Antiepileptic Drugs In Human Plasma Research Articles

Development and evaluation of a simple and easy high-performance liquid chromatography-ultraviolet system simultaneously suitable for determination of 24 anti-epileptic drugs in plasma.

We aim to establish a simple and easy high-performance liquid chromatography system coupled with an ultraviolet detector suitable for simultaneous determination of 24 antiepileptic drugs in human plasma. Optimized chromatographic separation was performed on a ZORBAX Eclipse Plus-C18 (4.6 × 150mm2 , 3.5 μm) column with acetonitrile and 5mM potassium dihydrogen phosphate water solution as mobile phase. Note that, 24 antiepileptic drugs were divided into three groups and eluted with different gradient procedures, respectively. The column temperature was maintained at 35°C and the detection wavelength was set at 210nm. Plasma was processed with ethyl acetate or acetonitrile. The calibration curves of 24 antiepileptic drugs demonstrated good linearity within the test range (r>0.996). The intra- and inter-batch precision and accuracy were all less than 15%, while extraction recoveries were in the range of 74.57-90.89% with the relative standard deviation values less than 15%. The validated methods have been successfully applied to determination of some antiepileptic drugs in rat or patient plasma. Those results indicated that the developed methods were simple and easy, and could be suitable for the determination of 24 antiepileptic drugs in plasma just by changing the gradient elution procedures of mobile phase.

Simple and efficient method for the quantification of antiepileptic drugs in human plasma by using magnetic graphene oxide-\u03b2-cyclodextrin composite as a sorbent

BackgroundIn recent days, solid-phase extraction methods are widely utilized for the extraction of drug molecules from plasma samples due to their easy operating procedures and low matrix effect. The trace-level solid-phase extraction of three structurally related antiepileptic drugs brivaracetam (BVC), eslicarbazepine acetate (ESL), and carbamazepine (CBZ) was investigated by using a magnetic porous material graphene oxide-β-cyclodextrin (MGO-CD). Morphology, magnetic properties, and structure of the synthesized MGO-CD were characterized by using FT-IR, SEM, XRD, and VSM.ResultsSolid-phase extraction (SPE) methods were used to extract the analytes from human plasma. Different extraction solvents such as acetonitrile (ACN), methanol (MeOH), acetone, chloroform (CHCl3), tertiary butyl diethyl ether (TBDE), and ethyl acetate (EtOAc) with variable polarities were used to extract drug molecules from MGO-CD. The linearity analysis showed good correlation coefficient values (R2) of 0.9989, 0.9995, and 0.9982 for BVC, ESL, and CBZ respectively. The LOD and LOQ ranges were found to be 6.14–28.32 ng mL−1 and 20.45–94.31 ng mL−1 respectively.ConclusionThe high accuracy and precision made the developed HPLC method with MGO-CD a suitable alternative for the bioequivalence study of BVC, ESL, and CBZ in human plasma. This developed HPLC-UV method has good efficiency for recoveries and good linearity and is simple to handle. And also, it gave low retention time for the three antiepileptic drugs within 8 min. It provides high efficiency for the extraction of trace-level substances from human plasma.

A UPLC-MS/MS method for simultaneous determination of nine antiepileptic drugs in human plasma and its application in TDM.

With the purpose of carrying out therapeutic drug monitoring (TDM) of nine antiepileptic drugs simultaneously in the clinic, a UPLC-MS/MS assay method was developed and validated. Separation of antiepileptic drugs and internal standard (naproxen and diazepam) was performed on an Agilent Eclipse XDB-C18 column (50.0×2.1mm, 1.7μm) using water and acetonitrile as mobile phase for gradient elution. Polarity switch ionization mode (positive-negative-positive) was performed in a total run time of 3.0min. The method validation was conducted based on bioanalytical method validation guidance, including specificity, calibration curve, precision, accuracy, recovery, matrix effect, stability and dilution integrity, and all of the results satisfied the requirements. Consequently, the proposed method was applied to the TDM of nine antiepileptic drugs and was proved to be sensitive, reliable and specific to determine antiepileptic drugs in human plasma simultaneously. Meanwhile, the TDM results showed that the plasma drug concentration of many patients was not within the effective therapeutic range, especially those taking topiramate, oxcarbazepine and levetiracetam, which was of great guiding significance to rational drug use and timely adjustment of the treatment plan. Therefore, individualized therapy based on advanced analytical methods and TDM theory is of great practical significance.

