Abstract

Background: Sufentanil, an opioid analgesic, is used as an induction agent for general anesthesia during surgery. Sufentanil is more active than other anesthetics and has a narrow therapeutic range. Therefore, a precise dosage regimen is necessary when administering sufentanil.

Objective: This study aimed to develop a bioanalytical method for the determination of sufentanil within the sensitive concentration range more than that in a previous study utilizing protein precipitation (PP) and determine the plasma concentration of sufentanil.

Methods: A method for quantitating sufentanil was developed using ultra–high performance liquid chromatography coupled with mass spectrometry (UPLC–MS/MS) and detection by electrospray ionization (ESI). The internal standard was sufentanil-d₅. Chromatographic separation was performed using an Acquity UPLC HSS T3 column (50 × 2.1 mm, 1.8 μm) from Waters (Milford, MA, USA). Protein precipitation (PP) was used for sample preparation, and gradient elution was conducted using a mobile phase consisting of 1 mL of 2M ammonium acetate in 99% formic acid in 1 L of water or in 1 L of acetonitrile. The total run time for the analysis was 5 min, and the flow rate was 0.4 mL/min.

Results: Standard curves were linear over ranges of 0.025–30 ng/mL for sufentanil with a correlation coefficient (r²) greater than 0.9998. The lower limit of quantification (LLOQ) was 0.025 ng/mL. The intra– and inter–day accuracies were 97.66%–108.8% and 101.25%–103.17%, respectively, and the precision did not exceed 15% for sufentanil.

Conclusion: This study developed a validated, simple, sensitive, and convenient UPLC–MS/MS method for quantifying sufentanil in human plasma. This method was applied to determine sufentanil concentration in the plasma of patients undergoing surgery. The bioanalytical method using PP showed a sufficiently sensitive concentration range. This method could be applied to various pharmacokinetic studies of sufentanil.

Keywords: Sufentanil, human plasma, bioanalysis, UPLC–MS/MS, protein precipitation (PP), MRM.