Mesoridazine Besylate Injection
» Mesoridazine Besylate Injection is a sterile solution of Mesoridazine Besylate in Water for Injection. It contains mesoridazine besylate (C21H26N2OS2·C6H6O3S) equivalent to not less than 90.0 percent and not more than 110.0 percent of the labeled amount of mesoridazine (C21H26N2OS2).
Packaging and storage— Preserve in single-dose containers, preferably of Type I glass, protected from light.
USP Reference standards 11
USP Endotoxin RS.

USP Mesoridazine Besylate RS.
note—Throughout the following procedures, protect test or assay specimens, the Reference Standard, and solutions containing them, by conducting the procedures without delay, under subdued light, or using low-actinic glassware.
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.
Bacterial endotoxins 85 It contains not more than 7.0 USP Endotoxin Units per mg of mesoridazine besylate.
pH 791: between 4.0 and 5.0.
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 C21H26N2OS2 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.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ravi Ravichandran, Ph.D.
Senior Scientist
(MDPP05) Monograph Development-Psychiatrics and Psychoactives
Reference Standards Lili Wang, Technical Services Scientist
85 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 2898