Schiff base network-1 incorporated monolithic column for in-tube solid phase microextraction of antiepileptic drugs in human plasma

A novel monolithic column incorporated with Schiff base network-1 (SNW-1) was prepared for in-tube solid phase microextraction (SPME) of antiepileptic drugs. The SNW-1 nanoparticles was synthesized by a solvent thermal method and embedded in the poly(glycidyl methacrylate-ethylene glycol dimethacrylate) (GMA-EGDMA) monolithic column by in situ polymerization. The amount of SNW-1 in polymerization solution for preparation of monolithic column was optimized. Fourier transform infrared spectrometry and scanning electron microscope were used to characterize the obtained monolithic column. The SNW-1-monolithic column was connected to the high-performance liquid chromatography (HPLC) system and applied for online extraction and analysis of antiepileptic drugs. The extraction conditions including sample solution flow rate, desorption time, acetonitrile content, pH of sample solution and sample volume were investigated. Under optimal conditions, the proposed SPME-HPLC method showed high extraction efficiency, good linearity, low limits of detection (0.2 ng/mL) and good repeatability (relative standard deviations < 2.41%). This method was also applied to the analysis of antiepileptic drugs in human plasma samples and the recoveries were in the range of 88.6–106.1% with RSDs less than 3.51%.

Determination of four antiepileptic drugs in plasma using ultra-performance liquid chromatography with mass detection technique.

Status epilepticus (SE) is considered the second most frequent neurological emergency. Its therapeutic management is performed using sequential antiepileptic drug regimens. Diazepam (DIA), midazolam (MID), phenytoin (PHT) and phenobarbital (PB) are four drugs of different classes used sequentially in the management of SE. A sensitive, selective, accurate and precise method was developed and validated for simultaneous determination of the four antiepileptic drugs in human plasma. Their separation and quantification were achieved using ultra-performance liquid chromatography (UPLC) with mass detection using carbamazepine as internal standard (IS). For the first three drugs and the IS, UPLC-MS/MS with electrospray ionization working in multiple reaction monitoring mode was used at the following transitions: m/z 285 → 193 for DIA; m/z 326 → 291 for MID; m/z 253 → 182 for PHT; and m/z 237 → 194, 237 → 192 for IS. For the fourth drug (PB), a molecular ion peak of PB [M + H] + at m/z 233 was used for its quantitation. The method was linear over concentration ranges 5-500 ng/mL for DIA and MID and 0.25-20 μg/mL for PHT and PB. Bioanalytical validation of the developed method was carried out according to European Medicines Agency guidelines. The developed method can be applied for routine drug analysis, therapeutic drug monitoring and bioequivalence studies.

A Parallel-Column LC–MS/MS Method for High-Throughput Analysis of Eight Antiepileptic Drugs in Clinical Therapeutic Drug Monitoring

Therapeutic drug monitoring (TDM), the practice of measuring drug plasma concentrations at multiple times, is necessary in the clinical management of drugs with narrow therapeutic windows, such as antiepileptic drugs (AEDs). This study describes a parallel two-column LC–MS/MS system for quantitative high-throughput analysis of AEDs in human plasma. It multiplexes two high-performance liquid chromatography (HPLC) systems into a single mass spectrometer, providing a twofold throughput increase compared to a generic single-column LC–MS/MS system. The validation results of specificity, matrix effects, recovery, linearity, precision, and accuracy were satisfactory. The intra-day precision and inter-day precision for the analysis of the eight AEDs were less than 7.62%, with the accuracy ranging between −5.06 and 14.00%. The method was used to monitor plasma levels of eight AEDs from 1773 patients on a regular basis. The parallel HPLC–MS/MS method has been demonstrated to be capable of processing large analytical samples. With a twofold increase in sample throughput and a better-coordinated workflow, the system can easily meet the high-throughput challenge in clinical TDM.

