Nafcillin for Injection

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

Nafcillin for Injection contains an amount of Nafcillin Sodium equivalent to not less than 90.0 percent and not more than 120.0 percent of the labeled amount of nafcillin (C₂₁H₂₂N₂O₅S).

1 Packaging and storage

Preserve as described in Packaging and Storage Requirements 〈659〉, Injection Packaging, Packaging for constitution.

1.1 USP Reference standards 〈11〉

USP Nafcillin Sodium RS

2 Constituted solution

At the time of use, it meets the requirements for Injections and Implanted Drug Products 〈1〉, Specific Tests, Completeness and clarity of solutions.

3 Identification

The retention time of the major peak for nafcillin in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

Bacterial Endotoxins Test 〈85〉-It contains not more than 0.13 USP Endotoxin Unit per mg of nafcillin.

Sterility Tests 〈71〉 - It meets the requirements when tested as directed for Membrane Filtration under Test for Sterility of the Product to be Examined.

pH 〈791〉: between 6.0 and 8.5, in the solution constituted as directed in the labeling.

Water Determination, Method I 〈921〉: between 3.5% and 5.3%.

Particulate Matter in Injections 〈788〉: meets the requirements for small-volume injections.

4 Other requirements

It meets the requirements for Uniformity of Dosage Units 〈905〉 and Labeling 〈7〉, Labels and Labeling for Injectable Products.

5 Assay

Acetic acid solution, 0.05 M Sodium acetate, Diluent, Mobile phase, Standard preparation, Resolution solution, and Chromatographic system-Proceed as directed in the Assay under Nafcillin Sodium.

Assay preparation 1 (where it is represented as being in a single-dose container)-Constitute Nafcillin for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Withdraw all of the withdrawable contents, using a suitable hypodermic needle and syringe, and dilute quantitatively with Diluent to obtain a solution having a concentration of about 0.4 mg of nafcillin (C₂₁H₂₂N₂O₅S) per mL.

Assay preparation 2 (where the label states the quantity of nafcillin in a given volume of constituted solution)-Constitute Nafcillin for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Dilute an accurately measured volume of the constituted solution quantitatively with Diluent to obtain a solution having a concentration of about 0.4 mg of nafcillin (C₂₁H₂₂N₂O₅S) per mL.

Procedure-Proceed as directed for Procedure in the Assay under Nafcillin Sodium. Calculate the quantity, in mg, of nafcillin (C₂₁H₂₂N₂O₅S) in the portion of constituted Nafcillin for Injection taken by the formula:

(C/1000)(L/D)(rᵤ/rₛ)

in which L is the labeled quantity, in mg, of nafcillin in the portion of Nafcillin for Injection taken; D is the concentration, in mg per mL, of nafcillin in Assay preparation 1 or Assay preparation 2, as appropriate, based on the volume of constituted Nafcillin for Injection taken and the extent of dilution; and the other terms are as defined therein.

Perform the above procedure on 10 containers where it is represented as being in a single-dose container and, if necessary, on 10 containers where the label states the quantity of nafcillin in a given volume of constituted solution. Use the individual results to determine the Uniformity of dosage units and the average thereof as the Assay value.