Sensitive and Robust Method for Estimation of Mometasone at Sub-pg/mL in Human Plasma Using Shimadzu LCMS-8060NX

Importance of the topic

Accurate measurement of mometasone furoate in human plasma is critical for pharmacokinetic and bioequivalence studies due to its low systemic exposure (<1% bioavailability) and sub-pg/mL circulating levels after inhaled dosing. A highly sensitive, selective, and robust analytical method enables reliable quantification in complex biological matrices and supports drug development and therapeutic monitoring.

Objectives and overview

This work describes the development and validation of a sensitive LC-MS/MS assay for quantifying mometasone furoate in human plasma using the Shimadzu LCMS-8060NX system. The method aimed to achieve a lower limit of quantification (LLOQ) of 0.5 pg/mL, a linear dynamic range of 0.5–20 pg/mL, and compliance with major US regulatory guidelines.

Methods and instrumentation

• Sample preparation: Single-step solid phase extraction (SPE) from 400 µL plasma. Cartridges conditioned with methanol and water, washed, dried, and eluted. SPE eluates evaporated, reconstituted in 100 µL solution, and transferred to vials.
• Chromatography: Shim-pack Velox C18 column (100 × 2.1 mm, 2.7 µm) at 50 °C, isocratic mobile phase methanol:0.01% formic acid in 5 mM ammonium acetate (90:10), flow rate 0.5 mL/min, injection volume 50 µL.
• Mass spectrometry: Shimadzu LCMS-8060NX with heated ESI source and UF-Qarray ion guide, positive MRM mode. MRM transition m/z 520.90 → 355.15 (CE ‑10 V), interface voltage 5 kV, interface temp 400 °C, DL temp 300 °C, heat block 400 °C, nebulizing gas 3 L/min, drying and heating gas 10 L/min.

Main results and discussion

• Selectivity: Six different plasma lots showed no interference at the analyte retention time. Blank and LLOQ spiked chromatograms confirmed method specificity.
• Linearity and sensitivity: Calibration curve linear from 0.5 to 20 pg/mL (r > 0.99). LLOQ 0.5 pg/mL, precision 15.0% RSD, accuracy 105.7%.
• Precision and accuracy: Intra- and inter-day precision and accuracy met acceptance criteria (±20% at LLOQ, ±15% at QC levels). Inter-day accuracy ranged 91.2–109.6% with RSD <17% at LLOQ.
• Recovery and matrix effect: Overall extraction recovery ~50% (RSD 14.6%). Matrix factors at LQC and HQC levels were 0.87 (RSD 8.4%) and 0.97 (RSD 3.9%), indicating minimal matrix suppression/enhancement.
• Carry-over: No detectable carry-over observed in blank injections following highest calibrator.

Benefits and practical applications

By combining simple SPE sample preparation with a robust LC-MS/MS platform, this method delivers sensitive and selective quantification of mometasone furoate at sub-pg/mL levels. It supports pharmacokinetic profiling, bioequivalence trials of inhaled and nasal spray formulations, and therapeutic drug monitoring in clinical research.

Future trends and potential uses

Anticipated developments include further miniaturization of sample preparation, automation of SPE workflows, application of similar workflows to other low-dose corticosteroids, and integration with high-throughput screening platforms. Enhanced ion-guide technologies and novel source designs may further increase sensitivity for ultra-trace analysis.

Conclusion

A first-of-its-kind LC-MS/MS assay for mometasone furoate in human plasma was established on the Shimadzu LCMS-8060NX, achieving an LLOQ of 0.5 pg/mL, excellent specificity, accuracy, and precision. The validated method is fit for demanding bioequivalence and pharmacokinetic studies.

Reference

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• 2. Daley-Yates PT. Inhaled Corticosteroids: Potency, Dose Equivalence and Therapeutic Index. Br J Clin Pharmacol. 2015;80:372–380. doi:10.1111/bcp.12637.