Highly Sensitive LC-MS/MS Method for Quantification of Beclomethasone in Human Plasma

Significance of the Topic

Beclomethasone dipropionate is a widely used inhaled corticosteroid characterized by very low systemic bioavailability, creating significant analytical challenges for sensitive quantification in pharmacokinetic and bioequivalence studies.

Objectives and Study Overview

This work aimed to develop and partially validate a rapid, robust LC-MS/MS method on the Shimadzu LCMS-8045 platform for quantifying beclomethasone in human plasma down to 5 pg/mL, using a deuterated internal standard and an extended calibration range to minimize reanalysis.

Methodology and Instrumentation

Sample Preparation:

• Single-step solid phase extraction (SPE) of 500 µL plasma with preconditioning, washing, and elution in acetonitrile.
• Dilution of eluate (1:1 v/v with water) prior to injection.

Chromatographic Conditions:

• Column: Shim-pack GIST C18 (50×2.1 mm, 3 µm).
• Mobile phase A: 2 mM ammonium trifluoroacetate in water; B: acetonitrile.
• Flow rate: 1.0 mL/min; column temperature: 40 °C; injection volume: 25 µL.

Mass Spectrometry:

• Instrument: Shimadzu LCMS-8045 with heated electrospray ionization and UF-Qarray ion guide.
• MRM transitions: BDP 521.4→411.3 and 521.4→319.1 (summed) for quantification; BDP-D10 531.3→416.0 as internal standard.

Main Results and Discussion

Calibration and Linearity:

• Linear range: 5–2000 pg/mL with correlation coefficient (r²) > 0.99.
• Signal-to-noise at LLOQ: > 15:1.

Precision and Accuracy:

• Intra- and inter-day precision < 15% (LLOQ < 20%), accuracy within ±15% (LLOQ within ±20%).

Recovery and Matrix Effects:

• Absolute recovery ~ 60% (RSD < 3%) across QC levels.
• IS-normalized matrix factor ~ 1.05 at LQC and 0.96 at HQC, indicating negligible matrix effects.

Selectivity and Carry-over:

• No significant interference in blank plasma or carry-over after high-concentration injections.

Benefits and Practical Applications

The method delivers rapid, high-throughput analysis with minimal plasma volume, enhanced picogram-level sensitivity, and an extended calibration curve that reduces reanalysis, supporting regulatory bioequivalence and pharmacokinetic investigations.

Future Trends and Applications

Future developments may include enhanced automation, miniaturized and multiplexed sample preparation, adaptation to other low-dose corticosteroids, and integration with pharmacokinetic/pharmacodynamic modelling to accelerate drug development.

Conclusion

This LC-MS/MS assay on the LCMS-8045 platform offers a robust, sensitive, and selective approach for quantifying beclomethasone in human plasma, meeting stringent requirements for clinical and regulatory studies.

References

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2. PubChem Compound Summary for CID 20469, Beclomethasone. National Center for Biotechnology Information (accessed March 2022).
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5. U.S. Food and Drug Administration. Bioanalytical Method Validation Guidance for Industry. 2018.