Olanzapine In Human Plasma Research Articles

An advanced and Facile Synthesized Graphene/Magnetic Fe3O4 Nanoparticles Platform for Subnanomolar Voltammetric Determination of Antipsychotic Olanzapine Drug in Human Plasma

Magnetite nanoparticles (Fe3O4 NPs) hold a promising performance towards sensing applications. Fe3O4 NPs were synthesized by economically viable method and characterized using different techniques. X-ray diffraction (XRD) pattern of Fe3O4 NPs matched consistently with the database in JCPDS card (19–0629) for magnetite. Their average size was around 16 nm. The values of saturation magnetization and pH at point of zero charge (pHzpc) of the NPs were found to be 61.50 emu g−1 and 7.4, respectively. A novel magnetite-graphene nanocomposite (Fe3O4-GR) was then synthesized based on ex situ approach (in which pre-synthesized Fe3O4 NPs were used to anchor the graphene nanosheets). Transmission electronic microscopy (TEM) and Scanning electronic microscopy (SEM) images indicate that GR nanosheets are decorated by Fe3O4 NPs. Further, Fe3O4-GR nanocomposite modified carbon paste electrode (Fe3O4-GR/CPE) was fabricated. Its effective surface area and surface morphology were studied using cyclic voltammetry and SEM techniqes, respectively. Among Fe3O4-GR/CPE, GR/CPE and Fe3O4/CPE, the electrochemical properties of Fe3O4-GR nanocomposite were superior to the individual GR and Fe3O4. Fe3O4-GR/CPE was utilized for determination of Olanzapine drug in its formulation and it exhibited also very low detection limit (LOD = 7.29 × 10−11 M) and good selectivity towards sensing of Olanzapine in human plasma.

Optimized UPLC-MS/MS method for the quantitation of olanzapine in human plasma: application to a bioequivalence study.

Aim: Olanzapine (OLZ) is the first-line, cost-effectiveness treatment for schizophrenia in China. A quantitative ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of OLZ in human plasma was developed.Results: LC separation was achieved on Waters XBrige C18 column. ESI+ was involved and multiple reaction monitoring transitions were at m/z 313.2→256.1 for OLZ and m/z 316.2→256.1 IS (d3-OLZ). The linear range was 0.1-20ng/ml with LLOQ of 0.1ng/ml. Accuracy and precision were within 10%. The validated method was successfully applied to a bioequivalence study of OLZ disintegrating tablets at dose of 5mg with 100% reproducibility evaluated by incurred sample reanalysis. Conclusion: A robust validated method was developed for quantitation of OLZ in human plasma.

The development and validation of a method for quantifying olanzapine in human plasma by liquid chromatography tandem mass spectrometry and its application in a pharmacokinetic study.

1. A rapid method using liquid chromatography tandem mass spectrometry for the quantification of olanzapine (OLZ) in human plasma was developed and validated. Venlafaxine was used as the internal standard (IS), and the samples were extracted from 400-μL human plasma with methyl tert-butyl ether for liquid-liquid extraction. 2. Chromatography was performed using an ACE C18, 125 × 4.6-mm i.d., 5-μm column. The mobile phase consisted of water with 0.1% formic acid for solvent A and acetonitrile with 0.1% formic acid for solvent B (50 : 50 v/v) in isocratic mode. The flow rate was 1.2 mL/min. The retention times for OLZ and the IS were 0.78 and 1.04 min, respectively. Tandem mass spectrometry operating in positive electrospray ionization mode with multiple reaction monitoring was used to detect OLZ and the IS (m/z: 313.1 > 256.1 and 278.1 > 260.2, respectively). 3. No significant matrix effects were observed on OLZ and the IS retention times, and the mean recovery of OLZ was 90.08%. The assay was linear in the concentration range of 1-20 ng/mL (R(2) = 0.9976). The intra- and inter-day precision were < 11.60% and the accuracy was < 1.66%. 4. This validated method was successfully applied to a pharmacokinetic study in which 10-mg OLZ tablets were administered to healthy volunteers and their plasma OLZ levels were monitored over time. The tests showed that the OLZ test and reference drug (Zyprexa(®)) were bioequivalent, as 90% of the confidence intervals were within the 80-125% interval proposed by regulatory agencies.

