"One shot" treatment of venereal diseases employing procaine penicillin G with aluminum monostearate (P. A. M.).

EVER since the discovery that penicillin was effective against syphilis efforts have been directed to the limitation of the number of injections to be given by the evolution of preparations which are either more slowly absorbed or more slowly excreted. The. slow absorption methods gained the initiative with the introduction in 1945 of penicillin in oil beeswax (Romansky and Rittman) and the success of delayed excretion procedures, employing caronamide, came only after the delayed absorption techniques ha~ become established arriving too late to enjoy general use. Penicillin in oil beeswax, however, proved by no means always easy to administer, especially in the himds of the general practitioner remote from the surgery or clinic. The discovery that procaine combined with penicillin in equimolecular amounts to form a crystalline salt procaine penicillin which, if injected in watery or an oily medium, will give blood levels of penicillin comparable with those obtained with penicillin in oil beeswax (Herrell et al.) was heralded as a major advance. Procaine penicillin was improved still further by the addition of a waterrepellent substance f aluminium monostearate, after a single intramuscular. injection of 600,000 units, of which detectable penicillin can be found in the blood for three to four days, while after a single dose of 2'0 or 2'4 million units for as long as a week or more (Young et al.).