Salsalate Capsules
»Salsalate Capsules contain not less than 90.0percent and not more than 110.0percent of the labeled amount of C14H10O5.
Packaging and storage— Preserve in tight containers.
Identification— Transfer a quantity of Capsule contents,equivalent to about 500mg of salsalate,to a stoppered glass test tube.Add 20mLof ether to the tube,close the tube tightly,shake by mechanical means for 10minutes,and filter.Evaporate the filtrate to dryness using a stream of nitrogen:the IRabsorption spectrum of a mineral oil dispersion of the residue thus obtained,exhibits maxima only at the same wavelengths as that of a similar preparation of USP Salsalate RS.
Disintegration á701ñ: 30minutes,simulated gastric fluid TS(without pepsin)being used.
Uniformity of dosage units á905ñ: meet the requirements.
Limit of salicylic acid—
Mobile phase,Diluent,Resolution solution,and Chromatographic system— Proceed as directed in the Assay.
Standard preparation— Dissolve an accurately weighed quantity of USP Salicylic Acid RSin Diluentto obtain a stock solution having a known concentration of about 0.5mg per mL.Transfer 3.0mLof this solution to a 100-mLvolumetric flask,dilute with Diluentto volume,and mix.This solution contains about 0.015mg per mL.
Test preparation— Use the Assay stock solutionprepared as directed in the Assay.
Procedure— Proceed as directed for Procedurein the Assay,except to inject equal volumes (about 10µL)of the Standard preparationand the Test preparation.Calculate the percentage of salicylic acid (C7H6O3)in the portion of Capsules taken by the formula:
10,000(C/OT)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Salicylic Acid RSin the Standard preparation,OTis the quantity,in mg,of salsalate in the portion of Capsules taken based on the labeled amount,and rUand rSare the salicylic acid peak responses obtained from the Test preparationand the Standard preparation,respectively:not more than 1.5%is found.
Assay—
Mobile phase ,Diluent,Salsalate standard preparation,Resolution solution,and Chromatographic system—Proceed as directed in the Assayunder Salsalate.
Assay preparation— Transfer as completely as possible the contents of not less than 20Capsules to a suitable tared container,and weigh.Mix,and transfer an accurately weighed portion of the powder,equivalent to about 100mg of salsalate,to a 100-mLvolumetric flask,dilute with Diluentto volume,and mix.Sonicate for about 10minutes,and mix.Filter a portion of this solution through a suitable filter of 0.5µm or finer porosity.Use the clear filtrate as the Assay stock solution.Transfer 2.0mLof the Assay stock solutionto a 100-mLvolumetric flask,dilute with Diluentto volume,and mix (Assay preparation).
Procedure— Separately inject equal volumes (about 10µL)of the Salsalate standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the salsalate peaks.Calculate the quantity,in mg,of salsalate (C14H10O5)in the portion of Capsules taken by the formula:
5000C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Salsalate RSin the Salsalate standard preparation,and rUand rSare the responses of the salsalate peaks obtained from the Assay preparationand the Salsalate standard preparation,respectively.
Auxiliary Information— Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist
Expert Committee:(PA2)Pharmaceutical Analysis 2
USP28–NF23Page 1750
Phone Number:1-301-816-8143