Edition: BP 2025 (Ph. Eur. 11.6 update)
Action and use
Corticosteroid.
DEFINITION
Hydrocortisone Sodium Phosphate Injection is a sterile solution of Hydrocortisone Sodium Phosphate in Water for Injections.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of hydrocortisone, C21H30O5
92.5 to 107.5% of the stated amount.
CHARACTERISTICS
A colourless or very pale yellow solution.
IDENTIFICATION
A. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Dilute a volume of the injection containing the equivalent of 0.25 g of hydrocortisone to 100 mL with water.
(2) 0.34% w/v of hydrocortisone sodium phosphate BPCRS in methanol.
(3) A mixture of equal volumes of solutions (1) and (2).
(4) A mixture of equal volumes of solution (1) and a 0.25% w/v solution of betamethasone sodium phosphate BPCRS in methanol.
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, allow to dry in air until the solvent has evaporated, spray with ethanolic sulfuric acid (20%), heat at 120° for 10 minutes and examine under ultraviolet light (365 nm).
MOBILE PHASE
A freshly prepared mixture of 20 volumes of acetic anhydride, 20 volumes of water and 60 volumes of butan-1-ol.
CONFIRMATION
The principal spot in the chromatogram obtained with solution (1) corresponds in position and colour to that in the chromatogram obtained with solution (2).
The principal spot in the chromatogram obtained with solution (3) appears as a single compact spot.
The chromatogram obtained with solution (4) exhibits two principal spots with almost identical Rf values.
B. Evaporate 0.1 mL to dryness on a water bath and dissolve the residue in 2 mL of sulfuric acid. A yellowish green fluorescence is produced immediately (distinction from betamethasone sodium phosphate, dexamethasone sodium phosphate and prednisolone sodium phosphate).
TESTS
Alkalinity
pH, 7.5 to 8.5, Appendix V L.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Dilute a volume of the injection with water to contain the equivalent of 0.75% w/v of hydrocortisone.
(2) 1.0% w/v of hydrocortisone sodium phosphate BPCRS in methanol.
(3) 0.020% w/v of hydrocortisone BPCRS in methanol.
CHROMATOGRAPHIC CONDITIONS
(a) Use as the coating silica gel GF254.
(b) Use the mobile phase as described below.
(c) Apply 2 μL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow to dry in air for 5 minutes and examine under ultraviolet light (254 nm).
MOBILE PHASE
1.2 volumes of water, 8 volumes of methanol, 15 volumes of ether and 77 volumes of dichloromethane.
LIMITS
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (3).
ASSAY
Dilute a volume containing the equivalent of 0.2 g of hydrocortisone to 1000 mL with water. To 5 mL add 15 mL of water, 2.5 g of sodium chloride and 0.5 mL of hydrochloric acid and extract with three 25-mL quantities of chloroform. Wash each chloroform layer with the same 1 mL quantity of 0.1M hydrochloric acid, add the washings to the aqueous solution and discard the chloroform. Extract the aqueous solution with two 10-mL quantities of tributyl orthophosphate, discard the aqueous phase and extract the combined tributyl phosphate solutions with two 25-mL quantities of a solution containing 10% w/v of sodium chloride and 1% w/v of anhydrous disodium hydrogen orthophosphate. Filter the extracts successively through absorbent cotton and wash the filter with 10 mL of the chloride–phosphate solution. Dilute the combined filtrates to 100 mL with the chloride–phosphate solution and measure the absorbance of the resulting solution at the maximum at 248 nm, Appendix II B, using in the reference cell a solution prepared in the same manner but using 20 mL of a solution containing 2.5 g of sodium chloride and 0.5 mL of hydrochloric acid and beginning at the words ‘Extract the aqueous solution…’. Calculate the content of hydrocortisone sodium phosphate as C21H30O5 taking 447 as the value of A(1%, 1 cm) at the maximum at 248 nm.
STORAGE
Hydrocortisone Sodium Phosphate Injection should be protected from light. The injection should not be allowed to freeze.
LABELLING
The strength is stated in terms of the equivalent amount of hydrocortisone in a suitable dose-volume.
