Amifostine for Injection
»Amifostine for Injection is a sterile,lyophilized crystalline substance suitable for parenteral use.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of amifostine (C5H15N2O3PS).
Packaging and storage— Preserve in tightContainers for Sterile Solidsas described under Injections á1ñ,at controlled room temperature.
Constituted solution— At the time of use,it meets the requirements for Constituted Solutionsunder Injections á1ñ.When constituted with 0.9%Sodium Chloride Injection,the solution must completely dissolve in 45seconds.
Bacterial endotoxins á85ñ— It contains not more than 0.2USP Endotoxin Unit per mg of amifostine.
Sterility á71ñ— It meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product to be Examined.
pHá791ñ: between 6.5and 7.5,in a solution constituted as directed in the labeling.
Water,Method Ic á921ñ: between 18.0%and 22.0%,when tested as directed in the test for Waterunder Amifostine.
Particulate matter á788ñ: meets the requirements for small-volume injections.
Related compounds—
TEST1—
Mobile phase— Prepare as directed in the Assayunder Amifostine.
Blank solution,Standard thiol solution,and Chromatographic system— Prepare as directed in the test for Related compoundsunder Amifostine.
Test solution— Transfer an accurately weighed quantity of Amifostine for Injection,equivalent to about 500mg of amifostine,to a 50-mLvolumetric flask,dissolve in 9mLof water,dilute with water to volume,and mix.Transfer 6.0mLof this solution to a 25-mLvolumetric flask,add 6.5mLof water,dilute with methanol to volume,and mix.
Procedure— Proceed as directed in the test for Related compoundsunder Amifostine.Calculate the percentage of amifostine thiol in the portion of Amifostine for Injection taken by the formula:
(134.24/207.17)(41.67C)(rU/rS),
in which the terms are as defined therein.Calculate the percentage of each of the other impurities in the portion of Amifostine for Injection taken by the formula:
100(ri/rA),
in which riand rAare the peak responses for each impurity and amifostine,respectively,obtained from the Test solution:not more than 0.1%of any individual impurity,excluding amifostine thiol,is found.
TEST2—
Mobile phase— Dissolve 0.28g of sodium 1-octanesulfonate in 700mLof water.Adjust with trifluoroacetic acid to a pHof 2.5.Prepare a filtered and degassed mixture of this solution and acetonitrile (7:3).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard disulfide solution— Transfer about 4.6mg of USP Amifostine Disulfide RS,accurately weighed,to a 100-mLvolumetric flask.Dissolve in 70mLof water,dilute with acetonitrile to volume,and mix.
Test solution— Transfer an accurately weighed quantity of Amifostine for Injection,equivalent to about 500mg of amifostine,to a 50-mLvolumetric flask,dissolve in 9mLof water,dilute with water to volume,and mix.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 247-nm detector and a 4.6-mm ×25-cm column that contains 5-µm packing L1.The flow rate is about 1mLper minute.Chromatograph the Standard disulfide solution,and record the peak responses as directed for Procedure:the column efficiency is not less than 1000theoretical plates;the tailing factor for the amifostine disulfide peak is not more than 2.5;and the relative standard deviation for replicate injections is not more than 4.0%.
Procedure— Separately inject equal volumes (about 10µL)of the Standard disulfide solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the amifostine disulfide peaks.Calculate the percentage of amifostine disulfide in the portion of Amifostine for Injection taken by the formula:
(266.47/412.31)(10C)(rU/rS),
in which 266.47and 412.31are the molecular weights of amifostine disulfide and amifostine disulfide tetrahydrochloride,respectively;Cis the concentration,in mg per mL,of USP Amifostine Disulfide RSin the Standard disulfide solution;and rUand rSare the peak responses obtained from the Test solutionand the Standard disulfide solution,respectively:not more than 2.0%of total impurities,including amifostine thiol and amifostine disulfide,is found.
Other requirements— It meets the requirements under Uniformity of Dosage Units á905ñand for Labelingunder Injections á1ñ.It also meets the requirements of the tests for Identificationand X-ray diffractionunder Amifostine.
Assay—
Mobile phase,Standard preparation,andChromatographic system— Prepare as directed in the Assayunder Amifostine.
Assay preparation— Transfer an accurately weighed quantity of Amifostine for Injection,equivalent to about 500mg of amifostine,to a 50-mLvolumetric flask,dissolve in 10mLof water,dilute with water to volume,and mix.Transfer 6.0mLof this solution to a 25-mLvolumetric flask,add 6.5mLof water,dilute with methanol to volume,and mix.
Procedure— Proceed as directed in the Assayunder Amifostine.Calculate the quantity,in mg,of amifostine (C5H15N2O3PS)in the portion of Amifostine for Injection taken by the formula:
208.33C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Amifostine RSin the Standard preparation;and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 115
Pharmacopeial Forum:Volume No.27(3)Page 2517
Phone Number:1-301-816-8305