Chlorphenamine Injection

Action and use

Histamine H₁ receptor antagonist; antihistamine.

Definition

Chlorphenamine Injection is a sterile solution of Chlorphenamine Maleate in Water for Injections free from dissolved air.

Content of chlorphenamine maleate, C₁₆H₁₉ClN₂,C₄H₄O₄

90.0 to 110.0% of the stated amount.

Characteristics

A colourless solution.

Identification

Carry out the method for thin-layer chromatography, Appendix III A, using silica gel GF₂₅₄ as the coating substance and a mixture of 20 volumes of 1m acetic acid, 30 volumes of methanol and 50 volumes of ethyl acetate as the mobile phase. Heat the plate at 105° for 30 minutes before use. Apply separately to the plate 2 µL of each of the following solutions. For solution (1) evaporate an appropriate volume to dryness in a current of nitrogen using the minimum amount of heat, dissolve the residue as completely as possible in sufficient chloroform to produce a solution containing 0.5% w/v of Chlorphenamine Maleate and centrifuge. Solution (2) contains 0.5% w/v of chlorphenamine maleate BPCRS in chloroform. After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm). The two principal spots in the chromatogram obtained with solution (1) correspond to those in the chromatogram obtained with solution (2). Spray the plate with dilute potassium iodobismuthate solution. The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).

TESTS

Acidity

pH, 4.0 to 5.2, Appendix V L.

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using silica gel GF₂₅₄ as the coating substance and a mixture of 10 volumes of diethylamine, 40 volumes of chloroform and 50 volumes of cyclohexane as the mobile phase but allowing the solvent front to ascend 12 cm above the line of application. Apply separately to the plate 10 µL of each of the following solutions. For solution (1) evaporate a suitable volume of the injection to dryness in a current of nitrogen using the minimum amount of heat, dissolve the residue as completely as possible in sufficient chloroform to produce a solution containing 5% w/v of Chlorphenamine Maleate and centrifuge. For solution (2) dilute 1 volume of solution (1) to 500 volumes with chloroform. After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm). Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.2%). Disregard any spot remaining on the line of application.

Assay

Dilute a volume containing 10 mg of Chlorphenamine Maleate to 500 mL with 0.25m sulfuric acid and measure the absorbance of the resulting solution at the maximum at 265 nm, Appendix II B. Calculate the content of C₁₆H₁₉ClN₂,C₄H₄O₄ taking 212 as the value of A(1%, 1 cm) at the maximum at 265 nm.

Storage

Chlorphenamine Injection should be protected from light.