SIMULTANEOUS DETERMINATION OF OLANZAPINE AND FLUOXETINE IN HUMAN PLASMA BY LC-MS/MS AND ITS APPLICATION TO PHARMACOKINETIC STUDY

A selective, sensitive, liquid chromatography–positive electrospray ionization tandem mass spectrometry method was developed and validated for the simultaneous quantification of fluoxetine and olanzapine in human plasma using duloxetine (IS) as an internal standard. The analytes and IS were extracted from a 0.250-mL aliquot of human plasma by liquid–liquid extraction using methyl tertiary butyl ether and n-hexane (80:20). The eluted samples were chromatographed with a run time of 3.20 min on X-terra RP8 4.6 × 50 mm, 5 µm column by using a 90:10 v/v mixture of acetonitrile and 5 mM ammonium acetate buffer (P H 5.00 ± 0.05) as an isocratic mobile phase at a flow rate of 0.4 mL/min, and analyzed by mass spectrometry in the multiple reaction monitoring mode using the respective [M+H] + ions, m/z 310.16 → 114.12 for fluoxetine, 313.19 → 256.12 for olanzapine, and 298.14→154.09 for the IS, respectively. Calibration plots were linear over the concentration range of 0.050 to 25.044 ng/mL for fluoxetine and 0.100 to 50.000 ng/mL for olanzapine. Intra-day and inter-day precision and accuracy for quality control samples of fluoxetine (0.150, 12.832, and 19.433 ng/mL) ranged between 2.95 to 10.02% and between 97.90 to 103.25% and for olanzapine (0.300, 25.000, and 38.515 ng/mL) ranged between 3.30 to 7.66% and between 100.75 to 103.11%, respectively. Matrix effect, recovery, and process efficiency experiment was conducted at five different standards, the absolute extraction efficiency was 83.32% for fluoxetine, 86.30% for olanzapine, and 77.73% for IS. This method was successfully applied on pharmacokinetic study.

Liquid Chromatography-Mass Spectrometry Method for the Determination of Olanzapine in Human Plasma and Application to a Bioequivalence Study

A rapid, sensitive and selective liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for the identification and determination of olanzapine (OLZ, CAS 132539-06-1) in human plasma. Following liquid- liquid extraction, OLZ and loratadine (IS, CAS 79794-75-5) were separated using a mobile phase consisting of acetonitrile: aqueous ammonium acetate solution (pH 4.0, 10 mM) = 56:44 (v/v) on an Agilent ZORBAX Eclipse XDB-CN (2.1mmx150mm I.D., 5μm) column and analyzed by electrospray ionization mass spectrometry in the selected ion monitoring (SIM) mode using the respective [M+H]+ ions, m/z 313.15 for OLZ and m/z 383.00 for loratadine. The chromatographic separation was achieved in less than 6.0 min. The assay exhibited a linear dynamic range of 0.5–50 ng/ml for OLZ in human plasma and had good accuracy and precision. Both intra- and inter-batch standard deviations were less than 15%. The validated LC–MS method was first applied to a bioequivalence study in 20 healthy male Chinese volunteers. Keywords: Application, Bioequivalence, Chinese volunteers, Determination, Identification, Human plasma, LC-MS, Loratadine, Olanzapine, Pharmacokinetics

LC–MS/MS assay for olanzapine in human plasma and its application to a bioequivalence study

