Identification—
A:
Place in a separator a volume of Injection equivalent to about 300 mg of lidocaine hydrochloride, add 2 mL of 2 N sodium hydroxide, and extract with four 15-mL portions of chloroform. Combine the chloroform extracts, and evaporate with the aid of a current of warm air to dryness. Dissolve the crystals so obtained in solvent hexane, evaporate with the aid of warm air, and dry the residue in vacuum over silica gel for 24 hours: the residue so obtained responds to
Identification test
A under
Lidocaine.
B:
It responds to the Identification test under Dextrose.
Assay for dextrose—
Determine the angular rotation of Injection in a suitable polarimeter tube (see
Optical Rotation 
781
). Calculate the percentage (g per 100 mL) of dextrose (C
6H
12O
6·H
2O) in the portion of Injection taken by the formula:
(100/52.9)(198.17/180.16)AR,
in which 100 is the percentage; 52.9 is the midpoint of the specific rotation range for anhydrous dextrose, in degrees; 198.17 and 180.16 are the molecular weights for dextrose monohydrate and anhydrous dextrose, respectively;
A is 100 mm divided by the length of the polarimeter tube, in mm; and
R is the observed rotation, in degrees.
