Part 159

The concluding portion of the process of extract-making, technically termed 'finishing-off,' requires the most scrupulous attention. As the evaporation advances, the heat should be lessened, and as soon as the extract acquires the consistence of thick treacle it should be removed altogether, and the remainder of fluid matter evaporated by the heat retained by the copper pan, the escape of vapour being promoted by assiduous and laborious stirring with a suitably shaped wooden spatula. This part of the process should be continued until a proper consistence is attained and the extract is nearly cold. When high-pressure steam or a chloride of calcium bath is employed, care must be taken to withdraw the heat before stirring the semi-liquid mass; as, if an extract having a temperature of about the boiling-point of water, or even a few degrees below it, is agitated, it becomes full of bubbles, and appears rough and puffy, and this appearance cannot be removed by subsequent stirring, or by any method but redissolving it in water and re-evaporation. This is especially the case with the extracts of sarsaparilla (simple and compound), gentian, liquorice, and most others of a similar class. A good laboratory man knows from experience the proper time for the removal of the heat, but unpractised persons often fail in this particular. In such cases should the heat retained by the evaporating pan, and by the extract, prove insufficient to complete the process, a little more may be cautiously applied. Without assiduous and laborious stirring in the way described, a very smooth and glossy extract cannot be produced. To promote this artificial appearance, some persons add 3% or 4% each of olive oil and gum arabic, dissolved in water, with about 1% or 2% of spirit of wine.

The consistence of the ordinary extracts of the shops is the same as that of electuaries and confections, and is described in the Ph. E. as equal to that of "thick honey." The instructions of the Ph. L. and D., to evaporate the mass "until it acquires a consistence proper for making pills," except in 2 or 3 cases (as _Ext. Colocynth. Comp._, &c.), is not adopted, and, indeed, would be found inconvenient in practice. Extracts evaporated to such a consistence are commonly termed 'pilular extracts,' and when evaporated so that they are quite dry, and brittle when cold, they are called 'hard extracts' (EXTRACTA DURA, L.).

_Pres._ Extracts should be put into pots as soon as taken from the pan, and, after being carefully and securely tied over with bladder, should be 'stored' in a dry situation. The London College orders "a small quantity of rectified spirit to be sprinkled upon all the softer extracts, to prevent them becoming mouldy." A better way is to employ a little spirit, holding in solution a few drops of oil of cloves, or a still less quantity of creasote. This should be added to them the last thing before removing them from the evaporating pan, and when they are nearly cold. The same object is effected by moistening the inside of the bladder (used to tie them over) with a few drops of oil of cloves or creasote. Hard extracts should be kept in bladders or gut skins, placed in stone pots, and well covered over. With care, extracts prepared from recent vegetable substances may be preserved twelve months, or from season to season; and those from dry ingredients, or such as are less inclined to spoil, for perhaps double that time; but beyond these periods their virtues cannot be relied on, and they should consequently be discarded, if remaining unused or unsold.

_Pur., &c._ The quality of an extract cannot be ascertained by mere inspection, nor is it readily discovered by chemical tests. A knowledge of these facts has induced the mercenary and fraudulent manufacturer to employ damaged and inferior drugs in their preparation, alike regardless of the welfare of the patient and the credit of the practitioner. A common practice with some manufacturers is, not only to pick out the least expensive variety of every drug for the preparation of their extracts, but the most inferior and often damaged and worthless portion of this already inferior article. The production of a smooth, bright, and glossy extract is all that is usually attempted by these individuals, and all that is sought after by the mass of purchasers, who mistake the simulation of the mere external signs of good quality for its actual existence. It is a fact, which we can verify from extensive experience in the laboratory, and from years of practical observation on this point, that extracts faithfully prepared from good materials do not possess the sightly and pleasing appearance of those commonly vended by the wholesale druggists. On comparing the extracts prepared by different metropolitan houses, we have found that those which have exhibited a remarkably bright and glossy appearance have been uniformly inferior, and sometimes nearly inert; whilst others, with a less prepossessing appearance, have been generally of good quality. These facts are well established by reference to the extracts of those houses and institutions that are remarkable for the superior quality of their preparations, and by comparing them with the common extracts of the shops supplied by the wholesale trade.

