pH4.3sodium phosphate buffer,Mobile phase,pH6.4sodium phosphate buffer,Standard preparation,Resolution solution,and Chromatographic system— Proceed as directed in the Assayunder Ticarcillin Monosodium.

Assay preparation 1 (where it is represented as being in a single-dose container)—Constitute Ticarcillin for Injection as directed in the labeling.Withdraw all of the withdrawable contents,and dilute quantitatively with pH6.4sodium phosphate bufferto obtain a solution having a concentration of about 0.9mg of ticarcillin (C15H16N2O6S2)per mL.

Assay preparation 2 (where the label states the quantity of ticarcillin in a given volume of constituted solution)—Constitute Ticarcillin for Injection as directed in the labeling.Dilute an accurately measured volume of the constituted solution quantitatively with pH6.4sodium phosphate bufferto obtain a solution having a concentration of about 0.9mg of ticarcillin (C15H16N2O6S2)per mL.

Procedure— Proceed as directed for Procedurein the Assayunder Ticarcillin Monosodium.Calculate the quantity,in mg,of ticarcillin (C15H16N2O6S2)withdrawn from the container or in the volume of constituted solution taken by the formula: in which Lis the labeled quantity,in mg per mL,of ticarcillin (C15H16N2O6S2)in the container or in the volume of constituted solution taken;Dis the concentration,in mg per mL,of ticarcillin in Assay preparation 1or Assay preparation 2,based on the labeled quantity in the container or in the portion of constituted solution taken,and the extent of dilution;Cis the concentration,in mg per mL,of USP Ticarcillin Monosodium Monohydrate RSin the Standard preparation;Pis the designated potency,in µg of ticarcillin per mg,of USP Ticarcillin Monosodium Monohydrate RS;and rUand rSare the ticarcillin peak responses obtained from the Assay preparationand the Standard preparation,respectively.