What are the main components of the 1952 Durham Humphrey Act? How was this law attempting to protect the public?

What are the main components of the 1952 Durham Humphrey Act? How was this law attempting to protect the public?

What are the main purpose and influence of the Kefauver-Harris Amendment of 1962? How was this law attempting to protect the public?
What is the main purpose of the Comprehensive Drug Abuse Prevention and Control Act of 1970?