Prednicarbate Ointment
» Prednicarbate Ointment contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of prednicarbate (C27H36O8), in a suitable ointment base.
Packaging and storage— Preserve in tight, light-resistant containers, and store at controlled room temperature.
USP Reference standards 11
USP Prednicarbate RS Click to View Structure
USP Prednicarbate Related Compound A RS Click to View Structure
1,2-Dihydroprednicarbate.
USP Prednicarbate Related Compound B RS Click to View Structure
Prednisolone-17-ethylcarbonate.
USP Prednicarbate Related Compound C RS Click to View Structure
Prednisolone-21-propionate.
Identification— It meets the requirements of the Identification test under Prednicarbate Cream.
Consistency— At room temperature, a string of Ointment having a length of 2 cm retains its shape on a glass plate for at least 10 minutes. It can be spread easily and has no visible lumps.
Microbial enumeration tests 61 and Tests for specified microorganisms 62 It meets the requirements of the tests for absence of Staphylococcus aureus and Pseudomonas aeruginosa. The total aerobic bacterial count does not exceed 100 cfu per g.
Minimum fill 755: meets the requirements.
Related compounds—
Solution A, Solution B, Mobile phase, Solution 1, Solution 2, and Resolution solution— Prepare as directed for the Assay under Prednicarbate Cream.
Standard stock solution— Prepare as directed for the Standard stock preparation in the Assay under Prednicarbate Cream.
System sensitivity solution— Prepare as directed in the test for Related compounds under Prednicarbate Cream.
Test solution— Prepare as directed for the Assay preparation under Prednicarbate Cream.
Chromatographic system— Prepare as directed for the Assay under Prednicarbate Cream. Chromatograph the System sensitivity solution, and record the peak responses as directed for Procedure: the signal-to-noise ratio is not less than 3. Chromatograph the Resolution solution, and record the responses as directed for Procedure: the relative retention times are about 0.57 for prednicarbate related compound B, 0.64 for prednicarbate related compound C, 1.0 for prednicarbate, and 1.04 for prednicarbate related compound A.
Procedure— Inject a volume (about 60 µL) of the Test solution into the chromatograph, record the chromatogram, and measure the peak responses. Calculate the percentage of each related compound and unknown impurity in the portion of Ointment taken by the formula:
100(ri / rs)
in which ri is the peak response for each impurity obtained from the Test solution, and rs is the sum of all the peak responses obtained from the Test solution: not more than 2.0% of prednicarbate related compound B and not more than 2.0% of prednicarbate related compound C is found; not more than 0.5% of any individual related compound is found; and not more than 5.0% of total related compounds is found.
Assay—
Solution A, Solution B, Mobile phase, Standard stock preparation, Standard preparation, Assay preparation, Solution 1, Solution 2, and Resolution solution— Prepare as directed in the Assay under Prednicarbate Cream.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 243-nm detector and a 4.0-mm × 25-cm column that contains 5-µm packing L1. The column temperature is maintained at 40. The flow rate is about 1 mL per minute. The chromatograph is programmed as follows.
Time
(minutes)
Solution A
(%)
Solution B
(%)
Elution
0–5 67 33 equilibration
5–45 67®40 33®60 linear gradient
45–50 40 60 isocratic
50–55 40®20 60®80 linear gradient
55–70 20 80 isocratic
70–75 20®67 80®33 linear gradient
75–85 67 33 isocratic
Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the resolution, R, between prednicarbate and prednicarbate related compound A is not less than 1.5. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor for the prednicarbate peak is between 0.7 and 1.5; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 60 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the quantity, in mg, of prednicarbate (C27H36O8) in each g of Ointment taken by the formula:
100(C/W)(rU / rS)
in which C is the concentration, in mg per mL, of USP Prednicarbate RS in the Standard preparation; W is the weight, in g, of Ointment taken; and rU and rS are the prednicarbate peak responses 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 Mary S. Waddell
Scientific Liaison
1-301-816-8124
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
61 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
1-301-816-8339
(GCM2010) General Chapters - Microbiology
62 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
1-301-816-8339
(GCM2010) General Chapters - Microbiology
USP35–NF30 Page 4397
Pharmacopeial Forum: Volume No. 32(3) Page 822