Development and Validation of a UHPLC-MS/MS Method for Ciprofol Detection in Plasma: Application in Clinical Pharmacokinetic Studies.

Objective: This study aimed to develop and validate an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the quantification of ciprofol in human plasma, with the goal of applying this method to pharmacokinetic studies in patients undergoing elective surgery under general anesthesia.

Methods: A methanol-based protein precipitation method was employed for sample preparation, using ciprofol-d6 as the internal standard. Chromatographic separation was achieved on a Shimadzu Shim-pack GIST-HP C18 column (3 µm, 2.1×150 mm) with a mobile phase consisting of 5 mmol·L⁻¹ ammonium acetate (A) and methanol (B). The flow rate was maintained at 0.4 mL·min⁻¹, and the column temperature was set at 40°C. Detection was performed using electrospray ionization (ESI) in negative ion mode with multiple reaction monitoring (MRM). The quantification ion pairs were m/z 203.100→175.000 for ciprofol and m/z 209.100→181.100 for the internal standard.

Results: Ciprofol exhibited excellent linearity across the concentration range of 5 to 5000 ng·mL⁻¹ (r > 0.999). The intra-batch and inter-batch precision values were within 4.30% to 8.28%, and the relative deviation ranged from -2.15% to 6.03%. The extraction recovery rate was 87.24% to 97.77%, and the matrix effect relative standard deviation (RSD) was less than 15%.

Conclusion: The developed UHPLC-MS/MS method is simple, rapid, accurate, and highly specific, making it suitable for the determination of ciprofol plasma concentrations and pharmacokinetic studies in clinical settings. This method provides a reliable analytical tool for future research on ciprofol in complex biological matrices.