THE ABSORPTION OF THIOUREA FROM OINTMENTS APPLIED TO WOUNDS

¹ Pharmacology Department, Research Laboratories, the Wm. S. Merrell Company, Cinncinnati, Ohio

Thiourea incorporated in, oil in water emulsion type, ointment bases in concentrations of 1 and 10 per cent was absorbed in sufficient amounts, when applied to wounds for periods of two weeks, to effect typical thyroid changes.

Lower concentrations of thiourea (0.05 and 0.1 per cent) did not cause thyroid hyperplasia when applied in a similar manner for periods as long as four weeks. Absorption of thiourea was influenced by the vehicle as is evidenced by the finding that the tragacanth containing ointment produced the most marked effect.

Six weeks after discontinuing treatment, thyroid tissue had either returned to normal, or it showed only slight evidence of thiourea effect.

Thiourea applied in ointments caused no abnormal proliferation of tissue locally.

Under the conditions of these experiments thiourea had no effect on erythrocyte, leucocyte, and differential cell counts. Hemoglobin concentrations for one group of animals receiving thiourea were lower than for other groups. However, values for all groups, including controls, were low; and it is probable that the observed differences are not significant.