Tolmetin sodium dihydrate (0.25 mM) does not attenuate lipid peroxidation in rat brain homogenate. Tolmetin (0.25, 0.5, 0.75, 1 mM) shows radical scavenging properties but without superoxide anion generation in rat brain homogenat.
Tolmetin sodium dihydrate (0.001-100 μM) shows anticancer activity againts HT-29 colon cancer cell line in a dose-dependent manner.
Tolmetin sodium dihydrate (0-100 μM) shows no effect on osteoblast growth.

Tolmetin sodium dihydrate (30,100 mg/kg; gavage; single dose or twice daily for 3 and 14 days) shows maximal ulcerogenic effect 4 h after the single dose, while potently decreases after 3 and 14 days of repeated administration in male Wistar rats weighing 180-200 g. Tolmetin causes gastric lesions in 100 mg/kg.
Tolmetin sodium dihydrate (5 mg/kg twice a day for 5 days) pre-treatment considerably attenuates quinolinic acid (QA)-induced neurotoxicity.