Rug Safety Evaluation and Pharmacovigilance

Hi there,
I want you to write 1000 words in Drug Safety Evaluation and Pharmacovigilance.
I have attached the assignemnt questions and the powerpoint.
there are three question in the assignment that are:
Write a 1000 word essay on the following:

What are the limitations of pre-marketing clinical trials in determining the safety profile of a new drug?
What other methods of safety monitoring are available once the drug is marketed and how do these differ from pre-marketing?