Aspects of surfactant toxicity

Abstract

Toxicity is a manifestation of an unwanted biological activity. In this chapter aspects of surfactant-induced toxicity will be discussed. The nature of the subject demands that it is dealt with on a selective basis; no attempt will be made here to be comprehensive. Some effort will be made, however, to relate surfactant properties with their biological effects. These biological effects, which are occasionally put to therapeutic use, are here regarded as side effects or toxic effects when elicited on administration of a medicine containing surfactants. Biological responses leading to toxicity which are the result of surfactant-induced hyper-absorption of another active ingredient such as discussed in Chapter 7, will not be considered. The chapter is divided into several parts. In the first part interaction of surfactant with biological substances such as proteins, lipids, membranes and enzymes will be surveyed in the hope that this might aid our understanding of reported ‘toxicities’. The second part of the chapter reviews reports on adverse reactions and unwanted effects derived from pharmaceutical products in animal and human subjects. The study of the absorption, distribution and metabolism of surfactant molecules is not a well developed art. We know too little of this topic, yet it is vital for our understanding of the interactions of amphipathic molecules with their biological environments. The impurity or heterogeneity of most commercial surface-active agents, however, does not assist us in gaining an understanding at the molecular level of toxic events which they might induce.