General Notices
Action and use
Corticosteroid.
DEFINITION
Hydrocortisone Cream contains Hydrocortisone in a suitable basis.
The cream complies with the requirements stated under Topical Semi-solid Preparations and with the following requirements.
Content of hydrocortisone, C21H30O5: 90.0 to 110.0% of the stated amount.
IDENTIFICATION
A. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
For creams containing more than 0.5% w/w of Hydrocortisone:
(1) Mix a quantity containing 25 mg of Hydrocortisone with 10 mL of methanol (90%), add 50 mL of hot hexane and shake. Separate the lower layer, add 5 g of anhydrous sodium sulfate, mix and filter through a glass microfibre filter (Whatman GF/C is suitable).
(2) 0.25% w/v of hydrocortisone BPCRS in methanol.
(3) A mixture of equal volumes of solutions (1) and (2).
For creams containing 0.5% w/w or less of Hydrocortisone:
(1) Prepare in the same manner as solution (1) above but use a quantity containing 5 mg of Hydrocortisone.
(2) 0.05% w/v of hydrocortisone BPCRS in methanol.
(3) A mixture of equal volumes of solutions (1) and (2).
CHROMATOGRAPHIC CONDITIONS
(a) Use as the coating silica gel G.
(b) Use the mobile phase as described below.
(c) Apply 5 μL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in air, spray with alkaline tetrazolium blue solution and examine in white light.
MOBILE PHASE
1.2 volumes of water, 8 volumes of methanol, 15 volumes of ether and 77 volumes of dichloromethane.
CONFIRMATION
The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2); if it does not, the principal spot in the chromatogram obtained with solution (3) appears as a single, compact spot.
B. In the Assay, the chromatogram obtained with solution (2) shows a peak with the same retention time as the peak due to hydrocortisone in the chromatogram obtained with solution (3).
ASSAY
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
For creams containing more than 0.5% w/w of Hydrocortisone:
Prepare a 0.5% w/v solution of betamethasone (internal standard) in methanol (solution A).
(1) Disperse, by shaking, a quantity of the cream containing 25 mg of Hydrocortisone in 40 mL of a mixture of 3 volumes of methanol and 1 volume of a 15% w/v solution of sodium chloride. Add 50 mL of hot hexane, shake and separate the lower layer. Repeat the extraction using a further two 10-mL quantities of the methanolic sodium chloride solution. To the combined extracts add 5 mL of solution A and sufficient water to produce 100 mL, mix and filter through a glass microfibre paper (Whatman GF/C is suitable).
(2) Prepare in the same manner as solution (1), but add 5 mL of methanol in place of the 5 mL of solution A.
(3) Dissolve 25 mg of hydrocortisone BPCRS in 45 mL of methanol, add 5 mL of solution A and add sufficient water to produce 100 mL.
For creams containing 0.5% w/w or less of Hydrocortisone:
Prepare a 0.110% w/v solution of betamethasone (internal standard) in methanol (solution B).
(1) Disperse, by shaking, a quantity of the cream containing 5 mg of Hydrocortisone in 40 mL of a mixture of 3 volumes of methanol and 1 volume of a 15% w/v solution of sodium chloride. Add 50 mL of hot hexane, shake and separate the lower layer. Repeat the extraction using a further two 10-mL quantities of the methanolic sodium chloride solution. To the combined extracts add 5 mL of solution B and sufficient water to produce 100 mL, mix and filter through a glass microfibre paper (Whatman GF/C is suitable).
(2) Prepare in the same manner as solution (1), but add 5 mL of methanol in place of the 5 mL of solution B.
(3) Dissolve 5 mg of hydrocortisone BPCRS in 45 mL of methanol and add 5 mL of solution B and sufficient water to produce 100 mL.
CHROMATOGRAPHIC CONDITIONS
(a) Use a stainless steel column (10 cm × 5 mm) packed with octadecylsilyl silica gel for chromatography (5 μm) (Spherisorb ODS 1 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 2 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 240 nm.
(f) Inject 20 μL of each solution.
MOBILE PHASE
methanol (50%).
DETERMINATION OF CONTENT
Calculate the content of C21H30O5 in the cream using the ratios of the peaks and the declared content of C21H30O5 in hydrocortisone BPCRS.
