Development, validation, and routine application of a high-performance liquid chromatography method coupled with a single mass detector for quantification of itraconazole, voriconazole, and posaconazole in human plasma

Validation of a method for itraconazole and major metabolite hydroxyitraconazole for LC-MS/MS analysis with application in a formulation clinical study

A high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of itraconazole (ITZ) and hydroxyitraconazole (ITZ-OH) as part of a human pharmacokinetic study of novel tablet formulations. We demonstrated that 100 µL of plasma sample can be used with a protein precipitation extraction by optimizing different composition of acid in organic solvent for the precipitation solvent, giving comparable recovery to more time-consuming liquid-liquid or solid phase extractions. Additionally, we have shown that by monitoring the halogen isotopic peak for ITZ as well as optimizing chromatographic conditions, we are able to avoid carryover and endogenous interferences, allowing for a lower limit of quantification for our study. We validated the method to quantify ITZ and ITZ-OH from 1 to 250 ng/mL in human plasma and applied this to a formulation research clinical study (NCT04035187). This is the first itraconazole study to demonstrate robustness of the assay by performing interference testing of over-the-counter and common co-administered medications. We are also the first publication to perform incurred sample reanalysis (ISR) at the conclusion of a 672 sample clinical study to show reproducibility of assay performance.

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.

Assessment of greenness for the determination of voriconazole in reported analytical methods

Analytical research with adverse environmental impact has caused a severe rise in concern about the ecological consequences of its strategies, most notably the use and emission of harmful solvents/reagents into the atmosphere. Nowadays, industries are searching for the best reproducible methods. Voriconazole is a second-generation azole derivative used effectively in the treatment of Candida and Aspergillus species infections and oropharyngeal candidiasis in AIDS patients. Recently it has become the drug of choice in treating mucormycosis in several countries, which raises the need for production in large quantities. The present review deals with various recent important analytical techniques used to estimate voriconazole and its combination in pharmaceutical formulations and biological fluids. The methods show their own unique way of analyzing voriconazole in different matrices with excellent linearity, detection, and quantification limits. Additionally, this article deals with methods and solvents analyzed for their impact on the environment. This is followed by estimating the degree of greenness of the methods using various available assessment tools like analytical eco-scale, national environmental method index, green analytical procedure index, and AGREE metrics to confirm the environmental impact. The scores obtained with the evaluation tools depict the quantum of greenness for the reported methods and provide an ideal approach adopted for VOR estimation. Very few methods are eco-friendly, which shows that there is a need for the budding analyst to develop methods based on green analytical principles to protect the environment.

Salting-out homogeneous liquid-liquid microextraction for the determination of azole drugs in human urine: Validation using total error concept

A salting-out homogeneous liquid-liquid microextraction was proposed for the quantification of four azole drugs in human urine prior to high-performance liquid chromatography analysis. The procedure involved the mixing of the sample with acetonitrile in appropriate volumes followed by the addition of sodium sulfate solution in order to facilitate phase separation. The parameters influencing the extraction performance were studied and optimized using a two-step experimental design. The analytical procedure was thoroughly validated using the accuracy profiles as a graphical decision-making tool. The β-expectation tolerance intervals did not exceed the acceptance criteria of ±15% meaning that 95% of future results will be included in the defined bias limits. The limits of detection of the procedure were satisfactory, ranging between 0.01 and 0.03 μg/mL. The mean analytical bias in the spiking levels was satisfactory and ranged between -10.3 and 4.2% while the relative standard deviation was lower than 5.6%. Monte-Carlo simulations followed by capability analysis were employed to investigate the ruggedness of the sample preparation protocol. The developed method offers advantages compared to previously reported approaches for the same type of analysis including extraction efficiency and scaling down of the sample volume and extraction time.

Factorial design-assisted reversed phase-high performance liquid chromatography method for simultaneous determination of fluconazole, itraconazole and terbinafine

A 23 full factorial design model was used for the development of a new high performance liquid chromatography method with UV detection to estimate three antifungal drugs simultaneously. Fluconazole (FLU), itraconazole (ITR) and terbinafine (TRH) are co-administered for severe fungal infections. They have been determined using MOS-1 Hypersil C18 column and an isocratic eluent; methanol 95% and phosphate buffer 5% with 0.001% triethylamine. The pH was adjusted to 7, and the flow rate was 0.7 ml min-1. The three drugs were separated within less than 7 min at 210 nm. The developed method gave a linear response over 5-80 µg ml-1, 5-50 µg ml-1 and 1-50 µg ml-1 for FLU, ITR and TRH, respectively. It showed detection limits of 0.88, 0.29 and 0.20 µg ml-1 and quantification limits of 2.66, 0.88 and 0.60 µg ml-1 for the three drugs, respectively. The design of the experiment facilitated the optimization of different variables affecting the separation of the three drugs. The sensitivity of the designed method permitted the simultaneous estimation of ITR and TRH in spiked human plasma successfully.

