Manufacture of New Therapeutical Compounds.
Year: 1897

page_text: Date of Application, 23rd July, 1897-Accepted, 4th Sept., 1897
COMPLETE SPECIFICATION.
Manufacture of New Therapeutical Compounds.
'
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (which has been cominunicated to me from abroad by The Society of
Chemical Industry in Basle, Basle, Switzerland, Chemical Manufacturers) and in
what manner the same is be performed to be particularly described and ascertained
in and by the following statement :-
Up to the present time compounds have been prepared from equal molecules of
bismuth-oxyiodide and gallic acid (Patent No. 22902 of 1894) or methyl gallic acid
(Patent 15295 of 1896).
Of these bodies the bismuth oxyiodide gallate of Patent 22902 of 1894 has been
employed in therapeutics under the name of "Airol."
It has been discovered that new products of high therapeutic value can be obtained
from tannin with bismuth oxyiodide, or with the reagents by which this is produced;
.there are formed according to the choice of conditions of production, essentially three
different bodies, which may be represented by the following formulae:

page_text: It is therefore possible to modify the effect of the preparations, according, as the
monobismuth oxyiodide lake (Formula I.), the dibismuthoxyiodidelake (Formula II.)
or a dibismuthoxyiodide lake poorer in iodine (Formula III.) of the tannin is
produced.
The above products are suitable both as powder for wounds, as also for the
preparation of bandage gauze.
The property of the new products, of serving with advantage for the production of
handage gauze is explained by the fact that the tannin bismuth. contained therein
readily fixes itself on vegetable fibres in a similar manner to the tannin antimony of
the tannin-tartar emetic used, as well known dyeing as a mordant.
Example. 30 parts of crystallised bismuth nitrate are dissolved in 5 parts of
water, with addition of three parts of nitric acid, and to this solution are added
12 parts of a 20 per cent. sodium acetate solution.
A greatly diluted aqueous solution of 195 parts tannin and 95 parts potassium
iodide is then added the mixture being well stirred, when a dark brown precipitate
will at once be produced.
A dilute solution of 10.8 parts of bicarbonate of soda is then added, whereby the
previously brown precipitate is made to assume a light grey colour. The mass is
allowed to stand for some time, is then filtered, washed with a small quantity of
water, pressed and dried.
The body thus produced corresponds as regards its composition, with the above
given Formula I. of a monobismuthoxyiodide lake.
It forms a grey powder which is quite insoluble in water. On boiling with water.
the grey colour of the compound turns into a yellowish coloration with decomposition
and production of a tannin odour. The new tannin compound also is decomposed by
the influence of acids and alkalis, and after remaining a long time in a humid
atmosphere.
Under the direct influence of light, the grey colour of the new compound turns
gradually into a brown colour.
If in the process of the above example the quantity of bismuth nitrate and iodine
salt employed be doubled, and the quantities of acetate and bicarbonate be also
correspondingly increased a body is produced which represents essentially a
dibismuthoxyiodide lake (Formula II.). A doubling of the bismuth nitrate alone
while retaining the same quantity of sodium iodide on the other hand produces the
dibismuth lake poorer in iodine, and represented by Formula III.
The process for the preparation of these bismuth oxyiodide lakes of tannin can also
be modified, without alteration of the end result in such manner that first the
bismuth-tannin lakes are produced as intermediate bodies and then these are
converted into the iodide compounds by treatment with iodine salts. The tannin
(gallo-tannic acid) can also in some cases be replaced by other tannic acids, as also by
the condensation products of tannic acid with formaldehyde.

page_text: The new products or mixtures in one or other of the above described ways are in
particular intended for the preparation of bandage gauzes, and wound salves, as also
for wound powders.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. Process for the production or mono- and di-bismuth oxyiodide lakes of tannin or
any other tannic acid, or a condensation product of formaldehyde with tannin
consisting in bringing from 1 to 2 molecules of a bismuth salt, into reaction
with 1 to 2 molecules of an iodine salt, and one molecule of tannin (gallo-tannic acid)
or any other tannic acid or a condensation product of formaldehyde with tannin,
substantially as described.
2. As new manufactures the bismuthoxyiodide lakes of tannin or of other tannic
acids or of a condensation product of formaldehyde prepared according to the process
referred to in the first claim.