A good extract should be--1. Free from grit, and wholly soluble in 20 parts of the menstruum employed in its preparation, forming a nearly clear solution.--2. It should have a uniform texture and colour, and be of a proper consistence.--3. If a narcotic or active extract, it may be exhibited in proper doses, and its effects watched. Its activity may also be tested on any small animal.--4. An assay for the proximate vegetable principle (alkaloid, &c.) contained in the plant from which it has been prepared may be made. The extracts prepared from the expressed juices of plants, without straining off the coagulated albumen, are, of course, exceptions to the first test. Unfortunately, these tests are not always easily performed, and the last two are inapplicable to those extracts that exercise no very marked physiological action, unless when taken in repeated doses, long continued. This want of a ready means of accurately testing the qualities of extracts has enabled the fraudulent manufacturer to sell inferior articles with impunity, and often without the least fear or danger of detection.

In general, an extract more than six months old contains only half the activity of a similar one newly made. When more than twelve months old they should be rejected as worthless, and the stock renewed.

_Uses, &c._ The extracts of the shops are generally acknowledged to be the most varying, imperfect, and uncertain class of medicines belonging to modern pharmacy. They are mostly used in the same cases as the plants from which they are prepared, but in smaller doses.

_Concluding Remarks._ In the preparation of extracts the great desiderata to be aimed at are--to suit the menstrua and the methods of manipulating to the peculiar characteristics of the active constituents of the vegetable substances operated on. The pharmaceutist should always bear in mind that a perfect extract should be a concentrated, solid mass, representing, as near as possible, in medicinal efficacy, the materials from which it has been prepared, and capable of being redissolved, so as to form a solution closely resembling that from which it has been derived. An extract possessing equal strength to the whole mass of the ingredients from which it has been prepared is almost next to an impossibility, however desirable such a degree of perfection may be. The medicinal properties of all solutions of vegetable matter are injured by being reduced to the solid state; and this deterioration, more or less, takes place, whether the solvent be water, acetic acid, proof spirit, or alcohol. The volatile portions (the essential oils, the aroma, &c.) are nearly or wholly dissipated; and though these do not always form the principal or active ingredients of the vegetables from which extracts are prepared, yet they generally exercise a modifying and controlling influence over the other ingredients, which considerably alters their therapeutical action. The loss of aroma may often be a trifling deficiency, but in the extracts of aconite, henbane, hemlock, belladonna, and other narcotic plants, this is not the case. In these cases it is well known that the inert preparations are wholly deficient of the odour of the recent plant, and that in proportion as the odour is developed, so is their activity preserved. The powerful smell of the recently expressed juice of hemlock, with the scarcely perceptible odour of the extract (EXTRACTUM CONII, Ph. L.), offers an excellent example of this fact. The dose of the one often reaches 20 or 30 gr., whilst that of the other seldom exceeds 5 or 10 drops, or a portion equivalent in dry ingredients to considerably less than 1/2 gr.

When extracts are ordered in prescriptions, those of the 'Pharmacop[oe]ia' should be alone employed by the dispenser, as the substitution of others for them would not only be violating faith with the prescriber, but might also produce consequences alike injurious to the dispenser and the patient. Many medical gentlemen prefer extracts prepared by particular processes or persons, but such intention is always indicated in their prescriptions.

=Extract of Ac'onite.= _Syn._ EXTRACT OF WOLFSBANE, E. OF MONKSHOOD, INSPISSATED JUICE OF ACONITE; EXTRACTUM ACONITI (B. P., Ph. L. E. & U. S.), SUCCUS SPISSATUS ACONITI (Ph. D. 1826), L. _Prep._ 1. (B. P.) Take 112 lbs. of the fresh leaves and flowering tops, bruise them, press out the juice, heat it gradually to 130° F., and separate the green matter by a calico filter. Heat the strained liquor to 200° F. to coagulate albumen, and again filter. Evaporate the filtrate by a water bath to the consistence of a thin syrup; then add to it the green colouring matter previously separated, and stirring the whole together assiduously, evaporate at a temperature not exceeding 140° F. to a pill consistence.--_Dose_, 1 to 2 gr.

