» Digitoxin Injection is a sterile solution of Digitoxin in 5 to 50 percent (v/v) of alcohol, and may contain Glycerin or other suitable solubilizing agents. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C41H64O13.
Packaging and storage Preserve in single-dose or multiple-dose containers, preferably of Type I glass, protected from light.
USP Reference standards 11
USP Endotoxin RS
A: To a portion of Injection, equivalent to about 1 mg of digitoxin, add 10 mL of water, and extract with 10 mL of chloroform. Evaporate the chloroform extract on a steam bath with the aid of a current of air to dryness. Dissolve the residue in 2 mL of a solution prepared by mixing 0.3 mL of ferric chloride TS and 50 mL of glacial acetic acid, and underlay with 2 mL of sulfuric acid: at the zone of contact of the two liquids a brown color, which gradually changes to light green, then to blue, is produced, and finally the entire acetic acid layer acquires a blue color.
B: To a portion of Injection, equivalent to about 0.2 mg of digitoxin, add 10 mL of water, and extract with 10 mL of chloroform. Evaporate the chloroform extract on a steam bath with the aid of a current of air to dryness. Add 2 mL of a freshly prepared 1 in 100 solution of m-dinitrobenzene in alcohol, and allow to stand for 10 minutes with frequent shaking. Add 2 mL of a 1 in 200 solution of tetramethylammonium hydroxide in alcohol, and mix: a red-violet color develops slowly and then fades.
C: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that of the major peak in the chromatogram of the Standard preparation as obtained in the Assay.
Bacterial endotoxins 85 It contains not more than 111.0 USP Endotoxin Units per mg of digitoxin.
Alcohol content 611: between 90.0% and 110.0% of the labeled percentage of C2H5OH.
Other requirements It meets the requirements under Injections 1.
Mobile phase, Standard preparation, System suitability preparation, and Chromatographic system Prepare as directed in the Assay under Digitoxin.
Assay preparation Transfer an accurately measured volume of Injection, equivalent to about 1 mg of digitoxin, to a 25-mL volumetric flask. Dilute with Mobile phase to volume, and mix.
Procedure Proceed as directed for Procedure in the Assay under Digitoxin. Calculate the quantity, in µg, of C41H64O13 in each mL of the Injection taken by the formula:
25(C / V)(rU / rS)in which C is the concentration, in µg per mL, of USP Digitoxin RS in the Standard preparation, V is the volume, in mL, of Injection taken, and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2903