Preparation of magnetic metal organic framework and development of solid phase extraction method for simultaneous determination of fluconazole and voriconazole in rat plasma samples by HPLC

Fluconazole and voriconazole are the two broad-spectrum triazole antifungals. The present work described the fabrication method for the synthesis of the amino-modified magnetic metal-organic framework. This material was applied as a pre-sample treatment sorbent for the selective extraction of fluconazole and voriconazole in rat plasma samples. The material was fabricated by the chemical bonding approach method and was characterized by different parameters. The factors which affect the extraction efficiency of the sorbent material were also optimized in this study. Due to the optimization of solid-phase extraction conditions, the nonspecific interaction was reduced and the extraction recoveries of target drugs were increased in plasma samples. The extraction method was combined with the HPLC-UV method for the analysis. Excellent linearity (0.1-25 µg/mL), detections (0.02, 0.03 µg/mL) and quantification limits (0.04, 0.05 µg/mL) were resulted for fluconazole and voriconazole respectively. The maximum recoveries from spiked plasma samples of fluconazole and voriconazole were 86.8% and 78.6% and relative standard deviation were 0.9-2.8% and 2.2-3.6% respectively. Moreover, this sorbent material was used multiple times which was an improvement over single-use commercial sorbent materials. This validated method has practical potential for the simultaneous determination of these drugs in therapeutic drug monitoring studies as well as for routine pharmacokinetic evaluations.

Emerging role of clinical mass spectrometry in pathology

Mass spectrometry-based assays have been increasingly implemented in various disciplines in clinical diagnostic laboratories for their combined advantages in multiplexing capacity and high analytical specificity and sensitivity. It is now routinely used in areas including reference methods development, therapeutic drug monitoring, toxicology, endocrinology, paediatrics, immunology and microbiology to identify and quantify biomolecules in a variety of biological specimens. As new ionisation methods, instrumentation and techniques are continuously being improved and developed, novel mass spectrometry-based clinical applications will emerge for areas such as proteomics, metabolomics, haematology and anatomical pathology. This review will summarise the general principles of mass spectrometry and specifically highlight current and future clinical applications in anatomical pathology.

Validation of a Reversed-Phase Ultra-High-Performance Liquid Chromatographic Method With Photodiode Array Detection for the Determination of Voriconazole in Human Serum and Its Application to Therapeutic Drug Monitoring

BACKGROUND

Voriconazole is a broad-spectrum triazole antifungal agent. It is widely used in the treatment of invasive fungal infections in immunocompromised patients. Because the pharmacokinetics of voriconazole demonstrates considerable variability, monitoring its serum levels plays an important role in optimizing therapies against many clinically relevant fungal pathogens. The aim of this study was to validate a simple and rapid U-HPLC-PDA method with minimal sample preparation for routine therapeutic drug monitoring (TDM) of voriconazole.

METHODS

After protein precipitation with the internal standard solution (posaconazole 5.0 mg/L in acetonitrile), chromatographic separation was performed in 4 minutes using water and acetonitrile as mobile phases and an Acquity UPLC BEH HSS C18 column (2.1 × 100 mm, 1.7 µm). The temperature was set at 45°C and the flow rate was 0.4 mL/min. Photodiode array detection at 256 nm was used as detection system. The method was validated according international guidelines for linearity, accuracy, precision, selectivity, lower limit of quantitation, carry over, and stability under different conditions.

RESULTS

All performance parameters were within acceptance criteria, demonstrating that the validated method is fit for purpose. After assay validation, 115 serum samples collected from 41 patients were analyzed to report the experience of the laboratory in TDM of voriconazole. Results showed a large variability in voriconazole trough levels, suggesting that this drug should be frequently measured in patients under treatment to enhance therapies efficacy and improve safety.

CONCLUSIONS

In this study, a reproducible U-HPLC-PDA assay with a short analysis time, requiring only a small amount of serum, good accuracy and reproducibility was validated, which is suitable for routine TDM of voriconazole in serum.

Pharmacogenetic of voriconazole antifungal agent in pediatric patients

AIM

We explored the role of SNPs within the SLCO1B3, SLCO1B1, SLC22A6, ABCB1, ABCG2, SLCO3A1, CYP2C19, ABCC2, SLC22A1, ABCB11 and NR1I2 genes on voriconazole pharmacokinetics.