This paper describes a selective and sensitive assay for the determination of olanzapine (OLZ) in human plasma based on liquid chromatography–tandem mass spectrometry (LC–MS/MS). The analyte and quetiapine as internal standard (IS) were extracted from 200μL plasma via solid phase extraction on Waters Oasis HLB cartridges. Chromatographic separation was achieved on an ACE 5C18-300 column (100mm×4.6mm, 5μm) under isocratic conditions in a run time of 3.5min. Mass spectrometric detection involved electrospray ionization in the positive ion mode followed by multiple reaction monitoring (MRM) of the transitions at m/z 313/256 for OLZ and m/z 384/253 for the IS. The assay was linear in the range 0.10–40.0ng/mL with a lower limit of quantitation and limit of detection of 0.10 and 0.012ng/mL, respectively. Intra- and inter-day precision (as coefficient of variation) and relative recovery were <5.0% and >90%, respectively. The method was successfully applied to a bioequivalence study of 5 and 10mg OLZ disintegrating tablets in 40 healthy Indian males with reproducibility by incurred sample reanalysis in the range −7.43 to 8.07%.

Development and validation of a GC-EI-MS method with reduced adsorption loss for the quantification of olanzapine in human plasma

A simple and sensitive GC-EI-MS method using solvent extraction and evaporation was developed for the determination of olanzapine concentrations in plasma samples. Because olanzapine and promazine, which was used as the internal standard (IS), are nitrogenous bases, they can adsorb to the weakly acidic silanol groups on the surfaces of glass centrifuge tubes during solvent extraction and evaporation. Silylation of the glass tubes, addition of triethylamine (TEA), and use of a sample solution with a basic pH could prevent adsorption loss. The extraction method involved mixing plasma (500 μL) in a silylated glass tube with a promazine solution (2 μg/mL, 25 μL) in methanol containing 1% TEA. After addition of aqueous sodium carbonate (0.5 mol/L, pH 11.1, 1 mL) and extraction into 3 mL of dichloromethane/n-hexane (1:1, v/v) containing 1% TEA, the organic phase was evaporated to dryness in a silylated glass tube. The residue was dissolved in ethyl acetate containing 1% TEA (50 μL). For GC-EI-MS analysis, the calibration curves of olanzapine in human plasma were linear from 0.5 to 100 ng/mL. Intra- and interday precisions in plasma were both less than 7.36% (coefficient of variation), and the accuracy was between 94.6 and 110% for solutions with concentrations greater than 0.5 ng/mL. The limit of quantification was 0.5 ng/mL in plasma. The assay was applied to therapeutic drug monitoring in samples from three schizophrenic patients.

Development of a rapid and sensitive SPE‐LC‐MS/MS method for the simultaneous estimation of fluoxetine and olanzapine in human plasma

A high-performance liquid chromatographic assay with tandem mass spectrometric detection was developed to simultaneously quantify fluoxetine and olanzapine in human plasma. The analytes and the internal standard (IS) duloxetine were extracted from 500 μL aliquots of human plasma through solid-phase extraction. Chromatographic separation was achieved in a run time of 4.0 min on a Hypersil Gold C₁₈ column (50 × 4.6 mm, 5 µm) using isocratic mobile phase consisting of acetonitrile-water containing 2% formic acid (70:30, v/v), at a flow-rate of 0.5 mL/min. Detection of analytes and internal standard was performed by electrospray ionization tandem mass spectrometry, operating in positive-ion and multiple reaction monitoring acquisition mode. The protonated precursor to product ion transitions monitored for fluoxetine, olanzapine and IS were m/z 310.01 → 147.69, 313.15 → 256.14 and 298.1 → 153.97, respectively. The method was validated over the concentration range of 1.00-150.20 ng/mL for fluoxetine and 0.12-25.03 ng/mL for olanzapine in human plasma. The intra-batch and inter-batch precision (%CV) across four quality control levels was ≤ 6.28% for both the analytes. In conclusion, a simple and sensitive analytical method was developed and validated in human plasma. This method is suitable for measuring accurate plasma concentration in bioequivalence study and therapeutic drug monitoring as well, following combined administration.

