Urinary pharmacokinetic methodology to determine the relative lung bioavailability of inhaled beclometasone dipropionate.
Br J Clin Pharmacol
; 74(3): 456-64, 2012 Sep.
Article
em En
| MEDLINE
| ID: mdl-22299644
ABSTRACT
AIM:
Urinary pharmacokinetic methods have been identified to determine the relative lung and systemic bioavailability after an inhalation. We have extended this methodology to inhaled beclometasone dipropionate (BDP).METHOD:
Ethics Committee approval was obtained and all subjects gave consent. Twelve healthy volunteers received randomized doses, separated by >7 days, of 2000 µg BDP solution with (OralC) and without (Oral) 5 g oral charcoal, 10,100 µg inhalations from a Qvar(®) Easibreathe metered dose inhaler (pMDI) with (QvarC) and without (Qvar) oral charcoal and eight 250 µg inhalations from a Clenil(®) pMDI (Clenil). Subjects provided urine samples at 0, 0.5, 1, 2, 3, 5, 8, 12 and 24 h post study dose. Urinary concentrations of BDP and its metabolites, beclometasone-17-monopropionate (17-BMP) and beclometasone (BOH) were measured.RESULTS:
No BDP, 17-BMP or BOH were detected in any samples post OralC dosing. Post oral dosing no BDP was detected in all urine samples and no 17-BMP or BOH was excreted in the first 30 min. Significantly more (P < 0.001) BDP, 17-BMP and BOH were excreted in the first 30 min and the cumulative 24 h urinary excretions post Qvar and Clenil compared with Oral. The mean ratio (90% confidence interval) of the 30 min urinary excretions for Qvar compared with Clenil was 231.4 (209.6, 255.7) %.CONCLUSION:
The urinary pharmacokinetic methodology to determine the relative lung and systemic bioavailability post inhalation, using 30 min and cumulative 24 h post inhalation samples, applies to BDP. The ratio between Qvar and Clenil is consistent with related clinical and lung deposition studies.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Beclometasona
/
Carvão Vegetal
/
Glucocorticoides
/
Pulmão
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article