Previous studies showed that drugs that suppress prostaglandin synthesis were able to prevent adhesion formation following surgical trauma to the peritoneum. In our study, this premise was extended to examine the effects of various delivery systems on the ability of a nonsteriodal antiinflammatory drug, tolmetin, to prevent intraperitoneal adhesion formation after a standardized injury to the peritoneum. Continuous delivery of small amounts of tolmetin directly to the injury site following parietal peritoneal injury led to a significant reduction in the number and severity of adhesions formed. A single intraperitoneal injection of tolmetin in 5% Tween, however, required a relatively higher concentration of drugs to prevent adhesion formation. In a follow-up study of abrasion and devascularization of both uterine horns, the acid form of tolmetin was shown to be more potent than the sodium salt for the prevention of adhesion formation.