I. DETAILED REPORTS
Summarized Reports
CHEMICAL NATURE OF CHLORLYPTUS
Chlorlyptus is prepared by chlorinating eucalyptus oil until it has bound 30 per cent. of chlorin. “Chlorlyptol” is prepared in an analogous manner from eucalyptol. There has been some confusion as to the composition; but the principal constituent is now stated to be “a dichloride of eucalyptus oil,” to which the formula C10H16OCl2 has been assigned. It differs from the “chlorinated eucalyptus oil,” as ordinarily used for making dichloramin-T solutions, and which contains only 2⁄3 per cent. of chlorin.
AVAILABILITY OF CHLORIN IN CHLORLYPTUS
The chlorin content of chlorlyptus is almost entirely firmly bound, and therefore not “available,” in contrast to the group of so-called chlorinated antiseptics (i. e., the hypochlorite and chloramin type). For instance, it does not directly liberate iodin from iodid. It contains a very small quantity of free hydrochloric acid, or perhaps some acid esters, and liberates a little more on prolonged contact with water; but the total quantity liberated under reasonable conditions is very small. According to Hawk’s data, they correspond only to 1⁄8 per cent. HCl even after standing with water overnight and to only 1⁄5 per cent. of HCl after two weeks. The referee has shown that this quantity of acid has no therapeutic significance.
The “bound” chlorin of chlorlyptus, being chemically inactive, would have no more practical significance than the bound chlorin in common salt. The “ozone” said to be used during the preparation, to expel the HCl, has also practically disappeared, to judge by the slowness with which iodin is liberated from potassium iodid.
ACID FORMATION
Some constituents of chlorlyptus hydrolyze slowly and to a slight degree with the liberation of a trace of free hydrochloric acid. According to the data of Hawk’s report, the free acidity, in term of HCl, is 1⁄12 per cent. On standing with water over night, this increases to 1⁄8 per cent.
On this basis, Hawk proposed a theory that the claimed antiseptic effects of chlorlyptus are due to the continuous liberation of hydrochloric acid.
Experiments by the referee show this to be untenable. The traces of acid are neutralized and absorbed by the tissues so rapidly that an acid reaction is not maintained. These experiments are described in the appendix.
They were submitted to the manufacturers, who in the name of Mr. Weeks (May 9, 1919) concede this conclusion and state that “there is no doubt that the referee’s statements as to action in mouth, contact with living tissue and improbability that the acidity is effectively antiseptic is correct, and I am willing to accept the referee’s statement as conclusive in this respect.”
BACTERIAL CULTURE EXPERIMENTS
Mr. Weeks submitted a statement by Hawk to the effect that chlorlyptus has a phenol coefficient of 2.6, determined by the standard Hygienic Laboratory procedure.
He also quotes Rockefeller War Hospital that chlorlyptus kills Staphylococcus aureus in concentra of 1 dram: 1 gallon (about 1:1,000), but not in more dilute solutions.
More recently, he presented a more comprehensive report by Rivas, which is reproduced in the appendix. The essential results are tabulated herewith. This tabulation shows that chlorlyptus fails to kill the organisms after an hour’s exposure of the following concentrations:
Typhoid in bouillon, 10 per cent. of chlorlyptus.
Staphylococci in pus, 5 per cent. of chlorlyptus.
Staphylococci in serum, 1 per cent. of chlorlyptus.
It seems to the referee that a substance that is ineffective with an hour’s exposure to these concentrations is not at all likely to kill or check bacteria under clinical conditions. In other words, it is not an antiseptic in the ordinary sense.
The referee is not impressed by the superior power attributed by Rivas to chlorlyptus in the presence of pus. Inefficiency of 10 per cent. for one-half hour or of 5 per cent. for two hours seems a failure rather than a success. The referee also notes the absence of any data as to the relative efficiency of chlorlyptus against staphylococci in pus and in bouillon. The data on serum indicate that chlorlyptus is much weaker than phenol and show that it is less effective in the presence of pus than in other mediums.
