Calendula 200 Gm.

Cimicifuga 200 Gm.

Alcohol.

External.

3-7 Cc.

Cinchona 200 Gm.

Alc. 67.5 p., Water 25 p., Gly- 3-7 Cc.

cerin.

Cubeb 200 Gm.

Alcohol.

2-7 Cc.

Nutgall 200 Gm.

Alcohol, Glycerin.

Lotion.

20

Guaiac 200 Gm.

Alcohol.

1-4 Cc.

Guaiac 200 Gm.

Sp. Ammonia Arom. q. 8.

1-4 Cc.

Hops 200 Gm.

Dil. Alcohol.

3-12 Cc.

20

Hydrastis 200 Gm.

Dil. Alcohol.

1-3 Cc.

Fl. Ext. Ipecac 100 Cc., Deod. Tr. Opium 1000 Cc.

Rhubarb 200 Gm., Cinnamon, Cloves each 40 Gm., Nutmeg Dil. Alcohol, Glycerin.

3-8 Cc.

20

Valerian 200 Gm.

20

Ginger 200 Gm.

20

Benzoin 120 Gm., Purif. Aloes 20 Gm., Storax 80 Gm., Balsam

*See Footnote on page 225.

Sp. Ammon. Ar. q. s.

Alcohol.
Alcohol.

EXTRACTA FLUIDA-(Fluid Extracts).

FLUID EXTRACTS are concentrated fluid preparations of nearly uniform strength, representing the activity of the drug, volume for weight. When properly prepared they afford a permanent, active, concentrated liquid, representing the drug in definite proportions.

As required by the U. S. Pharmacopoeia, 1 cubic centimeter of the preparation represents the medicinal activity of 1 gramme of the drug. Previous to 1880, the strength was represented by 1 troy-ounce of the drug to 1 fluidounce of the fluid extract. On comparison it will be seen that our present fluid extracts are about 5 per cent. weaker than those of the Pharmacopoeia of 1870, thus:

100 troy ounces of drug (3110.4 Gm.) yield 100 fluidounces (2956.4 Cc.) of fluid extract.-U. S. P., 1870. 100 grammes of drug yield 100 Cc. of fluid extract.-U. S. P., 1880 and 1890.

It will be seen that according to the U. S. Pharmacopoeia of 1870, 3110.4 Gm. (100 troy ounces) of drug yielded 2956.4 Cc. (100) fluidounces) of fluid extract, instead of 3110.4 Cc., as the present Pharmacopoeia requires; hence there is a difference of 154 Cc. in the proportion of volume to drug, which render our present fluid extracts about 5 per cent. weaker as compared with those based on troy weight and fluidounces, and which is certainly a point in their favor.

The British Pharmacopoeia directs that its liquid extracts (with the exception of those of cinchona, glycyrrhiza, opium and pareira), be made of the strength of 1 avoirdupois ounce to 1 fluidounce imperial. They are practically identical with our

own.

The German Pharmacopoeia has introduced four fluid extracts, the method of preparation and strength of which is the same as those directed by the U. S. Pharmacopoeia.

The U. S. Pharmacopoeia directs that all fluid extracts be prepared by the process of percolation, with authority to employ the method of repercolation, if this be found desirable.

MENSTRUUM.-The U. S. Pharmacopoeia directs the employment of certain menstrua, which are selected with the view of extracting all the activity of the drug, and at the same time of affording a stable preparation. The different menstrua employed consist of alcohol, various mixtures of alcohol and water, and either of these in conjunction with glycerin. In two instances (triticum and castanea) boiling water is employed to exhaust the drug, with subsequent addition of alcohol, or alcohol and glycerin, to insure the stability of the preparation.

Acetic acid of a strength varying from about 60 per cent. to 20 per cent. or less, has been used by Dr. Squibb as a menstruum for drugs containing ethereal oils, aromatic resins, alkaloids, etc.

It is claimed to yield a very effective and palatable preparation; in experiments with nux vomica and belladonna this menstruum has proven its superiority to alcohol.

Fluid Extracts are prepared by "simple" or "fractional percolation." By "simple" percolation we understand that the entire drug is percolated at one operation; under this head we have the official process, that of vacuum percolation, and percolation combined with maceration and pressure. In "fractional percolation" the drug is divided into two or more portions, the reserved (first) percolate from each portion is set aside, while the subsequent (weaker) percolates are employed for macerating and percolating each subsequent portion. This process is known as that of repercolation.

PERCOLATION (U. S. Pharmacopoeia Process).