Determination of Olanzapine in Human Plasma by Reversed-phase High-performance Liquid Chromatography With Ultraviolet Detection

A sensitive high-performance liquid chromatographic method with ultraviolet absorbance detection for the determination of olanzapine in human plasma is described. Clozapine was used as internal standard. Analytes were concentrated from alkaline plasma by liquid-liquid extraction with n-hexane-isoamyl alcohol (90:10, vol/vol). The organic phase was back-extracted with 150 muL phosphate buffer (KH2PO4 with 25% H3PO4) 0.1 mol/L pH 2.2. The chromatographic separation required 6 minutes at a flow-rate of 1.0 mL/min and was carried out on a Water Spherisorb S5 C6 analytical column (250 mm x 4.6 mm ID) with a mobile phase water-acetonitrile 55:45 vol/vol containing 0.009 moL/L eptansulfonic acid sodium salt and 0.06 mol/L potassium phosphate monobasic pH 2.7. The peaks were detected at 254 nm. Mean recoveries for olanzapine and internal standard were 89.4+/-3.3% and 90.4+/-1.0%, respectively. Coefficient of variation value for intraday was 5.0% at concentrations of 10, 50, and 100 ng/mL and for interday was 4.0% at concentrations of 5 and 25 ng/mL. Accuracy, expressed as percent error, ranged from -8.00% to 1.24%. Limit of detection and limit of quantification for olanzapine were 2 and 5 ng/mL, respectively. The method is suitable for pharmacokinetic studies and therapeutic drug monitoring.

Development and validation of a sensitive liquid chromatography/electrospray tandem mass spectrometry assay for the quantification of olanzapine in human plasma

A simple, sensitive and rapid liquid chromatography/electrospray ionization tandem mass spectrometry (LC–ESI-MS/MS) method was developed and validated for the quantification of olanzapine, atypical antipsychotic drug, in human plasma using loratadine as internal standard (IS). Following liquid–liquid extraction, the analytes were separated using an isocratic mobile phase on a reverse phase C 18 column and analyzed by MS in the multiple reaction monitoring mode using the respective [ M + H] + ions, m/ z 313/256 for olanzapine and m/ z 383/337 for the IS. The assay exhibited a linear dynamic range of 0.1–30 ng/mL for olanzapine in human plasma. The lower limit of quantification was 100 pg/mL with a relative standard deviation of less than 10%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The average absolute recovery of olanzapine from spiked plasma samples was 85.5 ± 1.9%. A run time of 2.0 min for each sample made it possible to analyze more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies.

Assay of Olanzapine in Human Plasma by a Rapid and Sensitive Gas Chromatography-Nitrogen Phosphorus Selective Detection (GC-NPD) Method

A gas chromatography-nitrogen phosphorus selective detection (GC-NPD) method with a simple 1-step sample preparation was developed for the assay of the antipsychotic drug olanzapine in plasma. Within a time of analysis of 7 minutes, an HP-5 fused-silica capillary (25 m x 0.2 mm ID, 0.33-microm film thickness, 0.7 mL N2 as carrier gas) provided selectivity with respect to about 30 psychotropic drugs and the internal standard ethylolanzapine. Calibration was linear between 1 and 50 ng/mL and crossed the origin (LOD = 0.3 ng/mL). Intraday precision was 6.7%, 2.7%, and 1.4% at plasma concentrations of 1, 5, and 50 ng/mL, respectively. Interday precision was 4.6% at 20 ng/mL. Accuracy in commercial interlaboratory tests was 108.7% and 88.5%. The method also provided good accuracy in comparison with an HPLC method for patient samples (slope 1.003, r = 0.953) and spiked samples (slope 0.881, r = 0.998). GC-NPD with a simple sample preparation is regarded as an alternative for the assay of olanzapine plasma concentrations in therapeutic drug monitoring (TDM) and in pharmacokinetic studies. Smokers and patients taking concomitant carbamazepine had reduced plasma concentrations of olanzapine. Women and patients older than 60 years had increased plasma olanzapine concentrations.

