not found in the Pharmacopoeia, and which have been
officially recognized by Congress.

PHARMACEUTICAL OPERATIONS

USE OF HEAT

For all operations requiring a temperature below that of boiling
water, an ordinary copper water-bath is used; as the vapor can
escape freely, the temperature can not rise above that of boiling
water.

MECHANICAL SUBDIVISION OF DRUGS

It is usually necessary to reduce drugs to fine particles before
employing them in the various operations of pharmacy. One of the
most common of these procedures is called trituration, which is the
process of reducing a drug to a fine powder by rubbing it up in a
mortar ; the pestle is given a rotary motion with downward pressure,
describing a series of concentric circles from within outward, and
then from without inward; should the powder begin to cake, it is
separated from the surface of the mortar by a spatula.

(311)



312 MATERIA MEDICA, THERAPEUTICS, PHARMACY

SOLUTION

When a solid substance is dissolved in a liquid, both the process
and the liquid are termed solution.

The liquid used to produce the solution with a solid, is called a
menstruum or solvent. Sometimes two solids may be rubbed together,
so as to make a clear liquid, as for instance, camphor and chloral
hydrate.

Some hygroscopic solids are apt to run together and form cakes,
if powdered before solution ; such are the scale salts of iron, which
will dissolve more readily in scale form.

The term " solubility," when applied to a drug, and no solvent is
mentioned, always refers to water at ordinary temperature.

Saturated solutions are solutions which can not take up any more
of the substance at ordinary temperature.

Percentage Solutions. These are solutions which contain a cer-
tain definite percentage of a given substance. Percentage solutions
of solids should always be prepared by weight, while for liquid
substances, weight or volume may be employed.

The quantity of each ingredient necessary to make a specified
amount of any particular percentage solution, may be found as fol-
lows: Multiply the amount of solution desired in grammes by the
percentage, divide by 100, and the result will show the quantity of
solid drug necessary; subtracting this amount from the quantity of
solution desired, the remainder indicates the necessary amount vf
menstruum.

Some of the most useful solvents of drugs are alcohol, chloroform,
ether, glycerin, water, acids, alkaline solutions, and oils. The
resulting solutions are given various names, such as tinctures,
infusions, etc.

Water is the most useful of all solvents; nearly all salts of the
alkalies, earths, and metals are dissolved by it, and many vegetable
acids and salts of the alkaloids.

Alcohol is next in importance to water as a solvent. Its great
advantage over water is that it makes the preparations in which it
is employed keep indefinitely, while the watery solutions soon de-
compose. Resins, volatile oils, alkaloids, and glycosides dissolve in
alcohol, while gum, albumen and starch are insoluble.

Glycerin is used on account of its antiseptic qualities, when alcohol
can not be employed for any reason. It dissolves pepsin, tannins,



PHARMACY 313

some mineral salts and vegetable acids, and forms the basis of the
glycerites.

Ether is especially valuable as a solvent for oils, fats, resins, and
some alkaloids and neutral principles.

Chloroform resembles ether in its solvent properties, and also
dissolves phosphorus. It is non-inflammable and has a higher
boiling-point.

Acids are used with water or alcohol, to extract the active princi-
ples of such drugs as cinchona. They are also used in the prepara-
tion of vinegars.

Alkalies dissolve resinous bodies, and the oils are used as a basis
for liniments.

Infusions are made by pouring boiling water on vegetable sub-
stances, and letting them stand for various lengths of time.
Decoctions are made by boiling the drug in water, and are used
when there are no volatile principles to be driven off. Maceration
is a process of dissolving out active principles at ordinary tempera-
tures. The mixture must be frequently shaken.

Percolation or displacement is one of the most important and
generally useful processes of pharmacy. By means of it, a powder
contained in a suitable vessel has its solid constituents dissolved out,
by the descent of solvent through it. The apparatus in which the
process is carried on is known as a percolator, the resulting solution
as the percolate, and the residue as the marc. The directions of the
United States Pharmacopoeia are as follows :

"Percolation, as directed in this Pharmacopoeia, consists in sub-
jecting a substance or a mixture of substances, in powder, contained
in a vessel called a percolator, to the solvent action of successive
portions of a certain menstruum in such a manner that the liquid,
as it traverses the powder in its descent to the receiver, shall be
charged with the soluble portion of it, and pass from the percolator
free from insoluble matter.

