Simultaneous quantification of volitinib and gefitinib in rat plasma by HPLC-MS/MS for application to a pharmacokinetic study in rats

Effect of Single-Dose and Short-Term Administration of Si Jun Zi Tang on the Pharmacokinetics of Gefitinib in Rats

Background

Si Jun Zi Tang (SJZ), a four-herb Chinese medicine formula that has been described for approximately one thousand years, is often prescribed for cancer patients as a complementary therapy in China. However, the mechanism by which Si Jun Zi Tang enhances the efficacy of gefitinib is unclear.

Methods

We investigated how Si Jun Zi Tang affected the pharmacokinetics of gefitinib in rats. A rapid, specific, and reliable ultra-performance liquid chromatography method with mass spectrometry was established to determine the plasma concentration of gefitinib.

Results

The results showed that a single intragastrically administered dose of Si Jun Zi Tang increased the pharmacokinetic parameters of gefitinib (C _max, 3156.13 μg/L; A UC, 46281.5 μg/L/h) by 3 folds in rats compared with the administration of gefitinib alone (C _max, 1352.07 μg/L; AUC, 11823.7 μg/L/h). Si Jun Zi Tang could also alter the pharmacokinetics of gefitinib by prolonging the time to reach C _max.

Conclusions

Potential pharmacokinetic interactions between gefitinib and SJZ were evaluated, and SJZ extended T _max and T1/2 and increased the C _max and AUC of gefitinib. Long-term administration of gefitinib in combination with Si Jun Zi Tang would improve the efficacy of gefitinib.

Preconcentration and Detection of Gefitinib Anti-Cancer Drug Traces from Water and Human Plasma Samples by Means of Magnetic Nanoparticles

Along of widespread application of anti-cancer drug Gefitinib (GEF), it appears in human body fluids as well as clinical wastewater. Consequently, a reliable and easy-to-adapt detection technique is of essential importance to quantify the drug in different media. The extraction and quantitative detection of anti-cancer drug Gefinitib (GEF) is demonstrated based on a straightforward and efficient magnetic nanoparticle-assisted preconcentration route from water and human plasma samples. Iron oxide magnetic nanoparticles (Fe₃O₄) have been prepared with an average particle size of 15 nm and utilized as extractible adsorbents for the magnetic solid-phase extraction (MSPE) of GEF in aqueous media. The method is based on MSPE and preconcentration of GEF followed by High-Performance Liquid Chromatography-Ultraviolet Detection (HPLC-UV). The yield of GEF extraction under the optimum MSPE conditions were 94% and 87% for water and plasma samples, respectively. The chromatographic separation was carried out isocratically at 25 °C on a Phenomenex C8 reversed phase column (150 mm × 4.6 mm, with 5 µm particle size). The proposed method was linear over concentration ranges of 15.0–300.0 and 80.0–600.0 ng/mL for water and plasma samples with limits of detection of 4.6 and 25.0 ng/mL in a respective order. Relative standard deviations (%RSD) for intra-day and inter-day were 0.75 and 0.94 for water samples and 1.26 and 1.70 for plasma samples, respectively. Using the magnetic nanoparticles (MNPs) as loaded drug-extractors made the detection of the anti-cancer drug environmentally friendly and simple and has great potential to be used for different drug-containing systems.

Comparative study of intratracheal and oral gefitinib for the treatment of primary lung cancer

Oral gefitinib tablets are widely applied for the treatment of non-small cell lung cancer (NSCLC) though its broad distribution in the body may result in weak therapeutic efficiency and undesired side effects. Here, liposomal gefitinib dry powder inhalers (LGDs) were prepared using the injection-lyophilization method. LGDs were rough porous particles under a scanning electron microscope, which can be rapidly rehydrated to liposomes. LGDs and gefitinib powders were separately intratracheally (i.t.) administered into the lungs of primary lung cancer rats, while powdered gefitinib tablets were orally administered. Gefitinib was rapidly absorbed from the lung after i.t. administration of LGDs. The maximal gefitinib concentration in the circulation and the area under curve (AUC) of i.t. LGDs were higher than those of i.t. gefitinib powders and oral gefitinib. More importantly, much higher concentration and longer retention of gefitinib in the lung were shown after i.t. administration of LGDs and gefitinib powders but remarkably less drug distribution in the liver compared to oral gefitinib. LGDs showed higher therapeutic effect on rat primary lung cancer than i.t. gefitinib powders and oral gefitinib with reduction of inflammation, weak lung injury, and high apoptosis. Combination of inhalation and liposomes of anticancer drugs is a promising strategy for treatment of primary lung cancer.

