Gastric ulceration and the concentration of salicylate in plasma in rats after administration of 14C-labelled aspirin and its synthetic triglyceride, 1,3-dipalmitoyl-2(2'-acetoxy-[14C]carboxylbenzoyl) glycerol.

Triglycerides containing aspirin in place of one or more fatty acid residues of the molecule have been synthesized. Metabolism of the compound with the labelled (14C) drug residue introduced specifically into the 2-position of the triglyceride is reported. Plasma salicylate concentrations with this synthetic glyceride were determined and compared with those obtained with commercially available aspirin labelled with the 14C-isotope. Both compounds gave a therapeutic concentration of salicylate in the plasma after ingestion. The 1,3-di-fatty acyl-2-aspirin glyceride was absorbed through the intestine as 2-aspirin monoglyceride, some 20% of which was transported through the thoracic-duct chyle and about 30% through the portal system. Whereas pronounced ulceration of the rat stomach occurred with free aspirin, the above fatty acyl glyceride of aspirin produced no ulceration.