Comparison of two sustained-release theophylline preparations in adult patients with obstructive airways disease

The bioavailability profiles of two sustained-release oral theophylline preparations, Respbid and Theo-Dur, were compared in 19 adults with obstructive airways disease. Intravenous aminophylline was used as the reference standard. No significant differences were detected in fraction absorbed, peak-trough fluctuations, or time to peak concentrations.