New Method For Enantioseparation Of Chiral Drugs By Capillary Electrophoresis And Its Application Research

During the recent decades,there has been a dramatic increase in the number of studies on chiral separation.The investigation of the effective means to achieve stereoisomer separations continues to be of significant importance in the process of drug development.Over the last two decades capillary electrophoresis(CE)has been established as a very efficient technique for the separation of drug enantiomers,mainly due to its high efficiency,low consumption of sample,short analysis times,as well as low cost.Choosing the appropriate chiral selectors and additives is very important and difficult in developing a new effective method for enantioseparation of chiral drugs by capillary electrophoresis.In chiral CE separation,cyclodextrins(CDs)and their derivatives have been considered as the most widely used chiral selectors.In this thesis,two novel single-isomer cyclodextrin derivatives,heptakis {2,6-di-O-[3-(1,3-dicarboxyl propylamino)-2-hydroxypropyl]}?-cyclodextrin and heptakis {2,6-di-O-[3-(1,2-dicarboxyl ethylamino)-2-hydroxypropyl]}?-cyclodextrin,were synthesized and used as chiral selector in capillary electrophoresis for the enantioseparation of basic drugs.Two types of ?-CD derivates(anionic and neutral ?-CD derivates)were chosen and employed as the chiral selector to separate higenamine.The relatively poor concentration sensitivity of CE due to the limited sample volume and the short optical path length,limits CE application for sensitive detection of bio-analysis.On-line concentration technique is a satisfactory method that could solve this problem.A capillary electrophoresis method with on-line concentration techniques(CSEI)for the determination of RS-glycopyrrolate,RR-glycopyrrolate,SR-glycopyrrolate and SS-glycopyrrolate in plasma of rats was established.The copper(?)-L-isoleucine(Ile)was chosen and employed as the chiral selector to separate ofloxacin and its four impurities,and possible chiral recognition mechanism was also discussed.The research contents are as follows:1.Synthesis a novel single-isomer cyclodextrin derivative Glu-?-CD and application in chiral separations of 12 chiral drugs by CEA novel single-isomer cyclodextrin derivative,heptakis {2,6-di-O-[3-(1,3-dicarboxyl propylamino)-2-hydroxypropyl]}-?-cyclodextrin,glutamic acid-?-cyclodextrin(Glu-?-CD),was synthesized and used as a chiral selector in capillary electrophoresis for the enantioseparation of 12 basic drugs,including terbutaline,clorprenaline,tulobuterol,clenbuterol,procaterol,carvedilol,miconazole,econazole,homatropine methyl bromide,brompheniramine,chlorpheniramine and pheniramine.The influences of background electrolyte pH,concentration of Glu-?-CD and concentration of the buffer on separation were investaged and optimized.Moreover,the possible chiral recognition mechanism of brompheniramine,chlorpheniramine and pheniramine on Glu-?-CD was investigated using the semi-empirical Parametric Method 3.2.Synthesis a novel single-isomer cyclodextrin derivative Asp-?-CD and application in chiral separations of 13 chiral drugs by CEA novel single-isomer cyclodextrin derivative,heptakis ?2,6-di-O-[3-(1,2-dicarboxyl ethylamino)-2-hydroxypropyl]}-?-cyclodextrin(Asp-?-CD)was synthesized and utilized as the chiral selector to separate terbutaline,clorprenaline,tulobuterol,clenbuterol,procaterol,formoterol,carvedilol,econazole,miconazole,dioxopromethazine,promethazine,tropicamide and tramadol enantiomers by capillary electrophoresis.The primary factors affecting separation efficiency,which include the background electrolyte pH,the concentration of Asp-?-CD and phosphate buffer concentration were studied.Moreover,possible mechanisms of chiral recognition of Asp-?-CD were discussed.3.Enantioseparation of higenamine in capillary electrophoresis using several of?-cyclodextrin derivativesTwo types of ?-CD derivates,including anionic ?-CD derivates(CM-?-CD,S-?-CD)and neutral ?-CD derivates(2-HP-?-CD,M-?-CD),were chosen and employed as the chiral selector to separate higenamine.The two most important factors influencing chiral separation including background electrolyte pH and concentration of chiral selector were investigated and optimized.The proposed method was successfully applied for determination of RHigenamine in Nelumbins Plumula and R-/S-higenamine in Asari Radix et Rhizoma after validation with respect to accuracy and precision,linearity range,selectivity and repeatability.4.On-line preconcentration of glycopyrrolate stereoisomers with S-?-CD as chiral selectors in capillary electrophoresisBy comparing the two on-line preconcentration methods,cation-selective exhaustive injection and field-amplified sample stacking,a new capillary electrophoresis method with cation-selective exhaustive injection for the determination of RS-glycopyrrolate,RRglycopyrrolate,SR-glycopyrrolate and SS-glycopyrrolate in plasma of rats was established.After validation of the method in terms of its linearity,LOD,accuracy,precision and selectivity,this developed method can be well used for quantification of RS-glycopyrrolate,RR-glycopyrrolate,SR-glycopyrrolate and SS-glycopyrrolate in rat plasma.5.Enantioseparation of ofloxacin and its four structure analogues in capillary electrophoresis using copper(?)-L-isoleucine(Ile)as chiral selectorIn this research,copper(?)complexes with L-isoleucine were used as chiral additives for the enantioseparation of ofloxacin and its four related substances termed impurities A,C,E and F by ligand exchange-micellar electrokinetic chromatography.The primary factors affecting separation efficiency such as buffer pH,chiral selector concentration,SDS concentration and organic additive were investigated.Furthermore,the possible chiral recognition mechanism was also discussed briefly.