Cyclobenzaprine-d3 (hydrochloride) (CRM) (Synonyms: Flexeril-d3, Lisseril-d3, MK-130-d3)

Cyclobenzaprine-d₃ (hydrochloride) (CRM) contains three deuterium atoms at the terminal methyl group. It is intended for use as an internal standard for the quantification of cyclobenzaprine by GC- or LC-mass spectrometry. Cyclobenzaprine is a skeletal muscle relaxant that also has sedative properties.^1,2,3 It has been shown to antagonize muscarinic receptors (K_is = 25, 60, and 6 nM for M₁, M₂, and M₃, respectively), serotonin 5-HT₂ receptors (K_is = 56 and 330 nM for 5-HT_2C and 5-HT_2B, respectively), and histamine H₁ receptor (IC₅₀ = 20 nM).^4,5,6

1.Trivedi, R.K., and Patel, M.C.Development of a stability-indicating RP-UPLC method for rapid determination of metaxalone and its degradation products in solid oral dosage formSci.Pharm.80(2)353-366(2012) 2.Chou, R., Peterson, K., and Helfand, M.Comparative efficacy and safety of skeletal muscle relaxants for spasticity and musculoskeletal conditions: A systematic reviewJ. Pain Symptom Manage.28(2)140-175(2004) 3.See, S., and Ginzburg, R.Choosing a skeletal muscle relaxantAmerican Family Physician78(3)365-370(2008) 4.Gregori-PuigjanÉ, E., Setola, V., Hert, J., et al.Identifying mechanism-of-action targets for drugs and probesProc. Natl. Acad. Sci. USA109(28)11178-11183(2012) 5.Honda, M., Nishida, T., and Ono, H.Tricyclic analogs cyclobenzaprine, amitriptyline and cyproheptadine inhibit the spinal reflex transmission through 5-HT2 receptorsEuropean Journal of Pharmacology458(1-2)91-99(2003) 6.Lounkine, E., Keiser, M.J., Whitebread, S., et al.Large scale prediction and testing of drug activity on side-effect targetsNature486(7403)361-367(2012)