PATIENTS & METHODS

233 pediatric patients were enrolled. Drug plasma C_trough was measured by a HPLC-MS method. Allelic discrimination was performed by qualitative real-time PCR.

RESULTS

SLCO1B3 rs4149117 c.334 GT/TT (p = 0.046), ABCG2 rs13120400 c.1194 + 928 CC (p = 0.029) and ABCC2 rs717620 c.-24 GA/AA (p = 0.025) genotype groups significantly influenced C_trough. ethnicity (p = 0.042), sex (p = 0.033), SLCO1B3 rs4149117 c.334 GT/TT (p = 0.041) and ABCB1 rs1045642 c.3435 TT (p = 0.016) have been retained in linear regression model as voriconazole predictor factors.

CONCLUSION

Understanding how some gene polymorphisms affect the voriconazole pharmacokinetic is essential to optimally dose this agent.

Evaluation of Posaconazole Pharmacokinetics in Adult Patients with Invasive Fungal Infection

Mortality and morbidity due to invasive fungal infections have increased over the years. Posaconazole is a second-generation triazole agent with an extended spectrum of activity, which shows a high interindividual variability in its plasma levels, rendering dosing in many patients inconsistent or inadequate. Hence, posaconazole therapeutic drug monitoring, which is easily available in clinical practice, may improve treatment success and safety. The aim of the study was to describe posaconazole pharmacokinetics, and to evaluate the utility of therapeutic drug monitoring for therapy and prophylaxis in a cohort of adult patients. A fully validated chromatographic method was used to quantify posaconazole concentration in plasma collected from adult patients at the end of the dosing interval. Associations between variables were tested using the Pearson test. The Mann-Whitney test was used to probe the influence of categorical variables on continuous ones. A high inter-individual variability was shown. Of the 172 enrolled patients, among those receiving the drug by the oral route (N = 170), gender significantly influenced drug exposure: males showed greater posaconazole concentration than females (p = 0.028). This study highlights the importance of therapeutic drug monitoring in those with invasive fungal infections and its significant clinical implications; moreover we propose, for the first time, the possible influence of gender on posaconazole exposure.

Analysis of imidazoles and triazoles in biological samples after MicroExtraction by packed sorbent

This paper reports the MEPS-HPLC-DAD method for the simultaneous determination of 12 azole drugs (bifonazole, butoconazole, clotrimazole, econazole, itraconazole, ketoconazole, miconazole, posaconazole, ravuconazole, terconazole, tioconazole and voriconazole) administered to treat different systemic and topical fungal infections, in biological samples. Azole drugs separation was performed in 36 min. The analytical method was validated in the ranges as follows: 0.02–5 μg mL⁻¹ for ravuconazole; 0.2–5 μg mL⁻¹ for terconazole; 0.05–5 μg mL⁻¹ for the other compounds. Human plasma and urine were used as biological samples during the analysis, while benzyl-4-hydroxybenzoate was used as an internal standard. The precision (RSD%) and trueness (Bias%) values fulfill with International Guidelines requirements. To the best of our knowledge, this is the first HPLC-DAD procedure coupled to MEPS, which provides the simultaneous analysis of 12 azole drugs, available in the market, in human plasma and urine. Moreover, the method was successfully applied for the quantitative determination of two model drugs (itraconazole and miconazole) after oral administration in real samples.

Therapeutic drug monitoring of voriconazole for treatment and prophylaxis of invasive fungal infection in children

Voriconazole therapeutic drug monitoring is not consistently recommended due to its high interpatient and intrapatient variability. Here, we aimed to describe our experience with voriconazole for treatment and prophylaxis of invasive fungal infections in paediatric patients. A fully validated high-performance liquid chromatography-mass spectrometry method was used to quantify voriconazole concentration in plasma, at the end of dosing interval. A high interindividual variability was shown. We enrolled 237 children, 83 receiving intravenous and 154 oral voriconazole. A positive correlation between drug dose and drug plasma exposure was observed. Considering intravenous route, patients with higher serum creatinine had higher voriconazole concentrations; a positive correlation was found among drug exposure and age. Sex significantly influenced drug levels: males had higher median drug concentrations than females (P < 0.001). Close voriconazole pharmacokinetics monitoring should help individualize antifungal therapy for children.

