Fluorometholone Acetate
C24H31FO5 Mol. Wt. 418.5
Fluorometholone Acetate is Pregna-1,4-diene-3,20-dione, 17-(acetyloxy)-9-fluoro-11-hydroxy-6-methyl- (6α,11β);9-fluoro-11β,17-dihydroxy-6α-methylpregna-1,4-diene-3,20-dione, 17 acetate
Fluorometholone Acetate contains not less than 98.0 per cent and not more than 101.0 per cent of C24H31FO5, calculated on the dried basis.
Category. Corticosteroid.
Description. A white to yellowish crystalline powder.
Identification
- Determine by infrared absorption spectrophotometry (2.4.6). Compare the spectrum with that obtained withfluorometholone acetate RSor with the reference spectrum of fluorometholone acetate.
- When examined in the range 200 nm to 400 nm (2.4.7), a 0.001 per cent w/v solution inmethanolshows absorption maxima of fluorometholone acetate RS is similar to fluorometholone acetate.
Tests
Specific optical rotation (2.4.22). +25.0° to +31.0°, determined in a 2.0 per cent w/v solution in chloroform.
Related substances. Determine by liquid chromatography (2.4.14).
Test solution. Dissolve 50 mg of the substance under examination in 50.0 ml of acetonitrile.
Reference solution (a). A 0.003 per cent w/v solution of fluorometholone RS in minimum quantity of methanol and dilute to volume with acetonitrile.
Reference solution (b). A 0.1 per cent w/v solution of fluorometholone acetate RS in acetonitrile.
Reference solution (c). Mix reference solution (a) and reference solution (b) to obtain a 0.003 per cent w/v solution each of fluorometholone RS and fluorometholone acetate RS in acetonitrile.
Chromatographic system
– a stainless steel column 25 cm x 4.6 mm, packed with octadecylsilane bonded to porous silica (5 µm),
– mobile phase: a mixture of 60 volumes of a water and 40 volumes of acetonitrile,
– flow rate: 1.5 ml per minute,
– spectrophotometer set at 254 nm,
– injection volume: 20 µl.
Name Relative Correction
retention time factor
Fluorometholone 0.6 1.0
Compound 5OX1 0.89 1.0
Fluorometholone Acetate 1.0 -
Fluorometholone Diacetate 1.39 2.2
Fluorometholone Acetate, epoxy analog2 1.58 1.0
Fluorometholone Acetate, Delta 9(11)3 1.82 1.0
Fluorometholone Acetate, 7,9(11) Diene4 1.77 5.5
Individual unknown - 1.0
Total impurities - -
119b,11b-Epoxy-17-hydroxy-6a-methylpregna-1,4-dien-3,20-dione,
217-Acetoxy-9b,11b-epoxy-6a-methylpregna-1,4-dien-3,20-dione,
317a-Acetoxy-6a-methylpregna-1,4,9(11)-trien-3,20-dione,
417a-Acetoxy-6a-methylpregna-1,4,7,9(11)-tetraen-3,20-dione,
a relative to fluorometholone
Inject reference solution (c). The test is not valid unless the resolution between fluorometholone acetate and fluorometholone peaks is not less than 10.0, the column efficiency is not less than 10000 theoretical plates, the tailing factor is not more than 2.0, and the relative standard deviation for replicate injections is not more than 2.0 per cent in the chromatogram obtained with reference solution (b).
Inject reference solution (a), (b) and the test solution. Run the chromatogram at least 2.5 times of the retention time of the principal peak. In the chromatogram obtained with the test solution, the area of any peak corresponding to fluorometholone or fluorometholone diacetate is not more than 0.33 times the area of the principal peak in the chromatogram obtained with reference solution (a) (1.0 per cent), inject the test solution, the area of any peak corresponding to compound 5OX and fluorometholone acetate, epoxy analog is not more than 0.5 per cent, fluorometholone acetate, delta 9(11) is not more than 0.2 per cent, fluorometholone acetate, 7,9(11) diene is not more than 0.3 per cent. The area of any other secondary peak is not more than 0.1 per cent, and the sum of areas of all the secondary peaks is not more than 1.5 per cent calculated by area normalization. Disregard the peak due to fluorometholone and fluorometholone diacetate.
Loss on drying (2.4.19). Not more than 1.0 per cent, determined on 1.0 g by drying in an oven at 60° for 3 hours.
Assay. Determine by liquid chromatography (2.4.14).
Test solution. Dissolve 50 mg of the substance under examination in 50.0 ml of acetonitrile.
Reference solution (a). A 0.1 per cent w/v solution of fluorometholone acetate RS in acetonitrile.
Reference solution (b). A 0.1 per cent w/v solution of fluorometholone RS in minimum quantity of methanol and dilute in acetonitrile and mix equal volume of this solution and the reference solution (a), dilute with acetonitrile to a final concentration of about 0.003 per cent w/v solution each for fluorometholone RS and fluorometholone acetate RS.
Chromatographic system
– a stainless steel column 25 cm x 4.6 mm, packed with octadecylsilane bonded to porous silica (5 µm),
– mobile phase: a mixture of 60 volumes of a water and 40 volumes of acetonitrile,
– flow rate: 1.5 ml per minute,
– spectrophotometer set at 254 nm,
– injection volume: 10 µl.
Inject reference solution (b). The test is not valid unless the resolution between fluorometholone acetate and fluorometholone peaks is not less than 10.0, the column efficiency is not less than 10000 theoretical plates, the tailing factor is not more than 2.0, and the relative standard deviation for replicate injections is not more than 2.0 per cent with reference solution (a).
Inject reference solution (a) and the test solution.
Calculate the content of C24H31FO5 .
Storage. Store in well-closed containers.