Pharmacokinetic Studies with a Dual-Release Formulation of Levodopa, a Novel Principle in the Treatment of Parkinson’s Disease

The objectives of the two studies reported here were the investigation of the influence of tablet breaking and food on the pharmacokinetics of levodopa and 3-O-methyldopa (3-OMD) after administration of a new levodopa/benserazide formulation with a biphasic drug delivery profile (Madopar ® DR). Both studies had an open-label, randomised, two-way crossover design and were conducted in 12 healthy young subjects. The pharmacokinetics of levodopa and 3-OMD after one intact or two halved tablets were very similar with average C max and t max 1.9 mg·l –1 and 1.2 h, respectively. Administration of the formulation after a standard breakfast did not influence the extent of levodopa absorption but increased the absorption rate. C max and t max were on average 2.1 mg·l –1 and 1.3 h, respectively, in the fed condition and 1.5 mg·l –1 and 2.5 h in the fasted condition. The presence of food did not markedly affect the plateau in levodopa levels between about 1 and 3 h after intake. In conclusion, the release characteristics in healthy subjects of the new levodopa/benserazide formulation are influenced only to a minor extent by concomitant intake of food or by tablet breaking.