Background: A combination of alogliptin and pioglitazone is well tolerated. It does not increase
the risk of hypoglycemia. In order to study the bioavailability of aloglipitn in the presence of
pioglitazone, it is essential to have a method that can simultaneously detect both in human plasma. A
protein precipitation-based method was used to determine alogliptin and pioglitazone simultaneously in
human plasma. Protein precipitation causes ion suppression or enhancement in detection methods when
compared to other methods.
Objective: To simultaneously quantify alogliptin and pioglitazone in human plasma by LC-MS/MS
Methods: LC-MS/MS method for the simultaneous determination of pioglitazone and alogliptin in human
plasma using stable isotope labelled compounds internal standards. The simple and one step solid
phase extraction (SPE) was employed to extract the analytes from plasma. The extracted samples were
separated on a C18 column by using a 25:75 (v/v) mixture of acetonitrile and 5 mM ammonium formate
as the mobile phase at a flow rate of 0.5 mL/min.
Results: The calibration curves obtained were linear (r2= 0.99) over the concentration range of 12.0-
2438.0 ng/mL for pioglitazone and 1.0-202.0 ng/mL for alogliptin. The results of the intra- and interday
precision and accuracy studies were found to be within the acceptable limits. The analytes were
stable under different stability conditions. All the validation results were found to be within the acceptable
limits. The total analytical run time was 3.0 min. There was no interference from plasma matrices.
Conclusion: The developed method is precise and adequately sensitive for detection and quantification
of analytes. Thus, the method can be useful for bioavailability and bioequivalence (BA/BE) studies and
routine therapeutic drug monitoring with the desired precision and accuracy.