High-performance liquid chromatographic method for simultaneous determination of iloperidone and idebenone in spiked plasma

Background

Iloperidone (ILP) is a second-generation atypical antipsychotic agent and idebenone (IDB), a synthetic analogue of coenzyme Q10 is an important cell membrane antioxidant. No validated analytical method for simultaneous determination of ILP and IDB in rat plasma has been reported till date.

Objective

To develop and validate a simple reversed phase high performance liquid chromatography method for simultaneous determination of iloperidone and idebenone in rat plasma.

Methods

A liquid–liquid extraction method was used for deproteination of plasma samples using methanol as an extraction solvent. Chromatographic separations were done using isocratic conditions. Mobile phase containing acetonitrile and 0.025 M KH₂PO₄, pH 6 (60:40) at a flow rate of 1 mL/min was utilized for efficient separation. The UV detector was set at 277 nm. Risperidone was used as an internal standard.

Results

The limits of detection (LOD) for iloperidone and idebenone were 10 and 20 ng/ml, while the limits of quantification (LOQ) were 30 and 35 ng/ml, respectively. The standard curves for iloperidone and idebenone in plasma were linear over the range of 0.05–20 μg/ml, with the correlation coefficients of 0.9993 and 0.9985, respectively. All the validation parameters, such as accuracy, intra and inter-day precision were within the required limits. The samples were stable at −80 °C and −20 °C as compared to 4 °C storage temperature when subjected to repeated freeze–thaw cycles.

Conclusion

The proposed method proves to be a sensitive method because of its potential to simultaneously determine iloperidone and idebenone in rat plasma in a single HPLC run.