Study On The Analysis Method And Application Of Optical Isomers Drugs Based On UPC~2 Technology

The optical isomers can be divided into enantiomers and non-enantiomers,enantiomers having a chiral center and non-enantiomers having two or more isomers.Since the optical isomer molecules except that different polarization rotation angle,the other is substantially the same physical and chemical properties.Optical isomers are composition of the same the molecular,the physical and chemical properties are basically the same except for the polarization angle of rotation.Pharmacological effects of the different optical isomers is different,so study on the stereoselective pharmacokinetics of optical isomers in animals and healthy subjects is necessary.After oral administration,OXC is rapidly metabolized by cytosolic reductase enzymes to 10-hydroxycarbazepine(licarbazepine,Lic),Lie has a chiral center at position 10 and appears in plasma as an enantiomeric mixture of S-(+)-licarbazepine(S-Lic)and R-(-)-licarbazepine(R-Lic).This implies that the reductase is stereoselective,usually resulting directly or indirectly affect its pharmacological and toxicological characteristics.Therefore,the study stereoselectivity on the pharmacokinetics,not only allows people to deepen understanding of drug effects and adverse reactions of oxcarbazepine and Lie,but also help explore Lie racemate or a single enantiomer the possibility of drug treatment.So,the establishment of a rapid and reliable quantitation assay for the pharmacokinetic study is essential.Separate chiral metabolites Lie to put pressure chromatography aspect,which gives the challenge establishment of an enantioselective SFC-MS/MS method for simultaneous separation and quantification of oxcarbazepine and its chiral metabolites in beagle dog plasmaDengtaiye has been historically used in "dai" ethnopharmacy for the treatment of chronic pulmonary diseases in China(Compiling Group of Yunnan Traditional Chinese Medicine,1977).A serial of indole alkaloids,iridoids and terpenoids have been identified from the different parts of Alstonia scholaris plant.The majority of DTY constituents were indole alkaloids,in which four major bioactive compounds including scholarisine(DT-1),19-epischolarisine(DT-2),vallesamine(DT-3)and picrinine(DT-4)exhibited significant antibacterial,antifertility,antitussive,anti-asthma,and antitumor bioactivities.Although DTY has been proven effective in clinical trials and therapeutic application,the pharmacokinetic profiles of these representative constituents remain to be elucidated.Therefore,the establishment of a rapid and reliable quantitation assay for the pharmacokinetic study is essential.The quantitation method is not only challenged by the complexity of multi-component drugs,but also challenged by the similar physicochemical properties of diastereoisomer(DT-1 and DT-2).To address the above research difficulties,this study was aimed to develop supercritical fluid chromatography with tandem mass spectrometry(SFC-MS/MS)method to research the pharmacokinetic behaviors of oxcarbazepine and its chiral metabolites and DTY in vivo,which can provide new ideas and methods for the pharmacokinetic studys of isomer drugs.1、The development of an analytical method for oxcarbazepine and its chiral metabolites in beagle samples.We established a SFC-MS/MS method to simultaneously quantify oxcarbazepine and its chiral metabolites Lic in beagle plasma using carbamazepine as internal standard.The plasma samples were treated with liquid-liquid extraction.Separation was performed on an ACQUITY UPC2TM TrefoiTM CEL2 column(3.0×150 mm,2.5μm)maintained at 50℃ using a mobile phase containing SCCO2(purity≥99.99%):methanol(60:40,v/v)delivered at a flow rate of 2.3 mL/min.The back pressure was 2300 psi and 2.0 μL injected into the SFC-MS/MS system.Multiple reaction monitoring(MRM)module used the precursor→product ion transitions of m/z 253.2→208.1 for OXC,m/z 255.2→194.2 for R-and S-Lic and m/z 237.3→192.0 for the IS.The quantitative linear ranges were 5-1000 ng/mL for OXC and 0.5-100 ng/mL for S-Lic and R-Lic in beagle plasma.The intra-day and inter-day relative error(R.E.)and relative standard deviation(RSD)were less than ±15%.The method was successfully applied to a pharmacokinetic study involving a single oral administration of 16 mg/kg OXC as Trileptal@ tablets to beagle dogs.2.The development of an analytical method for DT-1,DT-2,DT-3 and DT-4 in rat plasmas.We established a SFC-MS/MS method to simultaneously quantify DT-1,DT-2,DT-3 and DT-4 in rat plasma using lamotrigine as internal standard.The plasma samples were treated with liquid-liquid extraction.Separation was performed on an ACQUITY UPC2TM TrefoilTM BEH 2-EP column(3.0×100 mm,1.7 μm)maintained at 50℃.The mobile phase consisting of carbon dioxide and methanol(2 mM ammonium formate)was performed as follows:15%methanol(2 mM ammonium formate)maintained at 0-2 min,15-19%methanol(2 mM ammonium formate)at 2-4 min,19-15%methanol(2 mM ammonium formate)at 4-6 min.The flow rate was 1.50 mL/min.The back pressure was 2000 psi and 2.0 μL injected into the SFC-MS/MS system.Multiple reaction monitoring(MRM)module used the precursor→product ion transitions of m/z 357.2→325.4 for DT-1 and DT-2,m/z 341.2→282.2 for DT-3,m/z 339.2→296.2 for DT-4 and m/z 256.1→43.0 for IS.The quantitative linear ranges were 50-10000 pg/mL for DT-1,DT-2,DT-3 and DT-4 in rat plasma.The intra-day and inter-day relative error(R.E.)and relative standard deviation(RSD)were 1.42-12.85%.The method was successfully applied to a pharmacokinetic study involving a single oral administration of 108 mg/kg DTY tablet to rats.