The investigation focuses on Parkinson’s disease, a brain disorder that causes shaking, stiffness and slow movement. The medication being examined is levodopa, a drug that replaces dopamine, a chemical needed for smooth movement. To help levodopa work better and cause fewer side effects, a second medicine called carbidopa is given first. Two ways of delivering levodopa are compared: an inhaled powder called Inbrija (inhaled means breathed in as a powder) and a new inhaled powder that comes pre‑measured, named Levodopa Cyclops™.

The purpose of the study is to determine the dose at which the two inhaled forms provide a similar amount of levodopa in the body. Healthy adult volunteers will receive a single dose of each product on separate occasions, with a short break between each period. Before each inhaled dose, participants will take carbidopa by mouth about one hour earlier while fasting (no food). The study will record how quickly the medicine appears in the blood and will monitor safety through basic medical checks.