EDITORIAL
T H E SELECTION OF ANTISEPTICS AND DISINFECTANTS
The search for ideal antiseptics and disinfectants, that is those
which will inhibit or destroy bacteria and still leave the tissue cells
individually and collectively unharmed, is a medical problem
dating almost from the discovery of pathogenic bacteria. It goes
almost without saying that the ideal has not been discovered, but
many different substances have been tested and found effective
in varying degrees against certain groups of bacteria in particular
systems or tissues of the body. In analyzing the situation there
appear to be two principal reasons for not having more nearly approached the ideal, first inadequate methods of testing, evaluating
and comparing antiseptics and disinfectants, second because the
scientific assay of these substances such as they are have been
disregarded by the profession through misinformation and indifference, disregarded by manufacturers through prejudice and
competition and disregarded by the public through lack of knowledge and through exploitation on the part of distributors and
manufacturers.
Regarding methods of examination, Reddish pointed out that
the phenol coefficient test was the natural outgrowth of the early
use and constant properties of phenol. The standard phenol
coefficient tests were based on the use of Eberthella typhi but as
both Tilley and Reddish have pointed out an antiseptic that is
effective against typhoid bacilli may be weak or ineffective
against Staphylococcus aureus and other organisms. For example, certain chloro-phenol compounds show reported coefficients
as low as 20 + against Eberthella typhi and 1200 + against Staphylococcus aureus. Such striking differences in effectiveness are
more apt to be noted with simple substances than with compound
substances or mixtures. Merthiolate as an instance has a phenol
coefficient of 50 using Eberthella typhi and 70 using Staphylococcus
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aureus. Not only are compounds and mixtures more uniform in
their activity but the activity is also enhanced beyond predicted
levels as noted in the author's work with phenols, thymols,
resorcinols and tricresols used in combination with certain organic
acids as citric, tartaric, benzoic, salicylic and tannic acids and inorganic acids especially hydrochloric. Such combinations of relatively inactive and non-toxic substances give phenol coefficients
five tofifteentimes the combined coefficients of the two substances
when used alone and bring their activity well within the range of
the mercury compounds and mixtures without increasing their
toxicity.
To increase the specific information obtainable from phenol
coefficients Reddish recommended the use of various pathogenic
organisms to be used in addition to Eberthella typhi and outlined
methods for their use. Hence one must know the method and
organisms used in doing the phenol coefficients as well as. the results of the test just as one must know the type of serological test
used for the diagnosis of syphilis as well as the result.
These improvements introduced by Reddish along with tests
for penetration, as the agar cup method of Allen, give adequate
methods for evaluation and comparison of the activity of antiseptics
both as regards the type of organism and conditions encountered
in clinical practice. The other large factor to be evaluated and
compared is general and local toxicity. General toxicity is readily
determined by intraperitoneal and intravenous injection of the
antiseptic. Local toxicity was studied by Lambert, Lambert and
Meyer, German, Buschsbaum and Bloom and most recently by
Salle and Lazarus, utilizing tissue cultures. The last named
investigators evolved the following formula:
it
.. . , „_
highest dilution showing no tissue growth
highest dilution showing no bacterial growth
These methods for determining local toxicity have not been
standardized as yet but promise much in the evaluation and comparison of antiseptics from the standpoint of tissue cell survival
and wound healing. It is quite probable that various types of
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tissue cells will have to be used in the ultimate development and
standardization of these tests.
After careful laboratory evaluation of antiseptics and disinfectants through a study of phenol coefficients and toxicity indices
it remains for the clinician to select the most effective material for
the particular invading organism or group of organisms as determined by culture. Data regarding the various antiseptics and
their effect on particular organisms along with toxicity indices is
available in the current medical literature, but this is apparently
overshadowed by advertisements, manufacturers propaganda and
high pressure salesmanship to such an extent that the most widely
heralded material becomes the one used for all purposes from the
treatment of minor wounds to skin sterilization, and from treatment of large burns and infected cavities to intravenous injection
for septicemia regardless of the infecting organism or the local
and general toxicity.
With our rapidly increasing group of active antiseptics and our
increasing efficiency in their evaluation the profession should be
more critical in their selection and more discriminating in their
application approaching the ultimate goal of specific therapy.
F. W. HABTMAN.