U.S. PHARMACOPEIA

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Clindamycin Phosphate Topical Suspension
» Clindamycin Phosphate Topical Suspension contains the equivalent of not less than 90.0 percent and not more than 110.0 percent of the labeled amount of clindamycin (C18H33ClN2O5S).
Packaging and storage— Preserve in tight containers.
Identification— The retention time of the clindamycin phosphate peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Minimum fill 755: meets the requirements.
pH 791: between 4.5 and 6.5.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay—
Mobile phase , Resolution solution, Standard preparation, and Chromatographic system—Proceed as directed in the Assay under Clindamycin Phosphate Gel.
Assay preparation— Using a suitable hypodermic needle and syringe, transfer an accurately measured volume of Topical Suspension, equivalent to about 20 mg of clindamycin (C18H33ClN2O5S), to a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Procedure— Proceed as directed for Procedure in the Assay under Clindamycin Phosphate Gel. Calculate the quantity, in mg, of clindamycin (C18H33ClN2O5S) in each mL of the Topical Suspension taken by the formula:
0.1(CE / V)(rU / rS),
in which V is the volume, in mL, of Topical Suspension taken, and the other terms are as defined therein.
Auxiliary Information— Staff Liaison : Brian D. Gilbert, Ph.D., Scientist
Expert Committee : (MDANT05) Monograph Development-Antibiotics
USP29–NF24 Page 541
Phone Number : 1-301-816-8223