Bioavailability of a sustained-release dyphylline formulation.

The bioavailability of dyphylline from sustained-release tablets, studied in seven normal subjects given a single dose of the drug, was 67.8 per cent of that from conventional tablets. In three subjects given 40 mg/kg dyphylline as sustained-release tablets every 8 hours for four days, serum dyphylline concentrations were maintained above 7.88 microng/ml once steady state was achieved. No adverse effects were noted, though in one subject peak serum dyphylline concentrations reached 30 microng/ml after multiple doses.