Relative systemic availability of budesonide in patients with asthma after inhalation from two dry powder inhalers.
BACKGROUND
To improve dosing consistency and product features, budesonide inhalation powder delivered via a dry powder inhaler (DPI) (DPI-A 200 microg) was redesigned to include lactose, a newly shaped mouthpiece, and a new dose indicator (DPI-B). Budesonide DPI-B is available in two strengths (90 microg, 180 microg).


OBJECTIVE
To compare the relative rate and extent of the systemic availability of budesonide inhaled via DPI-A and DPI-B and test for systemic absorption bioequivalence.


METHODS
Adults (n = 37) with asthma as defined by the American Thoracic Society were randomized in an open-label, crossover, single-center, single-dose study to budesonide DPI-A 200 microg x 4 inhalations, budesonide DPI-B 180 microg x 4 inhalations, or budesonide DPI-B 90 microg x 8 inhalations, on 3 days, each separated by a washout period of >or= 5 days. Plasma samples were collected immediately before and up to 12 h after dosing. Primary pharmacokinetic variables were area under the drug plasma concentration-time curve from 0 to infinity (AUC(0-infinity)) and maximum plasma concentration (C(max)); plasma concentration at 12 h (C(12h)) and time to maximum plasma concentration (T(max)) were secondary variables. Treatments were considered bioequivalent if the 90% confidence intervals (CIs) for their AUC(0-infinity) and C(max) ratios fell between 80 and 125%. Adverse events were collected.


RESULTS
The 90% CIs for the ratios of AUC(0-infinity) and C(max) for budesonide DPI-A 200 microg and DPI-B 180 microg and for both budesonide DPI-B strengths fell between 80% and 125% (AUC(0-infinity): budesonide DPI-B 180 microg x 4/DPI-A 200 microg x 4: 96.3% [90% CI: 90.9, 102.1]; budesonide DPI-B 180 microg x 4/DPI-B 90 microg x 8: 92.2% [90% CI: 87.0, 97.7]; C(max): (budesonide DPI-B 180 microg x 4/DPI-A 200 microg x 4: 100.4% [95% CI: 92.1, 109.4]; budesonide DPI-B 180 microg x 4/DPI-B 90 microg x 8: 94.4% [90% CI: 86.6, 102.9]). No differences in C(12h) and T(max) were found between treatments. All treatments were well tolerated.


CONCLUSIONS
Budesonide DPI-A 200 mug and DPI-B 180 mug have systemic absorption bioequivalence, and DPI-B 90 microg and 180 microg are dose-strength equivalent when administered at the same dose. These results may not be generalized to all patients with asthma, as this analysis included only patients with mild-to-moderate asthma aged >or= 19 years.
Persson
Gunnar
G
Department of Clinical Pharmacology, Clinical Research/Allergy Section, Lund University Hospital, Lund, Sweden.
Ankerst
Jaro
J
Gillen
Michael
M
Bengtsson
Thomas
T
Thorsson
Lars
L
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019819:Budesonide / Q000008:administration & dosage / Q000493:pharmacokinetics*; D016001:Confidence Intervals; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D036501:Metered Dose Inhalers; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016037:Single-Blind Method; D016896:Treatment Outcome
D001993:Bronchodilator Agents; D019819:Budesonide