Dextroamphetamine Sulfate Tablets
»Dextroamphetamine Sulfate Tablets contain not less than 93.0percent and not more than 107.0percent of the labeled amount of (C9H13N)2·H2SO4.
Packaging and storage— Preserve in well-closed containers.
Identification—
A: Transfer a portion of finely ground Tablets,equivalent to about 50mg of dextroamphetamine sulfate,to a suitable centrifuge tube.Add 25mLof water,shake vigorously,and centrifuge until clear.Decant the clear solution into a 250-mLseparator,add 5mLof 2.5Nsodium hydroxide,mix,and proceed as directed for theIdentification test underDextroamphetamine Sulfate Elixir,(Oral Solution,official June 1,2005)beginning with “and extract with 60mLof ether.”
B: The retention time of the major peak in the chromatogram of theAssay preparation corresponds to that in the chromatogram of theStandard preparation,as obtained in theAssay.
Dissolution,Procedure for a Pooled Sample á711ñ—
Medium: water;500mL.
Apparatus 1: 100rpm.
Time: 45minutes.
Determine the amount of (C9H13N)2·H2SO4dissolved by employing the following method.
Mobile phase— Dissolve 1.1g of sodium 1-heptanesulfonate in 575mLof water.Add 25mLof dilute glacial acetic acid (14in 100)and 400mLof methanol.Adjust by the dropwise addition of glacial acetic acid to a pHof 3.3±0.1,if necessary,filter,and degas the solution.Make adjustments if necessary (seeSystem SuitabilityunderChromatography á621ñ).
Chromatographic system(see Chromatography á621ñ)— The liquid chromatograph is equipped with a 210-nm detector and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 1.5mLper minute.The column temperature is maintained at 40.Chromatograph replicate injections of the Standard solution,and record the peak responses as directed forProcedure:the relative standard deviation is not more than 2.0%.
Procedure— Inject a volume (about 100µL)of a filtered portion of the solution under test into the chromatograph,record the chromatogram,and measure the response for the major peak.Calculate the quantity of (C9H13N)2·H2SO4dissolved in comparison with a Standard solution having a known concentration of USP Dextroamphetamine Sulfate RSin the sameMedium and similarly chromatographed.
Tolerances— Not less than 75%(Q)of the labeled amount of (C9H13N)2·H2SO4is dissolved in 45minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Isomeric purity— Pack a pledget of fine glass wool in the base of a 200-×25-mm chromatographic tube,with the aid of a tamping rod.Add 5g of chromatographic siliceous earth,and tamp firmly to compress the material to a uniform mass.
Finely powder a number of Tablets,equivalent to about 300mg of dextroamphetamine sulfate,mix the powder in a mortar with 5g of chromatographic siliceous earth,add 1mLof methanol and 0.5mLof ammonium hydroxide,and triturate to a uniform mixture.Transfer the mixture without delay to the chromatographic tube,and tamp as before.Wipe the mortar and pestle with a small amount of glass wool,and insert it into the tube on top of the column.Arrange a 125-mLseparator containing 35mLof 0.1Nsulfuric acid to receive the effluent.Pass 60mLof chloroform through the column.Shake the separator vigorously for 1minute,allow the layers to separate,and discard the chloroform.With the aqueous phase in the separator,proceed as directed in the test forIsomeric purity underDextroamphetamine Sulfate Elixir,(Oral Solution,official June 1,2005)beginning with “Add to the liquid in the separator 2.5g of sodium bicarbonate”.
Assay—
Mobile phase— Dissolve 1.1g of sodium 1-heptanesulfonate in 525mLof water.Add 25mLof dilute glacial acetic acid (14in 100)and 450mLof methanol.Adjust dropwise,if necessary,with glacial acetic acid to a pHof 3.3±0.1.Filter through a 0.5-µm membrane filter.Make adjustments if necessary (seeSystem SuitabilityunderChromatography á621ñ).
Standard preparation— Dissolve an accurately weighed quantity of USP Dextroamphetamine Sulfate RSin 0.12Nphosphoric acid to obtain a solution having a known concentration of about 0.3mg per mL.
Assay preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the mixed powder,equivalent to about 15mg of dextroamphetamine sulfate,to a 50-mLvolumetric flask.Add 40mLof 0.12Nphosphoric acid,and sonicate for 15minutes.Dilute with 0.12Nphosphoric acid to volume,and mix.Filter through a 0.5-µm membrane filter,discarding the first 20mLof the filtrate.
Chromatographic system(see Chromatography á621ñ)— The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 2mLper minute.Chromatograph replicate injections of theStandard preparation,and record the peak responses as directed forProcedure:the tailing factor is not more than 3,and the relative standard deviation is not more than 2.0%.
Procedure— Separately inject equal volumes (about 50µL)of theStandard preparation and theAssay preparation into the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of (C9H13N)2·H2SO4in the portion of Tablets taken by the formula:
50C(rU/rS),
in whichCis the concentration,in mg per mL,of USP Dextroamphetamine Sulfate RSin theStandard preparation;andrUandrSare the peak responses obtained from theAssay preparation and theStandard preparation,respectively.
Auxiliary Information— Staff Liaison:Salvador C.Salado,M.S.,Scientist and Latin American Liaison
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 609
Pharmacopeial Forum:Volume No.30(1)Page 94
Phone Number:1-301-816-8165