Clindamycin Phosphate Topical Suspension
»Clindamycin Phosphate Topical Suspension contains the equivalent of not less than 90.0percent and not more than 110.0percent 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 preparationcorresponds to that in the chromatogram of the Standard preparation,as obtained in the Assay.
Minimum fill á755ñ: meets the requirements.
pHá791ñ: between 4.5and 6.5.
Assay—
Mobile phase ,Resolution solution,Standard preparation,and Chromatographic system—Proceed as directed in the Assayunder Clindamycin Phosphate Gel.
Assay preparation— Using a suitable hypodermic needle and syringe,transfer an accurately measured volume of Topical Suspension,equivalent to about 20mg of clindamycin (C18H33ClN2O5S),to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Procedure— Proceed as directed for Procedurein the Assayunder Clindamycin Phosphate Gel.Calculate the quantity,in mg,of clindamycin (C18H33ClN2O5S)in each mLof the Topical Suspension taken by the formula:
0.1(CE/V)(rU/rS),
in which Vis the volume,in mL,of Topical Suspension taken,and the other terms are as defined therein.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 498
Phone Number:1-301-816-8335