In 1975, pemoline (Cylert) was approved by the U.S. FDA for use in the treatment of ADHD. While an effective agent for managing the symptoms, the development of liver failure in 14 cases over the next 27 years would result in the manufacturer withdrawing this medication from the market. New delivery systems for medications were invented in 1999 that eliminated the need for multiple doses across the day or taking medication at school. These new systems include pellets of medication coated with various time-release substances to permit medications to dissolve hourly across an 8–12 hour period (Metadate CD, Adderall XR, Focalin XR) and an osmotic pump that extrudes a liquid methylphenidate sludge across an 8–12 hour period after ingestion (Concerta).