Quantification of Serum Voriconazole, Isavuconazole, and Posaconazole by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Simultaneous Quantification of Seven Antifungal Agents in Human Serum Using Liquid Chromatography-Tandem Mass Spectrometry

Systemic antifungal agents are essential for high-risk patients undergoing immunosuppressive therapy or cancer chemotherapy because of the rapid increase in opportunistic fungal infections. Therapeutic drug monitoring is crucial to ensuring the efficacy and safety of antifungal agents owing to their pharmacokinetic variability. In the present study, we developed and validated a quantitative method for the simultaneous detection of seven commonly used antifungal drugs (amphotericin B, isavuconazole, voriconazole, fluconazole, posaconazole, caspofungin, and micafungin) using liquid chromatography-tandem mass spectrometry. Methanol (containing 0.1% formic acid) was used for protein precipitation and only 50 μL of serum was required for the analysis. Chromatographic separation was conducted using a Waters Acquity UPLC C8 column, and one stable isotope-labeled agent and two analogs were used as internal standards. The calibration curves ranged from 0.1 to 50 μg/mL for all agents, and the correlation coefficient (R2) for all calibration curves was above 0.9835. The intra-day precision (1.2-11.2%), inter-day precision (2.4-13.2%), and mean bias values (-10.9 to 13.6%) were within an acceptable range of ±15%. Successful implementation of the developed method in clinical practice would facilitate the effective monitoring of these antifungal agents.

Advancing posaconazole quantification analysis with a new reverse-phase HPLC method in its bulk and marketed dosage form

Introduction: Posaconazole is a widely used antifungal drug, and its accurate quantification is essential for quality control and assessment of its pharmaceutical products. This study aimed to develop and validate a reverse-phase high-performance liquid chromatography (HPLC) analytical method for quantifying Posaconazole in bulk and dosage form. Methods: The HPLC method was developed and validated based on International Conference on Harmonisation (ICH) guidelines. The developed method was then applied to quantify Posaconazole in a marketed tablet formulation. The method's specificity, linearity, precision, accuracy, robustness, and stability were evaluated. Results: The developed HPLC method showed good linearity over a 2-20 μg/mL concentration range. The percentage recovery of Posaconazole from the bulk and marketed formulations was found to be 99.01% and 99.05%, respectively. The intra-day and inter-day precisions were less than 1%, and the method was stable under different conditions. The HPLC method was successfully applied to quantify Posaconazole in the marketed formulation. Conclusion: The developed and validated HPLC method is reliable and efficient for analyzing Posaconazole in bulk and dosage forms. The method's accuracy, precision, specificity, linearity, robustness, and stability demonstrate its effectiveness. The method can be used for the quality control and assessment of Posaconazole-containing pharmaceutical products.

Progress of triazole antifungal agent posaconazole in individualized therapy

WHAT IS KNOWN AND OBJECTIVE

Posaconazole is the second-generation triazole antifungal agent with widespread clinical application. Posaconazole exposure is influenced by various factors such as drug interactions, disease state and diet, resulting in a high interindividual variability in many patients and failure to ensure therapeutic efficacy. Therefore, it is necessary to conduct individualized therapy on posaconazole to ensure the efficacy and safety of treatment.

METHODS

Articles were identified through PubMed using the keywords such as "posaconazole," "therapeutic drug monitoring" and "Population pharmacokinetics" from 1 January 2001 to 30 April 2022.

RESULTS AND DISCUSSION

In this paper, we review the individualized treatment studies of posaconazole from the three aspects of therapeutic drug monitoring, population pharmacokinetic study and Monte Carlo simulation to provide reference for in-depth individualized posaconazole dosing studies.

WHAT IS NEW AND CONCLUSION

This review suggests that therapeutic drug monitoring should be performed in patients taking posaconazole to adjust the dosage and assess the efficacy and cost-effectiveness of posaconazole under different clinical conditions and different dosing regimens through Monte Carlo simulations. In the future, a more detailed delineation and comprehensive examination of posaconazole PPK for specific populations requires further study.

