Fluticasone Propionate Ointment
DEFINITION
Fluticasone Propionate Ointment contains NLT 90.0% and NMT 110.0% of the labeled amount of fluticasone propionate (C25H31F3O5S).
IDENTIFICATION
•  A. Thin-Layer Chromatographic Identification Test 201
Standard solution:  0.17 mg/mL of USP Fluticasone Propionate RS in acetonitrile
Test solution:  Transfer a quantity of Ointment, equivalent to 100 µg of fluticasone propionate, to a 125-mL separatory funnel. Add 50 mL of hexane and 10 mL of acetonitrile to the separatory funnel. Stopper and shake the funnel until the Ointment is completely dispersed. Shake the separatory funnel for an additional min, and allow the phases to separate. Filter the lower layer through a 10-mL syringe containing a cotton plug into a 25-mL volumetric flask. Repeat the extraction with one 10-mL aliquot of acetonitrile, and filter the lower layer into the volumetric flask. Wash the cotton plug with 2 mL of acetonitrile, and collect the washings into the volumetric flask. Dilute the sample extract with acetonitrile to volume. Transfer one-half of the sample extract to a glass tube suitable for evaporation, and evaporate to dryness at about 40. Transfer the remainder of the sample extract into the same tube, and continue evaporating to dryness. Dissolve the residue in 0.6 mL of acetonitrile. [Note—The Test solution may be cloudy because of the presence of undissolved excipients. ]
Chromatographic system 
Adsorbent:  0.2-mm layer of chromatographic silica gel mixture on a high-performance thin-layer chromatographic plate, 5-µm particle size
Application volume:  40 µL
Developing solvent system:  Dichloromethane, ethyl acetate, and glacial acetic acid (30:8:1)
Analysis 
Samples:  Standard solution and Test solution
Separately apply the Standard solution and the Test solution to the plate. On the same plate, apply 20 µL of the Standard solution, allow the application to dry, and apply 20 µL of the Test solution on top of the dried 20-µL Standard solution spot. Allow each of the applications to dry thoroughly. Place the plate in a tank equilibrated with the developing solvent, and allow the developing solvent to travel 8 cm from the point of application. Remove the plate and allow to air-dry. Examine the plate under ultraviolet light at 254 nm.
Acceptance criteria:  The RF value of the principal spot from the Test solution corresponds to that of the Standard solution. [Note—If the excipients in the Ointment interfere with the appearance of the principal spot obtained for the Test solution, use the Standard solution and the Test solution overspot to confirm identity. ]
•  B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
ASSAY
•  Procedure
[Note—Protect the Standard solution and the Sample solution from direct light by using a light-protective volumetric flask and autosampler vials. ]
Buffer:  1.20 g/L of monobasic ammonium phosphate. Adjust with phosphoric acid to a pH of 3.50 ± 0.03.
Mobile phase:  Methanol, acetonitrile, and Buffer (46:14:40)
Diluent:  Methanol and water (80:20)
System suitability stock solution:  0.5 mg/mL of USP Fluticasone Propionate Nasal Spray Resolution Mixture RS in methanol. [Note—USP Fluticasone Propionate Nasal Spray Resolution Mixture RS is a mixture of fluticasone propionate and fluticasone propionate related compound D. ]
System suitability solution:  5 µg/mL of USP Fluticasone Propionate Nasal Spray Resolution Mixture RS in Diluent from System suitability stock solution
Standard stock solution:  0.25 mg/mL USP Fluticasone Propionate RS. Dissolve the standard first in a volume of methanol, equivalent to 80% of the final volume, and dilute with water to volume.
Standard solution:  4 µg/mL USP Fluticasone Propionate RS in Diluent, from Standard stock solution
Sample solution:  Equivalent to 4 µg/mL of fluticasone propionate. Transfer a quantity of Ointment, equivalent to about 100 µg of fluticasone propionate, to a 125-mL separatory funnel. Add to the separatory funnel 45 mL of hexane previously heated to about 60 in a water bath. [Note—Hexane is highly flammable. ] Stopper and shake vigorously until the Ointment is completely dispersed. Wash the stopper and neck of the separatory funnel with 5 mL of hexane heated to 60, and allow the funnel to cool to room temperature. Transfer 10 mL of Diluent into the separatory funnel, and shake the contents for 1 min. Allow the phases to separate, and filter the lower aqueous layer via a cotton wool plug, previously washed with Diluent, into a 25-mL volumetric flask. Repeat the extraction with two 5-mL aliquots of Diluent, filtering the lower layers into the volumetric flask. Wash the cotton plug with 2 mL of Diluent, and collect the washings into the volumetric flask. Dilute the sample with Diluent to volume.
Chromatographic system 
Mode:  LC
Detector:  240 nm
Column:  4.6-mm × 25-cm; 5-µm packing L1
Column temperature:  50
Flow rate:  1.5 mL/min
Injection size:  50 µL
System suitability 
Samples:  System suitability solution and Standard solution
Suitability requirements 
Resolution:  NLT 1.4 between fluticasone propionate and fluticasone propionate related compound D, System suitability solution
Tailing factor:  NMT 1.4, Standard solution (calculated using the width of the peak at 10% of the height)
Relative standard deviation:  NMT 2.0%, Standard solution
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of fluticasone propionate (C25H31F3O5S) in the portion of Ointment taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response of fluticasone propionate from the Sample solution
rS== peak response of fluticasone propionate from the Standard solution
CS== concentration of USP Fluticasone Propionate RS in the Standard solution (µg/mL)
CU== nominal concentration of fluticasone propionate in the Sample solution (µg/mL)
Acceptance criteria:  90.0%–110.0%
SPECIFIC TESTS
•  Microbial Enumeration Tests 61 and Tests For Specified Microorganisms 62: Meets the requirements of the tests for absence of Staphylococcus aureus and Pseudomonas aeruginosa. The total aerobic microbial count is NMT 100 cfu/g, and the total combined molds and yeasts count is NMT 10 cfu/g.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in collapsible tubes or tight containers, protected from light. Store between 2 and 30.
•  USP Reference Standards 11
USP Fluticasone Propionate RS Click to View Structure
USP Fluticasone Propionate Nasal Spray Resolution Mixture RS
This Reference Standard is a mixture of fluticasone propionate and fluticasone propionate related compound D, and the chemical names for both are given below:
Fluticasone propionate: S-Fluoromethyl 6,9-difluoro-11-hydroxy-16-methyl-3-oxo-17-propionyloxyandrosta-1,4-diene-17-carbothioate.
Fluticasone propionate related compound D: S-Methyl-6,9-difluoro-11-hydroxy-16-methyl-3-oxo-17-propionyloxy-androsta-1,4-diene-17-carbothioate.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Domenick Vicchio, Ph.D.
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1-301-998-6828
(SM42010) Monographs - Small Molecules 4
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
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(GCM2010) General Chapters - Microbiology
Reference Standards RS Technical Services
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