The testing phase is very important and when it comes to the new drugs it becomes mandatory before it was sent to the market.Morally speaking,no one has the right to take other life but when you see the other side of the coin you will realise this is better.Think about a scenario when you don't test a particular drug and release it in the market.You are playing with the lives of human beings.The damage will be manifold than playing with the Rats.
-Deepak.