The referee fails to grasp the bearing of the oil experiments on any clinical condition. Moreover, the inconstant results mentioned by Rivas suggest the possibility that the incorporation of the bacteria in oil may have prevented their effective distribution in the culture medium. If any significance is to be attached to these experiments, they should be checked by controls, without antiseptics.
SUMMARY OF RIVAS’ IN VITRO EXPERIMENTS
| Minimal Germicidal Concentrations | Maximal Not Germicidal Concentrations | |
| Typhoid Bacilli in Bouillon: | ||
| Chlorlyptus (Exp. 3) | 10%, 2 to 4 hours | 10% for 1 hour |
| 5% for 2 hours | ||
| Eucalyptus oil (Exp. 1) | 5% within 5 minutes | No data |
| Phenol (Exp. 5) | 1% within 10 min. | No data |
| Streptococci and Staphylococci in Olive Oil: | ||
| Chlorlyptus (Exps. 7 and 8) | 1%, almost at once, sometimes | No data |
| Eucalyptus oil | No data | No data |
| Phenol (Exps. 9 and 10) | 1%, almost at once, | No data |
| Staphylococci in Pus: | ||
| Chlorlyptus (Exp. 11) | 10% for 1 hour | 10% for 1⁄2 hour |
| 5% for 2 hours | ||
| Eucalyptus oil | No data | No data |
| Phenol | No data | No data |
| Staphylococci in Human Blood Serum: | ||
| Chlorlyptus (Exp. 12) | 5% in 1 hour | 1% in 1 hour |
| Eucalyptus oil | No data | No data |
| Phenol | 5% almost at once | 1% in 1 hour |
INFECTION EXPERIMENTS IN VIVO
Dr. Rivas reports two series of experiments, in each of which three guinea-pigs received staphylococcus suspensions in the peritoneum. One guinea-pig in each series was left untreated; the others received injections of chlorlyptus into the peritoneum at various intervals.
The following results were obtained:
| Chlorlyptus | Results | |
| Exp. 19, No. 1 | None | Survived |
| Exp. 20, No. 1 | None | Died |
| Exp. 19, No. 2 | At once | Died |
| Exp. 19, No. 3 | After 24 hours | Survived |
| Exp. 20, No. 2 | After 18 hours | Died |
| Exp. 20, No. 3 | After 24 hours | Died |
This shows mortalities of:
1 in 2, i. e., 50 per cent., without chlorlyptus.
3 in 4, i. e., 75 per cent., with chlorlyptus.
It is doubtful whether so small a series of experiments on so variable a phenomenon as is infection should receive any serious consideration. So far as they go, they would indicate that chlorlyptus is useless or worse.
TOXICITY
The referee determined the acute toxicity of chlorlyptus by hypodermic injection of oily solutions into white rats. Comparative experiments were made with ordinary eucalyptus oil. The details are given in the appendix. The end-results may be summarized as follows:
| Survived | Chlorlyptus | Eucalyptus Oil |
| 1.56 c.c. | ||
| 3.75 c.c. | ||
| 5.00 c.c. | ||
| 6.25 c.c. | 1.25 c.c. | |
| 8.65 c.c. | 2.5 c.c. (3 days) | |
| Died (in days) | 12.5 c.c. (1 day) | 3.75 c.c. (3 days) |
| 12.5 c.c. (1 day) | 5.00 c.c. (3 days) | |
| 18.75 c.c. (1 day) | 6.25 c.c. (11⁄2 days) | |
| M. F. D. | 8.75 to 12.5 c.c. per kg. | 1.25 to 2.5 c.c. per kg. |
Fatality.—The doses are calculated for cubic centimeters of the undiluted drugs per kilogram of rat.
