Packaging and storage
Preserve in single-dose or in multiple-dose containers,preferably of Type Iglass.
Labeling
The label indicates that the Injection is not to be used if its color is pinkish or darker than slightly yellow or if it contains a precipitate.
Identification
A:
Mix 10mLof Injection with 10mLof 3Nhydrochloric acid,cool to 0

in an ice bath,add 5mLof sodium nitrite solution (1in 5),stirring gently,add 2mLof a solution of 0.1g of 2-naphthol in 5mLof 1Nsodium hydroxide,and observe immediately:a bright orange-red precipitate is formed (
presence of a primary aminophenyl group).
B:
It responds to the tests for Chloride á191ñ.
C:
To about 25mLof Injection add 1drop of ferric chloride TS:the solution immediately turns a light green and changes to a light blue within 1minute.Add 2drops of 3Nhydrochloric acid:the color reverts to light green (presence of levonordefrin).
Assay for procaine hydrochloride
Transfer 25.0mLof Injection to a 250-mLbeaker,add 10mLof dilute hydrochloric acid (1in 2),15mLof water,and 1.0mLof formaldehyde solution,and allow to stand for 3minutes.Titrate with 0.1
Msodium nitrite VS,using starch iodide paper as an external indicator.Perform a blank determination,and make any necessary correction.Calculate the quantity,in mg,of C
13H
20N
2O
2·HCl in each mLof the Injection taken by the formula:
(272.78/25)(V2M2-0.5V1M1),
in which
V2is the volume,in mL,and
M2is the exact molarity of the 0.1
Msodium nitrite solution used in the titration,
V1and
M1are as defined under
Assay for tetracaine hydrochloride,and 272.78is the molecular weight of procaine hydrochloride.
Assay for tetracaine hydrochloride
Transfer 50.0mLof Injection to a 100-mLbeaker,add 5g of sodium acetate and 5mLof isopropyl alcohol,and stir until the sodium acetate is dissolved.Add 1.5mLof potassium thiocyanate solution (75in 100),and stir while cooling in an ice bath.Keep in the ice bath for 1hour,stirring about four times during the period.Do not stir excessively.Prepare a filtering crucible with double suitable filter paper,connect to a suction flask,and moisten the paper with a few drops of the clear supernatant.Remove the excess liquid by suction.Filter the mixture,and dry by suction.Transfer the entire contents of the crucible to the original beaker,and rinse the crucible with 10mLof dilute hydrochloric acid (1in 2),followed by 30mLof water.Transfer the rinsings to the beaker.Cool in ice,and titrate with 0.02
Msodium nitrite VS,using starch iodide paper as an external indicator.Perform a blank determination,using 10mLof dilute hydrochloric acid (1in 2)and 30mLof water,and make any necessary correction.Calculate the quantity,in mg,of C
15H
24N
2O
2·HCl in each mLof the Injection taken by the formula:
(300.83/50)(V1M1),
in which
V1is the volume,in mL,and
M1is the exact molarity of the 0.02
Msodium nitrite used in the titration,and 300.83is the molecular weight of tetracaine hydrochloride.
Assay for levonordefrin
Ferro-citrate solution,Buffer solution,and Standard preparation
Prepare as directed under
Epinephrine Assay á391ñ.
Procedure
Proceed as directed for
Procedureunder
Epinephrine Assay á391ñ.Calculate the quantity,in mg,of levonordefrin (C
9H
13NO
3)in each mLof the Injection taken by the formula:
(183.21/333.30)(0.05C/V)(AU/AS),
in which 183.21and 333.30are the molecular weights of levonordefrin and epinephrine bitartrate,respectively,
Cis the concentration,in µg per mL,of
USP Epinephrine Bitartrate RSin the
Standard preparation,and
Vis the volume,in mL,of Injection taken.