Experimental studies to develop local prophylactic agents against syphilis.

In this report a resume is given of a series of experimental studies carried out in rabbits to develop effective local prophylactic agents against syphilis transmitted by application of a spirochaetal emulsion to the penile mucous membrane (Table). These studies were made at the Venereal Disease Research Laboratory of the United States Public Health Service between 1941 and 1946. The development and composition of the most effective agent, Mapharsen (0.2 per cent.) in a I per cent. aqueous solution of alkyl aryl sulphate, has already been reported (Arnold and Mahoney, 1948). However, a large number of compounds were screened during the search, and no formal report has yet been made of the findings. The widespread use of prophylactic agents might be found desirable and necessary in the event of some future widespread mobilization. Also, in areas of high prevalence of chancroid, the armed services still might find desirable a local prophylactic agent effective against syphilis, gonorrhoea, and chancroid. Since the search for an effective agent against all three diseases should logically be based upon attempts to incorporate an effective antichancroid agent into a preparation which has already been found effective against syphilis and gonorrhoea both in vivo and in vitro (Arnold and Mahoney, 1948; Funes and Aguilar, 1952), it was thought desirable to give in some detail the results of the various studies which determined the efficacy of this preparation. In the course of these experimental studies, it was kept in mind that the desirable prophylactic preparation was one which would be simple to use, aesthetically acceptable, and not painful to the