2. (Ph. L.) Take of fresh leaves of aconite, 1 lb.; bruise them in a stone mortar, express the juice, and evaporate it, unstrained, to a proper consistence. The formulæ of the Ph. D. & U. S. are similar.

3. (Ph. E.) Beat the fresh leaves of aconite to a pulp, and express the juice, then subject the residuum to percolation with rectified spirit until the latter passes through without being materially coloured; unite the expressed juice and the percolated tincture, filter, distil off the spirit, and evaporate in a vapour or a water bath to a proper consistence. Stronger than the preceding.

_Obs._ A variable and uncertain preparation. Numbness and tingling follow its application to the limbs or tongue when it is of good quality.--_Product._ 1 cwt. of fresh leaves yield between 5 lbs. and 6 lbs. of extract. _Prop._ Anodyne, sudorific, and narcotic; very poisonous.--_Dose_, 1/2 gr. to 2 gr., made into a pill with liquorice powder; once or twice a day, in neuralgic pains, chronic rheumatism, glandular swellings, &c., gradually and cautiously increased to 5 or 6 gr.

4. (Alcoholic; E. A. ALCOHOLICUM, L.)--_a._ (P. Cod.) Aconite (in coarse powder), 1 lb.; proof spirit, 3-1/2 lbs. (say 2-1/2 pints); proceed by the method of displacement, and when all the spirit has penetrated the powdered mass, keep this covered with distilled water, until the liquid begins to cause a precipitate in falling into that which has previously passed through; next distil the spirit from the tincture, and evaporate the residuum to the proper consistence.

_b._ (Ph. U. S.) Aconite 1 lb.; spirit, sp. gr. ·935 (= 13 u. p.), 1 quart, or q. s.; as last.

_c._ (Ph. Baden.) From the tincture prepared with rectified spirit, and by either maceration or displacement. Stronger than the last two.

_d._ (Ph. Bor.) The juice is expressed from the fresh herb, which is then sprinkled with about 1/3 of its weight of water, and again pressed; the mixed and strained liquid is evaporated in a vapour bath, at 122° to 140° Fahr., to about one half; to this, as soon as cold, an equal weight of spirit (sp. gr. ·900) is added, and after frequent agitation for 24 hours, the whole is filtered, with pressure; the marc is treated with fresh spirit (equal to about 1-4th that first used) and again pressed; the mixed liquors are next filtered, and are, lastly, evaporated, as before, to the proper consistence.

_Obs._ Resembles the simple extract, but is much more powerful. It has been exhibited internally in the form of pills, and used externally, combined with ointment or spread on simple plaster.--_Dose_, 1/12 to 1/6 gr. every three hours.

5. (Ammoniated; E. A. AMMONIATUM, L.--Dr Turnbull.) Extract of aconite, 1 dr.; liquor of ammonia (strongest), 10 or 12 drops; mix.

6. (Dried); E. A. SICCUM, L.--P. Cod.) The expressed juice, strained through a sieve or coarse linen, is at once, without depuration, exposed in earthen dishes, in layers of about 2 lines deep, in a stove or current of dry air, to a temperature ranging between 95° and 104° Fahr., until reduced to dryness. The dried extract is to be packed in bottles.

7. (Saccharated; E. A. SACCHARATUM, L.) From extract of aconite (Ph. Bor.), 4 oz.; sugar of milk (in powder), 1 oz.; mix, and dry the mass in a warm place, adding sugar of milk, q. s. to make the whole equal in weight to that of the extract used (4 oz.). An excellent preparation, which keeps well. The other NARCOTIC EXTRACTS, as those of BELLADONNA, HEMLOCK, HENBANE, &c., are to be treated in a similar manner. See ACONITE, and _below_.

