METABOLISM AND ACUTE LUNG TOXICITY OF SOLUBILIZED DI(2-ETHYLHEXYL)PHTHALATE (DEHP) IN RATS.

Abstract

DEHP, a di-ester of phthalic acid, is highly water-insoluble oil that is widely used as a plasticizer to increase the pliability of vinyl plastics. The annual American production of phthalate esters is approximately one billion pounds. With recent evidence of the widespread environmental distribution of a number of different phthalate esters and contamination of human blood stored in vinyl plastic bags with DEHP, considerable interest has centered on the potential toxicologie hazard of these compounds. Because of its water insolubility, the physical state of DEHP in biological systems is of considerable concern, with particular interest in the nature of the formulations used in experimental animals for toxicologie testing. It has been reported that aqueous emulsions of DEHP—sonicated in 3% gum acacia or 4% serum albumin—were milky white and opaque. On the other hand, solubilization of DEHP in saline by the addition of a nonionic surfactant, Tween 80, was shown to result in a transparent solution with no microscopically visible particles at a resolution of 1 micron. The chapter describes the differences in biological disposition and action between the emulsified and solubilized forms of DEHP. It also focuses on the enhanced acute lethality and lung toxicity of the surfactant-solubilized DEHP.