Idoxuridine

(eye'' dox ure' i deen).

C9H11IN2O5

354.10

Uridine, 2¢-deoxy-5-iodo-.
2¢-Deoxy-5-iodouridine

[54-42-2].

» Idoxuridine contains not less than 98.0 percent and not more than 101.0 percent of C9H11IN2O5, calculated on the dried basis.

Packaging and storage— Preserve in tight, light-resistant containers.

USP Reference standards

—

USP Idoxuridine RS

Identification—

A: Infrared Absorption

197M

B: Ultraviolet Absorption

197U

—

Solution: 35 µg per mL.

Medium: pH 12.0 buffer (prepared from 7.46 g of potassium chloride and 24 mL of 1 N sodium hydroxide dissolved in 2000 mL of water).

Absorptivities at 279 nm, calculated on the dried basis for the test sample only, do not differ by more than 2.0%.

Loss on drying

731

— Dry about 500 mg, accurately weighed, in vacuum at 60

for 2 hours: it loses not more than 1.0% of its weight.

Assay— Dissolve about 250 mg of Idoxuridine, accurately weighed, in 20 mL of dimethylformamide that previously has been neutralized with 0.1 N sodium methoxide in toluene VS, a solution of 300 mg of thymol blue in 100 mL of methanol being used as the indicator. Titrate with 0.1 N sodium methoxide in toluene VS to a blue endpoint, taking precautions against absorption of atmospheric carbon dioxide. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N sodium methoxide is equivalent to 35.41 mg of C9H11IN2O5.

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Behnam Davani, Ph.D., M.B.A. Senior Scientific Liaison 1-301-816-8394	(SM12010) Monographs - Small Molecules 1
Reference Standards	RS Technical Services 1-301-816-8129 rstech@usp.org

USP35–NF30 Page 3476

Pharmacopeial Forum: Volume No. 29(4) Page 1033