Liquid chromatography–tandem mass spectrometry for clinical diagnostics

Mass spectrometry is a powerful analytical tool used for the analysis of a wide range of substances and matrices; it is increasingly utilized for clinical applications in laboratory medicine. This Primer includes an overview of basic mass spectrometry concepts, focusing primarily on tandem mass spectrometry. We discuss experimental considerations and quality management, and provide an overview of some key applications in the clinic. Lastly, the Primer discusses significant challenges for implementation of mass spectrometry in clinical laboratories and provides an outlook of where there are emerging clinical applications for this technology.

Tandem mass spectrometry is increasingly utilized for clinical applications in laboratory medicine. In this Primer, Thomas et al. discuss experimental considerations and quality management for implementing clinical tandem mass spectrometry in the clinic with an overview of some key applications.

A versatile high-performance LC-MS/MS assay for the quantification of voriconazole and its N-oxide metabolite in small sample volumes of multiple human matrices for biomedical applications

Voriconazole (VRC) pharmacokinetics, in particular its complex metabolism, is still not fully understood which challenges its optimal therapeutic use. To increase knowledge on the pharmacokinetics of this antifungal drug, it is essential to broaden the perspective and expand in vitro and clinical in vivo investigations in particular to aspects such as unbound plasma, target-site and metabolite concentrations. Innovative sampling approaches such as microdialysis, a minimally-invasive technique for the analysis of compound concentrations in target-site human tissue fluids, are associated with bioanalytical challenges, i.e. small sample volumes and low concentrations. Thus, a bioanalytical LC-MS/MS assay for the simultaneous quantification of VRC and its main N-oxide (NO) metabolite in human plasma, ultrafiltrate and microdialysate was developed and validated according to the European Medicines Agency guideline. Quantification was rapid, simple and feasible for clinically relevant concentrations from 5 to 5000 ng/mL in plasma and ultrafiltrate as well as from 4 to 4000 ng/mL in microdialysate. Due to the high sensitivity of the assay, only 20 µL of plasma or ultrafiltrate and 5 µL of microdialysate were required. For VRC and NO in all matrices, between-run accuracy was high with a maximum mean deviation of 7.0% from the nominal value and between-run precision was demonstrated by ≤ 11.8% coefficient of variation. Both compounds proved stable under various conditions. The assay suitability was demonstrated by the application to a clinical study quantifying simultaneously VRC and NO concentrations in plasma, ultrafiltrate and microdialysate. Additionally, the assay was successfully adapted for pharmacokinetic analyses in human tissue-derived in vitro experiments. Overall, by reducing the required sample volume, the bioanalytical method allows for an increased number of plasma samples in vulnerable populations, e.g. infants, and enables the generation of concentration-time profiles with a higher temporal resolution in microdialysis studies. Consequently, the developed assay is apt to elucidate the complex pharmacokinetics of VRC in clinical settings as prerequisite for therapy optimisation.

Implementation of a Dual-Column Liquid Chromatography-Tandem Mass-Spectrometry Method for the Quantification of Isavuconazole in Clinical Practice

Objectives  Therapeutic drug monitoring (TDM) of isavuconazole, which is a novel broad-spectrum antimycoticum against invasive fungal infections, ensures an effective exposure of the drug and minimizes the risk of toxicity. This study is aimed at evaluating the analytical performance of a dual-column liquid chromatography-tandem mass-spectrometry (LC-MS/MS) method for isavuconazole quantification.

Materials and Methods  The method was performed on a Voyager TSQ Quantum triple quadrupole instrument equipped with an Ultimate 3000 chromatography system (Thermo Fisher Scientific, San Jose, California, United States). Analytical and preanalytical requirements of the isavuconazole LC-MS/MS method were evaluated. Sample stability measurements were performed at room temperature (RT) and in serum tubes with separator gel.

