Sungkyunkwan University Suwon-si, Kyonggi-do, Republic of Korea
Purpose: Semaglutide, one of the most potent GLP-1 analogs, has widely been used to treat type II diabetes mellitus. Recent studies have shown that semaglutide also works on the brain, suggesting its potential utility for various diseases, including Parkinson’s disease and Alzheimer’s disease. This study aimed to develop a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of semaglutide in both plasma and brain to characterize the pharmacokinetics and brain distribution in rats. Methods: Semaglutide was extracted by simple protein precipitation with methanol from plasma and by solid phase extraction from brain tissue. Liraglutide was used as an internal standard. Gradient elution profiles with mobile phases comprising 0.1% formic acid in water and acetonitrile were used for chromatographic separation. Mass spectrometry was operated in the positive electrospray ionization in the multiple reaction monitoring (MRM) mode. The LC-MS/MS was validated according to the FDA guidance. Sprague-Dawley rats were given semaglutide by intravenous (IV, 0.02 mg/kg) and subcutaneous (SC, 0.2 mg/kg) injection. Semaglutide concentrations in the plasma and brain were determined by the LC-MS/MS method. The pharmacokinetic parameters of semaglutide were obtained by noncompartmental analysis. Results: The lower limit of quantification (LLOQ) of the LC-MS/MS assay was 0.5 ng/mL for both rat plasma and brain. Intra- and inter-day accuracy ranged from 91.48 - 111.33% in the plasma and from 99.67 - 106.67% in the brain. Precision was within 6.93% in the plasma and 6.00% in the brain. Following IV injections, the plasma concentrations of semaglutide showed a multi-exponential decline with a terminal half-life of 8.19 - 10.84 h in rats. Subcutaneous bioavailability of semaglutide was 83.62%. The brain tissue to plasma partition coefficient (Kp) value of semaglutide was estimated as less than 1%. Conclusion: A simple and sensitive LC-MS/MS method for quantification of semaglutide in the plasma and brain tissue was developed and validated. The pharmacokinetics and brain distribution of semaglutide were assessed in rats. The analytical method and pharmacokinetic information may be helpful towards a better understanding of the effect of semaglutide in the brain and further development of GLP-1 analogs for various brain diseases.
Acknowledgments: This work was supported by the Ministry of Trade, Industry and Energy of Korea Grant no. 20012631
