Action and use
Dopamine receptor antagonist; neuroleptic (veterinary).
DEFINITION
Azaperone Injection is a sterile solution of Azaperone in Water for Injections.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of azaperone, C19H22FN3O
90.0 to 110.0% of the stated amount.
CHARACTERISTICS
A clear, yellow solution.
IDENTIFICATION
A. To a volume containing 80 mg of Azaperone add 5 mL of 0.5M sulfuric acid and 20 mL of water. Extract the solution with 50 mL of ether, make the aqueous phase alkaline with 1M sodium hydroxide and extract with 50 mL of ether. Wash the ether extracts with two 10 mL-quantities of water, shake with anhydrous sodium sulfate, filter and evaporate to dryness.
The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of azaperone (RSV 08).
B. The light absorption, Appendix II B, in the range 230 to 350 nm of a 2-cm layer of the solution obtained in the Assay exhibits maxima at 242 nm and at 312 nm. The absorbances at the maxima are about 1.1 and about 0.38, respectively.
TESTS
Acidity
pH, 3.5 to 5.0, Appendix V L.
Related substances
Carry out in subdued light the method for thin-layer chromatography, Appendix III A, using a silica gel F254 precoated plate (Merck silica gel 60 F254 plates are suitable) and a mixture of 1 volume of ethanol (96%) and 9 volumes of chloroform as the mobile phase. Apply separately to the plate 10 μL of each of the following two solutions. For solution (1) dissolve the extracted residue obtained in Identification test A in sufficient chloroform to produce a solution containing 1% w/v of Azaperone. For solution (2) dilute 1 volume of solution (1) to 100 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) (1%).
ASSAY
To a volume containing 0.4 g of Azaperone add 25 mL of 0.5M sulfuric acid and sufficient water to produce 250 mL. Mix, transfer 10 mL of the solution to a separating funnel containing 10 mL of 0.05M sulfuric acid and shake with 20 mL of ether.
Wash the ether layer with two 10 mL quantities of 0.05M sulfuric acid. Make the combined acid extract and washings alkaline with 5 mL of 1M sodium hydroxide, add 50 mL of ether, shake and allow to separate. Extract the aqueous layer with 50 mL of ether. Wash the two ether solutions, in succession, with a 20 mL quantity of water and extract each of the two ether solutions, in succession, with two 20 mL quantities and one 5 mL quantity of 0.25M sulfuric acid. Combine the acid extracts and add sufficient 0.25M sulfuric acid to produce 100 mL. To 5 mL of the resulting solution add 5 mL of methanol and sufficient 0.25M sulfuric acid to produce 100 mL. Measure the absorbance of the resulting solution at the maximum at 242 nm, Appendix II B. Dissolve 40 mg of azaperone BPCRS in sufficient methanol to produce 250 mL, dilute 5 mL of the resulting solution to 100 mL with 0.25M sulfuric acid and measure the absorbance at 242 nm. Calculate the content of C19H22FN3O in the injection from the absorbances obtained using the declared content of C19H22FN3O in azaperone BPCRS.
STORAGE
Azaperone Injection should be protected from light.
