Design objectives of TDDS

1. Deliver the drug to the skin for percutaneous absorption at therapeutic levels at an optimal rate 2. Contain medicincal agents having the necessary physicochemical characteristics to release from the system and partition into the stratum corneum 3. Occlude the skin to ensure one way flux of the drug into the stratum corneum 4. Have a therapeutic advantage over other dosage forms and DDS 5. Not irritate or sensitize the skin 6. Adhere well to the patient's skin and have size, appearance, and site placement that encourage acceptance.