Development and Validation a UPLC-MS/MS Method for Quantification of Pentoxifylline in Beagle Plasma: Application for Pharmacokinetic Study of Food Effect

Purpose: To develop an UPLC-MS/MS method for the quantitative analysis of pentoxifylline in beagle dog plasma and apply it to a pharmacokinetic study of food effect.Methods: Sample separation was achieved using a Kinetex Phenyl-Hexyl column (50 x 2.1 mm, 1.7 mu m) with a gradient elution program in 5.5 min after a simple protein precipitation with methanol. Using the mobile phase that made up by 0.2% formic acid and 5mM ammonium formate water (A) and methanol (B). Quantitation was carried out using the positive ionization mode with multiple reaction monitoring (MRM). A randomized, single-dose, two-period crossover study was conducted in six fasted or fed beagles that received 400 mg pentoxifylline sustained-release tablets (Brand name: Shuanling (TM), CSPC Pharmaceutical Group). WinNonlin (R) software was used to calculate pharmacokinetic parameters.Results: The linear calibration range was 2-1000 ng/mL (r(2)> 0.99). Both intra- and inter-batch precision were less than 6.27%, and the accuracy ranged from 88.65% to 97.18%. Pentoxifylline was readily absorbed in fasted and fed dogs administered a dose of 400 mg (t(max):1.54h vs 1.83h). Compared to the fasted group, the AUC(0 -> t) and C-max in the fed group increased by 1.71-fold and 1.30-fold, respectively. In the fasted group, the AUC(0 -> t) and C-max values were 4684.08 h center dot ng/mL and 2402.33 ng/mL, respectively. In the fed group, these values were 8027.75 h center dot ng/mL and 3119.67 ng/mL. The difference in AUC(0-t) between the fed and fasted group was statistically significant.Conclusion: The novel optimized UPLC-MS/MS assay is an effective tool for the determination of pentoxifylline and has been successfully applied in pharmacokinetic studies of pentoxifylline in beagle dogs. The administration of pentoxifylline sustained-release tablets with food significantly increased the area under the time curve, and it is recommended that they should be administered during or shortly after feeding.

Automated summary

In this study, a UPLC-MS/MS method was developed for the quantitative analysis of pentoxifylline in beagle dog plasma and applied to a pharmacokinetic study. It was found that the administration of pentoxifylline sustained-release tablets with food significantly increased the AUC(0-t) and C-max values.