In this article, the author looks back on the use of Balsam of Peru in paraffin gauze dressings
My first contact with Balsam of Peru was during my first qualified work with pharmacy as deputy manager of Cofman's Pharmacy, 41 Bloomsbury Way in London (at the age of 21). I was attracted to the pleasant odour that was associated with certain products, but I did not link it with Balsam of Peru that was listed in the BP in 1932. Consequently, I would not learn what produced the fragrant perfume contained in Tulle Gras dressings until supplying Jelonet paraffin gauze dressing and seeing it used for the first time in about 1942 in the Royal Army Medical Corps during the 1939-45 war. After the war was over, a monograph covering paraffin gauze dressings was included in the 1949 British Pharmaceutical Codex.
At the beginning of 1947, I went to work for Smith & Nephew, and became responsible for the development and quality control of the company's "pharmaceutical" products, including Jelonet, S&N's paste bandages and Gypsona plaster of Paris bandages. This included a considerable amount of analytical work and drafting specifications for standards.
At that time the gauze impregnation formulation for Jelonet was a solution of Balsam of Peru dissolved in hot yellow soft paraffin. Not all of the balsam was soluble in the paraffin, and a black insoluble resin was deposited in the mixing vessel. To remove the resin particles it had been customary to pour the mixture through layers of cotton gauze "fents" (off-cuts taken from where loom-width material was joined in the production of factory rolls of the cloth). This was a messy, expensive hand-operated process. I suggested that the use of a pressure filter would allow the process to be mechanised, kept closed from the atmosphere and with a saving of both time and materials. By then aluminium slip-lid containers were replacing tinplate, soldered boxes, making the subsequent dry heat sterilisation process easier.
At that time, and for many years to come, it was the firm's practice to use any existing machinery that might be able to do the job when suitably modified. The engineers told me that there was an old, hand-operated filter that had been used to filter cod liver oil in the days of the company's founder Thomas James Smith. It was then that I found out that I was the first full-time pharmacist to be employed by the company since "T. J." had founded the company in 1856. His nephew, Horatio Nelson Smith (known as "H. N."), then aged 73, was the one who had been responsible for the company's success since he had joined his uncle as a partner in 1896.
H. N. had developed a number of successful products as a result of his pre-war contacts in Germany. He was still extremely active in many aspects of the company's work. I found him interesting, approachable and I am fairly sure that he must have recalled the presence of the old filter pump at that time. With the adapted filter I was able to demonstrate that it was possible to produce a clear solution of the balsam, free from resin particles formed in the hot paraffin. The Jelonet filtration process was then mechanised, using a gear pump that had been used previously for viscose fibre production. This unmodified pump was arranged to feed the antique, filtration press with a steady flow of hot liquid. It was obvious that the diatomaceous filter aid that we used would soon wear out a metal gear pump, so an order was put in for a modern filter press with a suitable wear-resistant stator.
The new pump that we investigated had a worm-like impeller that operated like an Archimedes screw within an elastic synthetic rubber stator. The manufacturers had told me that the wear would be very much reduced, judging from tests that they had carried out with our materials. I was reassured by this information, and the new machinery was purchased and installed. Everything worked well and I was very pleased with the results, until the chief engineer came to me a few months after the installation. He told me that the financial director had complained that, although the pump life and performance had been improved remarkably, some parts needed frequent replacement due to excessive wear.
Very soon after hearing this, and obviously showing my worry and concern, I happened to meet the chief cost accountant in another part of the factory. He asked me why I looked so downhearted and worried. When I told him about the pump costs he said that he would look up the details. It was not long before he came back to me, grinning all over his face, and told me to forget it.
"Those pump parts are each lasting at least three months. They are saving so much money, compared with the original process, that each has paid for itself at least a hundred-fold!"
In spite of this, I began to wonder whether the black resinous part of the balsam was really needed. At that time in 1950 the firm's consultants were investigating patient reactions to the various ingredients of the many surgical dressings made by the company.
Inquiries made to the Pharmaceutical Society's library resulted in my obtaining a copy of a new publication, "Myroxylon balsamum (L) Harms var pereirae (Royle) Baill, der Perubalsambaum", an excellent comprehensive work by Dr Jutta Bergemann of the German Federal Institute for forest and timber industry, Reinbek near Hamburg, published in the journal Pharmazie in 1950.
The article was published in five parts:
My knowledge of German at that time was almost non-existent but since the information needed would only be mentioned in part of the publication, I decided to have a go at translation with the aid of a German technical dictionary. I realised that information with regard to skin tests was from Part 4 of the work and I therefore asked for permission to have the relevant part translated professionally. Donald Burley, the chief chemist, was keenly interested in allergies, and he readily backed up my application. From recent correspondence with parts of the Smith & Nephew group it has become apparent that the translation is no longer available.
Since that time I have acquired a working knowledge of German, particularly in relation to pharmacy. So, this year, with new copies of Dr Jutta Bergemann's work supplied by the Society's library, I decided to translate the original article into English in order to learn more about the fascinating Balsam of Peru that originates from El Salvador and not Peru.
The following section from Part 4 of Dr Bergemann's work reads today almost like something taken from advertisements for old patent medicines:
"The most effective durable part of Peru balsam is the Cinnamein, that works as an antiseptic. Howev#er in addition, the total action of the Peru balsam as a complex remedy is not to be underestimated. Foremost is the effect on the skin.
