Current evidence of drug abuse or history of drug abuse within one year of allocation Inability to understand the protocol requirements, instructions and study-related restrictions, the nature, scope, and possible consequences of the study Unlikely to comply with the protocol requirements, instructions and study-related restrictions; e.g., uncooperative attitude, inability to return for follow-up visits, and improbability of completing the study Subject is the investigator or any sub-investigator, research assistant, pharmacist, study coordinator, other staff or relative thereof directly involved in the conduct of the study.