Biological Activity of Crystalline Procaine Penicillin In vitro and In vivo.

Abstract

Salivar, Hedger and Brown have descr. the prepn. and chem. properties of crystalline procaine penicillin. The present report deals with the biol. activity and with the absorption and excretion of, this form of penicillin and of other relatively insoluble salts of penicillin. Crystalline procaine penicillins G and dihydro-F are highly effective antibacterial agents in vitro and in vivo, and their oil solns., when injd. intramusc. in rabbits in a single dose of 30,000 U./kg. body wt., in most instances produce blood levels lasting 24-30 hrs. Preliminary observations in man have indicated that a single intramusc. injn. of 300,000 U. of crystalline procaine penicillin G in oil may produce detectable blood levels lasting 24-48 hrs. while penicillin may be excreted in the urine for at least 48-60 hrs. Toxicity of crystalline procaine penicillin is probably low. Other water-insoluble salts of penicillin, when suspended in oil, have also produced marked prolongation of blood levels.