MDL 19301 is a nonsteroidal anti-inflammatory agent.

MDL 19301 exhibits additional anti-inflammatory effects by inhibiting carrageenan pleurisy, adjuvant arthritis, and HOAc-induced writhing. Pharmacologically, it suppresses prostaglandin synthesis, blocks arachidonic acid-induced diarrhea (excluding prostaglandin-E2-caused), and prevents arachidonic-acid-stimulated rat platelet aggregation (excluding ADP-induced). Contrary to expectations, both MDL 19301 and MDL 16,861 show minimal antipyretic effects in rats. Remarkably, oral MDL 19301 administration reduces rat paw edema significantly, induced either by carrageenan (ED30=4.8 mg/kg) or an Arthus reaction (ED30=8.2 mg/kg p.o.), and does not cause gastric ulceration in fasted rats at doses up to 1,000 mg/kg, indicating a better therapeutic index than traditional non-steroidal anti-inflammatory drugs (NSAIDs). The anti-inflammatory effect of MDL 19301 (unlike MDL 16,861) diminishes with SKF525A co-administration, suggesting MDL 19301's prodrug status for MDL 16,861 and its lower ulcerogenic potential.