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

by Council on Pharmacy and Chemistry

TOTAL TRIBROMPHENOL

The content of tri­brom­phenate radical, C₆H₂Br₃O^-, was determined by the method of Kollo (Apotheker Zeitung, 1910, p. 99). It consists in titrating the filtrate of the bismuth oxid determination of Kollo, described under “C” (bismuth determinations), with normal hydrochloric acid, using phenol­phthalein as an indicator. The cubic centimeters of normal alkali consumed multiplied by the theoretical factor 0.331 gives the weight of tri­brom­phenol (combined and free) contained in the specimen.

The following results were obtained:

TABLE 2.—DETERMINATION OF TOTAL TRIBROMPHENOL IN BISMUTH TRIBROMPHENATE

	Gm. of Salt Taken	Gm. Tribromphenol Calculated from Theoretical Factor	Per Cent. of Total Tribromphenol
No. 1 (Research Council Spec.)	1.7817	1.0592	59.44
No. 2 (Merck & Co.)	0.9743	0.5627	57.75
No. 3 (Heyden Chem. Works)	2.0440	0.4303	21.04

UNCOMBINED TRIBROMPHENOL

The definite chemical formula given in New and Non­official Remedies for bismuth tri­brom­phenate and the statement that it is “only slightly soluble in ... alcohol ...” requires the absence of uncombined tri­brom­phenol, but no method for its detection or determination is provided.

In the U. S. Patent 516,358 (expired March 13, 1911), issued to Bruno Richard Seifert, assignor to Dr. F. Von Heyden, for “Phenol Bismuth Compound” the freedom from uncombined tri­brom­phenol was provided for by the direction to wash with alcohol the product obtained.

In the Swiss Pharmacopeia the permissible content of uncombined tri­brom­phenol is limited thus: