Co-crystal of tramadol-celecoxib: preclinical and clinical evaluation of a novel analgesic

CTC may provide a relevant addition to pain therapy due to its: i) unique co-crystal structure conferring differentiated intrinsic dissolution profiles on constituent APIs, ii) modified clinical pharmacokinetics (slower absorption of tramadol and faster absorption of celecoxib) compared with commercially available single-entity reference products (in agreement with modified dissolution rates), iii) superior benefit-risk ratio compared with reference products (suggested by preclinical synergistic antinociceptive effects, without potentiation of adverse effects), and iv) efficacy in a phase 2 trial of moderate to severe pain following extraction of ≥2 impacted third molars requiring bone removal, where CTC doses containing low doses of APIs exerted a significant effect. Phase 3 studies are currently ongoing.