Winter, Serge (2023) Supported liquid extraction combined with liquid chromatography tandem mass spectrometry for the quantitative analysis of a TLR7 agonist imiquimod LFX453 in plasma at low picogram per milliliter: method validation and its application to pharmacokinetic study in minipig. Biomedical chromatography BMC.. ISSN 0269-3879

Abstract

Sample preparation plays a pivotal role in the quantitative determination of low level of compounds in biological fluids by LC-MS/MS. In the present work, we have combined supported liquid extraction (SLE) and LC-MS/MS for the determination of low level a new TLR7 agonist imiquimod, LFX453 under development for the treatment of non-melanoma skin cancer and actinic keratosis. The samples were extracted on ISOLUTE® - SLE 96-well plate by using tert-butyl-methyl ether (MTBE) followed by evaporation and reconstitution of the dry residue with 150 µL of a 0.1% formic acid in acetonitrile/water (50/50, v/v) mixture. Samples were eluted at 0.750 mL/min on Ascentis Express® C18 column (50 mm × 2.1 mm, 2.7 μm) with a mobile phase consisting of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). A triple quadrupole mass spectrometer equipped with an electrospray source operating in positive mode was used as detection system. The method run time was 6.5 min and the low limit of quantification (LLOQ) was 1.00 pg/mL with 0.100 mL minipig plasma. Intra-run and inter-run precision and accuracy within the acceptance criteria were achieved during a 3-run validation for quality control samples at four concentration levels over a concentration ranging from 1.00 to 200 pg/mL. The absence of matrix effect demonstrated the usefulness of SLE for the sample preparation. In addition, recovery, 3 freeze thaw cycles and incurred samples reanalysis were validated. The present method was successfully applied to the measurement of LFX453 in plasma after topical application on minipig skin. Our data show that the present method is robust and reliable for the determination of low level of LFX453 in minipig plasma.

Item Type:	Article
Keywords:	TLR7 agonist imiquimod; LFX453; sample preparation; Solid liquid phase extraction; LC-MS/MS method validation
Date Deposited:	02 Dec 2023 00:46
Last Modified:	02 Dec 2023 00:46
URI:	https://oak.novartis.com/id/eprint/50152