- Background Chronic LD therapy is associated with motor complications often related to the drug's peripheral pharmacokinetics. LD's absorption is confined to the upper part of the GI tract and is characterized by a short clearance half-life. Accordion pill carbidopa-levodopa (AP CD-LD) is a unique gastro-retentive formulation designed for achieving stable LD plasma levels to reduce both motor fluctuations and daily dosing requirements. The AP is a multi-layer, planar structure that is composed of biodegradable films (IIG-listed excipients) folded in an accordion shape into a standard size capsule. Upon reaching the stomach, the capsule dissolves, the AP unfold and is usually retained in the stomach for up to 12 hours. Gastric retention is achieved under a regular calorie diet. The AP CD-LD combines immediaterelease and controlled-release profiles of the CD and LD constituents.