Clotrimazole and Hydrocortisone Acetate Cream

General Notices

Action and use

Antifungal and corticosteroid.

Definition

Clotrimazole and Hydrocortisone Acetate Cream contains Clotrimazole and Hydrocortisone Acetate in a suitable basis.

The cream complies with the requirements stated under Topical Semi-solid Preparations and with the following requirements.

Content of clotrimazole, C22H17ClN2

90.0 to 105.0% of the stated amount.

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.
(1) Shake a quantity of the cream containing 20 mg of Clotrimazole with 4 mL of dichloromethane for 30 minutes. Centrifuge and use the supernatant liquid.
(2) 0.5% w/v of clotrimazole BPCRS in dichloromethane.
chromatographic conditions
(a) Use as the coating silica gel (Merck silica gel 60 plates are suitable).
(b) Use the mobile phase as described below.
(c) Apply 10 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in air and then spray with dilute potassium iodobismuthate solution.
mobile phase

di-isopropyl ether. At the bottom of the chromatography tank, place a beaker containing 25 mL of 13.5m ammonia.

confirmation

The principal spot in the chromatogram obtained with solution (1) is reddish-brown and corresponds in position and colour to that in the chromatogram obtained with solution (2).

B. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Mix a quantity of the cream containing the equivalent of 22.4 mg of hydrocortisone with 10 mL of methanol (90%), add 50 mL of hot hexane and shake. Discard the upper layer, add 5 g of anhydrous sodium sulfate to the lower layer, mix and filter through a glass microfibre filter (Whatman GF/C is suitable) and use the filtrate.
(2) 0.25% w/v of hydrocortisone acetate BPCRS in methanol.
(3) 1 volume of solution (1) and 1 volume of 0.25% w/v of hydrocortisone acetate BPCRS in methanol.
chromatographic conditions
(a) Use as the coating silica gel (Merck silica gel 60 plates are suitable).
(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 and then spray with alkaline tetrazolium blue solution.
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 in position to that in the chromatogram obtained with solution (2). The principal spot in solution (3) appears as a single, compact spot.

C. In the Assay for clotrimazole, the chromatogram obtained with solution (1) shows a peak with the same retention time as the peak due to clotrimazole in the chromatogram obtained with solution (3).
D. In the Assay for hydrocortisone acetate, the chromatogram obtained with solution (2) shows a peak with the same retention time as the peak due to hydrocortisone acetate in the chromatogram obtained with solution (3).

TESTS

Related substances

Carry out the method for liquid chromatography, Appendix III D, using the following solutions in solvent A.

Solvent A50 volumes of acetonitrile R1 and 50 volumes of methanol.
(1) Add 30 mL of Solvent A to a quantity of the cream containing 7.5 mg of Clotrimazole and heat at 40° until fully dispersed. Allow the mixture to return to room temperature and dilute to 50 mL. Cool in ice for 5 minutes, filter through a 0.45-µm membrane filter and use the filtrate.
(2) Add 30 mL of Solvent A to a quantity of the cream containing the equivalent of 7.5 mg of hydrocortisone and heat at 40° until fully dispersed. Allow the mixture to return to room temperature and dilute to 50 mL. Cool in ice for 5 minutes, filter through a 0.45-µm membrane filter and use the filtrate.
(3) 0.00015% w/v of 2-chlorotritanol BPCRS.
(4) 0.000168% w/v of hydrocortisone acetate BPCRS.
(5) 0.0168% w/v of hydrocortisone acetate BPCRS and 0.000084% w/v of prednisolone acetate BPCRS.
(6) Dilute 1 volume of solution (3) to 10 volumes.
chromatographic conditions
(a) Use a stainless steel column (25 cm × 4.6 mm) packed with octadecylsilyl silica gel (5 µm) (Waters X-Bridge C18 is suitable).
(b) Use gradient elution and the mobile phase described below.
(c) Use a flow rate of 1.5 mL per minute.
(d) Use a column temperature of 40°.
(e) Use detection wavelengths of 210 nm and 245 nm.
(f) Inject 20 µL of each solution.
mobile phase
Mobile phase A1.5 g/L of potassium dihydrogen orthophosphate in water adjusted to pH 3.0 with 10% v/v orthophosphoric acid.
Mobile phase Bacetonitrile R1.
Mobile phase Cmethanol.

