Idoxuridine hydrate (5-Iodo-2′-deoxyuridine, 5-IUdR, IdUrd) is a competitive inhibitor of phosphorylases. As an iodinated thymidine analogue, it effectively inhibits DNA polymerase and hinders viral replication, making it useful in the treatment of viral eye infections such as herpes simplex keratitis. Against feline herpesvirus, Idoxuridine has been found to have an IC50 value of 4.3 μM [1].

Idoxuridine (2-10 μM, 72 hours) hydrate has the IC 50 value of 4.3 μM of antiviral [1]. Cell Proliferation Assay [1] Cell Line: Crandell-Reese feline kidney (CRFK) cells Concentration: 2-10 μM Incubation Time: 72 hours Result: Showed the IC 50 value of 4.3 μM. Cell Cytotoxicity Assay [1] Cell Line: Crandell-Reese feline kidney (CRFK) cells Concentration: 5-50 μM Incubation Time: 72 hours Result: Reduced by 10.8% relatively in CRFK cells.

Idoxuridine (intraperitoneal injection, 50-200 mg/kg, 3 times, 3 hours interval) hydrate can stimulate the production of hemolysin plaque-forming cells (HPFC) to sheep red blood cells (SRBC) in C3HeB/FeJ female and male mice and A/J male mice [2]. Animal Model: C3HeB/FeJ female and male mice and A/J male mice, aged 2 to 4 months [2] Dosage: 50-200 mg/kg Administration: Intraperitoneal injection, 3 times, 3 hours interval Result: Stimulated the production of hemolysin plaque-forming cells (HPFC) to sheep red blood cells (SRBC) in the dose range of 50-200 mg/kg.