" When the process is successfully conducted, the first portion of
the liquid, or percolate, passing through the percolator, will be nearly
saturated with the soluble constituents of the substance treated ; and
if the quantity of menstruum be sufficient for its exhaustion, the
last portion of the percolate will be nearly free from color, odor,
and taste, other than those of the menstruum itself.

"Percolators. The percolator most suitable for the quantities




314 MATERIA MEDICA, THERAPEUTICS, PHARMACY

contemplated by this Pharmacopoeia should be nearly cylindrical, or
slightly conical, with a funnel shaped termination at the smaller end.
(See Fig. 218.) The neck of this funnel end
should be rather short, and should gradually and
regularly become narrower toward the orifice, so
that a perforated cork, bearing a short glass tube,
may be tightly wedged into it from within until
the end of the cork is flush with the outer edge
of the orifice. The glass tube, which must not
project above the inner surface of the cork,
should extend from 3 to 4 Cm. beyond the outer
surface of the cork, and should be provided with
a closely fitting rubber tube, at least one- fourth
FIG. 218. Percolator, longer than the percolator itself, and ending in
another short glass tube, whereby the rubber tube may be so sus-
pended that its orifice shall be above the surface of the menstruum in
the percolator, a rubber band holding the tube in position.

" The shape of a percolator should be adapted to the nature of
the drug to be operated upon. For drugs which are apt to swell,
particularly when a feeble alcoholic or an aqueous menstruum is
employed, a conical percolator is preferable. A cylindrical or only
slightly tapering percolator may be used for drugs which are not
liable to swell, and when the menstruum is strongly alcoholic, or
when ether or some other volatile liquid is used for extraction.
The size of the percolator selected should be in proportion to the
quantity of drug extracted. When properly packed in the perco-
lator, the drug should not occupy more than two-thirds of its height.
The percolator is best constructed of glass, but, unless otherwise
directed, may be made of any suitable material not affected by the
drug or menstruum.

" The percolator is prepared for percolation by gently pressing a
small tuft of cotton into the neck above the cork, and this may then
be moistened by pouring a few drops of the menstruum upon the
cotton, to facilitate the passage of the first portion of percolate,
which is often very dense.

" The Process. The powdered substance to be percolated (which
must be uniformly of the fineness directed in the formula, and
should be perfectly air dry before it is weighed) is put into a basin,



PHARMACY 315

the specified quantity of menstruum is poured on, and the powder
thoroughly stirred with a spatula, or other suitable instrument,
until it appears uniformly moistened. The moist powder is then
passed through a coarse sieve No. 40 powders, and those which
are finer, requiring a No. 20 sieve, while No. 30 powders require a
No. 15 sieve for this purpose. Powders of a less degree of fine-
ness usually do not require this additional treatment after the 'mois-
tening. The moist powder is now transferred to a sheet of thick
paper and the whole quantity poured from this into the percolator.
It is then shaken down lightly and allowed to remain in that con-
dition for a period varying from fifteen minutes to several hours,
unless otherwise directed ; after which the powder is pressed, by
the aid of a plunger of suitable dimensions, more or less firmly, in
proportion to the character of the powdered substance and the alco-
holic strength of the menstruum, strongly alcoholic menstrua, as a
rule, permitting firmer packing of the powder than the weaker.
The percolator is now placed in position for percolation, and, the
rubber tube having been fastened at a suitable height, the surface
of the powder is covered by an accurately fitting disk of filtering
paper, or other suitable material, and a sufficient quantity of the
menstruum poured on through a funnel reaching nearly to the sur-
face of the paper. If these conditions be accurately observed, the
menstruum will penetrate the powder equally until it has passed
into the rubber tube and has reached, in this, a height correspond-
ing to its level in the percolator, which is now closely covered to
prevent evaporation. The apparatus is then allowed to stand at
rest for the time specified in the formula.