Dr. Rivas reports a series of toxicity experiments on guinea-pigs. Assuming a uniform weight of 400 gm. per animal, his results (details in appendix) may be summarized as:
| Minimal Fatal Dose C.c. per Kg. | Maximal Survived Dose C.c. per Kg. | |
| Chlorlyptus, peritoneal (Exp. 14) | 7.5 c.c. | 5.0 c.c. |
| Chlorlyptus, pleural (Exp. 15) | 5.0 c.c. | 2.5 c.c. |
| Eucalyptus oil, peritoneal (Exp. 16) | 2.5 c.c. | No Data |
| Eucalyptus oil, pleural (Exp. 16) | 1.25 c.c. | No Data |
| Dichloramin-T, peritoneal (Exp. 16) | 1.25 c.c. | No Data |
The comparative toxicity in the various series is therefore approximately as follows:
| Chlorlyptus | : | Eucalyptus | |
| Referee, rats, hypodermic | 1⁄5 | : | 1 |
| Rivas guinea-pig, peritoneal | 1⁄3 | : | 1 |
| Rivas guinea-pig, pleural | 1⁄4 | : | 1 |
Evidently, the toxicity of chlorlyptus is about one-fourth of that of eucalyptus oil. The difference is considerable, but not fundamental. Moreover, the symptoms of chlorlyptus resemble the characteristics of eucalyptus oil.
According to the tabulation of Barker and Rowntree,[136] the mean fatal dose of eucalyptus oil for man, in the twenty-nine clinical cases reported in the literature, is about 20 c.c. If the toxicity ratio of the two substances were the same as for the rat experiments (a rather hazardous assumption), the fatal dose of chlorlyptus for man would be about 80 c.c.
IRRITATION
Rivas’s Experiment 14 shows that chlorlyptus gives very definite irritation, apparently similar to that produced in Experiment 16 by eucalyptus oil in one-fourth the dose.
Incidentally, the referee may add from personal experience that the “chlorlyptus oil, 5 per cent. Cl” is markedly irritating in the nostrils, although marked “non-irritating” on the label.
II. APPENDIX: SPECIAL REPORTS
A. COMPARISON OF CHLORLYPTUS WITH CHLORINATED EUCALYPTOL
From the Chemical Laboratory of the American Medical Association
According to the label, “Chlorlyptus” is a “Synthatized Chlorinated Oil of Eucalyptos, with Acid Reaction, containing approximately 30 per cent. Chlorine and possesses excellent Germicidal Properties, when made under our special process.” It is manufactured by the Weeks Chemical Company, Philadelphia, Pa. This product was submitted to the Council on Pharmacy and Chemistry by the manufacturers, and in turn the Laboratory was asked to examine it with the idea of comparing it with the nonproprietary brands of “chlorinated eucalyptol” (used as a solvent for dichloramine-T; see New and Nonofficial Remedies, 1919, p. 70). In the submission, certain tests were described, most of which were followed. Among the statements given under the chemical properties of chlorlyptus are:
“On distillation, chlorlyptus begins to boil at about 100 C. The temperature rises as the distillation continues, accompanied by the decomposition of the chlorlyptus and the evolution of hydrochloric acid and chlorine.”
“When brought into contact with water, chlorlyptus undergoes a process of hydrolysis ...”
Notwithstanding the foregoing the statement is made on the label that chlorlyptus “is a Stable Compound, not affected by heat, light or water.”
The following comparisons of chlorlyptus, chlorinated eucalyptol-Abbott and chlorinated eucalyptol-Squibb were made:
Chlorlyptus is a viscous, dark brown liquid, with an acrid odor and having a specific gravity of 1.2098. Chlorinated eucalyptol-Abbott is a mobile, light yellow liquid, with a eucalyptus odor, having a specific gravity of 0.9317. Chlorinated eucalyptol-Squibb is a mobile, colorless liquid, and its specific gravity is 0.9303.
An alcoholic solution of silver nitrate added to an alcoholic solution of chlorlyptus yields a heavy precipitate of silver chloride. In the case of the Abbott chlorinated eucalyptol a slight turbidity is caused by this test; the Squibb product shows no reaction.
A 10 per cent. solution of potassium iodide is overlaid with an equal volume of chlorlyptus. Iodine is slowly liberated, being noticeable in one-half hour. With chlorinated eucalyptol-Abbott, a trace of free iodine is discernible after four hours, while with chlorinated eucalyptol-Squibb there is no free iodine present. When the respective products are shaken with an alcoholic solution of potassium iodide, no iodine is immediately liberated, thus showing the absence of “active chlorine” (difference from the hypochlorite derivatives).
