Rectal absorption of lysozyme and heparin in rabbits in the presence of non-surfactant adjuvants.

Abstract

Ethylacetoacetate enamines of phenylalanine and phenylglycine enhanced the rectal absorption of macromolecular drugs such as lysozyme and heparin in rabbits. Glycerine-1, 3-diacetoacetate, 1, 2-isopropylideneglyceryl-3-acetoacetate and ethylacetoacetylglycolate also enhanced the rectal absorption of lysozyme and heparin. Lysozyme is a basic compound and heparin is an acidic compound, so the non-surfactant adjuvants used in this study can promote the rectal absorption of macromolecular compounds irrespective of their electrochemical properties. The coadministration of calcium ion inhibited the adjuvant action, so complex formation of the adjuvant with calcium ion may occur, reducing the efficacy of these compounds as adjuvants.