Sub-picogram level Bio-analytical method for quantification of Desmopressin in human plasma using LCMS-8060NX

Importance of the Topic

Desmopressin is a synthetic analogue of vasopressin with enhanced antidiuretic potency, reduced pressor effects, and prolonged half-life. Precise quantification at sub-picogram levels in human plasma is critical for bioequivalence studies, therapeutic drug monitoring, and clinical pharmacokinetic evaluations.

Study Objectives and Overview

The primary goal was to develop and partially validate an ultrasensitive LC-MS/MS method for measuring desmopressin in human plasma. The approach emphasizes minimal sample volume, high specificity, and reproducible performance across sub-picogram concentration ranges.

Materials, Methodology and Instrumentation Used

Sample Preparation:

• Human plasma anticoagulated with K2EDTA, spiked with calibration standards (0.25–40.00 pg/mL) and quality controls (0.25–20.00 pg/mL).
• SPE using conditioned cartridges; analyte eluted with methanol and reconstituted in 1 mM ammonium formate/methanol (50:50).

Chromatography and Detection:

• UHPLC: Shim-pack GIST C18 AQ column (1.9 µm, 50 × 2.1 mm), gradient elution with 1 mM ammonium formate in water and methanol, flow rate 0.5 mL/min, column temperature 60 °C.
• MS: Shimadzu LCMS-8060NX triple quadrupole with Nexera X2 UHPLC, ESI interface, MRM detection mode, optimized gas flows and temperatures.

Main Results and Discussion

Selectivity and Linearity:

• No significant interference observed in six lots of blank plasma; LLOQ signal free of matrix peaks.
• Calibration curve (0.25–40.00 pg/mL) displayed excellent linearity (r2 > 0.996).

Precision and Accuracy:

• Intra- and inter-day precision within 4–13% CV across LLOQ, low, medium, and high QC levels.
• Accuracy ranged from 98 to 117% at all concentration levels, meeting bioanalytical guidelines.

Recovery and Matrix Effects:

• Global recovery averaged 76.7% with 4.8% precision, consistent across QC levels.
• Matrix factors near unity (1.05 at LQC, 0.97 at HQC) indicated negligible ion suppression or enhancement.

Carry-over:
The method exhibited no detectable carry-over after highest standard injections.

Benefits and Practical Applications

This protocol achieves sub-picogram sensitivity using minimal plasma volume, making it ideal for clinical pharmacokinetic, bioavailability, and bioequivalence studies, as well as routine therapeutic monitoring.

Future Trends and Applications

Further advancements may include automated high-throughput workflows, integration with high-resolution mass spectrometry for metabolite profiling, and multiplexed assays for peptide panels in personalized medicine.

Conclusion

The developed LC-MS/MS method on the Shimadzu LCMS-8060NX with Nexera X2 UHPLC is highly sensitive, selective, and reproducible for quantifying desmopressin in human plasma. Validation results support its application in clinical and regulatory bioanalytical settings.

References

• Smart Metabolites Database, Shimadzu Corporation trademark information.
• ChemSpider 4470602, accessed May 04, 2023.