» Cefoxitin Injection is a sterile solution of Cefoxitin Sodium and one or more suitable buffer substances in Water for Injection. It contains Dextrose or Sodium Chloride as a tonicity-adjusting agent. It contains the equivalent of not less than 90.0 percent and not more than 120.0 percent of the labeled amount of cefoxitin (C16H17N3O7S2).
Packaging and storage Preserve in Containers for Injections as described under Injections 1. Maintain in the frozen state.
Labeling It meets the requirements for Labeling under Injections 1. The label states that it is to be thawed just prior to use, describes conditions for proper storage of the resultant solution, and directs that the solution is not to be refrozen.
USP Reference standards 11
USP Endotoxin RS
Identification The chromatogram of the Assay preparation obtained as directed in the Assay exhibits a major peak for cefoxitin, the retention time of which corresponds to that exhibited in the chromatogram of the Standard preparation obtained as directed in the Assay.
Bacterial endotoxins 85 It contains not more than 0.13 USP Endotoxin Unit per mg of cefoxitin.
Sterility 71 It meets the requirements when tested as directed for Membrane Filtration under Test for Sterility of the Product to be Examined.
pH 791: between 4.5 and 8.0.
Particulate matter 788: meets the requirements for small-volume injections.
Mobile phase , Phosphate buffer, Standard preparation, and Chromatographic systemPrepare as directed in the Assay under Cefoxitin Sodium.
Assay preparation Allow 1 container of Injection to thaw, and mix. Dilute an accurately measured volume of Injection quantitatively with Phosphate buffer to obtain a solution containing about 0.3 mg of cefoxitin per mL. Use this solution within 5 hours.
Procedure Proceed as directed in the Assay under Cefoxitin Sodium. Calculate the quantity, in mg, of cefoxitin (C16H17N3O7S2) in each mL of the Injection taken by the formula:
(CP / 1000)(L / D)(rU / rS)in which L is the labeled quantity, in mg, of cefoxitin (C16 H17N3O7S2) in each mL of Injection taken; D is the concentration, in mg per mL, of the Assay preparation, based on the volume of Injection taken and the extent of dilution; and the other terms are as defined therein.
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USP35NF30 Page 2564