=Extract of Aconite Root.= _Syn._ EXTRACTUM ACONITI RADICIS ALCOHOLICUM, L. _Prep._ (Dr Fleming; Dr Turnbull.) From a tincture of the root made with rectified spirit. It is said to be 12 times as strong as the extract of the leaves.

=Extract of Ag'aric=. _Syn._ EXTRACTUM AGARICI, L. _Prep._ (P. Cod.) From the infusion of white agaric (_Polyporus officinalis_) prepared with cold water. Purgative.--_Dose_, 1 to 4 gr.

=Extract of Alcorno'co.= _Syn._ EXTRACTUM ALCORNOCÆ, L. _Prep._ From a decoction of alcornoco bark (South American). Astringent and tonic.--_Dose_, 5 to 20 gr. in phthisis, &c.

=Extract of Al'oes.= _Syn._ PURIFIED ALOES, WASHED A.; EXTRACTUM ALOËS BARBADENSIS (B. P.), EXTRACTUM ALOËS (Ph. L.), E. A. AQUOSUM (Ph. D.), L. _Prep._ 1. (B. P.) Barbadoes aloes, in small pieces, 1 lb.; treated with 1 gall. of boiling water for 12 hours, and the clear liquid evaporated.--_Dose_, 1 to 3 gr. B. P. 2 to 6 gr.

2. (B. P.) Socotrine aloes, 1 lb., treated with 1 gall. of boiling water for 12 hours, and the clear liquid evaporated to dryness.

3. (Ph. D.) Aloes (hepatic), 4 oz.; water, 1 quart; boil till dissolved; when cold, decant the clear liquid, and evaporate as before.

4. (Ph. Bor. 1847.) By macerating powdered aloes in cold water for 48 hours, with frequent agitation, and then evaporating in a water bath at a temperature not exceeding 150° to 165° Fahr., until a pilular consistence is attained.

_Obs._ The second is the form commonly adopted in the laboratory. When made with the juice of borage, burgloss, &c., it forms the old 'ALOES INSUCCATA,'--_Dose_, 5 to 15 gr. See ALOES and EXTRACT OF BARBADOES ALOES.

=Extract of Aloes, prepared with Sulphuric Acid.= _Syn._ EXTRACTUM ALOËS ACIDO SULFURICO CORRECTUM (Germ. Ph.). _Prep._ Dissolve extract of aloes, 8 ounces, in distilled water 32 ounces, then gradually add sulphuric acid, 1 oz. (by weight), and evaporate to a dry extract.

=Extract of Anem'one.= See EXTRACT OF PASQUE FLOWER.

=Extract of Angel'ica.= _Syn._ EXTRACTUM ANGELICÆ, L. _Prep._ 1. (Ph. Baden.) From a tincture of the root, prepared with spirit sp. gr. ·944 (= 21-1/2 u. p.).

2. (Ph. Bor.) Angelica root and rectified spirit, of each 2 parts; water, 9 parts; digest, strain, and evaporate. Inferior to the preceding.

3. (Dr Moir.) Angelica root, 2 lbs.; rectified spirit, 1 gall.; make a tincture; to the 'marc' add proof spirit, 1 gall., and repeat the digestion; filter the two tinctures separately, mix, distil off the spirit, and evaporate. Balsamic, stomachic, and tonic.--_Dose_, 10 to 20 gr. The last is the most balsamic and agreeable.

=Extract of Ap'ples.= _Syn._ CHALYBEATED E. OF A.; EXTRACTUM FERRI POMATUM, L. _Prep._ 1. (Ph. Bor.) Crab-apples (unripe), 6 lbs.; peel them and reduce them to a pulp; add iron wire (in small coils), 1 lb.; digest in a vapour bath for about a week, express, strain, decant, and evaporate in a porcelain vessel, with constant stirring, to the consistence of a soft extract; dissolve the residuum in water, 4 parts, strain and evaporate as before.--_Dose_, 5 to 10 gr.; as a chalybeate tonic. The formula of the Ph. Baden is nearly similar.

