Medium: water;900mL.

Apparatus 1: 100rpm.

Time: 45minutes.

Procedure— Determine the amount of (C12H19NO3)2·H2SO4dissolved,employing the procedure set forth in the Assay,making any necessary modifications.

Tolerances— Not less than 75%(Q)of the labeled amount of (C12H19NO3)2·H2SO4is dissolved in 45minutes.

Ion-pair solution,Mobile phase,System suitability solution,and Chromatographic system— Proceed as directed in the Assayunder Terbutaline Sulfate.

Standard preparation— Dissolve an accurately weighed quantity of USP Terbutaline Sulfate RSin Mobile phase,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a known concentration of about 1mg per mL.Transfer 10.0mLof the solution so obtained to a 100-mLvolumetric flask,add 10mLof 0.05Nsulfuric acid,dilute with water to volume,and mix.

Assay preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 10mg of terbutaline sulfate,to a 100-mLvolumetric flask.Add 10mLof 0.05Nsulfuric acid and 20mLof water,and shake for 15minutes.Dilute with water to volume,mix,and filter.

Procedure— Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of terbutaline sulfate [(C12H19NO3)2·H2SO4]in the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Terbutaline Sulfate RSin the Standard preparation;and rUand rSare the terbutaline peak responses obtained from the Assay preparationand the Standard preparation,respectively.