Irritant action due to physico-chemical parameters of test solutions.

The irritant action of various buffer solutions was determined by the mouse skin test. All results for isosmolal solutions differing in initial pH values and buffer capacities could be satisfactorily represented by a general model which could be used to predict the irritancy of solutions with unphysiological pH values in contact with mucous membranes. The results obtained with hyperosmolal solutions are as yet too limited for such a general statement, but it appears that increasing osmolality gradually overrides the effect of the pH value. The relevance of the results to the prediction of irritant potentialities for man has been assessed by comparison with results of rabbit-eye tests carried out by Friedenwald et al. (Archs Ophthal., N.Y. 1944, 31, 279).