2. (Ph. Germ.) Reduce 5 lbs. of unripe apples to a pulp; mix them with cut straw, and press. To the strained juice after removal of the sediment add 1-1/2 oz. of reduced iron. When this has dissolved, to the cooled liquid add as much water as will make up 4-3/4 lbs. Filter, and reduce to a thick extract.

=Extract of Ar'nica.= _Syn._ EXTRACT OF ARNICA FLOWERS; EXTRACTUM ARNICÆ FLORUM, L. _Prep._ 1. (P. Cod.) From the dried flowers, as ALCOHOLIC EXTRACT OF ACONITE--P. Cod.

2. (Ph. Græca, 1837.) From a tincture of the flowers, prepared with rectified spirit, 3 parts, and water, 5 parts.--_Dose_, 2 to 6 gr.; as a stimulant in various diseases accompanied with debility, deficient nervous sensibility, paralysis, dropsies, diarrh[oe]a, amenorrh[oe]a, dysentery, &c.

=Extract of Arnica-Root.= _Syn._ EXTRACT OF ARNICA; EXTRACTUM ARNICÆ RADICIS, L. _Prep._ 1. (Ph. Baden.) As EXTRACT OF ANGELICA--Ph. Baden.

2. (Ph. Græca.) From tincture of the root, prepared as No. 2 (_above_). The form of the Hamburg Codex is nearly similar.--_Dose, &c._ As the last.

=Extract of Art'ichoke.= _Syn._ EXTRACTUM CYNARÆ, L. _Prep._ From the fresh leaves of the artichoke, as EXTRACT OF ACONITE--Ph. L.--_Dose_, 3 to 6 gr., twice or thrice daily; in rheumatism, &c.

=Extract of Aspar'agus.= _Syn._ EXTRACTUM ASPARAGI, L. _Prep._ 1. (Soubeiran.) From the expressed juice of the shoots, clarified and evaporated by a gentle heat.

2. From the juice of the roots, as No. 1. Both are diuretic.--_Dose_, 15 gr. to 1/2 dr., or more.

=Extract of Bael.= _Syn._ EXTRACTUM BELÆ LIQUIDUM, L. B. P. Bael, 1; distilled water, 15; rectified spirit, 1/8; macerate for 12 hours in 5 of the water, pour off the liquid, repeat the operation twice for 1 hour; press, filter, and evaporate to 1, including the spirit. A fluid ounce is equal to a solid ounce.--_Dose_, 1 to 2 dr.

=Extract of Balsam Apple.= _Syn._ EXTRACTUM BALSAMIMÆ. The inspissated juice of the balsam apple.--_Dose_, 5 to 15 drops in dropsy.

=Extract of Bark.= See EXTRACT OF CINCHONA.

=Extract of Belladon'na.= _Syn._ EXTRACT OF DEADLY NIGHTSHADE, INSPISSATED JUICE OF BELLADONNA; EXTRACTUM BELLADONNÆ (B. P., Ph. L. E. & D.), SUCCUS SPISSATUS BELLADONNÆ, L. _Prep._ 1. (B. P.) Take 112 lbs. of fresh leaves and tender branches, bruise in a stone mortar or other suitable apparatus, and press out the juice, heat it gradually to 130° F., separate the green colouring matter by a calico filter, heat the strained liquor to 200° F. to coagulate the albumen, and again filter; evaporate the filtrate by a water bath to the consistence of a thin syrup, then add to it the green colouring matter previously separated, and, stirring the whole together assiduously, continue the evaporation at a temperature not exceeding 140°, until the extract is of a suitable consistence for forming pills.--_Dose_, 1/4 to 1/2 gr., gradually increased to 1 or 2 gr.

2. (Ph. E.) Express the juice from the bruised fresh plant, sprinkle the 'marc' with water, and again apply pressure; mix the expressed liquids, filter them, and evaporate the filtered liquor in a vapour bath to the consistence of an extract.

3. (Ph. D.) From the leaves, collected when the plant begins to flower. The expressed juice is allowed to stand for 24 hours, and the clear portion is decanted; the sediment is placed on a calico filter, washed with an equal bulk of cold water, and the filtrate mixed with the expressed juice. The mixed liquid is next heated in a water bath, to coagulate its albumen, and after being skimmed, and filtered through flannel whilst hot, the washed sediment is added, and the whole evaporated, as before.

