HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Stewart, B. A. Articles by Milavetz, G. Search for Related Content PubMed PubMed Citation Articles by Stewart, B. A. Articles by Milavetz, G.

Demonstration of In Vivo Bioequivalence of a Generic Albuterol Metered-Dose Inhaler to Ventolin^*

^* From Healthcare Professional Associates, Amarillo, TX (Dr. Stewart); Allergy/Pulmonary Division, Department of Pediatrics, College of Medicine (Drs. Ahrens and Han, and Ms. Lux), and Division of Clinical and Administrative Pharmacy, College of Pharmacy (Dr. Milavetz), The University of Iowa, Iowa City, IA; and Norton Healthcare, Ltd, Harlow, UK, and Baker Norton Pharmaceuticals, Inc (Drs. Carrier and Frosolono), Miami, FL, subsidiary companies of the IVAX Corporation, Miami, FL.

Correspondence to: Richard C. Ahrens, MD, The University of Iowa, Department of Pediatrics, 200 Hawkins Dr, Iowa City IA 52242-1083; e-mail: richard-ahrens{at}uiowa.edu

Study objective: To use histamine bronchoprovocation and bioassay statistical procedures to evaluate the in vivo bioequivalence of a generic albuterol metered-dose inhaler (MDI).

Design: A randomized, double-blind, balanced, crossover design was used to determine the potency of each generic albuterol MDI actuation relative to Ventolin (Glaxo Wellcome; Research Triangle Park, NC) administration. One treatment was administered on each of 4 study days. A histamine bronchoprovocation procedure was initiated 1.25 h before and 15 min after administration of the study treatment.

Patients: Twenty-four nonsmoking subjects with mild-to-moderate asthma were studied (18 to 65 years of age; FEV₁, > 60% of predicted; and provocative concentration of histamine causing a 20% fall in FEV₁ [PC₂₀], 8 mg/mL at screening).

Interventions: One and four actuations (90 and 360 µg, respectively) of the generic MDI and of Ventolin MDI. Placebo inhalers were used to maintain blinding of inhaler and doses.

Measurements and results: The primary outcome variable was histamine PC₂₀ measured after study treatment administration. A significant dose-effect relationship was present (p < 0.0001). Deviation from parallelism of the generic and Ventolin dose-response curves (p = 0.95) and differences in overall mean response between the two formulations (p = 0.68) were not significant. Using Finney 2 x 2 bioassay statistical procedures, we estimated that one actuation of the generic albuterol MDI was equivalent to 1.01 puffs of Ventolin (90% confidence interval, 0.69 to 1.50).

Conclusion: The generic albuterol MDI delivers a quantity of albuterol to the ß₂-receptor site in the lung that is the bioequivalent to Ventolin. Further, this study reinforces the validity of this statistical methodology for determining in vivo bioequivalence.

Key Words: albuterol • asthma • bronchial provocation tests • histamine

This article has been cited by other articles:

				M.T. Newhouse, P. Patel, and M. Parry-Billings Protection against methacholine-induced bronchospasm: salbutamol pMDI versus Clickhaler(R) DPI Eur. Respir. J., May 1, 2003; 21(5): 816 - 820. [Abstract] [Full Text] [PDF]

				R. C. AHRENS, M. E. TERESI, S.-H. HAN, D. DONNELL, J. A. VANDEN BURGT, and C. R. LUX Asthma Stability after Oral Prednisone . A Clinical Model for Comparing Inhaled Steroid Potency Am. J. Respir. Crit. Care Med., October 1, 2001; 164(7): 1138 - 1145. [Abstract] [Full Text] [PDF]