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Methadone Hydrochloride Injection
» Methadone Hydrochloride Injection is a sterile solution of Methadone Hydrochloride in Water for Injection. It contains, in each mL, not less than 9.5 mg and not more than 10.5 mg of methadone hydrochloride (C21H27NO·HCl).
Packaging and storage
Preserve in single-dose or in multiple-dose, light-resistant containers, preferably of Type I glass.
Identification
It meets the requirements under IdentificationOrganic Nitrogenous Bases
Bacterial endotoxins
pH
Other requirements
It meets the requirements under Injections
Assay
Internal standard solution
Weigh about 100 mg of procaine, and dissolve in 20 mL of methylene chloride.
Standard preparation
Weigh accurately about 10 mg of USP Methadone Hydrochloride RS, transfer to a 60-mL separator, add 1 mL of water and 2 mL of 0.5 N sodium hydroxide, and proceed as directed for Assay preparation, beginning with extract with three 10-mL portions of chromatographic grade methylene chloride.
Assay preparation
Transfer 1.0 mL of Injection, equivalent to 10 mg of methadone hydrochloride, to a 60-mL separator, add 2 mL of 0.5 N sodium hydroxide, and extract with three 10-mL portions of chromatographic grade methylene chloride, combining the extracts in a vessel containing about 3 g of anhydrous sodium sulfate. Transfer 2.0 mL of Internal standard solution to the vessel containing the extracts, insert the stopper, and mix. Decant about 15 mL of the methylene chloride solution to a test tube, and evaporate to a volume of 2 to 3 mL, using vacuum or a stream of nitrogen.
Procedure
Use a suitable gas chromatograph equipped with a flame-ionization detector and a glass column 1.2-m long and 4-mm in diameter, packed with 3% phase G2 on 100- to 200-mesh support S1A. Maintain the column temperature at 170
W(RU / RS)
in which W is the weight, in mg, of USP Methadone Hydrochloride RS in the Standard preparation; and RU and RS are the ratios of the peak areas of methadone to the peak area of procaine in the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3840
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