"Already in pre-Columbian times the natives of the central Americas and Mexico put balsam-soaked cloths on their wounds. Also today the balsam still is gladly taken as promoting wound granulation, especially since it also works antiseptically and as a disinfectant. Soiled and suppurating wounds or also crushed finger wounds are cured when treated quickly with Peru balsam and leave no large scars behind. One uses it to treat tuberculous ulcers, ulcus cruris, carbuncles and boils, cracked nipples and chilblains. For many skin diseases Peru balsam is a popular remedy to treat herpes and irritation, rashes and above all against scabies it works by moderating and curing. Also it is indicated as the means against suppurating bones and for painting on laryngeal tuberculosis. Balsam-soaked tampons are used for irritable noses or mucous membranes, or the balsam is inhaled. In addition it prevents caries and finds application against infected jaws.
"Internal application is of particular value, where it deals with irritable or sore epithelia or endothelia: for respiratory illnesses and urogenital organs, especially for irritation with purulent secretion, for bronchitis, chronic cystitis, nephrophilitis and pyelocystitis. Here the aromatic acids and their esters work not only as antiseptics but also benzyl benzoate as cramp relief, eg, on the smooth muscular system of the bronchi.
"Peru balsam was also used against typhoid fever and gout, against chronic rheumatism, paralyses and asthmatic complaints. One takes it as antiseptic for trismus and tetanus, which have arisen from wounds. As a strengthening remedy for gastro-intestinal chills, for colds, headache and diseases of the hair roots.
"In the Anal del Instituto Médio Nacional de El Salvador Bd 8 there is a report on successful application of Peru balsam for syphilis. H. Alfaro mentions that lung tuberculosis can be cured through treatment with balsam.
"Dr Landerer, Hamburg, recorded 124 complete healing from 158 cases (?).
"In modern therapy isolated Cinnamein materials of the balsam are injected for infections.
"A too long and intense treatment with Peru balsam can cause damage. A 2 per cent over-sensitivity of the skin against Peru balsam was observed in the skin of healthy persons and up to 10 per cent in unhealthy skins. In some cases kidney and stomach damage appears. After longer regular application of Peru balsam desquamative nephritis, loose, enlarged, greatly fattened kidney, necrosis of the small intestine epithelium or also damage to the gastro-intestinal mucous membrane were observed. Caution with the application of Peru balsam is advised, especially to children. Lohaus . . . reports the fatal poisoning of a baby through Peru balsam.
"Peru balsam is very popular in perfumery, because it intensifies and lengthens the fragrance. One adds it to ointments, hair pomades, hair-restorers and mouthwashes; Peru balsam makes soap fragrant and foaming. The balsam is needed in slighter quantities for different other manufacturers. For example, one includes it in chocolate varieties as substitute vanilla. According to Standley it is needed for different purposes in technology."
Not all of these uses were shown in the BPC 1949, but that edition did include its use "as an antiseptic for ulcerated surfaces such as bedsores" and "combines with sulphur, as a parasiticide, especially in scabies". The latter must have been the origin of the use of benzyl benzoate application for the treatment of scabies in the forces during the previous war. What intrigued me most was that "the dose of balsam of Peru stated in the BP 1932 was 0.3 to 1 millilitre (5 to 15 minims)".
There is only one mention in Bergemann's work of what might have been the black resin deposited in the Jelonet process: "Also still found in the balsam was: free cinnamic acid (about 8-10 per cent) free benzoic acid . . . , small quantities of styracin, besides vanillin, a trace of cumarin, benzyl-alcohol and styrol." I wondered whether styrol could have been part of the deposited resin.
In 1839, the German pharmacist Eduard Simon stated that polymerisation of styrene converted it into solid styrol, later renamed metastyrol. As late as 1930, little commercial use had been found for the polymer because of brittleness and crazing (minute cracking), which were caused by impurities that brought about cross-linking of the polymer chains.
The references made to damage and over-sensitivity of the skin in Dr Bergemann's work confirmed S&N's need for sensitivity tests. A number of tests were initiated with the help of the medical personnel of various manufacturing companies who used Jelonet to treat wounds and burns. The results of one such series, involving 9,140 burns at a large steelworks in Sheffield, were reported in 1957 in a letter to the British Medical Journal (October 12, 1957, p883).
In 1951, soon after these tests began, Smith & Nephew Research Ltd had been formed in Hertfordshire. Donald Burley was transferred to the new company and I chose to join him in the technology division. The new laboratory facilities, with over 50 staff members and a large library, had been acquired when Smith & Nephew had acquired the former Herts Pharmaceuticals. The sensitivity work was taken over by the analytical and biological division in the then new laboratories at Hunsdon, Hertfordshire.
As a result of our findings, I was deputed to discuss the matter with the late Dr Kenneth Capper, then editor of the British Pharmaceutical Codex, with a view to the Paraffin Gauze Dressing monograph being changed to accord with what would be the new Jelonet product, formulated without Balsam of Peru. Dr Capper had a good knowledge of surgical dressings and he knew about possible skin irritation with Tulle Gras. With the information supplied by Smith & Nephew Research Ltd and following the correspondence in the BMJ, Balsam of Peru was not included in the monograph in the next edition of the British Pharmaceutical Codex.
Balsam of Peru is now mainly used in perfumery, but it continues to be used today in Tulle Gras preparations and in haemorrhoidal preparations included in the present British National Formulary, and warnings are given to patients concerning skin reactions.
ACKNOWLEDGMENTS I must express my appreciation to the library of the Royal Pharmaceutical Society of Great Britain, to Dr Sasha Barrow (centre for economic botany, Royal Botanic Gardens, Kew), to Dr Axel Helmstaedter, of Govi Verlag, publishers of Pharmazie, and to the Royal Society of Chemistry library.
Mr Hammond is a pharmacist, now retired, from Southport, Merseyside