Packaging and storage—
Preserve in single-dose containers, preferably of Type I glass, protected from light.
Identification—
Dilute a volume of Injection, equivalent to about 50 mg of mesoridazine besylate, with 0.01 N hydrochloric acid to 25 mL, and proceed as directed under
Identification—Organic Nitrogenous Bases 
181
, beginning with “Transfer the liquid to a separator”: the Injection meets the requirements of the test.
Other requirements—
It meets the requirements under
Injections 1.
Assay—
[NOTE—Conduct this procedure with minimum exposure to light.
] Proceed with Injection as directed under
Salts of Organic Nitrogenous Bases 501, except to use 1.0 mL each of the
Standard Preparation and the
Assay Preparation in the
Procedure, and determine the absorbances at the wavelength of maximum absorbance at about 262 nm. Calculate the quantity, in mg, of C
21H
26N
2OS
2 in each mL of the Injection taken by the formula:
(386.59 / 544.75)(0.05C / V)(AU / AS),
in which 386.59 and 544.75 are the molecular weights of mesoridazine and mesoridazine besylate, respectively;
C is the concentration, in µg per mL, of
USP Mesoridazine Besylate RS in the
Standard Preparation; and
V is the volume, in mL, of Injection taken.
