Azithromycin Capsules
» Azithromycin Capsules contain the equivalent of not less than 90.0 percent and not more than 110.0 percent of the labeled amount of azithromycin (C38H72N2O12).
Packaging and storage
Preserve in well-closed containers. Where packaged in unit-of-use containers, each container contains six 250-mg Capsules, and the label indicates the intended sequential day of use for each Capsule.
Identification
The retention time of the azithromycin peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Dissolution 711
[noteUse water that has a resistivity of not less than 18 Mohm-cm.]
pH 6.0 sodium phosphate buffer
Prepare 6 L of 0.1 M dibasic sodium phosphate, adjust with about 40 mL of hydrochloric acid to a pH of 6.0 ± 0.05, add 600 mg of trypsin, and mix.
Medium: pH 6.0 sodium phosphate buffer;
900 mL.
Apparatus 2:
100 rpm.
Time:
45 minutes.
Standard solution
Transfer about 15 mg of USP Azithromycin RS, accurately weighed, to a 50-mL volumetric flask. Add 25 mL of Medium, and sonicate briefly to dissolve. Dilute with Medium to volume, and mix. Transfer 2.0 mL of this solution to a 25-mL volumetric flask, dilute with Mobile phase (prepared as directed in the Assay) to volume, and mix. Transfer 4.0 mL of this solution to a second 25-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Test solution
Filter a portion of the solution under test through a filter having a porosity of 0.5 µm or less. Transfer 2.0 mL of the filtrate to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix. Transfer 4.0 mL of this solution to a second 25-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Procedure
Determine the amount of azithromycin (C38H72N2O12) dissolved, using filtered portions of the solution under test, and employing the procedure set forth in the Assay, making any necessary modifications. Calculate the quantity, in mg, of azithromycin (C38H72N2O12) dissolved by the formula:
70.31(CP)(rU / rS)
in which C is the concentration, in mg per mL, of USP Azithromycin RS in the Standard solution; P is the potency, in µg, of azithromycin (C38H72N2O12) per mg of USP Azithromycin RS; and rU and rS are the azithromycin peak responses obtained from the Test solution and the Standard solution, respectively.
Tolerances
Not less than 75% (Q) of the labeled amount of azithromycin (C38H72N2O12) is dissolved in 45 minutes.
Uniformity of dosage units 905
meet the requirements.
Water, Method I 921:
not more than 5.0%.
Assay
Mobile phase, Standard preparation, Resolution solution, and Chromatographic system
Proceed as directed in the Assay under Azithromycin.
Assay preparation
Remove, as completely as possible, the contents of not fewer than 20 Capsules, and weigh accurately. Mix the combined contents, and transfer an accurately weighed quantity of the powder, equivalent to about 250 mg of anhydrous azithromycin, to a 250-mL volumetric flask. Add about 175 mL of acetonitrile, and shake by mechanical means for 30 minutes. Dilute with acetonitrile to volume, and mix. Place about 40 mL of the resulting suspension in a centrifuge tube, and centrifuge. Transfer 2.0 mL of the clear supernatant to a 50-mL volumetric flask, dilute with Mobile phase to volume, and mix. Transfer 2.0 mL of this solution to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Procedure
Proceed as directed for Procedure in the Assay under Azithromycin. Calculate the quantity, in mg, of azithromycin (C38H72N2O12) in the portion of Capsules taken by the formula:
(312.5CP / 4)(rU / rS)
in which C is the concentration, in mg per mL, of USP Azithromycin RS in the Standard preparation; P is the potency, in µg of azithromycin (C38H72N2O12) per mg, of USP Azithromycin RS; and rU and rS are the azithromycin peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
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Chromatographic Column
USP32NF27 Page 1615
Pharmacopeial Forum: Volume No. 27(6) Page 3394
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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