Determination of olanzapine in human blood by liquid chromatography–tandem mass spectrometry

A liquid chromatographic–tandem mass spectrometric (LC–MS–MS) assay was developed and validated to quantitatively determine olanzapine (OLZ) concentrations in human blood. Liquid–liquid extraction, using n-butanol:cyclohexane (3:47, v/v), was used to isolate OLZ and its internal standard, LY170158, from the biological matrix. Chromatographic resolution of OLZ from endogenous interferences and known metabolites was accomplished with a MetaChem Monochrom HPLC column (4.6×150 mm, d p 5 μm). Detection occurred using a Perkin-Elmer Sciex API III Plus triple quadrupole mass spectrometer using positive ion APCI and multiple reaction monitoring (MRM). The linear dynamic range was from 5 to 500 ng ml −1 based on a 0.25-ml aliquot of human blood. The inter-day precision (%RSD) and accuracy (%RE) ranged from 3.65 to 10.64 and from −2.14 to 3.07, respectively. Modifications to an existing assay for the determination of OLZ in human plasma were necessary. A different structural analog was used as the internal standard due to instability observed for the original analog when using human blood as the matrix. A second modification was the addition of the anti-oxidant sodium ascorbate to inhibit degradation of OLZ in human blood, as has been noted by other investigators. Upon fortification of human blood with sodium ascorbate (final concentration, 0.33 m M), OLZ was found to be stable for at least 1 week at −70°C as well as through two freeze–thaw cycles. This assay, which will be used to investigate the distribution of OLZ in human blood, grants insight into the proper sample handling conditions needed to perform valid determinations of OLZ in human blood.

A high-performance liquid chromatography assay with ultraviolet detection for olanzapine in human plasma and urine

Olanzapine is a commonly used atypical antipsychotic medication for which therapeutic drug monitoring has been proposed as clinically useful. A sensitive method was developed for the determination of olanzapine concentrations in plasma and urine by high-performance liquid chromatography with low-wavelength ultraviolet absorption detection (214 nm). A single-step liquid–liquid extraction procedure using heptane-iso-amyl alcohol (97.5:2.5 v/v) was employed to recover olanzapine and the internal standard (a 2-ethylated olanzapine derivative) from the biological matrices which were adjusted to pH 10 with 1 M carbonate buffer. Detector response was linear from 1–5000 ng ( r 2>0.98). The limit of detection of the assay (signal:noise=3:1) and the lower limit of quantitation were 0.75 ng and 1 ng/ml of olanzapine, respectively. Interday variation for olanzapine 50 ng/ml in plasma and urine was 5.2% and 7.1% ( n=5), respectively, and 9.5 and 12.3% at 1 ng/ml ( n=5). Intraday variation for olanzapine 50 ng/ml in plasma and urine was 8.1% and 9.6% ( n=15), respectively, and 14.2 and 17.1% at 1 ng/ml ( n=15). The recoveries of olanzapine (50 ng/ml) and the internal standard were 83±6 and 92±6% in plasma, respectively, and 79±7 and 89±7% in urine, respectively. Accuracy was 96% and 93% at 50 and 1 ng/ml, respectively. The applicability of the assay was demonstrated by determining plasma concentrations of olanzapine in a healthy male volunteer for 48 h following a single oral dose of 5 mg olanzapine. This method is suitable for studying olanzapine disposition in single or multiple-dose pharmacokinetic studies.

Determination of the novel antipsychotic drug olanzapine in human plasma using HPLC with amperometric detection

A new sensitive high performance liquid chromatograpic method has been developed for the analysis of the novel antipsychotic drug, olanzapine, in human plasma. Chromatography was performed on a reversed-phase column (C8, 150×4.6 mm i.d., 5 μm) with acetonitrile-phosphate buffer (pH=2.5) as the mobile phase. The detection voltage was +900 mV and the cell and column temperature were 50°C. The flow rate was 1 mL min−1.

