Determination Of Pharmaceutical And Bacteriostat Components In 2 Kinds Of Eye Drops By High-precision Capillary Electrophoresis And Study On The Different Interaction Between Hp-β-CD And Pharmaceuticals

Pharmaceutical excipients are an important part of pharmaceutical preparations.They undergo in vivo processes together with active ingredients,.The quality and safety of pharmaceutical excipients are also very important.The thesis applies capillary electrophoresis and quantitative proton nuclear magnetic resonance spectroscopy（¹H-q NMR）to analyze and study pharmaceutical excipients.High-precision quantitative capillary electrophoresis was applied to determine the active ingredient sodium cromoglycate and the excipient ethylparaben in sodium cromoglycate eye drops,and the taurine and ethylparaben in taurine eye drops,respectively.Besides,capillary electrophoresis was used to determine the binding constants of hydroxypropyl-β-cyclodextrin（HP-β-CD）from different manufacturers with 2pharmaceuticals,showing discrepant interactions between them.To study the reason of those discrepency,the reseach further investigated the content and degree of substitution at different positions of HP-β-CD by ¹H-q NMR.Four parts are as follows:1.The method for the simultaneous determination of sodium cromoglycate and ethyl paraben in sodium cromoglycate eye drops was established with high-precision quantitative capillary electrophoresis instrument using an uncoated elastic silica capillary column 75μm×60 cm（effective length 45 cm）.The effects of experimental conditions on the separation were investigated.The 15 mmol/L borax buffer（p H 9.0）was then selected as running buffer,and the separation voltage was-15 k V,the detection wavelength was 210 nm.The experimental results showed that the 2 components were well separated,and the intraday relative standard deviations（RSD）of the peak areas of sodium cromoglycate and ethylparaben were both within 1.9%,which is significantly improved compared with that use of classic capillary electrophoresis equipment.The linear correlation coefficients of sodium cromoglycate（in the concentration range of 0.5～5.5 mg/m L）and ethylparaben（in the concentration range of 0.01～0.51 mg/m L）were 0.9929 and 0.9983,respectively.The recovery rate of each component was in the range of 93.1%～100.6%.The method shows good precision,simple operation and fast analysis speed with accurate and reliable experimental results.It has been applied to determine the 2 components in real sodium cromoglycate eye drops.2.A method for the high-precision determination of taurine and ethylparaben in taurine eye drops by micellar capillary electrokinetic chromatography was established.The experimental conditions were selected as follows:uncoated elastic quartz capillary column75μm×60 cm（effective length 45 cm）,15 mmol/L borax-boric acid（containing 20 mmol/L SDS,p H 9.0）running buffer,separation voltage-15 k V,detection wavelength 210 nm.The results show that the 2 components were well separated,and the intraday relative standard deviation（RSD）of the peak areas of taurine and ethylparaben are both within 1.7%.The linear correlation coefficients of taurine（in the concentration range of 5.02～40.77 mg/m L）and ethylparaben（in the concentration range of 0.05～0.33 mg/m L）were 0.9987 and 0.9989,respectively.The recovery rate of the 2 analytes were in the ranges of 94.7%～102.6%.The method shows good precision and has been applied for the simultaneous determination of taurine and ethylparaben in real taurine eye drops.3.The binding constants of levofloxacin,vitamin B₂,and HP-β-CD were determined by capillary electrophoresis with mobility shift method.With levofloxacin and vitamin B₂as samples,HP-β-CD as buffer additive,capillary separation was performed at 25°C.According to the change of the migration time of each component,the binding constant K_bbetween the 2drugs and HP-β-CD were calculated by Scatchard equation.The relative standard deviations（RSD）of the migration time of each component was less than 0.8%.The results show that the binding constants between HP-β-CD produced by different manufacturers and the same drug are different.4.The quantitative nuclear magnetic resonance spectroscopy（q NMR）for determination of HP-β-CD was established to evaluate its degree of substitution at different positions.The HP-β-CD sample was directly dissolved in the deuterated reagent and determined by¹H-q NMR.The deuterated dimethyl sulfoxide was selected as the solvent,the reference reagent potassium hydrogen phthalate was the internal standard,the pulse width P1=14.1μs,the delay time d1=7 s,and the number of scans NS=32.The results showed that the content of HP-β-CD produced by different manufacturers was in the range of 86.5%～92.6%.The degree of substitution of HP-β-CD produced by different manufacturers present diffirent at different substitution positions,and the difference is consistent with above determination of the binding constant by capillary electrophoresis.The method is simple and does not require complicated sample pretreatment,which has been applied to determine HP-β-CD and characterize the degree of substitution of different substitution positions.Combining above-mentioned capillary electrophoresis mobility shift method to determine the binding constant,the q NMR method has been applied to evaluate the difference of HP-β-CD samples.