Co-crystal of Tramadol–Celecoxib in Patients with Moderate to Severe Acute Post-surgical Oral Pain: A Dose-Finding, Randomised, Double-Blind, Placebo- and Active-Controlled, Multicentre, Phase II Trial

Background Co-crystal of tramadol–celecoxib (CTC), containing equimolar quantities of the active pharmaceutical ingredients (APIs) tramadol and celecoxib (100 mg CTC = 44 mg rac–tramadol hydrochloride and 56 mg celecoxib), is a novel API-API co-crystal for the treatment of pain. We aimed to establish the effective dose of CTC for treating acute pain following oral surgery.