Comparative Study on the Pharmacokinetics of Ibrutinib and Its Phospholipid Complex in Beagle Dogs / 中国药房

ABSTRACT

OBJECTIVE： To establish a method for the determination of ibrutinib concentration in Beagle dogs， and to compare the pharmacokinetic difference of ibrutinib and its phospholipid complex in Beagle dogs. METHODS： The male Beagle dogs were randomly divided into Ibrutinib suspension group and Ibrutinib phospholipid complex group （using 0.5％ Carboxymethylcellulose sodium solution and water as solvent， mass concentration of 5 mg/mL）， with 3 dogs in each group. All Beagle dogs were given relevant medicine suspension （15 mg/kg） intragastrically， and 2 mL of blood were collected from the forelimb vein before administration and 0.017， 0.083， 0.25， 0.5， 1， 2， 4， 8 and 12 h after administration. Plasma concentration of ibrutinib was were determined by HPLC. Using tolbutamide as internal standard， the determination was performed on Betasil C18 column with mobile phase consisted of acetonitrile-water （contained 0.5％ triethylamine， pH value adjusted to 3.2 with glacial acetic acid）（45 ∶ 55， V/V） at the flow rate of 1.0 mL/min. The detection wavelength was set at 256 nm， and the column temperature was 25 ℃. The sample size was 20 μL. The pharmacokinetic parameters of Beagle dogs in 2 groups were calculated by using DAS 2.1.1 software. The difference of ibrutinib and its phospholipid complex were investigated by t-test. RESULTS： The linear range of ibrutinib was 5-5 000 ng/mL （r＝0.999 8）； lower limit of quantitation was 5 ng/mL； minimum detection limit was 1.3 ng/mL. RSDs of intra-batch and inter-batch were lower than 10％； the accuracy was 98.81％-106.20％； the extraction method did not influence the determination of the substance to be measured. Pharmacokinetic parameters of Ibrutinib suspension and Ibrutinib phospholipid complex with signal intragastric administration were as follows： tmax were（2.00±0.09） and （0.25±0.03）h； cmax were（610.67±21.36） and （2 308.72±100.41）ng/mL； AUC0-12 h were （4 516.67±383.43） and （9 394.16±874.21）ng·h/mL； AUC0-∞ were （6 174.32±525.27） and （10 717.33±897.62）ng·h/mL，with statistical significance （P＜0.05）. The relative bioavailability of Ibrutinib phospholipid complex was 207.99％. CONCLUSIONS： Established HPLC method is simple， specific and sensitive， and can be used for plasma concentration determination and pharmacokinetic study of ibrutinib. The pharmacokinetic parameters of phospholipid complex prepared from ibrutinib changed significantly， drug absorption is accelerated and bioavailability is improved significantly.