applied sciences_  
Development and Validation of 96-Microwell-Based Spectrophotometric and High-Performance Liquid Chromatography with Fluorescence Detection Methods with High Throughput for Quantitation of Duvelisib and Seliciclib in Their Bulk Forms and Capsules  
[PERSON], [PERSON] (c), [PERSON], [PERSON], [PERSON] (c) and [PERSON] (c)  
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia  
Correspondence: [EMAIL_ADDRESS]  
The Food and Drug Administration (FDA) has approved duvelisib (DUV) for managing follicular lymphoma, small lymphocytic lymphoma, and relapsed or refractory chronic lymphocytic leukemia. Seliciclib (SEL) is a candidate drug for these cancers, neurodegenerative disorders, renal diseases, several viral infections, and chronic inflammation disorders. This work describes the development and validation of a 96-microwell-based spectrophotometric method (MW-SPM) and a high-performance liquid chromatography with fluorescence detection method (HPLC-FD) for the quantitation of DUV and SEL in their bulk forms and capsules. The MW-SPM is based on the formation of colored charge transfer complexes (CTCs) as products for the reactions of DUV and SEL, as n-electron donors, with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), as a \(\pi\)-electron acceptor. The absorption intensity of the CTCs was measured by using an absorbance plate reader at 450 nm. The stoichiometric ratios of DUV:DDQ and SEL:DDQ were 1:1 and 1:2, respectively, and accordingly the reaction mechanisms were postulated. The HPLC-FD involved the chromatographic separation of DUV and SEL on a Hypersil(tm) Phenyl HPLC column (250 mm length \(\times\) 4.6 mm i.d., 5 um particle diameter) with a mobile phase composed of acetonitrile-acetate buffer, pH 4.5 (35:65, \(\mathrm{\SIUnitSymbolMicro}\)/\(\mathrm{\SIUnitSymbolMicro}\)) at a flow rate of 2.2 mL/min. DUV and SEL were detected at 370 nm after excitation at 280 nm. SEL was used as an internal standard (IS) for quantitation of DUV, and DUV was used as an IS for quantitation of SEL. Both MW-SPM and HPLC-FD were validated according to the guidelines of the International Council for Harmonization (ICH) for validation of analytical procedures. The linear ranges for both DUV and SEL were 14.52-200 \(\mathrm{\SIUnitSymbolMicro}\)/well (100 \(\mathrm{\SIUnitSymbolMicro}\)) and 0.12-3.2 \(\mathrm{\SIUnitSymbolMicro}\)/mL for MW-SPM and HPLC-FD, respectively. LOD values in MW-SPM for DUV and SEL were 4.4 and 3.17 \(\mathrm{\SIUnitSymbolMicro}\)/well, respectively; however, those for HPLC-FD were 0.03 and 0.05 \(\mathrm{\SIUnitSymbolMicro}\)/mL, respectively. The accuracy and precision of both methods were confirmed as the recovery values were \(\geq\)98.5% and the values of relative standard deviations (RSD) were \(\leq\)2.41%. Both methods were satisfactorily applied to the quantitation of DUV and SEL in their capsules; the mean recovery values were \(\geq\)99.2%. Both methods have simple procedures and high analytical throughput. Moreover, they consume a small volume of organic solvent; thus, they are economic and eco-friendly. Accordingly, the methods are valuable for routine use in quality control (QC) laboratories for quantitation of DUV and SEL in their bulk forms and capsules.  
duvelisib; seliciclib; 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; 96-microwell spectrophotometry; high performance liquid chromatography; high throughput pharmaceutical analysis