Naltrexone Hydrochloride Tablets
»Naltrexone Hydrochloride Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of naltrexone hydrochloride (C20H23NO4·HCl).
Packaging and storage Preserve in tight containers.
Identification The retention time of the major peak for naltrexone in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation,as obtained in the Assay.
Apparatus 2: 50rpm.
Determine the amount of C20H23NO4·HCl dissolved using the method described below.
0.05M Buffer solution Dissolve 7.0g of monobasic sodium phosphate in 1Lof water.
Mobile phase Prepare a mixture of 600mLof 0.05M Buffer solution,1.1g of sodium 1-octane sulfonate monohydrate and 400mLof methanol.Adjust with dilute sodium hydroxide to a pHof 6.7±0.05,if necessary,filter,and degas.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Chromatographic system (see Chromatography á621ñ) The liquid chromatograph is equipped with a 280-nm detector and a 3.9-mm ×15-cm column that contains packing L1and is heated to 45.The flow rate is about 1mLper minute.Chromatograph replicate injections of the Standard solution,and record the peak responses as directed for Procedure: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 amount of C20H23NO4·HCl dissolved in comparison with a Standard solution having a known concentration of USP Naltrexone RSin the same Mediumand similarly chromatographed.
Tolerances Not less than 80%(Q)of the labeled amount of C20H23NO4·HCl is dissolved in 60minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Solution A,Solution B,Mobile phase,Resolution solution,Standard preparation,and Chromatographic system Proceed as directed in the Assayunder Naltrexone Hydrochloride.
Assay preparation Transfer not fewer than 20Tablets to a tared container,and determine the average Tablet weight.Grind the Tablets to a homogeneous mixture.Transfer an accurately weighed portion,equivalent to about 250mg of naltrexone hydrochloride,to a 100-mLvolumetric flask.Add about 80mLof 0.1Mphosphoric acid,and shake or sonicate for at least 30minutes.Dilute with 0.1Mphosphoric acid to volume,mix,and filter.
Procedure Proceed as directed for Procedurein the Assayunder Naltrexone Hydrochloride.Calculate the quantity,in mg,of naltrexone hydrochloride (C20H23NO4·HCl)in the portion of Tablets taken by the formula:
(377.86/341.40)100C(rU/rS),in which the terms are defined therein.
Auxiliary Information Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist
Expert Committee:(PA2)Pharmaceutical Analysis 2
USP28NF23Page 1330Pharmacopeial Forum:Volume No.29(4)Page 1053