Oleates: Further Investigations into their Nature and Action
Authors: J. V. Shoemaker
Journal: BMJ (1884)

THz use of fatty vehicles for applying medicinal substances to the cutaneous envelopment of the body, for the purpose either of pro- ducing a local effect, or with a view of making a constitutional im- pression, is probably as old as medicine itself, and there is no doubt that inunctions played a most important part in the early history of medicine.The fatty bodies so used were at that time the oils ex- pressed from the seeds and fraits of plants, as well as fats of both domestic and wild animals, to each of which different actions were attributed.It is not beyond the recollections of the older members of our profession when dog's fat, snake-oil, bear's oil, though not dissimilar in nature, or only so in an unimportant modification, had the most varied and often absurd therapeutic actions claimed for them.As in many other ways and instances, chemistry came to the succour of our benighted science, and showed for fats and oils gene- rally a similar constitution, depending on the presence of basic and acid radicals ; the latter of which being present in various modifica- tions, while'the former, a propenyl or glyceryl, is generally found as a constant component thereof.When Chevreul, in 1811, already proclaimed the chemistry of the fats and oils, and isolated the fatty acids from their bases, the first step in the direction of a more thorough understanding of their nature and action had been taken.For the fatty acids, especially the one termed oleic acid, it was soon found that it could be united to other bases as well as the one that it was originally associated with.This is undoubtedly the first comprehensive knowledge we have of a class of remedial substances which form the subject of this page, and are known as oleates.While, as such, they had been in use for ages previous to this period, they had been applied empirically only, with- out a knowledge of their constitution.Thus, we had lead-plaster, soaps, etc., but they were only known as such, and not as salts, or combinations of a fatty acid with metallic or alkaline bases, which stamped them respectively as lead oleopalmitates and sodium or potas- sium oleopalmitates or stearates.Their medicinal application in vari- ous ways, by using oleic acid as solvent for alkaloidaf substances, was subsequently agitated by Professor Attfield in 1862 and a paper on their use in medicine by Mr. John Marshall in 1872 brought them prominently to the attention of the medical profession.His interest- ing communication and suggestions soon occupied the profession at large, and chemists were busily occupied to further perfect both the acid and the products therefrom.It was about this time that Dr. L. Wolff, a well known chemist of Philadelphia, was experimenting on oleic acid and its derivatives, and interested me in his investiga- tions, which we jointly pursued from that timae on.The oleic acid of the market of that period was a niost unsightly, dark, rancid body of very offensive odour, known to the trade as the red oil of the candle-makers, the refuse after the separatiQn of most of the stearic acid, which is utilised for illuminating purposes.It repre- sented a complex of oxyoleic acid, stearic acid, along with numerous volatile fatty products; and if, either alone or in combination, applied to the skin, it proved an irritant rather than a mild vehicle and carrier of medical substances.Purification of this acid availed very little, and to this day its use, though advocated by mercenary manu- facturers, is often accompanied, as I shall point out hereafter, with frequently unpleasant and injurious resultsAs the oleates, as then known, were ad bpst only oleic solutions, or solutions of some oleato in a large excess o'f such oleic acid, te dis- appointments and, disadvantages tAey prodl iiced were c4culated to [1242] sriouy intrfe e with the suctessful introduction t cl of remedies'.Whlle Oloo acidsufficientlypure to overcme these ob' jections could be had, -and was produced by Dt.Wolff for fle, the price, in consequence upon the manner of its production at tha time, was such that it preclulded its extensive uce in -hospital orx gen&al practice ; our principal objet, then, was first toproduce an acid sfi- ciently pure, while at the same time within the reach of people of ordinary means.These oleates are the remedies of which I spoke in my paper pre- sented to the Pennsylvania State Medical Society in 1879, and the use of which I advocated at that time, and suggested as subjects of im- 'NA' T% WAV WAft .;oIT"It, 14"'v