Bioavailability, efficacy, and tolerance of two sustained-release theophylline dosage forms in adult patients with bronchial asthma.

Twenty otherwise health adults with a diagnosis of reversible obstructive airways disease were treated for one month in a single-blind crossover study with approximately equivalent doses of Elixophyllin SR capsules or Theo-Dur tablets. Both products provided evidence of efficacy by improvement in pulmonary function tests, and both were well tolerated. There were no significant differences between the two products with regard to bioavailability, efficacy, or tolerance. Both dosage forms appeared to have similar kinetic properties within the context of the study.