Pharmacokinetic profile and incurred sample stability of hydroxychloroquine in Volumetric Absorptive Microsampling (VAMS) using high-performance liquid chromatography-photodiode array

Background: Hydroxychloroquine (HCQ) is a quinoline compound derived from chloroquine used to treat SLE. An in vitro stability evaluation was conducted to develop and validate the hydroxychloroquine analysis method. However, an assessment of the incurred sample stability is needed to ensure drug effectiveness, as in vitro evaluation doesn't reflect drug metabolism processes in the body. Objective: This research aims to obtain a pharmacokinetic profile of hydroxychloroquine using Volumetric Absorptive Microsampling (VAMS) as a safe sampling technique to use during the COVID-19 pandemic and evaluate the incurred sample stability of hydroxychloroquine samples. Methods: The chromatographic conditions used were column C18 (Waters, XBridge; 250 × 4.6 mm; 5μm); mobile phase acetonitrile-1% diethylamine (65:35); flow rate of 0.8 mL/min; column temperature 45°C; PDA detector analysis wavelength of 332 nm; and chloroquine as internal standard. Results: The pharmacokinetic profile of hydroxychloroquine in VAMS samples gave results that the Cmax ranged from 322.61-505.32 ng/mL with an average of 425.33 ± 65.90 ng/mL; tmax was 4 hours; mean t1/2 was 23.32 ± 9.65 hours; mean AUC0-72 was 5103.63 ± 1419.66 ng.h/mL; mean AUC0-∞ was 5763.97 ± 2155.26 ng.h/mL, and the AUC ratio was above 80%. Conclusion: The incurred sample stability of hydroxychloroquine in VAMS met the 2011 EMEA Bioanalytical Guideline requirements up to day 30.