What is the difference between ms contin and kadian (morphine)?

Duration of Action: Kadian seems to reliably work for 12 to 24 hours for "tolerant" patients. Ms conting lasts only 6 to 8 hours and is seldom dispensed by pharmacies due to the multiple companies making a generic version. The generics have even more variabilty in their duration. Kadian uses a delivery mechanism that is more reliable over a longer period. They both contain morphine as the active drug.