Trioxsalen Click to View Image C14H12O3 228.24
2,5,9-Trimethyl-7H-furo[3,2-g]1]benzopyran-7-one [3902-71-4]. »Trioxsalen contains not less than 97.0percent and not more than 103.0percent of C14H12O3,calculated on the dried basis. [Caution—Avoid exposing the skin to Trioxsalen. ] Packaging and storage— Preserve in well-closed,light-resistant containers. USP Reference standards á11ñ USP Trioxsalen RS. Identification— A: Infrared Absorption á197Mñ. B: Ultraviolet Absorption á197UñSolution: 5µg per mL. Medium: chloroform. C: The retention time of the major peak in the chromatogram of the Assay preparationcorresponds to that of the Standard preparationas obtained in the Assay. Loss on drying á731ñ Dry it at 105for 6hours:it loses not more than 0.5%of its weight. Residue on ignition á281ñ: not more than 0.5%. Related compounds— In the chromatogram obtained from the Assay preparationin the Assay,the sum of the responses of any peaks detected,other than the major peak due to trioxsalen,is not more than 2.0%of the total of all the peak responses and the response of the peak occurring at retention time relative to trioxsalen of about 0.75is not more than 1.5%of the total of all responses. Organic volatile impurities,Method Vá467ñ: meets the requirements. Solvent— Use dimethyl sulfoxide. Assay— Mobile phase— Prepare a filtered and degassed mixture of methanol and water (70:30).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ). Standard preparation— Dissolve an accurately weighed quantity of USP Trioxsalen RSin tetrahydrofuran to obtain a solution having a known concentration of about 1mg per mL.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix. Assay preparation— Transfer about 100mg of Trioxsalen,accurately weighed,to a 100-mLvolumetric flask,dissolve in tetrahydrofuran,dilute with tetrahydrofuran to volume,mix,and filter.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix. Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 4.6-nm ×25-cm column that contains packing L1.The flow rate is about 1mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the tailing factor for the trioxsalen peak is not more than 2.0,and the relative standard deviation for replicate injections is not more than 2.0%. Procedure— Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C14H12O3in the portion of Trioxsalen taken by the formula: 2000C(rU/rS), in which Cis the concentration,in mg per mL,of USP Trioxsalen RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively. Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist Expert Committee:(PA6)Pharmaceutical Analysis 6 USP28–NF23Page 1988 Phone Number:1-301-816-8389