" To begin percolation, the rubber tube is lowered and its glass
end introduced into the neck of a bottle previously marked for the
quantity of liquid to be percolated, if the percolate is to be measured,
or of a tarred bottle, if the percolate is to be weighed; and by raising
or lowering this receiver the rapidity of percolation may be in-
creased or decreased as may be desirable. A layer of men-
struum must constantly be maintained above the powder, so
as to prevent the access of air to its interstices, until all^ has
been added, or the requisite quantity of percolate has been obtained.
This is conveniently accomplished, if the space above the powder
will admit it, by inverting a bottle containing the entire quantity of
menstruum over the percolator in such a manner that its mouth may



316 MATERIA MEDICA, THERAPEUTICS, PHARMACY

dip beneath the surface of the liquid, the bottle being of such shape
that its shoulder will serve as a cover for the percolator.

" When the dregs of a tincture, or of a similar preparation, are
to be subjected to percolation, after maceration with all or with the
greater portion of the menstruum, the liquid portion should be
drained off as completely as possible, the solid portion packed in a
percolator, as before described, and the liquid poured on, until all
has passed from the surface, when immediately a sufficient quantity
of the original menstruum should be poured on to displace the
absorbed liquid, until the prescribed quantity has been obtained."

SEPARATION OF SOLIDS FROM LIQUIDS

Filtration is the process of separating solids from liquids so as to
render the latter more transparent. Colation or straining is differ-
ent from filtration only in that it is less thorough. For straining,
filter-bags, conical in form, and made of felt or flannel, are usually
employed.

For filtration, two kinds of paper filters are used, plain and plaited.
Plain filters are usually employed when it is desired to collect the
solid matter, called the precipitate. It is made by doubling a circu-
lar sheet of filter paper upon itself, then refolding this in the middle ;
the filter is then opened in such a manner that there is one thickness
on one side and three thicknesses of paper on the other side of the
cone, which exactly fits an ordinary funnel.

A plaited filter exposes a much larger filter surface, that does not
come in contact with the funnel, thus effecting a much more rapid
filtration. The method of preparing a plaited filter is shown in all
works on pharmacy. In plaiting a filter, do not extend the creases
entirely to the apex, for the point of the filter may be so much
weakened that the weight of the liquid would tear it. The upper
edge of the filter should not reach the top of the funnel; this is in
order to allow the funnel to be covered to keep out dust. The
filter should be moistened with water after placing in the funnel,
and before adding the liquid to be filtered; the latter should be
poured quietly on the side of the filter, so as not to rupture the
point. In filtering into a bottle, place a piece of twine between the
funnel and bottle, to allow the escape-.of air.

The process of separating a liquid from the solid, by pouring off
the liquid, after the solid settles, is called decantation; it may be
greatly assisted and the spilling of the liquid avoided, by using a
glass rod as a director.



PHARMACY



317



When the solid substance or precipitate is light and easily mixed
with the liquid, it is better to use a siphon. This usually consists of
an ordinary glass tube, bent at a rather acute angle, and with the
two arms of different length. The siphon is first entirely filled with
the liquid to be drawn off, and the shorter arm is then inserted in
the liquid, taking care to keep the end of the longer arm below the
surface level. The empty siphon may be inserted into the liquid
and the flow started by suction on the long arm, provided the liquid
is not corrosive or poisonous. A rubber tube may be used as a
siphon, in place of a glass tube, and in the same way.

SEPARATION OF VOLATILE MATTER

Volatile .substances are separated from those which are less vola-
tile, by the action of heat, and the process is known as vaporization.

The process of separating a volatile liquid from a less volatile
one, by heat, is called evaporation.

When the purpose sought is to obtain the volitile liquid, it is called
distillation.

When the purpose is to obtain the solid, it is called desiccation.

When it is wished to separate a volitile solid from another solid
body, it is called sublimation.

OFFICIAL PREPARATIONS 1



Liquids.


Solids.


Made without perco-
lation or macera-


Made by percolation


Made by percolation


Made without perco-
lation or macera-


tion.


or maceration.


or maceration.


tion.2


Aqueous Solutions.
Waters.


Aqueous Liquids.
Infusions.


Extracts.
Resins.


Powders.
Triturations.


Solutions.


Decoctions.




Masses.


Aqueous Solutions


Alcoholic Liquids.




Confections.


Containing Sweet


Tinctures.
Wines.




Pills.
Troches.


or Viscid Sub-


Fluidextracts.




Cerates.


stances.


Oleoresinous Liquids.




Ointments.


Syrups.
Honeys.
Mucilages.


