Thiamine Mononitrate Oral Solution (Monograph under this new title—to become official June 1,2005) (Current monograph title is Thiamine Mononitrate Elixir) »Thiamine Mononitrate Oral Solution contains not less than 95.0percent and not more than 115.0percent of the labeled amount of thiamine mononitrate (C12H17N5O4S). Packaging and storage— Preserve in tight,light-resistant containers. USP Reference standards á11ñ USP Thiamine Hydrochloride RS. Identification— A: It meets the requirements for Identificationtest Bunder Thiamine Hydrochloride Injection. B: To 5mLof Oral Solution add 2mLof sulfuric acid,cool,and superimpose 2mLof ferrous sulfate TS:a brown ring is produced at the junction of the two liquids. Alcohol content,Method IIá611ñ: between 90.0%and 110.0%of the labeled amount of C2H5OH,acetone being used as the internal standard. Assay— Mobile phase,Internal standard solution,Standard preparation,andChromatographic system— Prepare as directed in the Assayunder Thiamine Hydrochloride Oral Solution. Assay preparation— Quantitatively dilute an accurately measured volume of Oral Solution with Mobile phaseto obtain a solution containing about 500µg of thiamine mononitrate per mL.Pipet 10mLof the resulting solution and 10mLof Internal standard solutioninto a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix. Procedure— Proceed as directed for Procedurein the Assayunder Thiamine Hydrochloride Oral Solution.Calculate the quantity,in mg,of thiamine mononitrate (C12H17N5O4S)in each mLof the Oral Solution taken by the formula: (327.36/337.27)C(L/D)(RU/RS), in which 327.36and 337.27are the molecular weights of thiamine mononitrate and thiamine hydrochloride,respectively;Cis the concentration,in mg per mL,of USP Thiamine Hydrochloride RSin the Standard preparation;Lis the labeled quantity,in mg per mL,of thiamine mononitrate in the Oral Solution;Dis the concentration,in mg per mL,of thiamine mononitrate in the Assay preparationon the basis of the labeled quantity and the extent of dilution;and RUand RSare the ratios of the peak responses of thiamine to methylparaben obtained from the Assay preparationand the Standard preparation,respectively. (Official June 1,2005) Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist Expert Committee:(DSN)Dietary Supplements:Non-Botanicals USP28–NF23Page 1909 Pharmacopeial Forum:Volume No.28(2)Page 381 Phone Number:1-301-816-8389