[Bioavailability of a new theophylline chewable pill]

Oral administration of theophylline as a chewable tablet is an alternative to the conventional parenteral route used in the treatment of acute dyspnoea in asthma bronchiale and other obstructive pulmonary diseases. To investigate the bioavailability of this preparation, a randomised 2-period cross-over study on the pharmacokinetics of a 100 mg theophylline single dose was conducted comparing oral administration as a chewable tablet (test medication) or as solution (reference) in 14 healthy male volunteers (age 21-31 years, body weight 60-90 kg). Bioequivalence of the tested formulations could be confirmed basing on the primary pharmacokinetic parameters (AUC, Cmax) for the extent and rate of theophylline absorption. The criterion of bioequivalence was also met for the secondary parameters, including terminal elimination half-life, mean residence time, time point of maximal plasma concentration and the ratio Cmax/AUC. Hence, the chewable theophylline tablet is bioequivalent to theophylline given as a solution. With regard to therapeutic efficacy, equivalence to medication by droplets can be expected.