IODONUCLEOID

An Iodin Product Under a Misleading Name

Information has been frequently asked concerning Iodonucleoid, a product not included in New and Nonofficial Remedies. The Association Laboratory after investigating this preparation reported as follows:

This preparation was at one time considered for inclusion with New and Nonofficial Remedies, and at that time was examined in this laboratory. The examination showed that iodonucleoid contains:

Phosphorus	0.79	per cent.
Calcium	0.43	per cent.
(Equal to 0.6 per cent. CaO).
Iodin	24.2	per cent.

When 2 gm. was dissolved in tenth-normal potassium hydroxid volumetric solution and acetic acid added until faintly acid, an abundant, white, flocculent precipitate formed. This precipitate was collected, washed with water, transferred to a beaker, phenolphthalein added and tenth-normal potassium hydroxid volumetric solution run in until a pink color was produced. This required 15 c.c. of tenth-normal alkali. Subtracting from the 2 gm. of iodonucleoid the 24 per cent. iodin, leaves 1.52 gm.; this divided by the c.c. of alkali used indicates an equivalent weight of 1013.

Authorities differ widely regarding the amount of phosphorus contained in nuclein from different sources, the figures ranging from 2.9 per cent. to as high as 10 per cent. If the nuclein from which iodonucleoid purports to be made contained but 2.9 per cent. phosphorus, the preparation, after allowing for 24 per cent. iodin, should still contain 2.2 per cent. phosphorus instead of the 0.79 per cent. found by analysis. A true nuclein should contain no calcium. If iodonucleoid is a casein compound of iodin we might expect to find, if the casein had been freed from milk by acidulation without further purification, both calcium and phosphorus. The equivalent weight of casein is given by Long (Jour. Am. Chem. Soc., 1906, xxviii, 372) as 1124. This figure was obtained on a casein of high purity, and the figure of 1013 given above agrees fairly well with Long’s figure for casein. The evidence, therefore, indicates that iodonucleoid is a compound of iodin and casein, and not a nuclein compound.

The findings of the laboratory were at that time submitted to Prof. John H. Long of Northwestern University, who said:

“We have also made a number of examinations of iodonucleoid. We determined in it the iodin and found the amount 24.2 per cent. by weight, which is a little more than that claimed by the manufacturer. We have also tested the solubility of this substance and find it to behave about as your laboratory did. As you know, we have been making a number of preparations from casein, and recently we have determined the combining power of casein with various acids, including hydriodic acid. This acid when evaporated in moderately strong solution with casein yields finally a hard, dry mass, which may be ground up to a powder resembling very closely the preparation under discussion. Various amounts of iodin may be combined here, depending on the strength of the iodin solution used, and we have secured some containing over 35 per cent. of iodin. Several of these preparations resemble closely iodonucleoid, so far as solubility, appearance and reaction with alkalies on titration are concerned. I am unable, therefore, to distinguish this preparation from the casein compounds which we are making.”

From this it would appear that iodonucleoid is not a compound of nuclein, as indicated by the name, but instead is a casein compound of iodin.

Iodonucleoid, then, seems to be another one of the many iodin “substitutes” which have been put on the market. Other iodin substitutes are Iodalbin, manufactured by Parke, Davis & Co.; Iodipin manufactured by E. Merck & Co., and Sajodin, manufactured by the Farbenfabriken of Elberfeld Co. As these products have been examined by the Council and found eligible for inclusion with New and Nonofficial Remedies, physicians who wish to use substitutes for potassium iodid would do well to use them instead of a product presented under a misleading name. Physicians should understand, however, that these organic iodin compounds are non-irritating because the iodin is held in such combination that it is much less active. It seems probable that they are therapeutically active only to the extent that the iodin content is dissociated from the organic compound and concerted into ionic iodin.

A discussion of a number of iodin substitutes is found in an article by von Notthafft (Monatsh. f. prakt. Dermat., Oct. 15, 1910, p. 343), which was abstracted and commented on in The Journal, March 4, 1911, p. 685. Von Notthafft believes that the lower degree of toxicity which these remedies exhibit has its basis in a feebler activity; either the substitutes evolve too little iodin or they split it off with greater difficulty. Physicians should, therefore, view with some distrust the claims of manufacturers that their products are not only non-irritating but at the same time possess unusual therapeutic efficiency. This will apply with especial force if there is any tendency to conceal the nature or origin of the combination.—(The Journal A. M. A., July 22, 1911.)