Vidarabine
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C10H13N5O4·H2O 285.26

9H-Purin-6-amine, 9--d-arabinofuranosyl-, monohydrate.
9--d-Arabinofuranosyladenine monohydrate [24356-66-9].

Anhydrous 267.25 [5536-17-4].
» Vidarabine has a potency equivalent to not less than 845 µg and not more than 985 µg of C10H13N5O4 per mg.
Packaging and storage— Preserve in tight containers.
Labeling— Where it is intended for use in preparing injectable or other sterile dosage forms, the label states that it is sterile or must be subjected to further processing during the preparation of injectable or other sterile forms.
Identification, Infrared Absorption 197K.
Specific rotation 781S: between 56.0 and 65.0 (= 365 nm).
Test solution: 10 mg of anhydrous vidarabine per mL, in dimethylformamide.
Bacterial endotoxins 85 Where the label states that Vidarabine is sterile or must be subjected to further processing during the processing of injectable dosage forms, it contains not more than 0.5 USP Endotoxin Unit per mg of vidarabine. Where it is intended for use in preparing ophthalmic dosage forms, it is exempt from the requirements.
Sterility 71 Where the label states that Vidarabine is sterile, it meets the requirements when tested as directed for Direct Inoculation of the Culture Medium under Test for Sterility of the Product to be Examined, except to transfer 2 g of solid specimen to each test medium.
Loss on drying 731 Dry about 100 mg in vacuum at 100 and at a pressure not exceeding 5 mm of mercury for 4 hours: it loses between 5.0% and 7.0% of its weight.
Assay—
Mobile phase— Dissolve 2.2 g of docusate sodium in 10 mL of glacial acetic acid and 500 mL of methanol in a 1000-mL volumetric flask. Dilute with water to volume, and mix. Pass this solution through a membrane filter having a 1-µm or finer porosity.
Standard preparation— Dissolve about 24 mg of USP Vidarabine RS, accurately weighed, in 150 mL of water in a 200-mL volumetric flask by heating to 100 for 10 minutes. Cool, dilute with water to volume, and mix.
Assay preparation— Using Vidarabine, prepare as directed for Standard preparation.
Chromatographic system (see Chromatography 621)—The chromatograph is equipped with a 254-nm detector and a 4-mm × 30-cm column that contains packing L1. Chromatograph three replicate injections of the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation is not more than 3.0%.
Procedure— Introduce equal volumes (approximately 10 µL) of the Assay preparation and the Standard preparation into the instrument, operated at room temperature, by means of a suitable microsyringe or sampling valve. Adjust the operating conditions so that satisfactory chromatography and peak responses are obtained. Use a detector sensitivity setting that gives a peak height for vidarabine that is at least 50% of scale. Measure peak responses at the same retention times obtained with the Assay preparation and the Standard preparation. Calculate the potency, in µg of C10H13 N5O4 per mg, of the Vidarabine taken by the formula:
F(rU / rS)(WS / WU)
in which F is the potency of USP Vidarabine RS, in µg of vidarabine per mg; rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively; and WU and WS are the amounts, in mg, of USP Vidarabine RS and Vidarabine taken, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ahalya Wise, M.S.
Scientist
1-301-816-8161
(MDANT05) Monograph Development-Antibiotics
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
85 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339
(MSA05) Microbiology and Sterility Assurance
71 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 3858