Selective and highly accurate analysis of desmopressin from human plasma

Significance of the Topic

The accurate quantification of therapeutic peptides in biological matrices is critical for pharmacokinetic studies, dosing optimization, and safety monitoring. Desmopressin, a synthetic nonapeptide analogue of vasopressin, requires highly sensitive and selective analytical methods to distinguish it from endogenous peptides and matrix interferences in human plasma. This workflow addresses common challenges such as low recovery, matrix effects, and carryover, enabling reliable bioanalysis in biopharmaceutical and clinical laboratories.

Goals and Study Overview

This study aimed to develop an efficient, high-throughput workflow combining micro-elution solid-phase extraction (SPE) with ultra-high pressure liquid chromatography (UHPLC) and tandem mass spectrometry (LC-MS/MS) for the quantitation of desmopressin in human plasma. Key objectives included maximizing recovery, minimizing matrix effects, and achieving rapid analysis with robust precision and accuracy across a calibration range of 10–5000 pg/mL.

Methodology

Sample preparation utilized a mixed-mode weak cation exchange micro-elution SPE format. Plasma samples spiked with desmopressin and an octreotide internal standard underwent conditioning, loading, washing, and elution steps in a 96-well format. The final eluate was diluted and directly injected into the UHPLC system. Method optimization included screening SPE chemistries, minimizing carryover with 1 % TFE in wash solutions, and selecting the optimal SRM transitions by favoring the +2 charge state in methanol-based mobile phases.

Instrumentation Used

• Thermo Scientific SOLAµ WCX 96-well SPE plate
• Thermo Scientific Vanquish UHPLC system (system base, binary pump H, split sampler HT, column compartment H)
• Accucore Vanquish C18+ column (1.5 µm, 100 × 2.1 mm)
• Thermo Scientific TSQ Quantiva triple quadrupole mass spectrometer with positive electrospray ionization

Main Results and Discussion

The method achieved excellent linearity (r2 = 0.9981) from 10 to 5000 pg/mL using 1/x weighting. Extraction recoveries exceeded 97 % for both desmopressin and the internal standard at all QC levels. Matrix effects were below 4 % across the calibration and quality control points. Intra-run precision (%RSD) ranged from 2.6 % to 8.4 %, and accuracy biases were within ±4 %. The UHPLC separation resolved desmopressin, the internal standard, and key plasma interferences within 2.8 minutes. Carryover was eliminated by optimized wash protocols, confirming a robust assay suitable for large sample batches.

Benefits and Practical Applications

• High sensitivity (LLOQ = 10 pg/mL) and broad dynamic range support low-dose pharmacokinetics.
• Micro-elution SPE reduces solvent consumption and eliminates post-extraction processing.
• Fast UHPLC gradient and high throughput are compatible with routine bioanalysis and QC operations.
• Reproducible performance with minimal matrix interference ensures reliable data for clinical studies.

Future Trends and Opportunities

Emerging trends include further miniaturization of sample preparation, automated on-line SPE-LC-MS/MS platforms, and integration of high-resolution accurate-mass detection for multiplexed peptide assays. The described workflow can be adapted to other therapeutic peptides and biologics, supporting expanding needs in biopharmaceutical development and personalized medicine.

Conclusion

A highly selective, sensitive, and rapid SPE-UHPLC-MS/MS method for desmopressin in human plasma was established. The workflow delivers exceptional recovery, minimal matrix effects, and robust precision and accuracy, making it suitable for high-throughput bioanalysis in pharmaceutical and clinical research settings.

References

• Neudert L., Zaugg M., Wood S., Struwe P. A High Sensitivity Dual Solid Phase Extraction LC-MS/MS Assay for the Determination of the Therapeutic Peptide Desmopressin in Human Plasma. White Paper, 2011.