A validated high-performance liquid chromatography-tandem mass spectrometry method for quantification of gefitinib and its main metabolites in xenograft mouse tumor: Application to a pharmacokinetics study

Monitoring gefitinib and its metabolites may help to explore the underlying mechanisms of gefitinib resistance. The concentration of gefitinib and its metabolites in tumor tissues could influence its anticancer activities more than that in the plasma. In the present study, a rapid and specific HPLC-MS/MS method was developed and validated to simultaneously determine gefitinib, M387783, M523595, M537194 and M608236 in tumor tissues of H1975 human lung cancer xenografts of nude mice. The established HPLC-MS/MS method was validated for specificity, linearity, accuracy and precision, matrix effect and recovery, carryover and dilution integrity, and analyte stability. The standard curves were linear (r²  ≥ 0.99) over the range of 0.5-100 ng/mL for M608236 and 1-200 ng/mL for gefitinib, M523595 and M537194 as well as M387783. The accuracy ranged from -8.35 to 6.03% relative error; and the precision was <15% relative standard deviation. Recoveries (87.74-99.96%) and matrix effects (86.60-106.40%) were satisfactory in the biological matrix examined. Stability studies showed that the analytes were stable during the assay procedure and storage. Finally, the validated method was successfully applied to study the pharmacokinetics profiles for gefitinib and its metabolites in nonsmall cell lung cancer (NSCLC) xenograft mouse tumors. Meanwhile, MTT assay showed that gefitinib had a more powerful inhibitory effect than its four major metabolites in H1975 NSCLC cells. This validated HPLC-MS/MS method may be applied to help understand the mechanisms of gefitinib resistance in EGFR-mutant nonsmall cell lung cancer.

Development and validation of a sensitive LC-MS/MS method for determination of gefitinib and its major metabolites in human plasma and its application in non-small cell lung cancer patients

Gefitinib, the first approved oral epidermal growth factor receptor (EGFR) inhibitor, has been demonstrated effective in cancers with EGFR active mutations. In this study, we established and validated a method for determining gefitinib and its main metabolites, M605211, M387783, M537194 and M523595 in patients with non-small cell lung cancer (NSCLC) by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The mobile phase was water: acetonitrile (35:65, v/v) with 0.1% formic acid at a flow-rate of 0.35 mL/min, within a 3 min run time. Gefitinib and its main metabolites were separated on a X-Terra RP18 column (50 × 2.1 mm, 3.5 μm) at 40 ℃ and subjected to mass analysis using positive electro-spray ionization (ESI). The calibration ranges of gefitinib and M523595 were 0.5-1000 ng/mL, and other compounds were 0.05-100 ng/mL with the correlation coefficients (r²) ≥ 0.99. Accuracies ranged from 92.60%-107.58 and the inter- and intra-assay precision were less than 15% for all analytes in quality control samples. There was no significant matrix effect. The ranges of extraction recoveries were 86-105% for all analytes and IS. Thirty plasmas were obtained from Sun Yat-sen university cancer center. The mean plasma concentration of (± SD) of gefitinib M537194, M523595, M387783 and M605211 were 247.18 (± 140.39) ng/mL, 7.78 (± 6.74) ng/mL, 101.09 (± 93.44) ng/mL, 1.6 (± 0.9) ng/mL and 11.63 (± 4.98) ng/mL, respectively. The validated LC/MS/MS method was effectively used in the determination of gefitinib and its four metabolites in NSCLC patients.