The Manufacture of Improved Preparations of Iron for Medicinal Purposes, and Solvents therefor
Year: 1897

page_text: Date of Application, 24th June, 1897-Accepted, 6th Nov, 1897
The Manufacture of Improved Preparations of Iron for Medicinal
Purposes, and Solvents therefor
I, ERNST DOLLE, of 3 Wilhadistrasse, Bremen, in the German Empire, 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:—
This invention relates to the manufacture of improved preparations of iron for
medicinal purposes, and more particularly to the manufacture of a specific iron
preparation intended for the use of sufferers froin chlorosis and anaemia, and affording
the great advantage of not affecting the teeth.
All ferruginous liquors hitherto known contain iron in solution and are attended
with the serious drawback that they attack and blacken the teeth.
The iron specific formning the subject of this invention contains pyrophosphate of
iron (pyrophosporsaures Eisenoxyd) in a suspended form, which is obtained by the
addition of pyrophosphate of soda in solution to a solution of diluted
perchloride of iron, the chloride of sodium being removed as it forms.
:
The iron preparation thus obtained contains iron in an undissolved condition, so
that it is incapable of affecting the teeth.
Now in this connection the question naturally arises as to how the iron preparation
should be treated in the stomach to enable the iron to dissolve there and to
produce the desired effect on the system. In a general way provision for this is
inade in the acid gastric juice itself, which contains hydrochloric acid, having the
property of dissolving the pyrophosphate of iron (pyrophosphorsaures Eisenoxyd)
contained in the preparation. Besides, the other fluids contained in the stomach
are capable of effecting the solution.
To avoid the necessity, however, of bringing about the solution of the iron at the
expense of the gastric juices as this, more especially in the case of invalids may not.
be practicable and as, apart from that, the proportion of hydrochloric acid yielded
widely differs or fluctuates in the case of each individual, the stomach should
preferably be supplied with a special solvent in addition to the iron preparation
proper; the order of succession in which the two preparations are to be taken
being, of course, optional.
The solvent consists of a mixture of pyrophosphate of soda, bicarbonate of soda
and tartaric or citric acid, and in order to improve the taste, an edulcorant, such as
sugar, saccharine, sykose (a sweet preparation derived from benzoic acid) or the like,
as well as one or more aromatizers, such as citron oil or the like, may be superadded..
This solvent can be produced in various ways, the ingredients being preferably
mixed in the following proportions :-

page_text: It is important, that for each dose of iron milk, sufficient pyrophosphate of soda
be employed to effect the solution thereof.
The ferruginous specific prepared from pyro-phosphate of soda and a solution
of chloride of iron, which it is proposed to describe as iron milk furthermore
has the important advantage of being exactly like ordinary milk in colour
and appearance, so that it will be readily taken by anæmic and chlorotic
children as milk, while the preparations hitherto obtained, say, from phosphate of
soda and chloride of iron in solution, exhibit a greenish or yellowish tinge distasteful
to children.
A further advantage accruing from the preparation of the iron milk from
pyrophosphate of soda and chloride of iron in solution is that it yields a pure
solution of common salt from which by a process or cycle of operations presently to
be described valuable bye-products may be obtained. The formation of the cominou
salt solution may be ascribed to the fact that the pyrophosphate of soda is not
liable to weather and therefore in all cases gives uniformly proportioned solutions,
whereas phosphate of soda weathers very readily so that the proportion of water of
crystallization which it contains is not constant as a rule.
In preparing the iron milk, a dilute solution of chloride of iron is mixed with a
solution of pyrophosphate of soda, whereby pyrophosphate of iron (pyrophos-
phorsaures Eisenoxyd) is set free, while over the precipitate there collects a clear
solution of chloride of sodium (common salt). From the liquid containing
coinmon salt which after the removal of the clear solution is still mixed with the
precipitate, the common salt is washed out with a mixture of alcohol and water..
The addition of alcohol is necessary because pyrophosphate of iron (pyrophos-
phorsaures Eisenoxyd) dissolves in water with difficulty, while in alcohol it is
insoluble.
The pyrophoshate of soda dissolves in as few as 11 parts of hot water, so
that the hot solution may be prepared at very little cost, while a very voluminous
precipitate subsequently forms.
The common salt solution separated from the iron milk may be utilized as
follows:
(1.) From pure chloride of sodium and pure sulphuric acid there develops
hydrochloric acid, and this is conducted to the solution of common salt, obtained
as stated, until a state of saturation is reached.
H₂SO 2 NaCl = Na₂SO, + 2 HCI
(2.) Chloride of sodium separates while at the same time pure hydrochloric acid is
formed.
(3.) The common salt separated from the hydrochloric acid may either be used
directly for the preparation of fresh quantities of hydrochloric acid gas, or it may
be obtained in a chemically pure state by crystallizing out.
(4.) The pure hydrochloric acid separated from the common salt serves for the
preparation of the solution of chloride of iron required for the production of
iron milk, thus :-
2 HCI + Fe = FeCl₂ + H₂
FeCl2 + Cl =
- FeClg
(5.) From the sulphate of soda remaining behind in the process of manufacture
of hydrochloric acid gas, soda may be obtained by Leblanc's process (by mixing with
carbon and chalk and heating to incandescence).
AT
Nag08, +20-200, + Nu₂s
CaCO3 + NaS = CaS † Na₂CÔ¸
(6.) A portion of the soda solution is neutralized with phosphoric acid, a solution
of phosphate of soda being obtained :—
H₂PO + Na₂CO, Na₂HPO + CO₂ + H₂O
=

