PROCESS FOR THE STABILIZATION OF CHLORAMINES OR SALTS OF HYPOCHLOROUS ACID

METHODE DE STABILISATION DE CHLORAMINES OU DE SELS D'ACIDE HYPOCHLOREUX

English Abstract

ABSTRACT OF THE INVENTION
A process for the stabilization of chloramines or salts of
hypochlorous acid in dried form using oxidation-resistant
reversibly dehydratable substances is described.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the stabilization of chloramines or
salts of hypochlorous acid in dried form, compris-
ing the addition of an oxidation-resistant revers-
ibly dehydratable substance.
2. The process as claimed in claim 1 wherein the sub-
stance is maltose, calcium acetate or trisodium
citrate dihydrate.
3. The process as claimed in claim 1, wherein the
dried form is obtained by freeze-drying.
4. The process as claimed in at least one of claims
1 to 3, wherein the substances are employed in
concentrations of 0.3-30 per cent by weight.

5. The process as claimed in claim 1, and substantially as
described herein.

Description

2~ 4~2
BEHRINGWERKE AXTIENGESELLSCHAFT 88/B 040 - Na 741
Dr. Ha/Sd
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Process for the stabilization of chloramines or salts of
hypochlorous acid
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The invention relates to a process for the stabilization
of chloramines or salts of hypochlorous acid in dried
form using reversibly dehydratable oxidation-resistant
substances. -
Chloramines a6 agents oxidizing methionine to methionine
sulfoxide are of importance in the clinical chemistry of
fibrinolysis. They make it possible to measure fibrino-
lytic activity virtually independent of the presence of
alpha-2-antiplasmin.
. ;. - .. ,::
Solutions of chloramines, however, can be kept only for
a limited period, especially when oxidizable substances
are present. It is therefore useful to provide the chlor-
amines in lyophilised form. Common lyophilisation fillers
such as mannitol or RFicoll are, however, unsuitable, as
they react with oxidants.
: ;, . -;
It is therefore the aim of the invention to provide a
process for the stabilization of chloramines.
Surprisingly, oxidants of the chloramine type, such a8
chloramine-T, chloramine-L or their salts or salts of
HOCl in dried, preferably lyophilised form, are
stabilized by reversibly dehydratable oxidation-resistant
substances.
The invention thus relates to a process for the stabi-
lization of chlor~mines or salts of hypochlorous acid in
dried form, comprising the addition of an oxidation-
resistant reversibly dehydratable substance.
Preferred substances are sugars, preferably maltose, or
salts, preferably trisodium citrate dihydrate or calcium
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acetate.
The substance 6uch as sugars, preferably maltose, or
salts are employed in concentrations from 0.1-30, prefer-
ably 1-5% (per cent by weight).
In lyophilised form, the oxidants stabilized in this way
retain their oxidative strength even if the reagents are
stored for more than two weeks at 37C.
The invention is further defined in the claims and is
described in detail in the following example .
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Example
Stabilization of chloramine by hygroscopic substances
450.7 mg chloramine-T (or 341.7 mq chloramine-B) were
taken up in 20 ml of distilled water together with
94.3 mg of tranexamic acid and 600 mg in each case of - :~
maltose monohydrate, calcium acetate or trisodium citrate
dihydrate and the pH-values were ad~usted to pH 10.
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After complete dissolution the solutions were used in the
~ehringwerke PAI-CAP test as a substitute for the
"Oxidant" reagent. Additionally, the solutions were lyo-
philised in portions of 1 ml and stored in solid (lyo-
philised) form and in dissolved form at 37C and a
PAI-CAP test was carried out with these reagents. Tris
buffer or "Standard Sl" from the Behringwerke PAI-test
kit was employed as the sample in each case. The results
are given in the following table.
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Table -
chloramine-T chloramine-B .
measured plasmin act. (A/5 min).x 1000 :-
buffer Standard Sl act. decrease in Std.
Sl respect.to buffer(%) ~:~
maltose
immediate 1.298 1.210 7 10
after 1 week 1.271 1.076 15 23
after 2 weeks 1.078 0.909 16 25 .
calcium acetate
immediate 1.262 1.156 8 15 ~ . :
after 1 week 1.212 1.051 13 23 .
after 2 weeks 1.160 1.002 14 22
trisodium citrate dihydrate
immediate 1.363 1.205 12 15 --~
after 1 week 1.304 1.036 21 25 : .;~
after 2 weeks 1.190 0.971 18 20 : .
. . .
Mean values from two determinations ~ :~
Maltose, calcium acetate or trisodium citrate dihydrate
are found to be almost inert towards oxidation with re-'' ''"'~,'!.~ "~`'
spect to chloramines, which they stabilize.
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