- originator-generic At the end of maintenance period 1, the patients in each formulation group underwent an overnight switching to the same dose of the alternative formulation. The dose was kept stable during the whole length of trial. Clinical evaluations were performed at the end of each period (see flow chart enclosed). The tablets were encapsulated to maintain the blindness. A pharmacokinetic study with a fixed dose (100+25 mg) was performed in a sub-population of 14 subjects. The drugs was administered orally. In case of prolonged, not tolerable akinetic periods during the study, the patients could be rescued with an extra dose of levodopa. Any antiparkinsonian treatment modification or supplementation of antiparkinsonian drugs was not allowed during the study. Any other drug not specific for Parkinson's disease was evaluated by the investigators and allowed only if necessary and if not interfering with the study drugs.