Oleoresins.
Acetous Liquids.
Vinegars.




Plasters.
Papers.
Suppositories.


Emulsions.








Mixtures.








Glvcorites.








Alcoholic Solutions.








Spirits.








Elixirs.








Ethereal Solutions.








Collodions.








Oleaginous Solutions.








Liniments.

















1 Those used internally are in Roman type; those used externally, in italics.

2 The preparations in this class are mostly extemporaneous.



Aqua, ivaters, are solutions of volatile substances in water. They
do not keep well and should be freshly prepared.

Cerata, cerates, are ointments made stiff with wax.

Chartcc, papers, are medicated papers such as mustard paper.

Collodia, collodions, have as their basis a solution of gun-cotton in
alcohol and ether.

Decocta, decoctions, are made by boiling vegetable substances in
water ; little used.

Elixiria, elixirs, are sweetened, aromatic, alcoholic preparations
serving as a pleasant vehicle for medicines.

Emplastra, plasters, are solid compounds, usually spread on
muslin, and for external use. Example : Belladonna plaster.

Emulsa, emulsions, are suspensions of insoluble oily or resinous
substances in water by means of some other substance, such as gum
arabic or the yolk of egg known as the excipient.

Extracta, extracts, are semisolid preparations obtained by evapo-
rating watery or alcoholic solutions of the active principles of drugs.

Fluidextracta, fluidextracts, are permanent, concentrated solutions
(usually alcoholic) of vegetable drugs of such strength that i Cc. of
the fluidextract represents I Gm. of the drug.

Glycerita, glycerites, are mixtures of medicinal substances with
glycerin.

Infusa, infusions, are prepared by treating vegetable substances
with hot or cold, but not boiling water.

Linimenta, liniments, are solutions or mixtures of various sub-
stances in alcoholic or oily liquids, and intended for external use,
with rubbing.

Liquorcs, solutions, are solutions of non-volatile substances in
water.

Misturcc, mixtures, are suspensions of insoluble substances in
water by the aid of some viscid body.

Oleoresina, oleoresins, are liquid preparations consisting princi-
pally of natural oils and resins extracted by ether.

Pilulcc, pills, are spherical masses to be swallowed whole. They
consist of the active ingredients and the excipient, the latter being
the substance used to make the mass adhesive and plastic. Glycerin
and acacia are excipients.

Spiritus, spirits, are alcoholic solutions of volatile substances.

Suppositoria, suppositories, are solid bodies containing drugs



PHARMACY 319

usually incorporated with cacao butter and intended for use in the
vagina, rectum, or urethra.

Syrupi, syrups, are concentrated solutions 01 sugar in water with
or without medicinal substances.

Tdbella, tablets, consist of powdered drugs compressed into disc
shape by machinery. They are extensively used in the field supply
table because they are convenient for transportation and for accurate
dosage without weights or measures. Their disadvantages are that
they are so firmly compressed that if swallowed whole many of them
pass through the gastro-intestinal tract unchanged, and that there-
fore they must be first reduced to a powder before being taken.
Others are very irritating to the stomach and should be dissolved
freely in water before being administered.

Tincture, tinctures, are solutions of non-volatile substances in
alcohol. Tincture of iodine is an exception, iodine being a volatile
substance. Potent tinctures are of 10 per cent strength and other
tinctures usually 20 per cent.

Trochisci, troches or lozenges, are small cakes of medicines incor-
porated with a mass which usually has sugar for a basis. They are
used by allowing them to dissolve slowly in the mouth.

Unguenta, ointments, are soft, fatty mixtures of medicinal agents
usually with a basis of lard and wax or petrolatum.

NON-OFFICIAL FORMS OF MEDICINES

Bou'gia, bougie, a urethral suppository.

Ca'psula, capsule, a small, hollow, gelatin receptacle for medicines,
intended to be swallowed, and thus concealing the taste of its
contents.

Catapla'sma, poultice.

Cha'rtula, small paper, the subdivision of powders into separate
doses inclosed by small pieces of paper, folded.

Colly'rium, eye-water.

Di'scus, disk, a small, flat piece of medicated gelatin, used when
the dose is small, especially with alkaloids, for application to the eye,
or for use in hypodermatic syringe.

E'nema, enema, a rectal injection.

