Single- and multiple-dose pharmacokinetics of inhaled indacaterol in healthy Chinese volunteers

Indacaterol is an inhaled, ultra–long-acting β₂-agonist that provides 24-h bronchodilation with once-daily dosing in patients with chronic obstructive pulmonary disorder. This study evaluated the pharmacokinetics, safety, and tolerability of multiple daily inhaled doses of indacaterol 150 or 300 μg once daily in healthy Chinese volunteers. This was a single-center, randomized, double-blind, multiple-dose, parallel-group study, placebo-controlled trial including two doses of indacaterol: 150 and 300 μg. Serum indacaterol was quantified using high-performance liquid chromatography-mass spectrometry with a lower limit of quantification of 0.01 ng/mL. The pharmacokinetic parameters were analyzed using non-compartmental analysis and included C _max, T _max, and AUC_0–24h on Day 1 and AUC_0–24h,ss, C _max,ss, C _min,ss, C _av,ss, T _max,ss, T _1/2, T _1/2,acc, CL/F, V _z/F, and R _acc on Day 14 (after repeated once-daily doses). Safety analyses were recorded using physical examination, biochemical tests, and ECG. Indacaterol steady state was achieved after 12–14 days of daily dosing. The mean effective half-life of indacaterol (based on drug accumulation at steady state) was 33.9 and 35.8 h for 150 and 300 μg, respectively. Systemic exposure to indacaterol increased 1.27 and 1.34-fold between the 150- and 300-μg doses on Day 1 (first dose) and Day 14 (repeated dose), respectively. Indacaterol 150 and 300 μg were safe and well tolerated in these volunteers. The pharmacokinetics of multiple inhaled doses of indacaterol 150 and 300 μg (for 14 days) were consistent with moderate systemic accumulation at steady state after repeated once-daily inhalation in healthy Chinese volunteers.