A High Sensitivity LC/MS/MS Method for Quantitative Determination of Telmisartan in Human Plasma

Importance of the topic

A precise and highly sensitive quantification of telmisartan in human plasma is essential for pharmacokinetic, bioequivalence, and therapeutic drug monitoring studies. Improving analytical throughput and reducing costs without compromising sensitivity supports large‐scale clinical research and routine laboratory testing.

Objectives and overview of the study

This application note describes the development and evaluation of a high‐sensitivity LC/MS/MS method on the Shimadzu LCMS‐8050 platform with heated ESI for quantifying telmisartan in human plasma using a streamlined protein‐precipitation procedure.

Methodology and instrumention

• Sample preparation: Three‐to‐one ratio of acetonitrile to plasma for protein precipitation, no SPE cleanup required.
• Chromatography: Nexera UHPLC with ZORBAX Eclipse Plus C18 column (3.0 × 100 mm, 1.8 μm), isocratic elution (40% water/60% acetonitrile with 0.04% formic acid), flow rate 0.4 mL/min, column oven at 50 °C.
• Mass spectrometry: LCMS‐8050 triple quadrupole with heated ESI in positive mode; optimized MRM transitions for telmisartan (515.2 → 276.1, 515.2 → 497.2 m/z) and irbesartan internal standard (429.2 → 207.0, 429.2 → 195.1 m/z) with tailored collision and bias voltages.

Main results and discussion

• Linearity: Calibration range from 1 to 2000 pg/mL, correlation coefficient (R2) > 0.999.
• Sensitivity: Lower limit of quantitation (LLOQ) at 1 pg/mL post‐precipitation (equivalent to 4 pg/mL in pretreated plasma) with signal‐to‐noise ratio ≈11.
• Accuracy and precision: LLOQ accuracy 82.8%, precision (RSD) 13.3%; QC samples at 5 and 20 pg/mL showed accuracy 93.8%–123.5% and RSD < 3.2%.
• Recovery and matrix effects: Recoveries between 89% and 132%; slight ion enhancement observed, with a minor interference peak from plasma, underscoring the need for full validation.

Benefits and practical applications

• High throughput: Simplified sample prep accelerates batch processing.
• Cost savings: Eliminates SPE cartridges and lengthy cleanup.
• Robust sensitivity: Suitable for low‐level telmisartan assays in PK and bioequivalence studies.

Future trends and possibilities

• Formal method validation for clinical and regulatory compliance.
• Application to other low‐abundance pharmaceuticals and metabolites.
• Coupling with automated liquid handling for increased throughput.
• Exploration of enhanced ionization sources for further sensitivity gains.

Conclusion

The presented protein‐precipitation LC/MS/MS approach on the LCMS‐8050 delivers excellent sensitivity (LLOQ 1 pg/mL) and robustness for telmisartan quantitation in human plasma, combining simplicity, speed, and reliability for bioanalytical applications.

Reference

• Shimadzu Application News AD‐0077, 2015