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

Nitrogen and sulfur-doped carbon quantum dots as fluorescent nanoprobes for spectrofluorimetric determination of olanzapine and diazepam in biological fluids and dosage forms: application to content uniformity testing

A validated, sensitive, and simple spectrofluorimetric method was developed for the analysis of two important CNS-acting drugs, olanzapine and diazepam, in their commercial tablets without the need for any pretreatment steps. The developed method relied on the quantitative quenching effect of each of olanzapine and diazepam on the native fluorescence of nitrogen and sulfur-doped carbon quantum dots (NS@CQDs). NS@CQDs were prepared from thiosemicarbazide and citric acid by a facile one-pot hydrothermal technique. The synthesized NS@CQDs were characterized by different spectroscopic and microscopic techniques. NS@CQDs produced a maximum emission peak at 430 nm using 360 nm as an excitation wavelength. Calibration curves showed a good linear regression over the range of 5.0–200.0 and 1.0–100.0 μM with detection limits of 0.68 and 0.29 μM for olanzapine and diazepam, respectively. The adopted method was used for the determination of the investigated drugs in their tablets with high % recoveries (98.84–101.70%) and low % RSD values (< 2%). As diazepam is one of the most commonly abused benzodiazepines, the developed method was successfully applied for its determination in spiked human plasma with high % recoveries and low % RSD values, providing further insights for monitoring its potential abuse. The quenching mechanism was also studied and confirmed to be through dynamic and static quenching for olanzapine and diazepam, respectively. Due to the high selectivity and sensitivity, content uniformity testing of low-dose tablets was successfully performed by applying the United States Pharmacopoeia guidelines. The method's validation was performed in compliance with ICHQ2 (R1) recommendations.

Accurate Quantification of Nervous System Drugs in Aqueous Samples at Trace Levels by Binary Solvent Dispersive Liquid-Liquid Microextraction-Gas Chromatography Mass Spectrometry

Pharmaceutical products are widely consumed globally and are commonly found in wastewaters as a result of constant excretion and disposal into sewers. The present study proposes an efficient binary solvent dispersive liquid-liquid microextraction (BS-DLLME) method that was developed for preconcentration of 7 nervous system drug active compounds from aqueous media for their determination at trace levels by gas chromatography-mass spectrometry. The drug analytes included 3 antidepressants, 2 antipsychotics, 1 antiepileptic, and 1 antidementia. Optimum conditions of the BS-DLLME method were acquired by univariate optimization of parameters including type of binary solvents, ratio of binary solvents, type of disperser solvent, volume of binary solvents, and volume of disperser solvent. Detection and quantification limits were calculated in the range of 0.28 to 6.5 µg/L. Municipal wastewater, medical wastewater, synthetic domestic wastewater, and lake water were utilized as real samples in spike recovery experiments; and the results (94-106%) indicated the method's applicability and accuracy at quantifying the analytes in complex matrices. Environ Toxicol Chem 2021;40:1570-1575. © 2021 SETAC.

Exploring the phototransformation and assessing the in vitro and in silico toxicity of a mixture of pharmaceuticals susceptible to photolysis

The present study comprehensively investigates the phototransformation and ecotoxicity of a mixture of twelve pharmaceutically active compounds (PhACs) susceptible to photolysis. Namely, three antibiotics (ciprofloxacin, levofloxacin, moxifloxacin), three antidepressants (bupropion, duloxetine, olanzapine), three anti-inflammatory drugs (diclofenac, ketoprofen, nimesulide), two beta-blockers (propranolol, timolol) and the antihistamine ranitidine were treated under simulated solar irradiation in ultra-pure and river water. A total of 166 different transformation products (TPs) were identified by ultra-high performance liquid chromatography coupled with Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap HRMS), revealing the formation of twelve novel TPs and forty-nine not previously described in photolytic studies. The kinetic profiles of the major TPs resulting from a series of chemical reactions involving hydroxylation, cleavage and oxidation, dehalogenation, decarboxylation, dealkylation and photo substitution have been investigated and the transformation pathways have been suggested. Additionally, an in vitro approach to the toxicity assessment of daphnids was contrasted with ecotoxicity data based on the Ecological Structure Activity Relationships (ECOSAR) software comprising the in silico tool to determine the adverse effects of the whole mixture of photolabile parent compounds and TPs. The results demonstrated that photolysis of the target mixture leads to a decrease of the observed toxicity.