Pharmacokinetic evaluation of oral itraconazole for antifungal prophylaxis in children

Itraconazole is a first-generation triazole agent with an extended spectrum of activity; it is licensed in adults for superficial and systemic fungal infections; no recommendation has been yet established for use in children patients. Its variable and unpredictable oral bioavailability make it difficult to determine the optimal dosing regimen. Hence, therapeutic drug monitoring, highly available in clinical practice, may improve itraconazole treatment success and safety. The aim of the study was to describe in paediatrics the oral itraconazole pharmacokinetics, used for prophylaxis. Moreover, we evaluated the utility of its therapeutic drug monitoring in this cohort. A fully validated chromatographic method was used to quantify itraconazole concentration in plasma collected from paediatric patients, at the end of dosing interval. Associations between variables were tested using the Pearson test. Mann-Whitney U test has been used to probe the influence of categorical variables on continuous ones. Any predictive power of the considered variables was finally evaluated through univariate and multivariate linear and logistic regression analyses. A high inter-individual variability was shown; ethnicity (beta coefficient, β -0.161 and interval of confidence at 95%, IC -395.035; -62.383) and gender (β 0.123 and IC 9.590; 349.395) remained in the final linear regression model with P value of .007 and .038, respectively. This study highlights that therapeutic drug monitoring is required to achieve an adequate target itraconazole serum exposure.

Development and Validation of Voriconazole Concentration by LC-MS-MS: Applied in Clinical Implementation

BACKGROUND

Voriconazole (VRZ) is a triazole antifungal used for treatment of invasive fungal infection, which is a life-threatening condition. Therapeutic drug monitoring is recommended for identifying the optimal dose in patients who have hepatic/renal impairment or reduced function of the CYP2C19 metabolizing enzyme.

METHODS

One hundred microliters of sample plasma was extracted by protein precipitated with 200 μl of acetonitrile containing fluconazole as internal standard (IS). After vortexing and centrifugation, supernatant was dried and reconstituted with 100 μl of mobile phase (ACN: 0.1% formic acid in 10 mM Ammonium acetate) (50:50 v/v) before injected. The column was C18, 2.7 μm, 3.0 × 50 mm at flow rate of 0.5 ml/min with retention time of 0.5 and 0.75 min for VRZ and IS, respectively. The tandem mass spectrometer was set in multiple reactions monitoring (MRM) mode with the following transition; VRZ m/z 350.10→281.10 and 307.20→220.20 (IS).

RESULTS

The accuracy and precision inter- and intra-day were less than 9%, over the range 0.05-10 μg/ml. The linearity was consistent (r² = 0.9987) and recovery was more than 85.0% for both analyses.

CONCLUSION

This method is applicable for routine monitoring of patients' VRZ plasma level with fast and accurate runtime to assess CYP2C19 genotype.

Voriconazole and atazanavir: a CYP2C19-dependent manageable drug-drug interaction

AIM

To investigate the pharmacokinetics of voriconazole when administered to HIV-positive patients receiving treatment with atazanavir-containing therapies according to CYP2C19 genotype.

MATERIALS & METHODS

We describe four HIV-positive patients with pulmonary aspergillosis treated with voriconazole and atazanavir-based regimens (with or without ritonavir). They were managed by assessing their CYP2C19 genotype (CYP2C19*2, rs4244285, G>A, real-time PCR) and therapeutic drug monitoring (HPLC-based validation methods).

RESULTS & CONCLUSION

Voriconazole exposure was variable but Ctrough levels were above 1000 ng/ml in all patients; one CYP2C19 intermediate metabolizer required lower doses of voriconazole (50 mg twice daily) to obtain satisfactory drug concentrations. Atazanavir and ritonavir plasma levels were moderately reduced (area under the curve: -23 and -26%, respectively); raltegravir exposure seemed increased by voriconazole administration (area under the curve: 2.5-fold higher) in a single subject. Coadministration of atazanavir and voriconazole may be feasible in selected HIV-positive patients; therapeutic drug monitoring and CYP2C19 genotyping may optimize exposure of both drugs.

