Cephapirin Sodium Intramammary Infusion
» Cephapirin Sodium Intramammary Infusion is a suspension of Cephapirin Sodium in a suitable vegetable oil vehicle. It contains the equivalent of not less than 90.0 percent and not more than 120.0 percent of the labeled quantity of cephapirin (C17H17N3O6S2). It contains a suitable dispersing agent.
Packaging and storage
Preserve in well-closed unit-dose disposable syringes at controlled room temperature.
Labeling
Label it to indicate that it is for veterinary use only.
Identification, Infrared Absorption
![]() ![]() ![]()
Water, Method I
![]() ![]()
Assay
Solution A, Solution B, Mobile phase, Extraction solution, Dilution buffer, 10% Acetic acid solution, System suitability solution, Standard preparation, and Chromatographic system
Proceed as directed in the Assay under Cephapirin Benzathine.
Assay preparation
Express the entire contents of a syringe of the Intramammary Infusion into a centrifuge tube. For each mL of Intramammary Infusion, add 1.0 n-heptane and 1.0 mL of Extraction solution, cap, and mix on a vortex mixer at high speed for 5 minutes. Centrifuge for 5 minutes at a speed sufficient to break the emulsion. Remove the aqueous layer, and pass through a 0.45-µm nylon filter, discarding the first 0.5 mL. Transfer 2.5 mL of the filtered aqueous phase into a 25-mL volumetric flask that contains a solution composed of 15.0 mL of Dilution buffer and 7.0 mL of acetonitrile. Add water to volume, and mix well to obtain a single phase.
Procedure
Separately inject equal volumes (about 2 µL) of the duplicate Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the areas of the major peaks. Calculate the quantity, in mg, of cephapirin (C17H17N3O6S2) in each syringe of Intramammary Infusion taken by the formula:
10PW(VU / VS)(rU / rS)
in which P is the assigned potency, in µg of cephapirin per mg, of USP Cephapirin Sodium RS; W is the quantity of USP Cephapirin Sodium RS, in mg, used to prepare the Standard preparation; VS is the final volume, in mL, of the Standard preparation; VU is the entire volume of Intramammary Infusion, in mL, in one syringe; and rU and rS are the peak area and the average peak area of the cephapirin peaks obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP32NF27 Page 1878
Pharmacopeial Forum: Volume No. 30(2) Page 472
|