When chlorlyptus is dissolved in concentrated sulphuric acid, some blackening occurs and the odor of hydrogen chloride is very noticeable. Both the Abbott and Squibb brands of chlorinated eucalyptol give a reddish mixture, with no perceptible evolution of hydrogen chloride, and still retain the characteristic eucalyptol odor.
On heating, chlorlyptus decomposes and begins to boil at from 103 to 105 C. Then a higher fraction comes over at 178 C. The distillate has a sharp odor, is acid, and frees very little iodine from potassium iodide. Chlorinated eucalyptol-Abbott does not seem to decompose. Some gaseous substance is given off at 80 C, but the liquid distills at 173 C. The distillate has no acid odor, is neutral, and liberates no iodine from potassium iodide. (In both cases the distillation was not carried to completion, approximately only about half of the volume being distilled over.)
PRELIMINARY TESTS ON CHLORLYPTUS AND CHLORINATED EUCALYPTOL
| Chlorlyptus | Chlorinated Eucalyptol-Abbot | Chlorinated Eucalyptol-Squibb | |
| Odor | Acrid | Like eucalyptus | Like eucalyptus |
| Density and color | Dark brown; viscous, heavier than water | Light yellow; mobile; lighter than water | Colorless; mobile; lighter than water |
| AgNO3 added to alcoholic solution | Heavy ppt. | Slight turbidity | Clear |
| Equal parts with KI solution | Gives free iodin slowly, noticeable in 1⁄2 hour | Gives free iodin in 4 hours; not much | No free iodin in 4 hours |
| Equal parts with 10% KI, 10% KIO3 solution | Much iodin immediately | Small amount of free iodin in few numbers; does not noticeably increase | No free iodin in 3 hours |
| Equal parts with conc. H2SO4 | Some blackening; odor of HCl | Reddish mixture; no HCl; eucalyptol odor | Same |
| Alcohol KI | No iodin liberated | Same | Same as Abbott product |
| Heating | Decomposes and boils at 103–105 C.; then higher fraction comes over at 178 C.; distillate has sharp odor, is acid, but frees very little I2 from KI; distillation not completed | Apparently does not decompose; some gas given off when T=80; the liquid distilled at 173 C.; the distillate did not have much odor; no HCl gas detected; no I2 from KI; distillate was neutral (distillation not completed) |
The addition of chlorlyptus to a mixture of 10 per cent. potassium iodide, 10 per cent. potassium iodate solution, brings about the liberation of iodine, increasing perceptibly on standing. This shows that the hydrogen chloride is gradually split off, and in time will cause a solution having a considerable degree of acidity. When this test is carried out on chlorinated eucalyptol-Abbott, a small amount of iodine is liberated in a few minutes but does not increase, showing a slight initial acidity without further hydrolysis. Chlorinated eucalyptol-Squibb yields no free iodine after standing three hours.
When the chlorine content of chlorlyptus is determined according to the method of Carius, the amount is found to be 29.6 per cent. (The manufacturers give a method of determining chlorine by Hunter’s fusion method. It is believed that in this method hydrogen chloride may be lost, and this opinion is substantiated by the firm’s statement, “Chlorlyptus analyzed in this manner shows approximately 25 per cent. of chlorine.”) The chlorine content of chlorinated eucalyptol-Abbott is found to be 0.67 per cent., and that of the Squibb brand to be 0.62 per cent. (about one-fiftieth as much as in chlorlyptus).
To sum up: Chlorlyptus differs from chlorinated eucalyptol in odor, color, density, in reaction to silver nitrate, potassium iodide, sulphuric acid and the aqueous solution of potassium iodate and potassium iodide. The distillation of the two products occurs differently. Chlorlyptus contains nearly 30 per cent. of chlorine, which is approximately fifty times as much as in chlorinated eucalyptol. Thus it appears to have considerable chlorine in the negative form (Cl-) which may be relatively easily split off as hydrogen chloride.