A Study of the Safety and Tolerability of a Single Dose Administration of CVT-301 (Levodopa Inhalation Powder)

All subjects will receive 1 dose of CVT-301 and 1 dose of placebo inhalation powder, to be taken concomitantly with their standard oral medication in 2 dosing periods. The order of treatment will be randomized, with subjects assigned to 1 of 2 sequences CVT-301 (A) administered first, followed by placebo (B), or the reverse order (BA)

All subjects will receive 1 dose of CVT-301 and 1 dose of placebo inhalation powder, to be taken concomitantly with their standard oral medication in 2 dosing periods. The order of treatment will be randomized, with subjects assigned to 1 of 2 sequences CVT-301 (A) administered first, followed by placebo (B), or the reverse order (BA)