4. (Ph. U. S.) The expressed juice is heated to the boiling-point, filtered and evaporated (see _below_).

_Obs._ The P. Cod. directs this extract to be made by two different formulæ. The product of the one resembles that of the Ph. L.; that of the other, that of the Ph. E. That of the Ph. L., from retaining the fecula, is the weakest preparation.--_Dose_, 1/2 gr. to 1 gr., gradually increased to 3 or 4 gr.; as an anodyne in neuralgia, tic-douloureux, &c.; as an antispasmodic to relieve rigidity and spasms, in various affections of the uterus, rectum, urethra, bladder, &c., and in hooping-cough; in various maladies of the eyes; and as a resolvent and discutient in several glandular diseases. It has been highly recommended as a preservative against scarlet fever. It is most frequently employed externally, under the form of a plaster, ointment, or lotion. It is poisonous.

5. (Alcoholic; E. B. ALCOHOLICUM, L.)--_a._ (P. Cod.) As ALCOHOLIC EXTRACT OF ACONITE--P. Cod.

_b._ (Ph. U. S.) As the last (nearly), using spirit of ·935 (=about 13 u. p.).

_c._ (Moir.) The expressed juice is coagulated by heat, cautiously applied, and filtered; the filtrate is reduced to the consistence of a syrup, and mixed with an equal volume of nearly anhydrous alcohol (say of 90%); the clear portion is lastly evaporated, as before.

_Obs._ The above is much more powerful than the common extract, and is chiefly used in external applications. See BELLADONNA, and _below_.

=Extract of Belladonna Ber'ries.= _Syn._ EXTRACTUM BACCARUM BELLADONNÆ, L. _Prep._ (P. Cod.) From the expressed juice of the berries, evaporated to the consistence of thick honey.--_Dose_, 1 to 5 gr.

=Extract of Bis'tort.= _Syn._ EXTRACTUM BISTORTÆ, L. _Prep._ 1. (P. Cod.) From the dried root of bistort or snake-weed (_Polygonum Bistorta_), by percolation with temperate distilled water.

2. From the infusion made with boiling water, or from the decoction. Astringent and tonic.--_Dose_, 10 gr. to 1/2 dr.

=Extract of Bit'ter-sweet.= _Syn._ EXTRACT OF WOODY NIGHTSHADE; EXTRACTUM DULCAMARÆ, L. _Prep._ 1. From the decoction of the stalks.

2. (Ph. U. S.) From the dried stalks, by percolation with temperate water. Diaphoretic, diuretic, and narcotic.--_Dose_, 3 to 6 gr.; in chronic asthma, rheumatism, and chest diseases; and particularly in chronic skin diseases.

=Extract, Black.= See EXTRACT OF COCCULUS.

=Extract of Black Pepper.= See EXTRACT OF PEPPER.

=Extract of Bladder-wrack.= _Syn._ EXTRACTUM FUCI VESICULOSI. From the dried plant of the bladder-wrack. Given in obesity.

=Extract of Bor'age.= Syn. EXTRACTUM BORAGINIS, L. _Prep._ 1. (P. Cod.) From the dried herb (_Borago officinalis_).

2. (Ph. Lusit.) From the clarified juice of the fresh plant. Exhilarating, restorative, and pectoral.--_Dose_, 10 to 30 gr., or more.

=Extract of Box.= _Syn._ EXTRACTUM BUXI, E. CORTICIS B., L. _Prep._ (P. Cod.) From the tincture of the root bark, prepared (with proof spirit) by displacement, as EXTRACT OF ACONITE--P. Cod.

=Extract of Broom.= _Syn._ EXTRACT OF BROOM TOPS; EXTRACTUM SCOPARII, E. SPARTII SCOPARII, L. From decoction of broom tops. Diuretic and cathartic; and, occasionally, emetic.--_Dose_, 20 gr. to 1 dr.; in dropsy, &c. It is now seldom used.