Oxacillin for Injection
» Oxacillin for Injection contains an amount of Oxacillin Sodium equivalent to not less than 90.0 percent and not more than 115.0 percent of the labeled amount of oxacillin (C19H19N3O5S).
Packaging and storage— Preserve in Containers for Sterile Solids as described under Injections 1, at controlled room temperature.
Constituted solution— At the time of use, it meets the requirements for Constituted Solutions under Injections 1.
Identification— The retention time of the oxacillin peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Bacterial endotoxins 85 It contains not more than 0.2 USP Endotoxin Unit per mg of oxacillin.
Sterility 71 It meets the requirements when tested as directed for Membrane Filtration under Test for Sterility of the Product to be Examined.
Uniformity of dosage units 905: meets the requirements.
Procedure for content uniformity— Perform the Assay on individual containers using Assay preparation 1 or Assay preparation 2, or both, as appropriate.
pH 791: between 6.0 and 8.5, in the solution constituted as directed in the labeling.
Water, Method I 921: not more than 6.0%.
Particulate matter 788: meets the requirements for small-volume injections.
Assay—
Mobile phase , Standard preparation, and Chromatographic system—Proceed as directed in the Assay under Oxacillin Sodium.
Assay preparation 1 (where it is represented as being in a single-dose container)—Constitute Oxacillin 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, and stepwise if necessary, with water to obtain a solution containing about 0.1 mg per mL of oxacillin. [note—Use this solution on the day prepared.]
Assay preparation 2 (where the label states the quantity of oxacillin in a given volume of constituted solution)—Constitute Oxacillin for Injection with 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, and stepwise if necessary, with water to obtain a solution containing about 0.1 mg per mL of oxacillin (C19H19N3O5S). [note—Use this solution on the day prepared.]
Procedure— Proceed as directed in the Assay under Oxacillin Sodium. Calculate the quantity, in mg, of oxacillin (C19H19N3O5S) in the constituted solution taken by the formula:
(L / D)(CE / 1000)(rU / rS)
in which L is the labeled quantity, in mg, of oxacillin in the container or in the volume of constituted solution taken; D is the concentration, in mg per mL, of oxacillin in Assay preparation 1 or in Assay preparation 2, on the basis of the labeled quantity in the container or in the volume of constituted solution taken, respectively; C is the concentration, in mg per mL, of USP Oxacillin Sodium RS in the Standard preparation; E is the oxacillin equivalent, in µg per mg, of USP Oxacillin Sodium RS; and rU and rS are the oxacillin peak responses obtained from the Assay preparation and the Standard preparation, respectively. Where the test for Uniformity of dosage units has been performed using the Procedure for content uniformity, use the average of these determinations as the Assay value.
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Topic/Question Contact Expert Committee
Monograph Ahalya Wise, M.S.
Scientist
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(MDANT05) Monograph Development-Antibiotics
Reference Standards Lili Wang, Technical Services Scientist
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85 Radhakrishna S Tirumalai, Ph.D.
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Senior Scientist
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(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 3148