Clindamycin Phosphate
(klin'' da mye' sin fos' fate).
C18H34ClN2O8PS 504.97
l-threo--d-galacto-Octopyranoside, methyl 7-chloro-6,7,8-trideoxy-6-[[(1-methyl-4-propyl-2-pyrrolidinyl)carbonyl]amino]-1-thio-, 2-(dihydrogen phosphate), (2S-trans)-.
Methyl 7-chloro-6,7,8-trideoxy-6-(1-methyl-trans-4-propyl-l-2-pyrrolidinecarboxamido)-1-thio-l-threo--d-galacto-octopyranoside 2-(dihydrogen phosphate) [24729-96-2].
» Clindamycin Phosphate has a potency equivalent to not less than 758 µg of clindamycin (C18H33ClN2O5S) per mg, calculated on the anhydrous basis.
Packaging and storage— Preserve in tight containers.
Labeling— Where it is intended for use in preparing injectable dosage forms, the label states that it is sterile or must be subjected to further processing during the preparation of injectable dosage forms.
USP Reference standards 11
USP Clindamycin Phosphate RS Click to View Structure
USP Endotoxin RS
Identification, Infrared Absorption 197M
Test specimen: undried.
Crystallinity 695: meets the requirements.
pH 791: between 3.5 and 4.5, in a solution containing 10 mg per mL.
Water, Method I 921: not more than 6.0%.
Other requirements— Where the label states that Clindamycin Phosphate is sterile, it meets the requirements for Sterility and Bacterial endotoxins under Clindamycin for Injection. Where the label states that Clindamycin Phosphate must be subjected to further processing during the preparation of injectable dosage forms, it meets the requirements for Bacterial endotoxins under Clindamycin for Injection.
Assay—
Buffer solution— Add 14 mL of phosphoric acid to 4000 mL of HPLC grade water. Add 10 mL of ammonium hydroxide, and adjust with ammonium hydroxide to a pH of 3.90 ± 0.05.
Organic solution— Prepare a mixture of acetonitrile and methanol (900:100).
Diluent— Prepare a degassed mixture of Buffer solution and Organic solution (80:20).
Solution A— Prepare a degassed mixture of Buffer solution and Organic solution (920:80).
Solution B— Prepare a degassed mixture of Buffer solution and Organic solution (520:480).
Mobile phase— Use variable mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation— Accurately weigh about 22 mg of USP Clindamycin Phosphate RS. Add 10.0 mL of Diluent, shake briefly, and sonicate for about 5 minutes to dissolve. Allow to cool to ambient temperature.
Assay preparation— Accurately weigh about 22 mg of Clindamycin Phosphate. Add 10.0 mL of Diluent, shake briefly, and sonicate for about 5 minutes to dissolve. Allow to cool to ambient temperature.
Chromatographic system— The liquid chromatograph is equipped with a 214-nm detector and a 4.6-mm × 25-cm column that contains packing L7. The flow rate is about 1.2 mL per minute. Maintain the column at a constant temperature of about 40. The chromatograph is programmed as follows.
Time
(minutes)
Solution A
(%)
Solution B
(%)
Elution
0 95.0 5.0 equilibrium
0–40 95.0®5.0 5.0®95.0 linear gradient
40–41 5.0®95.0 95.0®5.0 linear gradient
41–46 95.0 5.0 isocratic
Chromatograph the Standard preparation, and record the peak areas as directed for Procedure: the resolution between clindamycin phosphate and its nearest related compound is not less than 1.0, determined as follows. Between the peaks, draw a line perpendicular to the base line at the valley that separates the two peaks. The height of the valley from the base line is not more than 40 percent of the height of the related compound peak. Calculate the resolution, R, using peak widths at half height. The relative standard deviation determined from the clindamycin phosphate peak is not more than 2.0%.
Procedure— Separately inject equal volumes (about 25 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the areas of the clindamycin phosphate peaks. Calculate the quantity, in µg, of clindamycin (C18H33ClN2O5S) in the portion of Clindamycin Phosphate taken by the formula:
(PWS / WU)(rU / rS)
in which P is the potency, in µg of clindamycin per mg, of USP Clindamycin Phosphate RS; WS is the weight, in mg, of USP Clindamycin Phosphate RS taken to prepare the Standard preparation; WU is the weight, in mg, of Clindamycin Phosphate taken to prepare the Assay preparation; and rU and rS are the peak areas for clindamycin phosphate obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ahalya Wise, M.S.
Senior Scientific Liaison
1-301-816-8161
(SM12010) Monographs - Small Molecules 1
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 2706
Pharmacopeial Forum: Volume No. 29(1) Page 57