A Simple and Accurate LC-MS/MS Method for the Determination of Indobufen in Human Plasma and Its Clinical Application

As an antithrombotic agent, indobufen is widely used in China. However, the relationship between drug concentration and therapeutic efficacy in specific patient populations remains unclear. Therefore, it is crucial to establish a method for quantifying indobufen concentrations in human plasma to guide dosage recommendations. An electrospray ionization (ESI) power supply was utilized in conjunction with multireaction monitoring (MRM) in positive ion mode. Protein precipitation was employed to extract indobufen from the plasma sample. Separation was carried out using a ChromCORE-C18 column with a gradient elution of the mobile phase, which was composed of 0.1% formic acid in water (Solvent A) and methanol (Solvent B) at a flow rate of 0.3 mL/min. The typical standard curve equation was Y = 0.763X + 0.0986 (r = 0.9993), demonstrating a good linear relationship within the range of 0.5-30 μg/mL. All methodological outcomes complied with regulatory guidelines. In patients with moderate renal insufficiency, it is advisable to reduce the dosage to 100 mg once daily. For patients with severe renal insufficiency, the dosage should be reduced to 1/3-1/4 of the standard dose. For patients undergoing continuous renal replacement therapy (CRRT), indobufen can be gradually eliminated, and most patients do not require dose adjustment.