When the chromatograms are recorded under the prescribed conditions the retention times relative to hydrocortisone acetate (retention time, about 22 minutes) are: hydrocortisone (Hydrocortisone Acetate impurity A), about 0.80; epi-hydrocortisone acetate (Hydrocortisone Acetate impurity F), about 0.93; prednisolone acetate (Hydrocortisone Acetate impurity C), about 0.98; clotrimazole, about 1.1 and 2-chlorotritanol (Clotrimazole impurity A), about 1.6.

system suitability

The test is not valid unless, in the chromatogram obtained with solution (5), the peak-to-valley ratio between prednisolone acetate and hydrocortisone acetate is at least 12.

limits
For Clotrimazole at 210 nmIn the chromatogram obtained with solution (1):

the area of any peak corresponding to 2-chlorotritanol is not greater than 2 times the area of the principal peak in the chromatogram obtained with solution (3) (2%).

For Hydrocortisone Acetate at 245 nmIn the chromatogram obtained with solution (2):

the area of any peak corresponding to hydrocortisone is not greater than 1.5 times the area of the principal peak in the chromatogram obtained with solution (4) (1.5%);

the area of any peak corresponding to epi-hydrocortisone acetate is not greater than 1.5 times the area of the principal peak in the chromatogram obtained with solution (4) (1.5%);

the area of any peak corresponding to prednisolone acetate is not greater than 0.6 times the area of the principal peak in the chromatogram obtained with solution (4) (0.6%)

the area of any other secondary peak is not greater than half the area of the principal peak in the chromatogram obtained with solution (4) (0.5%);

the sum of the areas of all secondary peaks is not greater than 5 times the area of the principal peak in the chromatogram obtained with solution (4) (5%);

Disregard any peak with an area less than the area of the principal peak in the chromatogram obtained with solution (6) (0.1%).

Assay

Carry out the method for liquid chromatography, Appendix III D, using the following solutions in Solvent A, as described under Related substances.

(1) Add 30 mL of Solvent A to a quantity of the cream containing 7.5 mg of Clotrimazole and heat at 40° until fully dispersed. Allow the mixture to return to room temperature and dilute to 100 mL. Cool in ice for 5 minutes, filter through a 0.45-µm membrane filter and use the filtrate.
(2) Add 30 mL of Solvent A to a quantity of the cream containing the equivalent of 7.5 mg of hydrocortisone and heat at 40° until fully dispersed. Allow the mixture to return to room temperature and dilute to 100 mL. Cool in ice for 5 minutes, filter through a 0.45-µm membrane filter and use the filtrate.
(3) 0.0075% w/v of clotrimazole BPCRS and 0.0084% w/v of hydrocortisone acetate BPCRS.
(4) 0.0168% w/v of hydrocortisone acetate BPCRS and 0.000084% w/v of prednisolone acetate BPCRS.
chromatographic conditions

The chromatographic conditions described under Related substances may be used with an injection volume of 10 µL.

system suitability

The test is not valid unless, in the chromatogram obtained with solution (4), the peak-to-valley ratio between prednisolone acetate and hydrocortisone acetate is at least 12.

determination of content

In the chromatogram obtained at 210 nm with solution (1); calculate the content of C22H17ClN2 in the cream using the declared content of C22H17ClN2 in clotrimazole BPCRS.

In the chromatogram obtained at 245 nm with solution (2); calculate the content of C21H30O5 in the cream using the declared content of C23H32O6 in hydrocortisone acetate BPCRS. Each mg of C21H30O5 using is equivalent to 1.12 mg of C23H32O6.

Impurities

The impurities limited by the requirements of this monograph include those listed under Clotrimazole and Hydrocortisone Acetate.