Simultaneous determination of macitentan and its active metabolite in human plasma by liquid chromatography-tandem mass spectrometry

Stability Indicating RP-HPLC-DAD method for simultaneous estimation of tadalafil and macitentan in synthetic mixture for treatment of pulmonary arterial hypertension

OBJECTIVE

High Performance liquid chromatography is an integral analytical tool in assessing drug product stability. A simple, selective, precise, accurate and stability indicating RP-HPLC method was developed and validated for analysis of Tadalafil and Macitentan in synthetic mixture.

MATERIAL AND METHOD

Chromatographic separation was performed using Phenomex Gemini C18 (25cm×4.6nm, 5μm) Column. The mobile phase consists of (10mM Ammonium Acetate in water and [Methanol: ACN 20: 80% v/v]) (40: 60% v/v). The flow rate was set to be 1.0mL/min. The injection volume was 10.00μL. The detection was carried out at 260nm at column temperature 35°C.

RESULTS

The method was validating according to ICH Q2R1 guideline for accuracy, precision, reproducibility, specificity, robustness and detection and quantification limits. Stability testing was performed on Tadalafil and Macitentan and it was found that these degraded sufficiently in all applied chemical and physical conditions. Linearity for Tadalafil and Macitentan was observed 0.4-100μg/mL and 0.1-25μg/mL with correlation coefficient at 0.9999. LOD and LOQ 0.008μg/mL and 0.024μg/mL and 0.001μg/mL and 0.0029μg/mL for Tadalafil and Macitentan respectively.

CONCLUSION

The developed RP-HPLC method was found to be suitable for the determination of both the drugs.

Development and Validation of Novel UPLC-MS/MS Method for the Analysis of Macitentan in Pharmaceutical Formulations

Introduction:

Macitentan is an endothelin receptor antagonist drug used in the treatment of pulmonary arterial hypertension.

Materials and Methods:

A new, sensitive, simple, accurate and rapid ultra-performance liquid chromatography in combination with tandem triple quadruple mass spectrometry (UPLC-MS/MS) method has been developed and validated for the determination of macitentan in pharmaceutical formulations. Macitentan and bosentan which are used as internal standard (IS) were detected using atmospheric pressure chemical ionization (APCI) in positive ion, multiple reaction monitoring (MRM) mode by monitoring mass transitions (precursor to product) m/z 589.1→203.3 and 552.6→311.5, respectively. Chromatographic separation was carried out on reverse phase C18 column (5 µm, 4.6 * 150 mm). Water containing 0.2 % acetic acid in acetonitrile (10:90, v/v) was used as the mobile phase in the isocratic elution. The system was optimized with injection volume of 10 µL, column temperature of 35 °C and flow rate of 1 mL min-1 Retention times were 1.97 min for macitentan and 1.72 min for IS.

Results and Discussion:

The calibration curve with a high correlation coefficient (0.9997) was linear range 0.5-500 ng mL-1. The lower limit of quantitation (LLOQ) and average recovery values were determined as 0.5 ng mL-1 and 99.7 %, respectively. The developed novel method has been successfully applied for the determination of macitentan in pure form and pharmaceutical formulations.

Conclusion:

The present method is the first study developed and validated for the determination of macitentan from the pharmaceutical preparations and pure form by UPLC-MS/MS method in the literature.

Simultaneous quantification of endothelin receptor antagonists and phosphodiesterase 5 inhibitors currently used in pulmonary arterial hypertension

Combination treatment with endothelin receptor antagonists (ERA) and phosphodiesterase 5 inhibitors (PDE5I) improved efficacy of pulmonary arterial hypertension (PAH) therapy. However, drug-drug interactions, variable exposure, non-adherence can influence plasma levels. For these reasons, drug quantification may be advantageous particularly in patients with poor treatment responses. We developed, validated, and applied an assay for the simultaneous quantification of ambrisentan, bosentan, macitentan, sildenafil, and tadalafil as well as their main (and partly active) metabolites in human plasma. This method is based on LC-MS/MS separation for a rapid and sensitive quantification with stable isotopically labelled analogues as internal standards for each drug and metabolite. Sample preparation was carried out using a solid phase extraction protocol based on Oasis HLB material. The separation was achieved on a Kinetex C18 column and multiple reaction monitoring in negative ionization mode was used for sensitive detection. The calibrations were linear for all analytes with correlation coefficients >0.99 within the concentration range observed under a therapeutic PAH dosing scheme with lower limits of quantification between 0.34ng/mL (OH-ambrisentan) and 10ng/mL (despropyl-macitentan). Intra- and inter-day precision at LLOQ and QC levels ranged between 2.03% and 19.8%, and 0.65% and 14.0%, respectively. The sample turnover time was 12min. The applicability of this versatile LC/MS/MS assay was verified by the successful analysis of clinical routine samples of patients on PAH medication. This new method allows for the first time to assess trough drug and metabolite levels of the currently approved PDE5I and ERAs in PAH patients, thus enabling for measurement of samples in clinical routine.