Esse'ntia, spirits, essence, solution of volatile oil in alcohol.

Gargari'sma, gargle.



320 MATERIA MEDICA, THERAPEUTICS, PHARMACY



Gra'nulum, a small pill, a granule.

Hau'stus, draught, when a considerable amount of fluid is to be
swallowed at one dose.
Inhala'tio, inhalation, a vapor.
Inje'ctio, injection.
Lo'tio, lotion, a wash.
Po'tus, drink, a draught.
Su'ccus, juice.

Tablet triturates. Triturations compressed into small masses, for
exact dosage and convenience of administration.

Tablets, hypodermic. Small masses containing exact doses of sub-
stances used for hypodermatic administration; some innocent but
soluble substance is used as the basis.

Among the preparations which are most often made in the dis-
pensary are emulsions, pills, ointments, powders, and suppositories;
it is, therefore, necessary to consider these operations a little more
in detail.

Emulsions. Milk and yolk of egg are natural emulsions, the fat
in each case being divided into minute globules which are surrounded
with a film of albumen or casein by which they are suspended in
water; the artificial emulsions are imitations of those existing in
nature.

The most commonly used excipients are acacia and yolk of eggs

(vitellus), but emulsions made with
the latter must be used within a
few days, as they do not keep well.
The method of preparing an
emulsion which experience has
shown to be the best is as follows :
Add the oil, resin, etc., to a proper
quantity of the excipient and mix
both thoroughly in a mortar (Fig.
219). Then add enough water to
FIG. 219. Wedgewood Mortar and Pestle, equal one-half the weight of the
previous mixture, and triturate the whole rapidly and unceasingly
until the emulsion is homogeneous and of a whitish color. Next
add the remainder of the water slowly, with continual stirring,
finally incorporating the other ingredients, if any.




PHARMACY



321



Pills. Pills should not exceed five grains in weight unless com-
posed of a heavy substance such as calomel. The ingredients should
be weighed out separately, commencing with that of which the
smallest quantity is ordered, and thoroughly rubbed up in a mortar ;
the excipient is then added and the rubbing continued until the mass

is of the proper consist-
ence and does not show
any particles of any one
ingredient. If the mass
FIG. 220. Spatula. sticks to the pestle it is

removed with a spatula

(Fig. 220) and may be kneaded a few minutes in the fingers. It
should then be placed upon the pill tile, which has been previously
dusted with a little lycopodium, and rolled into a long cylinder by the
aid of a broad spatula until the mass is of a length corresponding to
the division on the tile scale which represents the number of pills to
be made.

The mass should then be placed along the scale and a cut made
through it with the spatula at each division, the pieces being at once
rounded separately into pills by the thumb and the two fingers of
each hand. A pill machine may be used for the division of the
portions (Fig. 221).

The pills are then left to dry while the label is being written, after
which they are placed in a pill box with a little lycopodium to pre-
vent their sticking together.

The excipient to be used is usually left to the discretion of the




FIG. 221. Pill Machine.



compounder. Some substances such as the softer extracts
gum resins need no excipient, but may be made at once into pills.
Among the more generally used excipienis are:
21



and



322 MATERIA MEDICA, THERAPEUTICS, PHARMACY

Glycerin: Valuable on account of its property of attracting mois-
ture and thus preventing the pills getting too hard.

Syrup: Should not be used for metallic salts, especially calomel,
which it reduces in a short time.

Mucilage of Acacia: For vegetable powders not adhesive.

Water: For vegetable powders containing mucilage.

Alcohol: For resinous substances.

Soap: Best for resinous and fatty substances and essential oils.

Ointments: Ointments are usually prepared by rubbing the ingre-
dients together in a mortar, or thoroughly incorporating them on a
pill-tile with the aid of a firm spatula. When resins or waxes are to
be incorporated with fats, or medicines are used which are soluble
in warm fats, melting is used. When extracts, powders, or gritty
substances are ordered, the ingredients should first be finely
powdered, then rubbed with a small quantity of the basis into a
smooth, impalpable paste, the remainder of the basis being added
gradually until the whole is thoroughly incorporated.

Soluble salts should be triturated with a little water before adding



Online LibraryCharles Field MasonA complete handbook for the sanitary troops of the U. S. army and navy and national guard and naval militia → online text (page 23 of 38)