Sensitive inexpensive HPLC determination of four antiepileptic drugs in human plasma: application to PK studies.

Recently, polytherapy regimen has been introduced for the treatment of epileptic patients for better seizure control with lesser side effects and better control of multiple seizure types. A simple, sensitive and highly specific reversed-phase HPLC method was developed for simultaneous determination of four antiepileptic drugs (AEDs), levetiracetam, lamotrigine, oxcarbazepine and carbamazepine, in real human plasma without interference from endogenous components of plasma. The method was proved to be linear in the range of 0.5-50 µg/ml for all drugs. It was successfully applied for clinical PK study of the AEDs in healthy volunteers following single administration. Also, this method was applied for simultaneous determination of the studied drugs in volunteers' plasma receiving synergistic binary combinations from the four AEDs when used as add-on therapy. The good precision and selectivity of the developed method allow it to be used for routine therapeutic drug monitoring of such drugs as a useful tool in epilepsy management.

Simultaneous determination of topiramate, carbamazepine, oxcarbazepine and its major metabolite in human plasma by SFC-ESI-MS/MS with polarity switching: Application to therapeutic drug monitoring

Antiepileptic drugs are the first choice for epilepsy treatment. Monitoring antiepileptic drugs is important to minimize their adverse side effects by choosing the optimum drug dosage. An accurate and high throughput supercritical fluid chromatography-tandem mass spectrometry method has been developed for the simultaneous quantification of several antiepileptic drugs in human plasma. Plasma samples were extracted with ethyl acetate and the upper organic layer was directly injected into the supercritical fluid chromatography/mass spectrometry (SFC-MS/MS) system without further nitrogen evaporation and subsequent reconstitution. The analytes were eluted on a UPC2TM BEH, 2-EP column (100×3mm, 1.7μm) at a flow rate of 1.0mL/min and multi-reaction monitoring (MRM) was performed for determination of the analytes and internal standard (IS) in polarity switching mode. Calibration curves were linear over the concentration ranges of 0.08–40, 0.01–15, 0.01–8 and 0.5–50μg/mL with lower limit of quantifications of 0.08, 0.01, 0.01and0.50μg/mL for topiramate, carbamazepine, oxcarbazepine and monohydroxycarbamazepine, respectively. This sensitive, accurate, novel method will be very useful for monitoring the above antiepileptic drugs and for pharmacokinetic studies.

A novel microextraction by packed sorbent–gas chromatography procedure for the simultaneous analysis of antiepileptic drugs in human plasma and urine

A simple, accurate, and sensitive microextraction by packed sorbent-gas chromatography-mass spectrometry method has been developed for the simultaneous quantification of four antiepileptic drugs; oxcarbazepine, carbamazepine, phenytoin, and alprazolam in human plasma and urine as a tool for drug monitoring. Caffeine was used as internal standards for the electron ionization mode. An original pretreatment procedure on biological samples, based on microextraction in packed syringe using C(18) as packing material gave high extraction yields (69.92-99.38%), satisfactory precision (RSD < 4.7%) and good selectivity. Linearity was found in the 0.1-500 ng/mL range for these drugs with limits of detection (LODs) between 0.0018 and 0.0036 ng/mL. Therefore, the method has been found to be suitable for the therapeutic drug monitoring of patients treated with oxcarbazepine, carbamazepine, phenytoin, and alprazolam. After validation, the method was successfully applied to some plasma samples from patients undergoing therapy with one or more of these drugs. A comparison of the detection limit with similar methods indicates high sensitivity of the present method over the earlier reported methods. The present method is applied for the analysis of these drugs in the real urine and plasma samples of the epileptic patients.

