Quantitative Determination of AZD3264, a Selective Ikb-Kinase IKK2 Inhibitor, in Dog Plasma by Solvent-Induced Phase Transition Extraction Coupled with HPLC-MS/MS and its Application to Pharmacokinetic Study in Dogs

Background: AZD3264 is a small molecule inhibitor of selective IkB-kinase IKK2 currently in preclinical development for the potential treatment of asthma and chronic pulmonary obstructive disorder.

Objective: A method for the quantitative analysis of AZD3264 was established and optimized by using HPLC tandem mass spectrometry in dog plasma.

Method: Plasma samples were pretreated using a solvent-induced phase transition extraction method with a methanol solution of omeprazole as the internal standard. Chromatographic separation was performed using a Thermo Hypersil GOLD-C18 (50 mm × 4.6 mm, 3 μm) column with the temperature maintained at 25°C. Mobile phase consisted of 0.1% formic acid in water and acetonitrile in a gradient mode at a flow rate of 0.6 mL/min. Mass spectrometric detection was carried out in selected reaction monitoring mode with positive electrospray ionization, and the mass transitions of AZD3264 and omeprazole were m/z 442.1 → 425.0 and m/z 346.0 → 198.0, respectively.

Results: The intra-batch accuracy was within 95.11-105.06% and the precision was within 6.50-9.98%. The inter-batch accuracy was within 96.83-102.80% with a precision of 7.62-9.50%. The selectivity, sensitivity, linearity, dilution linearity, extraction recovery and matrix effect, stability, and carry-over met all requirements of the guidelines for bioanalytical method validation. AZD3264 showed linear pharmacokinetic characteristics following intravenous administration to dogs at 0.3-2.7 mg/kg.

Conclusions: The developed and validated method was successfully employed in pharmacokinetic studies in dogs following intravenous administration at the doses of 0.3, 0.9, and 2.7 mg/kg.

Highlights: This was the first investigation of the in vivo pharmacokinetic characteristics of AZD3264 in dogs by LC-MS/MS with SIPTE method for plasma sample preparation.