Liquid chromatography tandem mass spectrometry in the clinical laboratory

Clinical laboratory medicine has seen the introduction and evolution of liquid chromatography tandem mass spectrometry in routine clinical laboratories over the last 10–15 years. There still exists a wide diversity of assays from very esoteric and highly specialist manual assays to more simplified kit-based assays. The technology is not static as manufacturers are continually making improvements. Mass spectrometry is now commonly used in several areas of diagnostics including therapeutic drug monitoring, toxicology, endocrinology, paediatrics and microbiology. Some of the most high throughput analyses or common analytes include vitamin D, immunosuppressant monitoring, androgen measurement and newborn screening. It also offers flexibility for the measurement of analytes in a variety of different matrices which would prove difficult with immunoassays. Unlike immunoassays or high-pressure liquid chromatography assays using ultraviolet or fluorescence detection, mass spectrometry offers better specificity and reduced interferences if attention is paid to potential isobaric compounds. Furthermore, multiplexing, which enables multiple analytes to be measured with the same volume of serum is advantageous, and the requirement for large sample volumes is decreasing as instrument sensitivity increases. There are many emerging applications in the literature. Using mass spectrometry to identify novel isoforms or modified peptides is possible as is quantification of proteins and peptides, with or without protein digests. Future developments by the manufacturers may also include mechanisms to improve the throughput of samples and strategies to decrease the level of skill required by the operators.

Current and future therapies for invasive aspergillosis

Invasive fungal infections have increase worldwide and represent a threat for immunocompromised patients including HIV-infected, recipients of solid organ and stem cell transplants, and patients receiving immunosuppressive therapies. High mortality rates and difficulties in early diagnosis characterize pulmonary fungal infections. Invasive pulmonary aspergillosis has been reviewed focussing on therapeutic management. Although new compounds have become available in the past years (i.e., amphotericin B lipid formulations, last-generation azoles, and echinocandines), new diagnostic tools and careful therapeutic management are mandatory to assure an early appropriate targeted treatment that represents the key factor for a successful conservative approach in respiratory fungal infections.

A simple high-performance liquid chromatography method for simultaneous determination of three triazole antifungals in human plasma

A rapid and simple high-performance liquid chromatography (HPLC) assay was developed for the simultaneous determination of three triazole antifungals (voriconazole, posaconazole, and itraconazole and the metabolite of itraconazole, hydroxyitraconazole) in human plasma. Sample preparation involved a simple one-step protein precipitation with 1.0 M perchloric acid and methanol. After centrifugation, the supernatant was injected directly into the HPLC system. Voriconazole, posaconazole, itraconazole, its metabolite hydroxyitraconazole, and the internal standard naproxen were resolved on a C(6)-phenyl column using gradient elution of 0.01 M phosphate buffer, pH 3.5, and acetonitrile and detected with UV detection at 262 nm. Standard curves were linear over the concentration range of 0.05 to 10 mg/liter (r(2) > 0.99). Bias was <8.0% from 0.05 to 10 mg/liter, intra- and interday coefficients of variation (imprecision) were <10%, and the limit of quantification was 0.05 mg/liter.

Multiplex ultra-performance liquid chromatography-tandem mass spectrometry method for simultaneous quantification in human plasma of fluconazole, itraconazole, hydroxyitraconazole, posaconazole, voriconazole, voriconazole-N-oxide, anidulafungin, and caspofungin

Therapeutic drug monitoring (TDM) may contribute to optimizing the efficacy and safety of antifungal therapy because of the large variability in drug pharmacokinetics. Rapid, sensitive, and selective laboratory methods are needed for efficient TDM. Quantification of several antifungals in a single analytical run may best fulfill these requirements. We therefore developed a multiplex ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method requiring 100 μl of plasma for simultaneous quantification within 7 min of fluconazole, itraconazole, hydroxyitraconazole, posaconazole, voriconazole, voriconazole-N-oxide, caspofungin, and anidulafungin. Protein precipitation with acetonitrile was used in a single extraction procedure for eight analytes. After reverse-phase chromatographic separation, antifungals were quantified by electrospray ionization-triple-quadrupole mass spectrometry by selected reaction monitoring detection using the positive mode. Deuterated isotopic compounds of azole antifungals were used as internal standards. The method was validated based on FDA recommendations, including assessment of extraction yields, matrix effect variability (<9.2%), and analytical recovery (80.1 to 107%). The method is sensitive (lower limits of azole quantification, 0.01 to 0.1 μg/ml; those of echinocandin quantification, 0.06 to 0.1 μg/ml), accurate (intra- and interassay biases of -9.9 to +5% and -4.0 to +8.8%, respectively), and precise (intra- and interassay coefficients of variation of 1.2 to 11.1% and 1.2 to 8.9%, respectively) over clinical concentration ranges (upper limits of quantification, 5 to 50 μg/ml). Thus, we developed a simple, rapid, and robust multiplex UPLC-MS/MS assay for simultaneous quantification of plasma concentrations of six antifungals and two metabolites. This offers, by optimized and cost-effective lab resource utilization, an efficient tool for daily routine TDM aimed at maximizing the real-time efficacy and safety of different recommended single-drug antifungal regimens and combination salvage therapies, as well as a tool for clinical research.