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Pharmacokinetics, bioavailability, and plasma protein binding study of glytrexate, a novel multitarget antifolate
Jiahong Xiang1,2, Mengqi Wu1,2, Jianchao Wang1,2
1Key Laboratory of Innovative Drug Research and Evaluation in Hebei Province, School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang, China.
Abstract:
Glytrexate, developed by our team, as a novel multitarget folate antagonist, has inhibitory effects on a variety of cancer cell types, especially KB tumor cells (IC50 0.078 nM), and thus has antitumor drug development prospects. However, its pharmacokinetics and plasma protein binding properties remain unknown. In this study a selective and sensitive liquid chromatography-tandem mass spectrometry (LC‒MS/MS) method was developed and verified to facilitate biological analysis. The bioanalysis method was applied to evaluate the stability, plasma protein binding, and pharmacokinetics of glytrexate. Glytrexate is more stable in human plasma than in rat plasma and in human liver microsomes. The binding of glytrexate to human plasma proteins was higher than that to rat plasma proteins, both of which were less than 30%, suggesting that glytrexate may be at a higher concentration at the pharmacologic target receptor(s) in tissues. Pharmacokinetic characteristics were determined by noncompartmental analysis after administration of single oral (12.5, 25 and 50 mg/kg) and intravenous (2 mg/kg) doses in rats. According to the rat oral pharmacokinetic characteristics, glytrexate had linear dynamics in a dose range of 12.5-50 mg/kg and a poor oral bioavailability of 0.57-1.15%. The investigation revealed that the intravenous half-life, AUC, and Cmax of glytrexate were higher than those of pemetrexed. Pemetrexed is generally produced as an injection preparation. This provides ideas for the development of glytrexate formulations. Therefore, glytrexate injection has clinical application prospects compared to oral administration. This study provides a basis for further investigations into the pharmacological effects and clinical uses of glytrexate.
Insights
Glytrexate, a novel anticancer agent, shows promise but has poor oral bioavailability. Its pharmacokinetic properties suggest potential for development as an intravenous injection, offering a new therapeutic option.
Area of Science:
- Pharmacology
- Drug Development
- Analytical Chemistry
Background:
- Glytrexate is a novel multitarget folate antagonist with demonstrated antitumor activity, particularly against KB tumor cells.
- Its pharmacokinetic and plasma protein binding properties were previously unknown, hindering further drug development.
- Understanding these properties is crucial for evaluating its therapeutic potential and formulation strategies.
Purpose of the Study:
- To develop and validate a selective and sensitive liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for glytrexate bioanalysis.
- To evaluate the stability, plasma protein binding, and pharmacokinetic characteristics of glytrexate in preclinical models.
- To compare the pharmacokinetic profile of glytrexate with that of pemetrexed and inform formulation development.
Main Methods:
- Development and validation of a liquid chromatography-tandem mass spectrometry (LC–MS/MS) method.
- Stability studies in human plasma and rat plasma, and human liver microsomes.
- Plasma protein binding assays.
- Pharmacokinetic studies in rats following single oral and intravenous administrations.
- Noncompartmental analysis of pharmacokinetic data.
Main Results:
- Glytrexate exhibited greater stability in human plasma than in rat plasma and human liver microsomes.
- Plasma protein binding was less than 30% for both human and rat plasma.
- Oral administration in rats showed linear pharmacokinetics within the tested dose range (12.5–50 mg/kg) but poor oral bioavailability (0.57–1.15%).
- Intravenous administration revealed a longer half-life, higher AUC, and Cmax for glytrexate compared to pemetrexed.
Conclusions:
- The developed LC–MS/MS method is suitable for glytrexate bioanalysis.
- Glytrexate demonstrates favorable stability and low plasma protein binding, suggesting potential for tissue distribution.
- Poor oral bioavailability indicates that glytrexate may be better suited for intravenous formulation, similar to pemetrexed, with promising clinical application prospects.
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