page_text: Most of the carbonic acid evolved in the course of this reaction escapes in the
form of gas and may be utilized as will be stated further on (paragraph 9).
(7.) Froin the phosphate of soda solution the salt is obtained by evaporation, the
carbonic acid which still remains behind in the solution being at the same time
eliminated. By heating the phosphate of soda to 300°, the saine is couverted into
pyrophosphate of soda :-
Na,CO, H₂O + CO₂ = 2 NaHCOg
Thus it will be seen that the method hereinabove described comprises a complete
cycle of operations resulting in a series of different products. What is particularly
deserving of note is the production of the chloride of iron solution required in the
manufacture of aromatic iron milk; and also the production of pyrophosphate of
soda and bi-carbonate of soda.
The aromatizing of the iron milk is an essential feature of the process, as, in
common with all ferruginous preparations hitherto known, iron milk possesses an
unpleasant metallic taste, which has greatly stood in the way of the diffusion of iron
preparations into more general use, and which it has up to the present time been
impossible to get rid of.
It has been ascertained by tests, however, that iron milk containing as it does a
considerable proportion of pyrophosphate of iron, may be entirely freed from the
objectionable flavour by being mixed with certain substances, viz., tincture of
cardamon, essence of orange, Bishop's Extract (from orange and lemon peel treated
with alcohol and white wine, with an admixture of glycerine), tincture of vanilla,
tincture of ginger, aromatic tincture, cinnamon tincture or cinnamon oil, acetic ether,
vanallin, spirits of wine and molasses.
The action of these substances upon the iron inilk is such that the objectionable
iron taste is completely annihilated:
The addition of molasses enables the iron to be still better held in suspension by
increasing the specific gravity.
The addition of alcohol enhances the "keeping" property of the preparation,
which, however, will long remain fit for use without the alcohol.
A good mixture for aromatizing iron milk has been obtained by proportioning the
ingredients as follows.
For every 1,000 parts of iron milk,
there
was taken,
Molasses
-
Alcohol
Essence of Orange
Bishop's Extract
Tincture of Vanilla
Tincture of Cinnamon
Aromatic Tincture
Tincture of Ginger
Tincture of Cardamon
Acetic Etber
Vanillin
I
120 parts
80
"
"
5
"
5
"
1.5
"
1.5
"
1
"
1.
"
.5
"
•1
"

page_text: It will, however, be understood that these proportions may be varied to suit
different tastes.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is.
First. The manufacture of a ferruginous preparation which will not affect the
teeth, wherein a dilute solution of chloride of iron is mixed with a solution of
pyrophosphate of soda, pyrophosphate of iron (pyrophosphorsaures Eisenoxyd) being
set free as a result, from which the cominon salt it contains is washed out with a
mixture of alcohol and water, whereby a preparation is obtained in which the iron is
present in au undissolved condition, so that it does not affect the teeth, such iron.
being dissolved by the gastric fluids on being conveyed into the stomach.
Second. A solvent consisting of a mixture of pyrophosphate of soda, bi-carbonate
of soda and tartaric acid, or citric acid, to which mixture, with a view to improving
its taste, an edulcorant such as sugar, saccharine, sykose or the like, and one or inore
aromatizers such as citron oil or the like are added; such solvent to be conveyed to
the stomach either before or after taking the iron preparation in order to cause it to
be dissolved and thereby to relieve the gastric juices from the task of effecting the
solution:
UI
1000
D. YOUNG & Co.,
11 and 12 Southampton Buildings, London, Agents for the Applicant.
D. YOUNG & Co.,
11 and 12 Southampton Buildings, London, Agents for the Applicant.