Pharmacokinetics (rat & human)

Line chart of rat i.v. PK (illustrative)

PK parameters (rat)

Dose_iv_mg_per_kg Vz_L_per_kg CL_L_per_h_per_kg ke_1_per_h t1_2_h (derived) F_oral_percent
2.5 6.2 0.7 0.113 6.14 20.7

Rat single-dose PK (validated UPLC-MS/MS; Sprague–Dawley)

  • Dose: 2.5 mg/kg i.v.; 20 mg/kg p.o.
  • Vz (i.v.): 6.2 ± 2.3 L/kg
  • CL: 0.7 ± 0.2 L/h/kg
  • Absolute oral bioavailability (F): 20.7% (Non-compartmental analysis from plasma concentration–time.)

    • From CL/Vz, kₑ ≈ 0.113 h⁻¹ → t½ ≈ 6.1 h (derived).


    Human exposure (kratom product; healthy volunteers)

    Following a kratom product orally, speciociliatine was the major circulating alkaloid with AUC₀-inf ≈ 5120 nM·h, about 12× mitragynine (AUC₀-inf ≈ 420 nM·h), despite ~4× lower content of speciociliatine than mitragynine in the product. PMC

    Interpretation for readers
  • The high circulating exposure suggests speciociliatine may disproportionately contribute to kratom’s systemic pharmacology compared with its label content; emphasize that these data reflect one product/setting and may vary by formulation and metabolism.