Souparnika, ideally D.Pharma is a Doctoral course in Pharmacy with a duration of 6 years, 5 years of course and 1 year mandatory internship. Now GPAT is an entrance exam for admission to M.Pharmacy which is a Post Graduation course. It will be a step down your academic track if you want to study M.Pharmac after D.Pharma. It is like going back to your 12th after studying B.Sc. So it is not helpful for you if you want to appear for M.Pharma after Pharma. D