LC–MS/MS assay of ropinirole in rat biological matrices: elimination of lysoglycerophosphocholines-based matrix effect

Aim: To adequately support PK evaluation of ropinirole in rats following intranasal administration, it was desirable to determine ropinirole concentrations in rat plasma, brain homogenate and microdialysate. Results & methodology: A robust LC-MS/MS method has been developed for the determination of ropinirole in biological samples. Liquid-liquid extraction using ethyl acetate eliminated matrix effect due to significantly reduced levels of lysoglycerophosphocholines. The assay was fully validated with dynamic ranges of 0.01-20 ng/ml for plasma and brain homogenate samples and 0.1-200 ng/ml for microdialysate samples. Conclusion: The proposed method was accurate and precise for the quantification of ropinirole in biological samples and was successfully applied to a microdialysis study of ropinirole in rats.