Development of a UPLC-MS/MS method for determination of pimavanserin tartrate in rat plasma: Application to a pharmacokinetic study

A Fully Validated UHPLC-MS/MS Method for the Estimation of Pimavanserin in Human (K2EDTA) Plasma and its Application to a Clinical Pharmacokinetic Study

A simple, fast and extremely sensitive for estimating Pimavanserin in human (K2EDTA) plasma using ultra high-performance liquid chromatography combined with tandem mass spectrometry (UHPLC-MS/MS) was newly developed and validated. Sample extraction was accomplished using a partition liquid extraction (LLE-liquid-liquid extraction) procedure utilizing extraction solvent, methyl tertiary butyl ether. Separation of the components, chromatography, was done using a C18 chromatographic analytical column employing acetonitrile:methanol: 0.1% formic acid solution (40:40:20 volume by volume) pumped with 0.800 mL/min as the flow rate. For Pimavanserin, the established methodology was linear throughout the calibration curve range from 0.25ng/mL till 50.0 ng/mL. Results of intraday and interday accuracy and precision of Pimavanserin met recent regulatory requirements. This methodology was effectively used to estimate Pimavanserin in vivo human (K2EDTA) plasma concentration for a clinical pharmacokinetic study.

Development of an analytical method for the determination of pimavanserin and its impurities applying analytical quality by design principles as a risk-based strategy

Pimavanserin is an atypical antipsychotic indicated for the treatment of hallucinations and delusions associated with Parkinson's disease psychosis. As it is a relatively new drug on the market, limited number of pharmacokinetic information and analytical methods are available. This paper presents an ultra-high performance chromatography for the simultaneous determination of pimavanserin and its four process impurities. The method was developed applying analytical quality by design (AQbD) principles as a risk-based approach. Critical method attributes (CMAs) were selected as a resolution between the worst separated compounds (impurity B and impurity C), a duration of analysis defined by the retention time of the last eluting peak (impurity D), a capacity factor of the first eluted impurity (impurity A), a tailing factor and a theoretical plate number. Risk assessment in the early stage of method development pointed out critical method parameters (CMPs): column temperature, gradient time and pH-value of the mobile phase (water phase, eluent A). Design of experiments (DoE), using DryLab®4 software, was applied to evaluate the influence of CMPs on CMAs and to determine method operable design region (MODR). Based on the risk assessment and the results of robustness and precision tests, a control strategy with system suitability criteria was proposed. Developed method was validated according to ICH Q2 (R1) guideline with respect to the selectivity, LOD, LOQ, linearity, precision, accuracy, robustness and stability. A forced degradation study was performed to provide an evidence of the stability-indicating property of the method. Degradation products of pimavanserin were identified using ultra high-performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-qTOF). Additionally, potential degradation products were assessed in silico with the help of Zeneth® software and good agreement with experimentally identified degradation products was achieved. Main degradation products were formed during acid and base hydrolysis (m/z 223.16 [M+H]⁺ at RRT 0.37) and under oxidative stress conditions (m/z 444.26 [M+H]⁺ at RRT 0.57). The results revealed that the pimavanserin undergoes degradation through acid and base hydrolysis of urea and N-oxidation of aliphatic tertiary amine.

Simultaneous Quantification of Brigatinib and Brigatinib-Analog in Rat Plasma and Brain Homogenate by LC-MS/MS: Application to Comparative Pharmacokinetic and Brain Distribution Studies

Brigatinib and brigatinib-analog are potent and selective ALK inhibitors with the similar structure. A simple and sensitive high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of brigatinib and brigatinib-analog in rat plasma and brain homogenate was developed and validated. Chromatographic separation was carried out on an ODS column with acetonitrile and 0.1% formic acid in water as the mobile phase with gradient elution at a flow rate of 0.5 mL/min. Detections were performed using a TSQ Quantum Ultra mass spectrometric detector with electrospray ionization (ESI) interface, which was operated in the positive ion mode. A simple protein precipitation preparation process was used. The lower limits of quantification (LLOQs) were 1.0 ng/mL and 0.5 ng/mL for analytes in rat plasma and brain homogenate, respectively. The intrabatch and interbatch precision and accuracy of brigatinib and brigatinib-analog were well within the acceptable limits of variation. The simple and sensitive LC-MS/MS method was successfully applied to the pharmacokinetic and brain distribution studies following a single oral administration of brigatinib and brigatinib-analog to rats. The above studies would lay a good foundation for the further applications of brigatinib and brigatinib-analog.

Quantification of Pimavanserin in Bulk and Tablet Dosage Form Using A Stability Indicating High Performance Liquid Chromatographic Method

Background: Pimavanserin, an antipsychotic agent, is used to treat patients suffering with Parkinson's disease. Till now no stability indicating reverse phase HPLC method was reported for the quantification of pimavanserin in bulk and tablet dosage form. Hence in the present study, a new sensitive, precise and accurate stability indicating reverse phase HPLC method with photodiode array detector has been developed for the quantification of pimavanserin in bulk and tablet dosage form. Methods: Separation and analysis of pimavanserin was achieved on Kromasil C18 (5 µm, 250 mm × 4.6 mm) column using 0.1M NaH2PO4, methanol and acetonitrile in ratio of 55:30:15 (v/v/v) as mobile phase at 25°C. The flow rate was 1.0 ml/min. The effluents were monitored with detector set at 239 nm. The method validation was done with regard to the guidelines by the International Conference on Harmonization. Pimavanserin was subjected to acid, alkali and neutral hydrolysis, hydrogen peroxide oxidation, thermal degradation, and photo (sunlight) degradation. Results: Linear relationship was obtained between the concentration of drug and peak area response in the range of 4.25-34.0 µg/ml. The limits of detection and quantitation were found to be 0.027 µg/ml and 0.089 µg/ml, respectively. All the validation characteristics were within the acceptance criteria. The peaks of degradation products were well resolved from the pimavanserin peak. Conclusion: The developed and validated method is able to quantify the pimavanserin in the presence of degradation products.