Determination of olanzapine in human plasma and serum by liquid chromatography/tandem mass spectrometry.

A liquid chromatographic/tandem mass spectrometric (LC/MS/MS) assay was developed for the quantitative determination of olanzapine (LY170053, OLZ) in human plasma and serum. Bond Elut C2 solid-phase extraction cartridges (single cartridge or 96-well format), in conjunction with a positive pressure manifold, were used to extract OLZ and its internal standard, LY170222, from the biological matrix. Chromatographic resolution of OLZ from endogenous plasma interferences and its metabolites was accomplished with a MetaChem monochrom HPLC (4.6 x 150 mm, dp 5 microns). Detection was effected with a Perkin-Elmer SCIEX API III Plus mass spectrometer using positive ion atmospheric pressure chemical ionization and a multiple reaction monitoring protocol. The linear dynamic range was from 250 pg ml-1 to 50 ng ml-1 of human plasma/serum using a 0.5 ml aliquot. The inter-day precision (relative standard deviation) and accuracy (relative error) in plasma ranged from 6.26 to 7.66% and from -3.54 to 7.52%, respectively. The intra-day precision and accuracy in serum ranged from 3.46 to 8.76% and from -8.06 to 12.46%, respectively. This assay is sensitive and selective, and will be used to support both human clinical and toxicological analyses. Furthermore, using the 96-well solid-phase extraction format, sample preparation can be easily automated.

Determination of olanzapine in human plasma and serum by liquid chromatography/tandem mass spectrometry

Determination of olanzapine in human plasma and serum by liquid chromatography/tandem mass spectrometry

Plasma level monitoring of olanzapine in patients with schizophrenia: determination by high-performance liquid chromatography with electrochemical detection.

A sensitive high-performance liquid chromatography method with electrochemical detection for the determination of olanzapine in human plasma is described. Olanzapine from plasma samples was isolated by a simple one-step liquid--liquid extraction with 15% methylene chloride in pentane with an extraction recovery of approximately 94% of the total olanzapine in plasma. The compound was separated on a cyano column. Under the conditions described, commonly coadministered drugs and other common antipsychotic drugs did not interfere with the analysis of olanzapine. The lower limit of determination of the assay was 0.25 ng of olanzapine per ml when 1 ml of plasma was used for the analysis. The interaassay and intraassay variance was (CV%) less than 10%. The standard curve was linear within the range of 0.25 to 50 ng/ml of olanzapine. This method has been used for the determination of plasma levels of olanzapine in patients with schizophrenia who were treated with daily oral doses of 10, 15, and 20 mg of olanzapine. The results indicate that the plasma level of olanzapine increases linearly with the administered daily oral dose (r = 0.6889, p = 0.01).

Analysis of olanzapine in human plasma utilizing reversed-phase high-performance liquid chromatography with electrochemical detection.

A sensitive reversed-phase HPLC method for the analysis of olanzapine in human plasma is described. Isolation of olanzapine from plasma was accomplished by solid-phase extraction utilizing an ion-exchange/reversed-phase cartridge designed for basic drug extraction. The drug was subsequently separated by reversed-phase HPLC and monitored by electrochemical detection (ED). Electrochemical analysis was used to detect olanzapine due to its uniquely low oxidative potential. Ascorbic acid was added to prevent oxidation during extraction. The limit of quantitation for the assay was established at 0.25 ng/ml utilizing a 1-ml human plasma sample. The average inter-day accuracy was 96.6% with a average precision (% C.V.) of 3.22% over the concentration range of 0.25 to 100 ng/ml. This method was applied to human plasma samples from human clinical trials with olanzapine. The HPLC-ED method compared favorably with a negative chemical ionization GC-MS method previously utilized for analysis of olanzapine in human plasma.