Comparison of HPLC-DAD and UPLC-MS/MS in Monitoring Serum Concentration of Lamotrigine

Background: Lamotrigine (LTG) is a broad-spectrum and first-line anti-epileptic drug. To monitor the serum levels of LTG in epileptic seizures patients, high-performance liquid chromatography with diode-array detection (HPLC-DAD) and ultra-performance liquid chromatography-- tandem mass spectrometry (UPLC-MS/MS) methods were established and compared. Methods: Imatinib was used as the internal standard (IS) for both methods. LTG and IS were detected at 246 nm by HPLC-DAD. In UPLC-MS/MS, LTG and IS positive ion were detected by multiple reaction monitoring (MRM), with m/z of 256/210.9 and 494/394.02, respectively. A total of 37 blood samples from epileptic patients were determined and studied by these two methods. Results: There was an acceptable linearity for the two methods. The concentration range of LTG was 0.59 ∼ 22.20 mg/L by HPLC, and 0.28 ∼ 23.97 mg/L by UPLC-MS/MS. The Pearson regression coefficient of Deming regression was 0.9653 (95% CI: 0.9332 to 0.9821). Bland–Altman method demonstrated that the concentration of LTG determined by UPLC-MS/MS was 8.3% higher than that determined by HPLC (limits of agreement, -32.0% to +48.6%). Conclusion: There was a significant correlation between the two methods. Both HPLC and UPLC- MS/MS can be used for routine clinical monitoring of LTG.