“A Development of a Modified USP Assay for Quinidine Sulfate Tablets”

Abstract

Abstract - The non-aqueous titration method of assay of quinidine sulfate tablets outlined in the U.S.P. was examined, modified and compared with a recently published non-aquoeus titration using Barium Acetate. All methods were applied on four different commerical brands of quinidine sulfate 200 mg. uncoated tablets. The methods were comparable in specificity and reliability. However, by performing the assays on individual tablets as for content uniformity test greater variation was encountered by the U.S.P. procedure, especially on changing the time of extraction solvent or the volume of base and/or drying the siliceous earth after filtering and before adding the base. Therefore, it is recommended that the U.S.P. assay be changed to include 0.8ml of 10% NaOH, the total extraction time be reduced to 20 minutes and that the siliceous earth be dryed after filtering and before adding the base.