Novel micro‐extraction by packed sorbent procedure for the liquid chromatographic analysis of antiepileptic drugs in human plasma and urine

A method for the simultaneous determination of the antiepileptic drugs, phenobarbital (PHB), phenytoin (PTN), carbamazepine (CBZ), primidone (PRM) and oxcarbazepine (OXC) in human plasma and urine samples by using micro-extraction in a packed syringe as the sample preparation method connected with LC/UV (MEPS/LC/UV) is described. Micro-extraction in a packed syringe (MEPS) is a new miniaturized, solid-phase extraction technique that can be connected online to gas or liquid chromatography without any modifications. In MEPS approximately 1 mg of the solid packing material is inserted into a syringe (100-250 μL) as a plug. Sample preparation takes place on the packed bed. The bed can be coated to provide selective and suitable sampling conditions. The new method is very promising, easy to use, fully automated, inexpensive and quick. The standard curves were obtained within the concentration range 1-500 ng/mL in both plasma and urine samples. The results showed high correlation coefficients (R(2) >0.988) for all of the analytes within the calibration range. The extraction recovery was found to be between 88.56 and 99.38%. The limit of quantification was found to be between 0.132 and 1.956 ng/mL. The precision (RSD) values of quality control samples (QC) had a maximum deviation of 4.9%. A comparison of the detection limits with similar methods indicates high sensitivity of the present method. The method is applied for the analysis of these drugs in real urine and plasma samples of epileptic patients.

Simple and accurate quantitative analysis of ten antiepileptic drugs in human plasma by liquid chromatography/tandem mass spectrometry

A simple, accurate, and sensitive liquid chromatography (LC)–tandem mass spectrometry (MS/MS) method has been developed for the simultaneous quantification of 10 antiepileptic drugs (AEDs; gabapentin (GBP), levetiracetam (LEV), valproic acid (VPA), lamotrigine (LTG), carbamazepine-10,11-epoxide (CBZ-epoxide), zonisamide (ZNS), oxcarbazepine (OXC), topiramate (TPM), carbamazepine (CBZ), phenytoin (PHT)) in human plasma as a tool for drug monitoring. d 10-Phenytoin ( d 10-PHT) and d 6-valproic acid ( d 6-VPA) were used as internal standards for the positive- and negative-ionization modes, respectively. Plasma samples were precipitated by the addition of acetonitrile, and supernatants were analyzed on a C18 reverse-phase column using an isocratic elution. Detection was carried out in selected reaction monitoring (SRM) mode. The calibration curves were linear over a 50-fold concentration range, with correlation coefficients ( r 2) greater than 0.997 for all AEDs. The intra- and inter-day precision was less than 12%, and the accuracy was between 85.9 and 114.5%. This method was successfully used in the identification and quantitation of AEDs in patients undergoing mono- or polytherapy for epilepsy.

Simultaneous HPLC-F analysis of three recent antiepileptic drugs in human plasma

An original high-performance liquid chromatographic method with fluorescence detection is presented for the simultaneous determination of the three antiepileptic drugs gabapentin, vigabatrin and topiramate in human plasma. After pre-column derivatisation with dansyl chloride, the analytes were separated on a Hydro-RP column with a mobile phase composed of phosphate buffer (55%) and acetonitrile (45%) and detected at λ em = 500 nm, exciting at 300 nm. An original pre-treatment procedure on biological samples, based on solid-phase extraction with MCX cartridges for gabapentin and vigabatrin, and with Plexa ® cartridges for topiramate, gave high extraction yields (>91%), satisfactory precision (RSD < 6.4%) and good selectivity. Linearity was found in the 0.2–50.0 μg mL −1 range for gabapentin, in the 1.0–100.0 μg mL −1 range for vigabatrin and in the 1.0–50.0 μg mL −1 range for topiramate, with limits of detection (LODs) between 0.1 and 0.3 μg mL −1. After validation, the method was successfully applied to some plasma samples from patients undergoing therapy with one or more of these drugs. Accuracy results were satisfactory (recovery >91%). Therefore, the method seems to be suitable for the therapeutic drug monitoring (TDM) of patients treated with gabapentin, vigabatrin and topiramate.

