Studies On Rapid Determination Of Oxcarbazepine Plasma Concentration By Two-dimensional Liquid Chromatography

BackgroundBlood drug concentration monitoring is an important means for guiding individual drug use,ensuring rational drug use and drug safety in clinical practice.The accuracy of the measurement results directly affects the judgment of physicians and the choice of treatment plan.The determination of the concentration of drugs and their effective metabolites in human serum requires scientific methods,advanced instruments and equipment,suitable experimental conditions,accurate data processing and rigorous methodological verification.At present,epilepsy patients are mainly treated with drugs.In order to achieve the ideal effect,drugs of different mechanisms of action are often combined to increase the therapeutic effect and reduce side effects.This requires that the plasma concentration determination method of oxcarbazepine should have a good degree of separation and anti-interference,so as to accurately separate and analyze the target components in serum,and not be interfered by other complex drug components.At present,the widely used method of high performance liquid pretreatment process is complex,separating degree is not enough,can’t meet the demand of the rapid determination of biological samples of medical institutions,the new technology of liquid chromatography tandem mass spectrometry（LC-MS/MS）using internal standard method to ensure its accuracy,also has the advantages of high sensitivity,but the testing cost is high,carried out in medical institutions to regular.In view of the above problems,this topic will be based on the characteristics of the use of medical institutions,two-dimensional liquid chromatography for rapid determination of Oxcarbazepine concentration in blood as a methodology validation study.ObjectiveBased on the study of the theory of two-dimensional Liquid Chromatography（2D-LC）and the characteristics of automatic column switching and good resolution,a method for rapid determination of oxcarbazepine in human plasma was established,it has the advantages of high accuracy,good stability,strong anti-interference ability,low cost and high sensitivity,which can provide monitoring data support for clinical individualized medication and ensure clinical medication safety.MethodThe new two-dimensional liquid chromatographic system is composed of a one-dimensional and a two-dimensional liquid chromatographic column and an intermediate transfer column,after on-line enrichment and preliminary purification on the first-dimensional column Aston-RG C₈（4.6×25 mm,5μm）,it was retained by transfer column Aston^TM SRR C₁₈（4.6×10 mm,3.5μm）and then transferred to the second-dimensional column Aston-RG C₁₈（4.6×100 mm,5μm）by column switching,after further separation,it is detected by an ultraviolet detector.An optimum experimental condition was obtained by the selection of column series combination and Pretreatment,chromatographic conditions,composition of mobile phase,Ph value and flow rate,determination of oxcarbazepine in human serum by two-dimensional liquid chromatography.ResultsA two-dimensional liquid-phase system was established by using a series of C₈ and C₁₈ columns of ion-exchange and reversed-phase liquid chromatography.The sample was pretreated with Acetonitrile,and the mobile phase was Acetonitrile:Ammonium Phosphate Solution=30:70（V:V）at p H 2.8 and 6.8,respectively,when the flow rate was 0.8 ml/min and 1.0 ml/min respectively,oxcarbazepine maintained a good linear relationship（r=0.9996）in the blood concentration range of 1.64-40.39μg/ml,with an accuracy of 95.8%-102.9%,the relative standard deviation（RSD）of intra-day and inter-day precision was less than 2.58%,and the instability of oxcarbazepine blood sample was less than 7.6%.The detection limit of the method was 0.04μg/ml.ConclusionIn this experiment,the concentration of oxcarbazepine in human plasma was determined by two-dimensional liquid chromatography.By optimizing the experimental conditions,a specific and anti-interference method was established,with high accuracy and sensitivity,good stability and resolution,low analysis cost,and a method that can meet the requirements of analysis of therapeutic drin human plasma,providing more timely and appropriate data support for guiding individualized treatment of patients,it is suitable for primary hospitals to carry out routine monitoring of blood drug concentration in emergency patients and patients with chronic diseases.