Purity ~99% (HPLC). A potent, selective, and competitive non-nucleotide antagonist of P2X3 and P2X2/3 receptors that blocks receptor-mediated Ca2+ flux (Ki = 22 and 92nM for rat P2X3 and P2X2/3 receptor and 22 and 9nM for human P2X3 and P2X2/3 receptor, respectively). Its R-enantiomer has significantly reduced activity at these receptors. Exhibits high selectivity over other purinergic receptors. Shown to reduce thermal and mechanical hyperalgesia in rat models (ED50 = 10-15uM/kg, s.c). Its anti-nociceptive effects have a rapid on-set and persist for up to 5 hours after sub-cutaneous administration. Also shown to block dorsal root ganglion currents in a dose-dependent manner (IC50 = 15nM). Solubility: H2O Primary Target: P2X3 Primary Target Ki: 22nM