Acepromazine Injection

General Notices

Action and use

Dopamine receptor antagonist; neuroleptic.

Definition

Acepromazine Injection is a sterile solution of Acepromazine Maleate in Water for Injections. The pH of the solution is adjusted to about 5 by the addition of Sodium Hydroxide.

The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.

Content of acepromazine, C19H22N2OS

92.5 to 107.5% of the stated amount.

Identification

A. To a volume containing the equivalent of 20 mg of acepromazine add 2 mL of water and 3 mL of 2m sodium hydroxide, extract with two 5 mL quantities of cyclohexane and evaporate to dryness under reduced pressure. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of acepromazine (RSV 01).
B. Complies with the test for identification of phenothiazines, Appendix III A, applying to the plate 1 µL of each of the following solutions. For solution (1) extract a volume containing the equivalent of 20 mg of acepromazine with two 5 mL quantities of chloroform and use the combined extracts. Solution (2) is a solution of acepromazine maleate BPCRS in chloroform containing the equivalent of 0.2% w/v of acepromazine.
C. To 5 mg of the residue obtained in test A add 2 mL of sulfuric acid. A yellow colour is produced which becomes deep orange on warming for 2 minutes.
D. To a volume of the injection containing the equivalent of 25 mg of acepromazine add 2 mL of 5m sodium hydroxide and shake with three 3 mL quantities of ether. Add 2 mL of bromine solution to the aqueous solution, warm in a water bath for 10 minutes, heat to boiling and cool. Add 0.25 mL to a solution of 10 mg of resorcinol in 3 mL of sulfuric acid and heat for 15 minutes in a water bath. A bluish black colour develops.

Tests

Acidity

pH, 4.5 to 5.5, Appendix V L.

Assay

To a volume containing the equivalent of 40 mg of acepromazine add 5 mL of 1m sodium hydroxide and extract with 50 mL quantities of chloroform until the chloroform extract is colourless. Wash the extracts with the same 10 mL of water and filter through a plug of absorbent cotton previously moistened with chloroform. Evaporate the combined extracts to dryness and dissolve the residue in 15 mL of acetic anhydride. Carry out Method I for non-aqueous titration, Appendix VIII A, using 0.02m perchloric acid VS as titrant and crystal violet solution as indicator. Each mL of 0.02m perchloric acid VS is equivalent to 6.529 mg of C19H22N2OS.

Storage

Acepromazine Injection should be protected from light.

Labelling

The strength is stated as the equivalent amount of acepromazine in a suitable dose-volume.