Summary and Conclusions
The toxicity, as determined by inhibition of phagocytosis, of 60 lots of penicillin sodium from ten manufacturers has been studied to determine the effect of purity on the toxicity of this salt of penicillin. Similar studies have been made of six different salts of penicillin prepared on a pilot plant basis and of seven different salts of penicillin prepared commercially. There is a correlation between the toxicity of penicillin preparations as measured by inhibition of phagocytosis and potency. The toxicity for leucocytes of the penicillin preparations studied is not dependent upon the cation used in their production. The weight of the penicillin preparations studied which completely inhibits phagocytosis appears to be the same, regardless of the type or potency of the salt tested. It is suggested that the inhibition of phagocytosis demonstrated in these studies may be the result of an osmotic pressure effect. The concentrations of crude penicillin necessary to inhibit phagocytosis are not obtained in the ordinary clinical use of this material.