Objective: To determine and validate of irbesartan and sinensetin simultaneously by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and application of this method to study a pharmacokinetic interaction of irbesartan and ethanol extract of Orthosiphon stamineus herba in rat plasma. Methods: The irbesartan and sinensetin were simultaneously extracted from plasma by protein precipitation with acetonitrile. Samples containing irbesartan and sinensetin were analyzed by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with C18 column Acquity® (100 mm × 2.1 mm), 1.7 μm particle size column at 40 °C. The gradient system of mobile phase composition was a mixture of acetonitrile and 0.1% formic acid (40:60 v/v), which was pumped at a flow rate of 0.3 ml/min. Mass detection was performed on Waters Xevo Triple Quadrupole equipped with an electro spray ionization (ESI) source at positive ion mode in the multiple reaction monitoring (MRM) mode. Irbesartan was detected at m/z 429.1>205.9, sinensetin was detected at m/z 373>342.9 and losartan as an internal standard was detected at m/z 423.05>404.9. Results: The method was validated according to EMEA guidelines which showed good reproducibility and linearity of 0.99, the lower limit of quantification (LLOQ) were 25 ng/ml and 250 ng/ml for irbesartan and sinensatin, respectively. The precision (% CV) values of within-run and between-run analysis is 9.3-5.25% and 1.52–5.47% (for irbesartan), 1.52–5.09% and 2.47–9.14% (for sinensetin) whereas the accuracy (% diff) of both irbesartan and sinensetin were less than 20%. Stability studies revealed that irbesartan and sinensetin have been stable for 24 h at room temperature, 24 h in the autosampler, 3 freeze-thaw cycles, and at least 30 d at-20 oC. The validated method was applied to evaluate pharmacokinetic interactions of irbesartan and ethanol extract of Orthosiphon stamineus herba in rat plasma. Conclusion: The developed LC/MS-MS method is valid to evaluate irbesartan and sinensetin simultaneous in vitro and showed good selectivity, linearity, accuracy, precision, matrix effect, and stability. The method was successfully applied to study the pharmacokinetics interaction of irbesartan and Orthosiphon stamineus herba in rat plasma.
|Number of pages||5|
|Journal||International Journal of Pharmacy and Pharmaceutical Sciences|
|Publication status||Published - 2016|
- Drug interaction
- Orthosiphon stamineus
- Validated method