A Comprehensive Review on Importance and Quantitation of Atypical Antipsychotic Drugs and their Active Metabolites in Commercial Dosage Forms

Background:

Schizophrenia is a severe mental illness that affects more than twenty-one million people throughout the world. Schizophrenia also causes early death. Schizophrenia and other related psychotic ailments are controlled by the prescription of antipsychotic drugs, which act by blocking certain chemical receptors in the brain and thus relieves the symptoms of psychotic disorder. These drugs are present in the different dosage forms in the market and provided in a certain amount as per the need of the patients.

Objective:

Since such medications treat mental disorders, it is very important to have a perfect and accurate dose so that the risk factor is not affected by a higher or lower dose, which is not sufficient for the treatment. For accurate assay of these kinds of drugs, different analytical methods were developed ranging from older spectrophotometric techniques to latest hyphenated methods.

Results:

The current review highlights the role of different analytical techniques that were employed in the determination and identification of antipsychotic drugs and their metabolites. Techniques such as spectrophotometry, fluorimetry, liquid chromatography, liquid chromatography-mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry employed in the method development of such antipsychotic drugs were reported in the review. Different metabolites, identified using the hyphenated techniques, were also mentioned in the review. The synthesis pathways of few of the metabolites were mentioned.

Conclusion:

The review summarizes the analyses of different antipsychotic drugs and their metabolites. A brief introduction of illnesses and their symptoms and possible medications were highlighted. Synthesis pathways of the associated metabolites were also mentioned.

Dual Fluorescence-colorimetric Silver Nanoparticles Based Sensor for Determination of Olanzapine: Analysis in Rat Plasma and Pharmaceuticals

The present work describes a dual-readout assay for the determination of an antipsychotic drug olanzapine using Rhodamine B modified silver nanoparticles (AgNPs). AgNPs, when mixed with Rhodamine B, quenched its fluorescence emission with high quenching efficiency as evident from the Stern Volmer plot. Transmission electron microscopy image and Dynamic Light Scattering histogram of Rhodamine B bound AgNPs showed a stable monodispersed nanosuspension. Addition of olanzapine to Rhodamine B-bound AgNPs resulted in reappearance of fluorescence, which was dependent on the amount of olanzapine added to the system. Besides displacing the surface bound Rhodamine B molecules, it caused aggregation of AgNPs which formed the basis of dual-readout sensor. Several parameters such as pH, reaction time and order of addition of the three components which may influence the analytical signal were studied and optimized. The method was validated for linearity, sensitivity, selectivity, accuracy, precision and recovery. Based on this dual-readout system, linear concentration range was established from 0.05 to 10 µM (fluorescence measurement) and 5.0 to 50 µM (colorimetric response) for olanzapine. The limit of detection (LOD) using fluorescence and colorimetric approach was 0.013 µM and 1.25 µM, respectively. The proposed method showed excellent selectivity for olanzapine in presence of several antipsychotic drugs, cations, sugars and amino acids. Finally, the method was successfully applied to a pharmacokinetic study of olanzapine in rats and also for analyzing pharmaceutical formulations.

Paradigm Shift in the Arena of Sample Preparation and Bioanalytical Approaches Involving Liquid Chromatography Mass Spectroscopic Technique

Sample preparation is a highly important and integral part of bioanalysis for cleaning up the complex biological matrices and thereby minimizing matrix effect. Matrix effect can jeopardize the precise quantification and adversely affect the reliability of liquid chromatography-mass spectrometry-based analytical results by alteration of analyte ionization. Matrix components result in suppression or enhancement of the intensity of analyte response. In spite of the high specificity and selectivity of tandem mass spectrometry, a relatively higher concentration of coeluted matrix elements present in biofluids may alter the efficiency of quantification of a bioanalytical method. Numerous literature reports different types of sample preparation techniques employed in bioanalysis. In this review, the strategies for selection of the appropriate sample clean-up technique in bioanalysis are discussed extensively. A paradigm shift in the arena of sample preparation and bioanalytical approaches involving the liquid chromatography-mass spectroscopic technique has been scrutinized. Current trends and possible future advancements in the field of biological sample extraction methods, including instrumental techniques are analyzed in detail.