New method for the determination of four antiepileptic drugs in human plasma by high performance liquid chromatography

The concurrent administration of several antiepileptic drugs for the treatment of seizure disorders has become common practice. Lamotrigine is a new antiepileptic given in combination with other antiepileptic drugs, but which is not routinely measured in clinical laboratories. An isocratic high-performance liquid chromatographic method is described for the simultaneous measuring lamotrigine, carbamazepine, phenobarbital and phenytoin within 10 minutes. The chromatographic system used an Hichrom Spherisorb CN column (20 cm×4 mm, i.d., 5 μm particle size), a μBondapak CN precolumn, and a mobile phase consisting of methanol : acetonitrile : 5 mM sodium acetate (5:20:75: by volume, pH adjusted to 6.3 with acetic acid). BWA 725C was used as internal standard. The drugs were extracted from 200 μl of plasma with ethyl acetate, acetonitrile and 5 mM sodium acetate. After evaporation of the organic layer and reconstitution in mobile phase, 25 μl of extract was eluted with mobile phase at a flow rate of 1.2 ml/min. The eluted drugs were detected by their absorption at 205 nm and quantified from their peak heights. The method was found to be rapid, relatively simple to perform and sufficiently sensitive to determine each drug over its entire therapeutic range. Lower limits of detection varied from 50–100 ng/ml, absolute recoveries from 93–98%, and mean intra- and inter-assay CVs were <3.0%.

Analysis of antiepileptic drugs in human plasma using micellar electrokinetic capillary chromatography

We describe a method for the simultaneous determination of antiepileptic drugs (ethosuccimide, phenytoin, primidone, phenobarbital, carbamazepine and valproic acid) by micellar electrokinetic capillary chromatography using sodium dodecyl sulphate as the micellar phase. Factors affecting the micellar electrokinetic separation were studied for the quantitative determination of these drugs in human plasma. The confirmation of the peaks and the specificity of the method were investigated by combining multiwavelength detection with micellar electrokinetic capillary chromatography.

Integrated Method for the Gas Chromatographic Determination of Antiepileptic Drugs in Human Plasma

Summary: The principles of three independent extraction methods were utilized to develop an integrated extraction scheme for use in routine therapeutic monitoring of seven antiepileptic agents. The final method, in which the three extraction methods were interfaced, permitted routine monitoring in a single 1 ml volume of human plasma of any one or combination of the following drugs: phenytoin (PHT), phenobarbital (PB), primidone (PD), 5-ethyl-5-phenylhydantoin (EPH), ethosuximide (ES), carbamazepine (CBZ), and valproic acid (VPA). An on-column methylation technique was used for simultaneous determination of PHT, PB, PD, EPH, and ES. CBZ and VPA were determined by independent methods as the underivatized compounds. Six appropriate internal standards were employed in the integrated method for quantitation of the drugs.

Integrated Method for the Gas Chromatographic Determination of Antiepileptic Drugs in Human Plasma

The principles of three independent extraction methods were utilized to develop an integrated extraction scheme for use in routine therapeutic monitoring of seven antiepileptic agents. The final method, in which the three extraction methods were interfaced, permitted routine monitoring in a single 1 ml volume of human plasma of any one or combination of the following drugs: phenytoin (PHT), phenobarbital (PB), primidone (PD), 5-ethyl-5-phenylhydantoin (EPH), ethosuximide (ES), carbamazepine (CBZ), and valproic acid (VPA). An on-column methylation technique was used for simultaneous determination of PHT, PB, PD, EPH, and ES. CBZ and VPA were determined by independent methods as the underivatized compounds. Six appropriate internal standards were employed in the integrated method for quantitation of the drugs.

High-speed liquid chromatographic determination of antiepileptic drugs in human plasma

A high-speed liquid Chromatographic method for the simultaneous determinations of diphenylhydantoin, phenobarbital and carbamazepine in human blood plasma is presented. This method involves two step extraction procedures with chloroform and uses 2 × 50 cm long stainless steel columns packed with a anion exchange resin, with a mobile phase of 4 mM ammonium phosphate buffer solution, pH 6.2 at a flow rate of 0.40 ml/min. The results presented show linear calibration curves and quantitative determinations as low as 1.0 μg of each drug added to 0.5 ml plasma. This method has a sensitivity sufficient to detect human plasma levels after therapeutic clinical doses.