Results  The isavuconazole LC-MS/MS method was linear over the concentration range of 0.2 to 12.8 mg/L. The coefficient of determination ( r² ) always exceeded 0.999. Within- and between-run precision ranged between 1.4 to 2.9% and 1.5 to 3.0%, the recovery between 93.9 and 102.7%. At RT, serum samples were stable for 3 days. Isavuconazole serum concentrations were significantly lower after incubation (18 hours) in serum tubes with separator gel at RT.

Conclusion  The dual-column isavuconazole LC-MS/MS is a reliable tool for the TDM of isavuconazole. Serum samples are stable for at least 3 days and should be collected in tubes without separator gel.

Correlation between enzyme multiplied immunoassay technique and high-performance liquid chromatography in the quantification of voriconazole in a paediatric population

The enzyme multiplied immunoassay technique (EMIT) is a new method for determining the plasma concentration of voriconazole (VRZ). This study aimed to investigate the correlation between EMIT and high-performance liquid chromatography/ultraviolet rays (HPLC/UV) in determining the plasma VRZ trough concentration in children, in China. A total of 419 blood samples were collected, and plasma VRZ concentrations were detected by the EMIT and HPLC methods. The results of 304 samples were analysed after excluding samples that were undetectable or beyond the quantification limit. A test result value of 0 was defined as undetectable, while concentrations outside the detection range (0.2 - 20.0 μg/ml for HPLC and 0.5 - 16.0 µg/ml for EMIT) were defined as beyond the quantification limit. Results from both methods were compared using the Passing Bablok regression, Bland-Altman plot analysis, and paired Wilcoxon test. The plasma VRZ concentrations determined by EMIT and HPLC showed a strong linear correlation through the linear regression equation Y_EMIT = 1.310 × HPLC +0.149 (R² = 0.9082). The Bland-Altman plot analysis showed poor level consistency as measured by the two methods. The paired Wilcoxon-test showed a significant difference between the two methods (p < .0001). Compared to EMIT, HPLC accurately detected plasma VRZ concentration, making it suitable for VRZ therapeutic drug monitoring. The numerical values of the EMIT-measured levels were higher than those of HPLC, which may be related to VRZ metabolites interference and co-administrated drugs.

Posaconazole therapy in children with cystic fibrosis and Aspergillus-related lung disease

There is emerging evidence for the role of posaconazole in the management of Aspergillus-related cystic fibrosis (CF) lung disease. The tolerability and efficacy of posaconazole in paediatric CF is not well established. We report a prospective study over a fifty-three month period evaluating the safety, tolerability, and efficacy of posaconazole in pediatric CF. Fourteen children (seven males, median age 13 years, range 3-17 years) received a total of twenty-three courses of posaconazole (13 oral suspension and 10 tablet formulation). Of these patient episodes, nine received posaconazole for emerging or active allergic bronchopulmonary aspergillosis (ABPA) and two required a combination of posaconazole and systemic corticosteroids for difficult-to-treat ABPA. A subgroup of patients (n = 12) with persistent isolates of Aspergillus fumigatus, in the absence of serological markers of ABPA, received posaconazole monotherapy for pulmonary exacerbations not responding to conventional broad-spectrum antibiotic treatment. Posaconazole levels, full blood count, electrolytes, and liver function were monitored on day 7 of treatment and then monthly. Posaconazole was well tolerated in all but three patients. Therapeutic plasma levels >1 mg/l were achieved in all receiving the tablet formulation in comparison to 60% on the liquid preparation. There was a modest but significant improvement in FEV1 (% predicted) demonstrated for the cohort as a whole (p = 0.015) following posaconazole therapy. Posaconazole is well tolerated in children as young as six years old, improvements in lung function are observed, and therapeutic plasma levels are readily achieved in patients taking the tablet formulation and in adherent patients taking the liquid formulation.