Improvements in the Manufacture of Granular Effervescible Mixtures.
Year: 1892

page_text: Date of Application, 15th July, 1892-Accepted, 20th Aug. 1892
COMPLIMIE DIUINICA TUN.
Improvements in the Manufacture of Granular Effervescible
Mixtures.
I, THOMAS KERFOOT of the Chester Street Works, Chester Street, Oxford
Road, Manchester, in the County of Lancaster, Manufacturing Pharmaceutical
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 granular effervescible mixtures of
which a familiar example is that commonly called citrate of magnesia.
It is well known that these mixtures are compounds of an acid, such as tartaric
or citric acid, and a bicarbonate such as the bicarbonate of soda, and that their
effervescence upon being mixed with water, arises from the liberation of carbon
Other
dioxide, consequent upon the combination of the acid with the alkaline base.
substances of a medicinal character, or as flavouring or colouring agents are some-
times mixed with the acid and carbonate, and in some cases, the acid may be
In the usual course of
substituted by a suitable biphosphate or bisulphate.
manufacture the moisture contained in the acid produces a reaction and causes the
liberation of some of the carbon dioxide, thus reducing the amount of effervescence
when the mixture is finally used.
The principal object of my invention is to avoid this loss, and for this purpose I
separately granulate and dry the acid and the alkaline constituents of the mixture,
which are thereafter intimately mixed and packed in air-tight vessels such as are
used for ordinary effervescible mixtures. By following this method of manufacture,
no appreciable liberation of carbon dioxide will take place until the mixture is
finally used.
I will hereinafter describe fully and particularly in what manner my invention
may be practically carried into effect, but I desire it to be understood that I do not
limit myself to any particular ingredients, to the proportions of such ingredients, to
any system of granulation, or mode of drying.
My method of manufacture is equally applicable to all effervescible mixtures and
compounds which are capable of granulation, and it may best be illustrated, by way
of example, by describing the processes which I adopt in the production of granular
effervescent citrate of magnesia (so-called).
The acid constituent may consist of ten parts of tartaric, or of citric acid or of a
mixture of them, and five parts of sugar, ali powdered and intimately mixed together
with just sufficient water to make the mixture slightly damp and sticky, so that it
will tend to cohere when pressed together. This mixture is quickly transferred to
and rubbed through a sieve having about eight meshes to the inch. The granules
so formed are then removed to a drying chamber which may be heated to about
100 degrees F., and are called the acid granules.
The alkaline constituent may consist of ten parts of bicarbonate of soda, five parts
of powdered sugar, and two parts of dried sulphate of magnesia in powder. This
mixture may be mixed granulated and dried, in precisely the same manner and by
the same means as hereinbefore described for the acid granules, and the granulated
product called the alkaline granules.
The acid and the alkaline granules are mixed in such proportions as may be
desired, and are then bottled for sale and use in the ordinary manner.
The whole or part of the sugar may be omitted, and instead of the water, a thin
syrup may be employed for damping the powders.
Medicinal, flavouring, and colouring agents, if used, or such of them as may be
used, may be added to the acid mixture or to the alkaline mixture before or during

page_text: granulation, or may be added te the mixed granules as the circumstances in each
case may render advisable.
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 hereinbefore described method of manufacturing granular effervescible
mixtures, which consists in separately granulating and drying the acid and the
alkaline constituents, and thereafter mixing them together, substantially as and for
the purpose set forth.
2. As a new article of manufacture, granular effervescible mixtures containing a
larger proportion of carbon dioxide than is contained in such mixtures as at present
produced, prepared substantially as hereinbefore described.
1039
WILLIAM E. HEYS,
Agent for the Applicant.
WILLIAM E. HEYS,
Agent for the Applicant.