Edrophonium Chloride Injection

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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Edrophonium Chloride Injection is a sterile solution of Edrophonium Chloride in Water for Injection. It contains not less than 95.0 percent and not more than 105.0 percent of the labeled amount of C₁₀H₁₆ClNO.

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

Labeling—Label the Injection in multiple-dose containers to indicate an expiration date of not later than 3 years after the date of manufacture, and label the Injection in single-dose containers to indicate an expiration date of not later than 4 years after the date of manufacture.

USP Reference standards 〈11〉—

USP Edrophonium Chloride RS

1 Identification—

Change to read:

A: Spectroscopic Identi

cation Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U (CN 1-May-2020) —Test solution versus standard solution prepared as directed in the Assay.

B: Place in a small separator a volume of Injection, equivalent to about 30 mg of edrophonium chloride, add 15 mL of pH 9.6 alkaline borate buffer (see Buffer Solutions in the section Reagents, Indicators, and Solutions) and 5 mL of a 1 in 1000 solution of thymol blue in pH 9.6 alkaline borate buffer, and mix. Add 10 mL of chloroform, shake thoroughly, and allow to settle: a yellow color is produced in the chloroform layer.

C: It responds to the tests for Chloride 〈191〉.

Bacterial Endotoxins Test 〈85〉—It contains not more than 8.33 USP Endotoxin Units per mg of edrophonium chloride.

pH 〈791〉: between 5.0 and 5.8.

Other requirements—It meets the requirements under Injections and Implanted Drug Products 〈1〉.

2 Assay—

Pipet a volume of Injection, equivalent to about 50 mg of edrophonium chloride, into a glass-stoppered, 50-mL centrifuge tube. Add 5mL of pH 8.0 phosphate buffer (see Buffer Solutions in the section Reagents, Indicators, and Solutions) and 5 g of sodium chloride. Wash the solution with four 20-mL portions of a mixture of equal volumes of solvent hexane and ether. Transfer the aqueous phase to a 100-mL volumetric flask, add 0.1 N hydrochloric acid to volume, and mix. Transfer a 5-mL aliquot of this solution to a 50-mL volumetric flask, add 0.1 N hydrochloric acid to volume, and mix test solution. Dissolve an accurately weighed quantity of USP Edrophonium Chloride RS in 0.1 N hydrochloric acid, and dilute quantitatively and stepwise with the acid to obtain a Standard solution having a known concentration of about 50μg per mL. Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 273nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in mg, of C₁₀H₁₆ClNO in each mL of the Injection taken by the formula:

(C/V)(A_U/A_S)

in which C is the concentration, in μg per mL, of USP Edrophonium Chloride RS in the Standard solution; V is the volume, in mL, of Injection taken; and A_U and A_S are the absorbances of the test solution and the Standard solution, respectively.