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 0.1-20 ng/ml with LLOQ of 0.1 ng/ml. Accuracy and precision were within 10%. The validated method was successfully applied to a bioequivalence study of OLZ disintegrating tablets at dose of 5 mg with 100% reproducibility evaluated by incurred sample reanalysis. Conclusion: A robust validated method was developed for quantitation of OLZ in human plasma.

Schizophrenia: recent advances in LC-MS/MS methods to determine antipsychotic drugs in biological samples

Schizophrenia is one of the most debilitating and costly illnesses worldwide. First-generation antipsychotics such as chlorpromazine and haloperidol succeeded in controlling the positive symptoms of schizophrenia, but had significant extrapyramidal effects that led to the search for new agents and the release of second-generation (or atypical) antipsychotics. These drugs had a lower risk of adverse motor symptoms. Therapeutic drug monitoring has become a useful tool to optimize schizophrenia treatment and HPLC-MS/MS has been considered the primary technique to monitor antipsychotics. This review comprises three sections: schizophrenia pathophysiology and treatment; recent advances in LC-MS/MS methods designed to measure levels of antipsychotics and their metabolites in plasma samples (selectivity, matrix effect and sensitivity); and the importance of therapeutic drug monitoring.

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.

A simple and automated online SPE-LC-MS/MS method for simultaneous determination of olanzapine, fluoxetine and norfluoxetine in human plasma and its application in therapeutic drug monitoring

An integration of sample pretreatment automation using online SPE technique could provide an easy to use, efficient, sensitive and high quality methods for TDM.

LC-MS/MS of some atypical antipsychotics in human plasma, serum, oral fluid and haemolysed whole blood

Therapeutic drug monitoring (TDM) of atypical antipsychotics is common, but published methods often specify relatively complex sample preparation and analysis procedures. The aim of this work was to develop and validate a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of amisulpride, aripiprazole and dehydroaripiprazole, clozapine and norclozapine, olanzapine, quetiapine, risperidone and 9-hydroxyrisperidone, and sulpiride in small (200 μL) volumes of plasma or serum for TDM purposes. The applicability of the method as developed to haemolysed whole blood and to oral fluid was also investigated. Analytes and internal standards were extracted into butyl acetate:butanol (9+1, v/v) and a portion of the extract analysed by LC-MS/MS (100 mm × 2.1 mm i.d. Waters Spherisorb S5SCX; eluent: 50 mmol/L methanolic ammonium acetate, pH* 6.0; flow-rate 0.5 mL/min; positive ion APCI-SRM, two transitions per analyte). Assay calibration (human plasma, oral fluid, and haemolysed whole blood calibration solutions) was performed by plotting the ratio of the peak area of the analyte to that of the appropriate internal standard. Assay validation was as per FDA guidelines. Assay calibration was linear across the concentration ranges studied. Inter- and intra-assay precision and accuracy were within 10% for all analytes in human plasma. Similar results were obtained for oral fluid and haemolysed whole blood, except that aripiprazole and dehydroaripiprazole were within 15% accuracy at low concentration (15 μg/L) in oral fluid, and olanzapine inter-assay precision could not be assessed in these matrices due to day-by-day degradation of this analyte. Recoveries varied between 16% (sulpiride) and 107% (clozapine), and were reproducible as well as comparable between human plasma, human serum, calf serum and haemolysed whole blood. For oral fluid, recoveries were reproducible, but differed slightly from those in plasma suggesting the need for calibration solutions to be prepared in this medium if oral fluid is to be analysed. LLOQs were 1-5 μg/L depending on the analyte. Neither ion suppression/enhancement, nor interference from some known metabolites of the antipsychotics studied has been encountered. The method has also been applied to the analysis of blood samples collected post-mortem after dilution (1+1, 1+3; v/v) in analyte-free calf serum.