Development And Validation Of Chromatographic Methods For The Analysis Of Rizatriptan Benzoate And Its Impurities

Triptans is used for the treatment of acute migraines. RizatriptanBenzoate, stimulating 5-HT1B/1D receptors in the brain, is one of thesecond-generation Triptans and has been widely used. Presently,Rizatriptan Benzoate and its preparations have being researched anddeveloped in China. This work is focused on the establishment andvalidation of chromatographic methods for the analysis of RizatriptanBenzoate and its impurities.Objectives:1. To establish an HPLC method for simultaneous determination ofRizatriptan Benzoate and its related substances.2. To establish a GC method for determination of the residual organicsolvents in Rizatriptan Benzoate.Methods:1. An HPLC method for simultaneous determination of RizatriptanBenzoate and its related substancesThe separation was performed using a C18 column (250 mm×4.6 mm, 5 μm). The mobile phase consisted of two solvents, A and B with gradientelution. The A solvent was acetonitrile－5 mmol·L^-1 sodiumheptanesulfonate (24:76, pH 3.4 adjusted with acetic acid). The B solventwas acetonitrile－5 mmol·L^-1 sodium heptanesulfonate (38:62, pH 3.4adjusted with acetic acid). The flow rate was 1.0 ml·min^-1. The columntemperature was 30℃. The detection wavelength was 227 nm.2. An Headspace GC method for determination of the residual organicsolvents in Rizatriptan BenzoateAn Agilent 6890N was equipped with an FID detector. The separationwas performed using a DB-624 capillary column (30 m×0.32 mm×1.80μm). The carrier gas is Nitrogen at a constant flow rate of 1.1 ml·min^-1. Thecolumn oven temperature program involved an initial temperature of 60℃for 3 min, increased to 165℃at 20℃·min^-1, then to 200℃at 50℃·min^-1and held for 5 min. The FID system was set at 250℃. A 1 ml aliquot ofheadspace gas was injected into the column using a split ratio of 10:1, withtemperature set at 200℃. The equilibration was made at 60℃for 30 min.Results:1. An HPLC method for simultaneous determination of RizatriptanBenzoate and its related substancesRizatriptan peak was successfully separated from its nearby impuritypeaks. The linear range for Rizatriptan Benzoate was 0.02^-16μg·ml^-1(r=1.0000). The average recoveries (n=3) for Rizatriptan Benzoate in low, middle and high concentration were 100.0% (RSD=0.96%), 100.8%(RSD=1.3%) and 102.6% (RSD =1.5%), respectively.2. An Headspace GC method for determination of the residual organicsolvents in Rizatriptan BenzoateMethanol, ethanol, acetone, ethyl acetate and isopropyl ether weresuccessfully separated from each other. Their limits of detection were4.4812, 4.6556, 0.8710, 2.3656 and 0.0078 ppm, respectively. Their linearranges were 2.820¹87.980μg·ml^-1(r=0.9995), 2.906²42.140μg·ml^-1(r=0.9979), 0.052¹72.300μg·ml^-1(r=0.9983), 0.005¹23.830μg·ml^-1(r=0.9990) and 1.436¹19.650μg·ml^-1(r=0.9988), respectively.Their average recoveries (n=9) were 96.7% (RSD=8.1%), 99.9%(RSD=9.7%), 95.1% (RSD=9.9%), 99.6% (RSD=9.3%) and 97.8%(RSD=6.9%), separately.Conclusions:1. An HPLC method for simultaneous determination of RizatriptanBenzoate and its related substancesThe proposed HPLC method is validated to be specific, accurate andsimple for simultaneous determination of Rizatriptan Benzoate and itsrelated substances. And it can identify out-of-control processes on the basisof trace impurity tests.2. An Headspace GC method for determination of the residual organicsolvents in Rizatriptan Benzoate The established headspace GC method is validated to be sensitive and simple for determination of the residual organic solvents in Rizatriptan Benzoate.