Bioavailability and pharmacokinetics profile of helicid in beagle dogs using gradient elution high performance liquid chromatography electrospray ionization mass spectrometry

• A novel LC–ESI-MS quantitation method was developed.
• The LOD and LLOQ were 0.3 and 1 ng/mL, respectively.
• A random two-period crossover study in 6 dogs was adopted.

A simple, sensitive and reliable gradient elution high performance liquid chromatography electrospray ionization mass spectrometry (HPLC–ESI-MS) method was developed for quantifying helicid in dog plasma. The limit of detection (LOD) and the lower limit of quantitation (LLOQ) were 0.3 and 1 ng/mL, respectively. This method was validated for selectivity, linearity, accuracy and precision, extraction recoveries, matrix effects, carry-over, cross-talk, dilution integrity, stability and incurred sample reanalysis (ISR). Bioavailability and pharmacokinetic parameters of helicid in beagle dogs were researched from a two period crossover design study. After intravenous administration (i.v.), helicid had a mean (±SD) AUC0–∞ of 12062.06 ± 2482.69 ng/mL h and terminal half-life (t1/2z) of 2.91 ± 1.37 h, while Cmax was 35613.23 ± 8157.18 ng/mL. Following intragastric gavage administration (i.g.), AUC0–∞ was 7589.16 ± 1797.20 ng/mL h along with a longer t1/2z of 4.10 ± 4.35 h. Cmax was researched at 0.58 ± 0.20 h. The absolute bioavailability (F) of helicid was 15.74 ± 1.87%.