Non-enhancement of sodium cromoglycate intestinal absorption by quaternary ammonium ions. An effect of salt on ion-pair formation?

Studies on the nature of rat small intestine perfusates indicate that this environment is thermodynamically unfavourable for the production of ion pairs between cromoglycate and alkylbenzyldimethylammonium ions. This is suggested as being the reason why, unlike previously found for ocular absorption of cromoglycate, these quaternary ammonium ions do not alter cromoglycate intestinal absorption.