Medium: 0.01Nhydrochloric acid;900mL.

Apparatus 2: 50rpm.

Time: 30minutes.

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 preparationin comparison with a Standard solution having a known concentration of USP Ritodrine Hydrochloride RSin the same Medium.

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

Procedure for content uniformity— Transfer 1Tablet to a 200-mLvolumetric flask,add about 5mLof water,and stir until disintegration is complete.Add about 150mLof methanolic sulfuric acid solution (0.005Msulfuric acid in methanol),continue stirring for an additional 15minutes,dilute with methanolic sulfuric acid solution to volume,and mix.Filter a portion of the mixture,discarding the first 20mLof the filtrate.Dissolve an accurately weighed quantity of USP Ritodrine Hydrochloride RSin methanolic sulfuric acid solution,and dilute quantitatively and stepwise with the same solvent to obtain a Standard solution having a known concentration of about 50µg per mL.Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 276nm,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 Tis the labeled quantity,in mg,of ritodrine hydrochloride in the Tablet,Cis the concentration,in µg per mL,of USP Ritodrine Hydrochloride RSin the Standard solution,Dis 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 AUand ASare the absorbances of the solution from the Tablet and the Standard solution,respectively.

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

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

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

Procedure— Proceed as directed in the Assayunder 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.