Cariprazine-d6 is intended for use as an internal standard for the quantification of cariprazine by GC- or LC-MS. Cariprazine is a dopamine D3 and D2 receptor antagonist and partial agonist.1 It binds to D3, D2S, and D2L receptors with Ki values of 0.085, 0.7, and 0.5 nM, respectively, as well as six additional human receptors (Kis = 0.58-208.9 nM) in a panel of 22 human and rat receptors, channels, and transporters at 1 μM. Cariprazine increases inositol phosphate accumulation (EC50 = 3.16 nM) and reduces quinpirole-induced increases in inositol phosphate accumulation (Kb = 0.6 nM) in A9 cells expressing the human D2 receptor. It inhibits forskolin-induced cAMP accumulation (EC50 = 2.63 nM) and reverses 7-OH-DPAT-induced inhibition of forskolin-induced cAMP accumulation (Kb = 0.27 nM) in CHO cells expressing the human D3 receptor. Cariprazine prevents phencyclidine-induced impairment of social recognition, spatial working memory, and extradimensional attention set-shifting in wild-type, but not D3 receptor knockout, mice when administered at doses ranging from 5 to 20 μg/kg.2 Formulations containing cariprazine have been used in the treatment of schizophrenia and bipolar disorder.

|1. Kiss, B., HorvÁth, A., NÉmethy, Z., et al. Cariprazine (RGH-188), a dopamine D3 receptor-preferring, D3/D2 dopamine receptor antagonist-partial agonist antipsychotic candidate: In vitro and neurochemical profile. J. Pharmacol. Exp. Ther. 333(1), 328-340 (2010).|2. Zimnisky, R., Chang, G., GyertyÁn, I., et al. Cariprazine, a dopamine D3-receptor-preferring partial agonist, blocks phencyclidine-induced impairments of working memory, attention set-shifting, and recognition memory in the mouse. Psychopharmacology (Berl) 226(1), 91-100 (2013).