Terpin Hydrate Oral Solution (Monograph under this new title—to become official June 1,2005) (Current monograph title is Terpin Hydrate Elixir) »Terpin Hydrate Oral Solution contains,in each 100mL,not less than 1.53g and not more than 1.87g of terpin hydrate (C10H20O2·H2O). Packaging and storage— Preserve in tight containers. USP Reference standards á11ñ USP Terpin Hydrate RS. Alcohol content,Method IIá611ñ: between 90.0%and 110.0%of the labeled amount of C2H5OH. Assay— Internal standard solution,Standard preparation,Chromatographic system,and System suitability test— Proceed as directed in the Assayunder Terpin Hydrate. Assay preparation— Pipet 10mLof Oral Solution into a separator,add 20mLof water and 10mLof 5Nsodium hydroxide,and extract with three 25-mLportions of chloroform,filtering each,successively,through cotton.Rinse the cotton with chloroform.To the combined rinse and extracts add 5.00mLof Internal standard solution,and mix. Procedure— Inject about 1µLof the Standard preparationinto a suitable gas chromatograph,and record the chromatogram.Similarly,inject about 1µLof the Assay preparation,and record the chromatogram.Calculate the quantity,in mg,of terpin hydrate (C10H20O2·H2O)in each mLof the Oral Solution taken by the formula: 0.1(190.28/172.27)WS(RU/RS), in which 190.28and 172.27are the molecular weights of terpin hydrate (C10H20O2·H2O)and anhydrous terpin (C10H20O2),respectively;WSis the weight,in mg,of USP Terpin Hydrate RS,calculated on the anhydrous basis;and RUand RSare the area-ratios of terpin to biphenyl obtained from the chromatograms for the Assay preparationand the Standard preparation,respectively. (Official June 1,2005) Auxiliary Information— Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist Expert Committee:(PA2)Pharmaceutical Analysis 2 USP28–NF23Page 1872 Pharmacopeial Forum:Volume No.28(2)Page 374 Phone Number:1-301-816-8143