pH 4.3 sodium phosphate buffer, Mobile phase, pH 6.4 sodium phosphate buffer, Standard preparation, Resolution solution, and Chromatographic system— Proceed as directed in the Assay under 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 pH 6.4 sodium phosphate buffer to obtain a solution having a concentration of about 0.9 mg 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 pH 6.4 sodium phosphate buffer to obtain a solution having a concentration of about 0.9 mg of ticarcillin (C15H16N2O6S2) per mL.

Procedure— Proceed as directed for Procedure in the Assay under 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 Calculate the quantity, in mg, of ticarcillin (C15H16N2O6S2) withdrawn from the container or in the volume of constituted solution taken by the formula: in which L is the labeled quantity, in mg per mL, of ticarcillin (C15H16N2O6S2) in the container or in the volume of constituted solution taken; D is the concentration, in mg per mL, of ticarcillin in Assay preparation 1 or Assay preparation 2, based on the labeled quantity in the container or in the portion of constituted solution taken, and the extent of dilution; C is the concentration, in mg per mL, of USP Ticarcillin Monosodium Monohydrate RS in the Standard preparation; P is the designated potency, in µg of ticarcillin per mg, of USP Ticarcillin Monosodium Monohydrate RS; and rU and rS are the ticarcillin peak responses obtained from the Assay preparation and the Standard preparation, respectively.