Medium: 0.01 N hydrochloric acid; 900 mL.

Apparatus 2: 50 rpm.

Time: 30 minutes.

Procedure— Determine the amount of C17H21NO3·HCl dissolved by employing the procedure set forth in the Assay, using a filtered portion of the solution under test as the Assay preparation in comparison with a Standard solution having a known concentration of USP Ritodrine Hydrochloride RS in the same Medium.

Tolerances— Not less than 80% (Q) of the labeled amount of C17H21NO3·HCl is dissolved in 30 minutes.

Procedure for content uniformity— Transfer 1 Tablet to a 200-mL volumetric flask, add about 5 mL of water, and stir until disintegration is complete. Add about 150 mL of methanolic sulfuric acid solution (0.005 M sulfuric acid in methanol), continue stirring for an additional 15 minutes, dilute with methanolic sulfuric acid solution to volume, and mix. Filter a portion of the mixture, discarding the first 20 mL of the filtrate. Dissolve an accurately weighed quantity of USP Ritodrine Hydrochloride RS in methanolic sulfuric acid solution, and dilute quantitatively and stepwise with the same solvent to obtain a Standard solution having a known concentration of about 50 µg per mL. Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 276 nm, with a suitable spectrophotometer, using methanolic sulfuric acid solution as the blank. Calculate the quantity, in mg, of C17H21NO3·HCl in the Tablet taken by the formula: in which T is the labeled quantity, in mg, of ritodrine hydrochloride in the Tablet, C is the concentration, in µg per mL, of USP Ritodrine Hydrochloride RS in the Standard solution, D is the concentration, in µg per mL, of ritodrine hydrochloride in the solution from the Tablet based upon the labeled quantity per Tablet and the extent of dilution, and AU and AS are the absorbances of the solution from the Tablet and the Standard solution, respectively.

(Official January 1, 2007)

Mobile phase, Standard preparation, and System suitability preparation— Proceed as directed in the Assay under Ritodrine Hydrochloride.

Assay preparation— Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 20 mg of ritodrine hydrochloride, to a 100-mL volumetric flask. Add about 70 mL of Mobile phase, stir for about 15 minutes, dilute with Mobile phase to volume, mix, and filter a portion to remove any particulate matter.

Chromatographic system— Proceed as directed in the Assay under Ritodrine Hydrochloride Injection.

Procedure— Proceed as directed in the Assay under Ritodrine Hydrochloride. Calculate the quantity, in mg, of C17H21NO3·HCl in the portion of Tablets taken by the formula: in which the terms are as defined therein.