The Propaganda for Reform in Proprietary Medicines, Vol. 2 of 2

by Council on Pharmacy and Chemistry

Free Iodin.—When examined by the method previously used[215] only minute traces of free iodin were found.

Total Iodin.—The methods employed were as follows: 1. Iodex was saponified by boiling for from two to three hours with alcoholic potassium hydroxid. The alcohol was then evaporated and the iodin determined by the method described in the U. S. Pharmacopeia for thymol iodid.

2. The same as Method 1, except that after ignition of the saponified mixture the halogen was determined by weighing as silver iodid.

3. The Carius method.

It should be noted that Methods 2 and 3 determine chlorin and bromin should any be present with the iodin.

When 5 gm. of Sample 1 was assayed by Method 1, it required 73.56 c.c. of tenth-normal sodium thiosulphate, equivalent to 3.11 per cent. of iodin. In a duplicate, 2.7565 gm. of Iodex required 38 c.c. of tenth-normal sodium thiosulphate, equivalent to 2.92 per cent. of iodin; average of the two, 3.02 per cent. of iodin.

A weight of 2.5800 gm. of Sample 1, assayed by Method 2, gave 0.1582 gm. of silver halid, equivalent to 0.0855 gm. of iodin, or 3.31 per cent.

A weight of 0.588 gm. of Sample 2, assayed by the Carius method, gave 0.0388 gm. of silver halid, indicating 0.02096 gm. of iodin, or 3.52 per cent. In a duplicate, 0.5342 gm. gave 0.0338 gm. of silver halid, indicating 0.01826 gm. of iodin, or 3.42 per cent.; average, 3.49 per cent. of iodin.

Liquid Iodex.—This is sold by Menley & James, Ltd., the firm selling Iodex Ointment. According to a circular in a trade package “the valuable properties of Free Iodine are available in Liquid ‘Iodex’ in a state of greatly enhanced activity; but the irritating, corrosive and hardening drawbacks of ordinary solutions of the drug are absent.” The label on a bottle reads as follows: “Liquid ‘Iodex’ (Liq. Iodi. M. & J.). A nonirritant preparation of iodine (2¹⁄₂%) ... This product contains Free Iodine....”

The sample of Liquid Iodex purchased on the open market was found to be a reddish liquid with an odor like oleic acid. It dissolved completely in chloroform.