Pharmacokinetics of scopolamine hydrobromide oral disintegrative microencapsule tablets in Beagle dogs determined with LC-MS/MS

The study aims to elucidate the characteristics of pharmacokinetics of scopolamine hydrobromide oral disintegrative microencapsule tablets in healthy Beagle dogs.  Chromatographic separation was performed on a C₁₈ column (100 mm × 3.0 mm, 3.5 μm) with methanol − 2 mmol·L⁻¹ ammonium formate (25∶75) as the mobile phase.  A trip-quadrupole tandem mass spectrum with the electrospray ionization (ESI) source was applied and positive ion multiple reaction monitoring mode was operated.  Six Beagle dogs were randomly devided into two groups.  They received oral single dose of scopolamine hydrobromide oral disintegrative microencapsule tablets 0.6 mg (test tablet) or scopolamine hydrobromide normal tablets (reference tablet).  Plasma samples were collected at designed time.  Plasma concentration of scopolamine hydrobromide was determined by LC-MS/MS and pharmacokinetic parameters were calculated.  The pharmacokinetic parameters of test tablet vs reference tablet were as follows: C_max: (8.16 ± 0.67) ng·mL⁻¹ vs (3.54 ± 0.64) ng·mL⁻¹; t_1/2: (2.83 ± 0.45) h vs (3.85 ± 0.82) h; t_max: (1.25 ± 0.27) h vs (0.42 ± 0.09) h; AUC_{0−12 h}: (25.06 ± 3.75) h·ng·mL⁻¹ vs (9.59 ± 1.02) h·ng·mL⁻¹; AUC_0−∞: (26.30 ± 3.92) h·ng·mL⁻¹ vs (10.80 ± 1.45) h·ng·mL⁻¹; MRT_{0−12 h}: (3.38 ± 0.34) h vs (3.86 ± 0.26) h; MRT_0−∞: (3.98 ± 0.63) h vs (5.37 ± 1.00) h.  The absorption rate and AUC of test tablet is different from that of reference tablet.  The bioavailability of test tablet is better than those of reference tablet.