ALLANTOIN AND UREA— KOBINSON 453 



The amount of allantoin in maggot excretions is too small and the 

 process of extraction too involved to make its use practical. More- 

 over, there is the natural dislike of a drug obtained that way. For- 

 tunately, pure allantoin prepared synthetically for academic purposes 

 was available in the United States. It is very slightly and slowly 

 soluble in water, 0.6 percent being saturation. In these experiments 

 a 0.5 percent solution was used. 



In cooperation with hospitals in Washington, New York, and Pitts- 

 burgh, the effect of allantoin in stimulatmg healing was carefully 

 tested. It was applied on gauze dressings thoroughly wetted wdth 

 the solution and renewed daily. The types of wounds treated were 

 chronic varicose ulcers, chronic osteomyelitis, and nonheahng heat 

 bums. After a few daily appUcations it became evident that allan- 

 toin was bringing about an improvement in the wound similar to that 

 produced by maggots. The odor was reduced, the wound became 

 cleaner, and small areas of normal pinldsh granulation tissue could be 

 seen growing in the wound, Tliis was followed in most cases by a 

 general development of such granulation tissue. 



The method of preparing allantoin solution for use was to heat a 

 Uter of sterile water to near the boihng point, then to add 5 grams 

 of allantoin crystals and gently heat without boiling until all the 

 crystals were dissolved. The preparation of a water solution should 

 be done with reasonably aseptic precautions, as the solution cannot 

 be autoclaved or boiled. Most commercial brands of the solution 

 now contain a disinfectant. Allantoin is stable, mild, and soothing, 

 and the solution has no taste or odor. 



Allantoin is a substance occurring naturally in animal tissues, and 

 it is also widely distributed among plants. It is a metabolic product 

 and generally regarded as waste material. When the nucleus of the 

 cell breaks down it yields nucleic acid, and gradually through a process 

 of simphfication uric acid is produced. Man and the manlilce apes 

 are unable to split uric acid any further, and it is, therefore, excreted 

 in the urine in that form. Strangely enough, other mammals have 

 in their tissues an enzyme called uricase, which oxidizes uric acid one 

 step further, and the result is the formation of allantoin, a stable end 

 product of metabohsm. Many lands of plants produce allantoin in 

 various parts of their structure. 



After a considerable number of chronic purulent cases had been 

 treated successfully and with no evidence of irritation or other harmful 

 effects, a prehminary report was pubUshed in the Journal of Bone and 

 Joint Surgery in April 1935 (Robinson, 1935). This was done to 

 acquaint medical readers of our findings and to enlarge the scope of 

 the clinical tests. The result of this report, however, was altogether 

 unexpected. Newspapers and journals took the story and at intervals 

 throughout the following year pubhshed accounts of it in their pages. 



