EFFECT OF COMPLEX FORMATION ON DRUG ABSORPTION .10. EFFECT OF POLYSORBATE 80 ON PERMEABILITY OF BIOLOGIC MEMBRANES

Low concentrations of a nonionic surfactant (poly‐sorbate 80) in the bathing solution increase significantly the absorption and exsorption rate constants of 4‐aminoantipyrine in goldfish. This effect is evident in absorption and exsorption studies involving chemical assays as well as in experiments in which absorption rate was determined indirectly on the basis of the time of onset of a pharmacologic effect. The ratio of rate constants with: without surfactant was similar in the three types of experiments. It is concluded that polysorbate 80 enhances drug transfer by a direct effect on the biologic membranes and not by interacting with the drug. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company