Table 5.

Derived parameters for glycopyrronium

Parameter	Abbreviation	Units	Model-based analysis*	Noncompartmental analysis†
Systemic clearance	CL	l h−1	44.9	42.5
Volume of distribution at steady state‡	Vss	l	102	82.7
Ratio Vss/CL	–	h	2.3	1.95
Absolute bioavailability inhaled without charcoal vs. i.v.	FTOT	–	56.5%	40%
Fraction of dose absorbed through GI tract	FGI	–	3.9%	–
Fraction of absorbed drug going through lung	FRLUNG	–	93.1%	90%
Fraction of absorbed drug going through GI tract	FRGI	–	6.9%	10%
Fraction of lung absorption via fast rate	Ffast	–	12%	–
Fraction of lung absorption via intermediate rate	Fmed	–	9%	–
Fraction of lung absorption via slow rate	Fslow	–	79%	–
Fast lung absorption half-life	t1/2fast	h	<∼0.03 (estimate)	–
Intermediate lung absorption half-life	t1/2med	h	0.45	–
Slow lung absorption half-life	t1/2slow	h	80	52 or 57§
Inferred absolute oral bioavailability	FORAL	–	8.2%	5%
GI tract absorption half-life	t1/2GI	h	2	–

^*Parameters of the population PK model (Table 2), or calculated from the population PK model parameters, with rate constants, K, expressed as half-lives, t_1/2 = ln(2)/K.

^†From Novartis, data on file (CL, V_ss) or Sechaud et al. [12].

^‡V₁ + V₂ + V₃.

^§Terminal half-lives estimated for the inhaled treatments. GI, gastrointestinal; i.v., intravenous; PK, pharmacokinetic.