U.S. PHARMACOPEIA

Search USP29  
Cephalothin Injection
» Cephalothin Injection contains an amount of Cephalothin Sodium equivalent to not less than 90.0 percent and not more than 115.0 percent of the labeled amount of cephalothin (C16H16N2O6S2).
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.
Bacterial endotoxins 85— It contains not more than 0.13 USP Endotoxin Unit per mg of cephalothin.
pH 791: between 6.0 and 8.5.
Particulate matter 788: meets the requirements for small-volume injections.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Other requirements— It responds to the Identification test A under Cephalothin Sodium and meets the requirements for Sterility under Cephalothin for Injection.
Assay—
Mobile phase, Standard preparation, Resolution solution, and Chromatographic system— Proceed as directed in the Assay under Cephalothin Sodium.
Assay preparation— Transfer an accurately measured volume of Injection, equivalent to about 100 mg of cephalothin (C16H16N2O6S2), to a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Procedure— Proceed as directed for Procedure in the Assay under Cephalothin Sodium. Calculate the quantity, in µg, of cephalothin (C16H16N2O6S2) in each mL of the Injection taken by the formula:
100(CP / V)(rU / rS),
in which C is the concentration, in mg per mL, of USP Cephalothin Sodium RS, in the Standard preparation; P is the assigned potency, in µg of cephalothin (C16H16N2O6S2) per mg, of USP Cephalothin Sodium RS; V is the volume, in mL, of Injection taken to prepare the Assay preparation; and rU and rS are the cephalothin peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Staff Liaison : Brian D. Gilbert, Ph.D., Scientist
Expert Committee : (MDANT05) Monograph Development-Antibiotics
USP29–NF24 Page 451
Phone Number : 1-301-816-8223