Application Research Of HPCE On The Separation And Analysis Of Structurally Similar Drugs

Objective:At chapter one,the cyclodextrins(CD)were used as electrolyte additives for the separation and determination of spironolactone/canrenone by capillary electrophoresis.In addition,the simple and fast method of high-performance capillary electrophoresis(HPCE)were established and developed for the separation and quantification of spironolactone and canrenone in pharmaceutical preparations and urine sample.The second chapter reported the use of a binary CD system in CE for the separation and determination of four alkaloids of Uncaria rhynchophylla and an effective and environmentally friendly method for simultaneous determination of uncaria alkaloids from the herbal and formulations was established.Methods:The high-performance capillary electrophoresis equipped with DAD was used for this paper.Separation parameters such as wavelength of detection,buffer concentration and pH,the type and concentration of cyclodextrin,and separation voltage were investigated.(1)The separation was carried out in an uncoated fused-silica capillary(57 cm× 75 ?m,50 cm to detector)and the satisfactory separation results of spironolactone and canrenone were achieved at the optimized condition when the electrolyte solution was at pH 5.5,20 m M phosphate buffer containing 4.5 g/L sulfated-?-CD,15 k V of electric field across the capillary applied at 25 ?,and the detection wavelength was at 260 nm;injection: pressure0.5 psi for 5 s.The content was determined by internal standard method,and fluocinonide was selected as the internal standard(IS).(2)The separation was carried out in an uncoatedfused-silica capillary(30.3 cm× 75 ?m,20.2 cm to detector)and the satisfactory separation condition of four uncaria alkaloids was achieved when the electrolyte solution was at pH5.7,40 m M phosphate buffer containing 161.7 m M 2-hydroxypropyl-?-CD and 2.21 m M mono-(6-ethylenediamine-6-deoxy)-?-CD,15 k V of electric field across the capillary applied at 25 ?,and the detection wavelength was at 250 nm;injection: pressure 0.5 psi for 5 s.Results:Under optimum conditions,good linearity was achieved with correlation coefficients from 0.9976 to 0.9997,and the analytes were baseline separated within 7 min with the high resolution of 3.6;the intraday RSD < 2.9% and interday RSD < 4.3%;the recoveries of samples were ranged from 99.0 to 106.8%.Under optimum conditions,good linearity was achieved with correlation coefficients from 0.9992 to 0.9995,and the four uncaria alkaloids were baseline separated within 13 min with the high resolution ranged from 2.2 to 8.3;the intraday RSD < 3.8% and interday RSD < 5.0%;the recoveries of the samples varied from 96.2 to 106.0%.Conclusion:(1)The experimental results of this study demonstrated that the separation of insoluble neutral drugs of spironolactone and canrenone by CE is possible.Meanwhile,the developed method is simple,rapid,and specific,which is a promising method for the QC of spironolactone pharmaceutical formulations and for the rapid simultaneous determination of the content of spironolactone and canrenone in urine samples.(2)The experimental results of this study demonstrated that the use of a binary CD system in CE for the separation and determination of four alkaloids in UR is effective.Meanwhile,it is the first time to develop an available method for the simultaneous analysis of four uncaria alkaloids from the herbal and formulations by CE method.Therefore,thisstudy has developed a novel,simple,rapid,and specific method,which is promising for the QC of the alkaloids in UR.