Packaging and storage— Preserve in single-dose or in multiple-dose containers, preferably of Type I glass. Protect from light.

USP Reference standards 11—
USP Aurothioglucose RS.

Identification— Transfer a volume of Injectable Suspension, equivalent to about 200 mg of aurothioglucose, to a centrifuge separator containing 20 mL of ethyl acetate and 50 mL of water. Shake the mixture thoroughly, and centrifuge until the liquid phases have been clearly separated. Withdraw the lower, aqueous phase, and filter, discarding the first 10 mL of the filtrate. Collect the filtrate in a glass-stoppered vessel, and proceed as directed in Identification test A under Aurothioglucose, beginning with “apply 10 µL of this solution.”

Other requirements— It meets the requirements under Injections 1.

Assay— Transfer with a pipet, calibrated to contain rather than to deliver, an accurately measured volume of Injectable Suspension, equivalent to about 200 mg of aurothioglucose, to a beaker containing 400 mL of acetone. Wash the pipet into the beaker with a small quantity of acetone, mix, allow the solids to settle, and decant the supernatant through a filter. Wash the solids with another 400-mL portion of acetone, and repeat the decantation. Transfer the solids to the filter with the aid of acetone, then transfer the filter and its contents to a short-necked, 300-mL Kjeldahl flask, add 5 mL of water, and proceed as directed in the Assay under Gold Sodium Thiomalate, beginning with “add 20 mL of nitric acid.” The weight of gold so obtained, multiplied by 1.991, represents the weight of C6H11AuO5S in the portion of Injectable Suspension taken.

Topic/Question	Contact	Expert Committee
Monograph	Clydewyn M. Anthony, Ph.D. Scientist 1-301-816-8139	(MDCCA05) Monograph Development-Cough Cold and Analgesics
Reference Standards	Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org

USP32–NF27 Page 1607