The U.S. Pharmacopoeia of 1890 directs that all fluid extracts be prepared by the process of percolation. 1000 Gm. of the drug of the proper degree of fineness are moistened, packed, macerated and percolated (see Percolation, page 191), until exhausted. From 700 to 900 Cc. of the first portion of the percolate are preserved, and the weaker portion is evaporated at a low temperature (50° C.), to the consistence of a soft extract, which is then dissolved in the reserved portion, to which enough menstruum is finally added to make the finished preparation measure 1000 Cc. The objections to the U. S. Pharmacopoeial process of 1870 were that the weak percolate, when evaporated to an ascertained volume, sustained a loss of most or all of its alcohol, leaving a more or less aqueous residue, which, when added to the strongly alcoholic reserved portion, caused a precipitation of more or less resinous or other active matter. The operator should be careful not to employ too high a degree of temperature in evaporating the weak percolates, otherwise injury or destruction of organic principles is liable to occur. The official process is often objected to, because of the employment of heat in part of the operation; however it must be remembered that from 75 to 90 per cent. of the activity of the drug is represented by the reserved portion, and that but a very small percentage is subjected to the action of heat, as a rule, which, if properly regulated, will not materially injure the preparation (exceptions are Allium, Prunus Virginiana, etc.).

REPERCOLATION ("fractional"* percolation), as described by Dr. Squibb, its originator (1866), "consists in the successive application of the same percolating menstruum to fresh portions of the substance to be percolated." Its object is the preparation of a fluid extract without the use of heat. The operation may be briefly described thus: 32 parts of the drug in powder are divided into four equal portions of eight parts each, one of which is

See Prof. Diehl's paper, Proceed. Am. Phar. Assoc.," 1878, p. 681.

moistened, packed, macerated, then percolated until exhausted, this weaker percolate being received in several distinct portions. The first six parts of the percolate are reserved, and the remaining portions are used successively for moistening and percolating the second eight parts of the powder. Of the second percolate 8 parts are reserved, and the weaker percolate which is again received in several portions, used for the following third portion, as directed above.

The

The third and fourth fractions of 8 parts each are then treated in the same manner, 8 parts of percolate being reserved from each fraction. Finally, the four reserved portions of 6+8+8+8 fluidounces are mixed to obtain 30 parts of fluid extract.* weak percolate remaining over from the last portion of the drug is set aside for a subsequent operation on a fresh lot of the same drug. The National Formulary gives the following directions:

FRACTIONAL PERCOLATION.-Take of the drug, in powder of the prescribed fineness, sixteen (16) troy ounces, and divide this into three portions, of eight (8), five (5) and three (3) troy ounces, respectively.

Moisten the first portion (8 troy ounces) with the menstruum and percolate in the usual manner. Set aside the first three (3) fluidounces of the percolate, and continue until twenty-four (24) fluidounces more of percolate have passed, which should be received in several portions, so that the more concentrated will be separate from the last, weak percolate.

Then moisten the second portion of the drug (5 troy ounces) with the most concentrated of the percolates received during the

*As a practical example of this operation a typical description of the preparation of a fluid extract, as given by Dr. Squibb, is cited :—

EXTRACTUM CINCHONÆ FLUIDUM—(Fluid Extract of Cinchona).
B Yellow Cinchona, in powder No. 50,
Stronger Alcohol, s. g. 0.819, 2 parts,
Glycerin, s. g. 1.250, 1 part,
Water, 2 parts, .

32 parts. For sufficient quantity of

menstruum.

Weigh the stronger alcohol, glycerin, and water in succession, in any convenient quantity at a time, into a tared bottle, and mix them thoroughly for a menstruum.

Moisten 8 parts of the cinchona with 8 parts of the menstruum, by thoroughly mixing them, and allow the mixture to stand 8 hours in a closely covered vessel. Then pass the moist powder through a No. 8 sieve, and pack it firmly in a percolator. Pour menstruum on top until the mass is filled with liquid and a stratum remains on top unabsorbed; cover the percolator closely and macerate for 48 hours. Then arrange the percolator for an automatic supply of menstruum, and start the percolation at such a rate as to give 1 part of percolate in about 4 hours. Reserve the first 6 parts of percolate and continue the percolation until the cinchona is exhausted, separating the percolate received after the reserved portion into fractions of about 8 parts each.

Moisten a second portion of 8 parts of the cinchona with 8 parts of the weak percolate-the portion that was obtained next after the reserved percolate-and allow the moist powder to stand for 8 hours in a vessel closely covered. Then pack it moderately in a percolator, and supply the percolator automatically with the remaining fractions of the weak percolate in the order in which they were received, and finally, with fresh menstruum until the cinchona is exhausted. Percolate in the same manner and at the same rate as with the first portion of cinchona, and reserving 8 parts of the first percolate, separate the weaker percolate into fractions of about 8 parts each.

Percolate the third and fourth portions of 8 parts each of the cinchona in the same way as the second portion.

Finally mix the four reserved percolates together to make 30 parts of finished fluid extract; and having corked, labeled, and numbered the bottles containing the fractions of weak percolate, set them away until the process for cinchona is to be resumed.

When this fluid extract is to be again made, repeat the process as with the second portion, and reserve 8 parts of the first percolate as finished fluid extract from each 8 parts of cinchona from that time forward so long as the fractions of weak percolate are carried forward with which to commence each operation.

Upon this small scale the percolate from the first portion should weigh from 3 to 4 times the weight of the powder; and for the repercolations from 5 to 7 times the weight of the powder.