This study will be an open-label, randomized, three-period cross-over pharmacokinetic evaluation of CVT-301 compared with the Reference Listed Drug (RLD), orally administered carbidopa/levodopa, in healthy volunteers.

The primary objective is to determine the relative bioavailability of two CVT-301 (dose levels 1 and 2) capsules compared with the Reference Listed Drug (RLD) on a per milligram basis.

Inclusion Criteria:

• In good general health as determined by medical history, physical examination, electrocardiogram (ECG), vital signs, and clinical laboratory evaluation;
• FEV1/FVC above the 5th percentile of the predicted normal distribution for age and gender;
• Body Mass Index (BMI) between 18 - 30 kg/m2

Exclusion Criteria:

• No flu-like syndrome or other respiratory infections within 2 weeks prior to the Screening Visit;
• Negative drug and alcohol testing;
• Negative pregnancy test for female subjects