Complaint
Specification of Analysis
| Product Name | Topiroxostat Powder |
| CAS | 577778-58-6 |
| Appearance | white powder |
| Molecular formula | C13H8N6 |
| Molecular Weight | 248.24 |
| Assay | 98% |
| Shelf Life | Two years |
| Storage | Store in a dry, cool and sealed place |
Topiroxostat is an inhibitor of xanthine oxidoreductase (IC50 = 5.3 nM), an enzyme that converts xanthine to urate. Formulations containing topiroxostat are effective in vivo, lowering urate levels in the serum of patients with hyperuricemia. In rats, but not primates, topiroxostat treatment results in the formation of xanthine crystals, resulting in nephritis. Topiroxostat also inhibits ATP-binding cassette transporter G2 (ABCG2; IC50 = 0.18 μM), a high-capacity urate transporter that functions in both renal and extrarenal urate secretion.
Function of Topiroxostat
Topiroxostat is an orally-administered, non-purine, selective xanthine oxidase (XO) inhibitor developed for the treatment of hyperuricemia specifically for patients with gout in Japan. The drug was discovered and developed by Fuji Yakuhin. In contrast to conventional XO inhibitors such as febuxostat, topiroxostat interacts with key amino acid residues of the solvent channel.
Topiroxostat, a selective xanthine oxidoreductase inhibitor, is used in Japan for the treatment of hyperuricemic patients with or without gout. In terms of the effectiveness of topiroxostat in lowering serum urate levels, the dose-response relationship has been evaluated; however, it remains to be verified. A randomized, multi-center, double-blinded study of topiroxostat was performed for Japanese hyperuricemic patients with or without gout. During the 16-week study, 157 Japanese hyperuricemic patients with or without gout were randomly assigned to receive a placebo, topiroxostat at 120 or 160 mg/day, or allopurinol at 200 mg/day. The primary endpoint of this study was to determine the lowering rate of serum uric acid levels compared to those of baseline at the end of administration. A dose-response relationship (regarding decreases in the serum urate levels) was confirmed for the placebo and topiroxostat at 120 and at 160 mg/day. Moreover, at the end of administration, the lowering rate of serum urate levels was determined to be ?44.8% in the topiroxostat 160-mg/day group. No significant difference in the incidence of adverse events was observed among all groups, including the allopurinol group. The serum urate-lowering effect of topiroxostat was found to have a dose-response relationship in Japanese hyperuricemic patients with or without gout.
