Oxacillin Sodium Capsules
» Oxacillin Sodium Capsules contain the equivalent of not less than 90.0 percent and not more than 120.0 percent of the labeled amount of oxacillin (C19H19N3O5S).
Packaging and storage— Preserve in tight containers, at controlled room temperature.
USP Reference standards 11
USP Oxacillin Sodium RS Click to View Structure
Identification— The chromatogram of the Assay preparation obtained as directed in the Assay exhibits a major peak for oxacillin, the retention time of which corresponds to that exhibited in the chromatogram of the Standard preparation obtained as directed in the Assay.
Dissolution 711
Medium: water; 900 mL.
Apparatus 1: 100 rpm.
Time: 45 minutes.
Procedure— Determine the amount of oxacillin (C19H19N3O5S) by a suitable validated spectrophotometric analysis of a filtered portion of the solution under test, suitably diluted with Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Oxacillin Sodium RS in the same medium.
Tolerances— Not less than 75% (Q) of the labeled amount of C19H19N3O5S is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Water, Method I 921: not more than 6.0%.
Mobile phase, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Oxacillin Sodium.
Assay preparation— Remove, as completely as possible, the contents of not less than 10 Capsules, and weigh. Mix, and transfer an accurately weighed portion of the powder, equivalent to about 100 mg of oxacillin (C19H19N3O5S), to a 200-mL volumetric flask, add water to volume, and mix for 10 minutes with the aid of a magnetic stirrer. Filter about 25 mL of the resulting solution, discarding the first 5 mL of the filtrate. Transfer 10.0 mL of the clear filtrate to a 50-mL volumetric flask, dilute with water to volume, and mix. [note—Use this Assay preparation on the day prepared. ]
Procedure— Proceed as directed for Procedure in the Assay under Oxacillin Sodium. Calculate the quantity, in mg, of oxacillin (C19H19N3O5S) in the portion of Capsule contents taken by the formula:
CE(rU / rS)
in which the terms are as defined therein.
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Topic/Question Contact Expert Committee
Monograph Ahalya Wise, M.S.
Senior Scientific Liaison
(SM12010) Monographs - Small Molecules 1
Reference Standards RS Technical Services
711 Margareth R.C. Marques, Ph.D.
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(GCDF2010) General Chapters - Dosage Forms
USP35–NF30 Page 4141