Development and Validation of a Novel Microwell-Based Fluorimetric Method Assisted with Fluorescence Plate Reader for High-Throughput Determination of Duvelisib: Application to the Analysis of Capsules and Plasma Samples

Abstract

Duvelisib (DUV) is a novel drug with a small molecular weight and characterized by dual phosphoinositide-3-kinase (PI3K)- and PI3K-inhibitory activity. The Food and Drug Administration (FDA) recently approved DUV for the management of small lymphocytic lymphoma (SLL) and relapsed or refractory chronic lymphocytic leukemia (CLL) in adult patients. In the current study, a microwell-based fluorimetric (MW-FLR) method was established for the quantitation of DUV in copiktra® capsules as well as plasma samples. The proposed MW-FLR method was carried out in a 96-microwell plate and involved measuring the native fluorescence of DUV by using a fluorescence plate reader at 405 nm after excitation at 340 nm. The preparation of plasma samples involved simple one-step protein precipitation prior to the analysis. The optimum conditions for the proposed method were established. Under these conditions, the fluorescence signals showed an excellent linear relationship with DUV concentrations in the sample solutions (r = 0.9995) in a concentration range of 25–800 ng/mL. The detection and quantification limits were 20.5 and 62.1 ng/mL, respectively. The method's accuracy and precision were acceptable as the recovery values were not less than 98.5% with low relative standard deviations (less than 6%). The presented MW-FLR method was adopted with truly good accuracy and precision to analyze copiktra capsules and DUV-spiked plasma samples. The method's results were found to be superior to those of reference methods. The MW-FLR method combined the advantages of the inherent high sensitivity of the fluorimetric measurement and the high analytical throughput of microwell-based methods. In addition, the method is characterized by the simplicity of the procedures and the green chemistry approach as it uses water as a solvent and low volumes of sample solutions. These advantages gave the method great value for the determination of DUV in quality control and/or clinical laboratories.