Comparative teratogenic effects of methyl salicylate applied orally or topically to hamsters.

Methyl salicylate was administered topically to pregnant hamsters at 7d9h and the teratogenic results were compared with those obtained following oral treatment with the same compound. Both treatments produced the same defect in embryos recovered at day 9: failure of fusion of the neural tube, especially in the area of the developing brain. Analysis of serum salicylate levels following both treatments produced similar curves and indicated that teratogenic levels of salicylate can reach the maternal circulation after topical exposure.