C7H5ClN3NaO4S2 317.71

2H-1,2,4-Benzothiadiazine-7-sulfonamide, 6-chloro-, 1,1-dioxide, monosodium salt.
6-Chloro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide monosodium salt [7085-44-1].

Packaging and storage— Preserve in Containers for Sterile Solids as described under Injections 1.

USP Reference standards 11— USP Chlorothiazide RS. USP Endotoxin RS.

Constituted solution— At the time of use, it meets the requirements for Constituted Solutions under Injections 1.

Identification, Ultraviolet Absorption 197U—

Bacterial endotoxins 85— It contains not more than 0.3 USP Endotoxin Unit per mg of chlorothiazide sodium.

Uniformity of dosage units 905: meets the requirements.

pH 791: between 9.2 and 10.0, in a solution prepared as directed in the labeling.

Residual solvents 467: meets the requirements.

Other requirements— It meets the requirements under Injections 1.

Assay— Transfer an accurately weighed portion of Chlorothiazide Sodium for Injection, equivalent to about 500 mg of chlorothiazide, to a 1000-mL volumetric flask, add sodium hydroxide solution (1 in 250) to volume, and mix. Transfer 5.0 mL of this solution to a 250-mL volumetric flask, dilute with sodium hydroxide solution (1 in 250) to volume, and mix. Concomitantly determine the absorbances of this solution and a Standard solution of USP Chlorothiazide RS in the same medium having a known concentration of about 10 µg per mL in 1-cm cells at the wavelength of maximum absorbance at about 292 nm, with a suitable spectrophotometer, using sodium hydroxide solution (1 in 250) as the blank. Calculate the quantity, in mg, of C7H6ClN3O4S2 in the portion of Chlorothiazide Sodium for Injection taken by the formula: in which C is the concentration, in µg per mL, of USP Chlorothiazide RS in the Standard solution; and AU and AS are the absorbances of the assay solution and the Standard solution, respectively.

Expert Committee : (MDCV05) Monograph Development-Cardiovascular

USP29–NF24 Page 483

Phone Number : 1-301-816-8305