Improvements in Cinchona Preparations.
Year: 1894

page_text: COMPLETE SPECIFICATION.
Improvements in Cinchona Preparations.
FREDERICK WILLIAM FLETCHER Beauchamp Lodge Enfield Middlesex
Manufacturing Chemist do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
It is well known that a large number of persons are unable to take preparations
of cinchona bark or its active principles, on account of the severe headache,
giddiness, singing in the ears, and other ill effects which result therefrom. It is also
a well known fact that when certain compounds of bromine are administered in
conjunction with the bark or its alkaloidal principles, the symptoms above referred
to are no longer produced. It is therefore, customary for physicians to prescribe
quinine and other alkaloids of the bark either in the form of neutral or acid
hydro bromates, or associated with some other bromine salt. There is, however, a
consensus of medical opinion that a preparation of the bark itself is much more
valuable as a tonic than the isolated alkaloids. In addition to the alkaloids,
cinchona bark contains cincho-tannic, kinovic, and kinic acids, besides volatile oil
and resin. These principles possess valuable tonic, aromatic and astringent
properties, and enable preparations of the bark to be borne without uneasiness in
cases in which the alkaloids alone, irritate the stomach, and produce nausea and
febrile symptoms.
In making liquid preparations of cinchona bark, it is usual to treat the bark
either with water, or with a mixture of water and hydrochloric or sulphuric acids,
or with a mixture of water and alcohol; and, in order that such preparations may
be taken by persons idiosyncratic to cinchona, it is necessary to administer in
conjunction with them one or more of the aforesaid compounds of bromine. The
objections to this are, in the case of liquid extracts of the bark prepared with
hydrochloric or sulphuric acids, that if hydrobromic acid be added, the medicine is
made undesirably and inconveniently acid, and if neutral bromine salt is employed,
double decomposition ensues, with formation of secondary compounds, the presence
of which is for many reasons objectionable. In the case of an extract or tincture
prepared with dilute alcohol, cinchona-red, and other tannins of the bark are
present in such large quantity that the preparation is inadmissible for persons
of weak digestion, and, moreover, on dilution with water, the aforesaid tannin
compounds are thrown down as copious precipitates, thus rendering the medicine
unsightly and unpleasant.
The improved process which I have devised, and for which I desire to obtain
Letters Patent, consists in the extraction of the bark by means of hydrobromic acid
of suitable strength. I have found that hydrobromic acid is an excellent solvent of
the active principles of the bark in their natural condition, and, that, by its use
extract of cinchona can be produced possessing the following important
advantages over any extract of cinchona at present in use:
an
1. It contains the whole of the alkuloids present in the bark.
2. In addition to the alkaloids my improved extract contains the kinic kinovic
and cincho-tannic acids, in addition to other natural and more or less undefined
constituents of the bark, all of which possess valuable tonic, aromatic and
astringent qualities.
3. The alkaloidal & other constituents of the bark being intimately associated
with bromine, my improved extract can be taken with advantage by persons other-
wise unable to derive benefit from preparations of cinchona, owing to the violent
headache and other distressing symptoms to which they give rise.

page_text: 4. My improved extract is perfectly miscible with distilled water.
5. Iron compounds, and more particularly bromide of iron, can be prescribed
with my improved extract without being decomposed, blackened in colour, or
precipitated. This property is possessed by no other extract of cinchona, and will
be of manifest value in cases in which the physician desires to administer iron in
conjunction with cinchona.
6. My improved extract is agreeable to the taste, and can be taken by the most
fastidious without repugnance.
My improved extract can be obtained by the following process, although I wish
it to be clearly understood that I do not limit myself to the relative proportions of
bark and hydrobromic acid therein given, nor to the mechanical details of the
process.
Any other suitable proportions, or any other suitable process, based on the
cardinal principle of using hydrobromic acid as the solvent medium can be adopted
as occasion requires.
I prefer to employ cinchona bark of the very finest quality, and containing not
less than from 8 to 10 per cent. of total alkaloids.
I
I take 15 pounds of such bark, and reduce it by grinding to the degree of fineness
technically known as No. 40. I then take 27 fluid ounces of hydrobromic acid of
specific gravity 1-275 and dilute the same with distilled water to the volume of
6 gallons. This diluted acid I shall hereinafter refer to as ❝ menstruum."
carefully and throughly damp the ground cinchona bark, with half a gallon of
menstruum, and set it aside for six hours to enable the acid to permeate the fibre
of the bark, and to allow the latter to swell. The damped bark is then packed in a
displacement apparatus, and percolated with the remainder of the menstruum. The
percolation is then continued with distilled water until the percolate ceases to
indicate the presence of alkaloid when tested by any suitable re-agent. To the
percolate, I then add 30 fluid ounces of glycerine, and evaporate the whole in a
vacuum apparatus, constructed of glass, stoneware or other material unaffected by
acids, until the volume is reduced to 240 fluid ounces. I then preserve it in closely
stoppered vessels. A fluid ounce of this extract will contain all the soluble
constituents of one ounce by weight of cinchona bark, in intimate association and
combination with bromine.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is.
1. The use of hydrobromic acid as a solvent for the extraction of the alkaloids
and other active principles of cinchona bark and the production thereby of-
2. An improved preparation of cinchona bark, containing in perfect solution, not
only the whole of the alkaloids, but also the cincho-tannic, kinic & kinovic acids,
and other constituents of the bark, in intimate association with bromine.
3. An improved preparation of cinchona bark, which can be taken without ill
effects by persons who have hitherto been unable to take cinchona bark or its
preparations on account of the headache, singing in the ears, giddiness and other
unpleasant symptoms thereby produced.
Dated this Second day of July 1894.