Clobetasol Propionate Cream
Clobetasol Propionate Cream is Clobetasol Propionate in a suitable cream base. It contains NLT 90.0% and NMT 115.0% of the labeled amount of clobetasol propionate (C25H32ClFO5).
• A. Thin-Layer Chromatographic Identification Test 201
Standard solution: 0.6 mg/mL of USP Clobetasol Propionate RS in chloroform
Test solution: Transfer a portion of Cream equivalent to 0.75 mg of clobetasol propionate to a 25-mL, plastic-stoppered centrifuge tube. Add 10 mL of methanol, and cap. Heat in a 60 water bath for 4 min, remove the tube from the bath, and shake vigorously. Repeat the heating and shaking. Cool to room temperature, add 3.5 mL of water, and mix. Centrifuge at 3500 rpm for 10 min. Transfer 5 mL of the supernatant to a 100-mL separator, add 1 g of sodium chloride and 10 mL of water, and mix. Extract with 5 mL of chloroform by shaking for 1 min, collect the lower layer, and evaporate with the aid of a stream of nitrogen to dryness. Dissolve the residue in 0.5 mL of chloroform.
Developing solvent system: Chloroform, acetone, and alcohol (100:10:5)
Acceptance criteria: The RF value of the principal spot obtained from the Test solution corresponds to that from the Standard solution.
Buffer: 0.05 M monobasic sodium phosphate. Adjust with 50% sodium hydroxide solution to a pH of 5.5.
Mobile phase: Acetonitrile, methanol, and Buffer (95:20:85)
Internal standard solution: 0.2 mg/mL of beclomethasone dipropionate in methanol
System suitability solution: 0.001 mg/mL of USP Clobetasol Propionate Related Compound A RS and 0.1 mg/mL of USP Clobetasol Propionate RS in Mobile phase
Standard solution: 0.04 mg/mL of USP Clobetasol Propionate RS and 0.08 mg/mL of beclomethasone dipropionate prepared as follows. Transfer 1.0 mg of USP Clobetasol Propionate RS to a 25-mL volumetric flask, add 10.0 mL of the Internal standard solution, and dilute with methanol to volume.
Sample solution: Nominally 0.04 mg/mL of clobetasol propionate. In a suitable flask, dissolve a portion of Cream equivalent to 1.0 mg of clobetasol propionate in 10.0 mL of the Internal standard solution and 15.0 mL of methanol, and shake vigorously to disperse the Cream. Centrifuge at about 3500 rpm for 10 min, and pass a portion of the supernatant through a filter of 0.45-µm pore size.
Detector: UV 240 nm
Column: 4.6-mm × 15-cm; packing L1
Flow rate: 1 mL/min
Injection size: 10 µL
Sample: System suitability solution
[NoteThe relative retention times for clobetasol propionate and clobetasol propionate related compound A are 1.0 and 1.1, respectively. ]
Resolution: NLT 1.5 between clobetasol propionate and clobetasol propionate related compound A
Column efficiency: NLT 5000 theoretical plates for the clobetasol propionate peak
Tailing factor: NMT 2.0 for the clobetasol propionate peak
Relative standard deviation: NMT 2.0% for the clobetasol propionate peak
Samples: Standard solution and Sample solution
[NoteThe relative retention times for clobetasol propionate and beclomethasone dipropionate are 1.0 and 1.6, respectively. ]
Calculate the percentage of clobetasol propionate (C25H32ClFO5) in the portion of Cream taken:
Result = (RU/RS) × (CS/CU) × 100
Acceptance criteria: 90.0%115.0%
• Minimum Fill 755: Meets the requirements
• Microbial Enumeration Tests 61 and Tests for Specified Microorganisms 62: The total aerobic microbial count does not exceed 102 cfu/g. It meets the requirements of the tests for absence of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella species.
• pH 791: 4.57.0
• Packaging and Storage: Preserve in collapsible tubes or in tight containers. Store at controlled room temperature. Do not refrigerate.
• USP Reference Standards 11
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USP35NF30 Page 2714