摘要：A comparative pharmacokinetic study between a sustained-release theophylline tablet (Theona[○!R] and aminophylline powder following multiple oral administrations every 12 h at a 200 mg theophylline dose was performed in ten healthy adult volunteers. As the results, theophylline in Theona[○!R] revealed almost completely absorbed as is aminophylline. A peak-trough difference with Theona[○!R] was less than half of that with aminophylline powder. These results suggest that Theona[○!R] has excellent characteristics as a sustained-release preparation. In addition, in order to investigate dose-dependent kinetics for theophylline, the relationship between average plasma level and dosage was examined with Theona[○!R]. The plasma level showed proportional change at the low concentrations. When the plasma level was close to 10 μg/ml, however, dosage increment results in an increasingly greater change of plasma level, which may indicate a high risk of toxicity.
