Isoxsuprine Hydrochloride Tablets
»Isoxsuprine Hydrochloride Tablets contain not less than 93.0percent and not more than 107.0percent of the labeled amount of C18H23NO3·HCl.
Packaging and storage— Preserve in tight containers.
Identification— Transfer a portion of finely powdered Tablets,equivalent to about 10mg of isoxsuprine hydrochloride,to a 60-mLbeaker,add about 20mLof water,mix,and filter.Transfer the clear filtrate to a 60-mLseparator,add 10mLof pH9.0alkaline borate buffer (see Buffer Solutionsin the section Reagents,Indicators,and Solutions),and shake vigorously to mix.Extract with 2mLof chloroform,filter the extract through a pledget of cotton,and mix the filtrate with 500mg of potassium bromide.Evaporate the chloroform,carefully removing the last trace of solvent in a small vacuum flask:the IRabsorption spectrum of a potassium bromide dispersion of the isoxsuprine so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Isoxsuprine Hydrochloride RSthat has been treated in the same manner.
Dissolution á711ñ—
Medium: water;900mL.
Apparatus 1: 100rpm.
Time: 45minutes.
Procedure— Determine the amount of C18H23NO3·HCl dissolved from UVabsorbances at the wavelength of maximum absorbance at about 269nm of filtered portions of the solution under test,suitably diluted with Dissolution Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Isoxsuprine Hydrochloride RSin the same medium.
Tolerances— Not less than 75%(Q)of the labeled amount of C18H23NO3·HCl is dissolved in 45minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Assay—
Buffer solution— Transfer about 1.32g of anhydrous dibasic ammonium phosphate to a 1-liter volumetric flask,add about 950mLof water,and mix.Adjust with phosphoric acid to a pHof 7.5,dilute with water to volume,and mix.
Mobile phase— Prepare a filtered and degassed mixture of methanol and Buffer solution(2:1).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard preparation— Dissolve an accurately weighed quantity of USP Isoxsuprine Hydrochloride RSin Mobile phase,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a known concentration of about 0.4mg per mL.
Assay preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 20mg of isoxsuprine hydrochloride,to a 50-mLvolumetric flask,and add about 25mLof Mobile phase.Shake by mechanical means for 30minutes,sonicate for ten minutes to dissolve,dilute with Mobile phaseto volume,mix,and filter.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 274-nm detector and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 1.5mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the column efficiency is not less than 1800theoretical plates,and the relative standard deviation for replicate injections is not more than 2.0%.
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 C18H23NO3·HCl in the portion of Tablets taken by the formula:
50C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Isoxsuprine Hydrochloride RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 1091
Phone Number:1-301-816-8305