Mobile phase,Standard solution,and Chromatographic system— Proceed as directed in the test for Limit of free chloramphenicolunder Chloramphenicol Sodium Succinate.

Test solution— Dissolve the contents of 1container in a volume of Mobile phaseto obtain a solution containing the equivalent of about 100mg of chloramphenicol per mL.Dilute this solution quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution containing the equivalent of about 0.5mg of chloramphenicol per mL.Pass a portion of this solution through a filter having a 0.5-µm or finer porosity,and use the filtrate.

Procedure— Separately inject equal volumes (about 10µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the areas for the free chloramphenicol peaks.Calculate the percentage of free chloramphenicol (C11H12Cl2N2O5)in the specimen taken by the formula: in which Cis the concentration,in µg per mL,of USP Chloramphenicol RSin the Standard solution;Dis the concentration,in mg per mL,of chloramphenicol equivalent in the Test solution,based on the labeled quantity in the container and the extent of dilution;and rUand rSare the chloramphenicol peak areas obtained from the Test solutionand the Standard solution,respectively.Not more than 2.0%is found.

Standard preparation— Proceed as directed in the Assayunder Chloramphenicol Sodium Succinate.

Assay preparation— Constitute 1container of Chloramphenicol Sodium Succinate for Injection as directed in the labeling.Dilute an accurately measured volume of the constituted solution quantitatively with water to obtain a solution having a concentration of about 20µg of chloramphenicol per mL.

Procedure— Proceed as directed in the Assayunder Chloramphenicol Sodium Succinate.Calculate the quantity,in mg,of chloramphenicol (C11H12Cl2N2O5),in each mLof the constituted Chloramphenicol Sodium Succinate for Injection taken by the formula: in which Lis the labeled quantity,in mg,of chloramphenicol in each mLof constituted solution;Dis the concentration,in µg per mL,of chloramphenicol in the Assay preparation,on the basis of the labeled quantity of chloramphenicol in each mLof constituted solution and the extent of dilution;Cis the concentration,in µg per mL,of USP Chloramphenicol RSin the Standard preparation;Pis the potency,in µg per mg,of USP Chloramphenicol RS;and AUand ASare the absorbances of the Assay preparationand the Standard preparation,respectively.