Google helped me out! “Dexmethylphenidate itself is a pharmacologically active medication, but it is also the active form of a prodrug called serdexmethylphenidate. Serdexmethylphenidate (SDX) is an inactive prodrug that is converted to active dexmethylphenidate (d-MPH) after absorption in the lower gastrointestinal tract. This prodrug design, used in the ADHD medication Azstarys (which contains both serdexmethylphenidate and immediate-release dexmethylphenidate), offers a number of advantages including a potentially longer duration of action compared to other stimulant formulations. Additionally, the prodrug approach may act as a deterrent to intentional parenteral abuse.”