In Vitro Pharmacological Profile of Ipragliflozin, a Sodium Glucose Co-transporter 2 Inhibitor.

Ipragliflozin, a selective sodium glucose cotransporter 2 (SGLT2) inhibitor, is used for the treatment of type 2 diabetes mellitus. To date, the only known in vitro pharmacological characteristic of ipragliflozin is its selectivity for SGLT2 over SGLT1, which was previously reported by our group. Therefore, in this study, we investigated other in vitro pharmacological characteristics of ipragliflozin and compared them with those of phlorizin, a naturally occurring SGLT inhibitor. Selectivity of ipragliflozin and phlorizin for human (h) SGLT2 over hSGLT3, hSGLT4, hSGLT5, hSGLT6 and hSodium/myo-inositol (MI) cotransporter 1 (hSMIT1) was examined in Chinese hamster ovary (CHO) cells overexpressing each transporter using specific radio-ligands. Ipragliflozin had higher selectivity for hSGLT2 than other hSGLTs. Phlorizin showed lower selectivity for hSGLT2 compared to ipragliflozin. Studies using CHO cells overexpressing hSGLT2 demonstrated that both ipragliflozin and phlorizin competitively inhibited SGLT2-mediated methyl-α-D-glucopyranoside (AMG) uptake with an inhibitory constant (K) of 2.28 and 20.2 nM, respectively. Ipragliflozin, but not phlorizin, inhibited hSGLT2 in a wash-resistant manner, suggesting that binding of ipragliflozin to hSGLT2 was persistent. These data demonstrate that ipragliflozin is a competitive inhibitor of SGLT2, has high selectivity for SGLT2 over not only SGLT1 but also other SGLT family members, and binds persistently to hSGLT2.