Hello, 

Im Sorry but you cannot do M.Pharm after D.Pharm. In order to do M.Pharm, you must need to have an Undergraduate degree.

D.Pharm is Diploma in pharmacy which includes 2 year programme , where as B.Pharm is an undergraduate degree which is 4 year programme. You can do M.Pharm if you have completed B.Pharm. Also, one similarity between D.pharm and B.pharm is that both requires a 6 month internship to be done before getting the degree. These two - B.Pharm and D.Pharm are the common pharmocology programmes. They need to be approved either by AICTE - All India Council of Technical Education or PCI - Pharmacy Council of India. Especially B.Pharm must be approved by either of them for undergoing further studies.
So what are all B.Pharm, M. Pharm, D.Pharm and Phram.D? 

D.Pharm - This a Diploma course in Pharmacy which is a 2 year programme. In order to join D.Pharm you need to pass 10+2 with minimum 40% aggregate and Physics , Chemistry and Biology / Mathematics as necessary subjects. You cannot Do M.Pharm after D.pharm.

 B.Pharm - This is an undergraduate degree , which is a 4 year programme. You can do B.Pharm after your 10+2 with Physics , Chemistry, Biology or mathematics as necessary subjects along with the Entrance exam ranks. You also have option to get admitted to 2nd year B.Pharm as lateral entry after your D.Pharm as well from a PCI recognised institute.

M.Pharm - M.Pharm is a Postgraduate programme . It is a 2 year programme. You can join M.Pharm only after completing B.pharm from PCI approved institute and 55% aggrgate in 4 years of B.Pharm. In order to get admission in M.Pharm you need to Take GPAT (Graduate Pharmacy Aptitude Test). This entrance exam allows you to get admission in AICTE approved Institution. 

Pharm D - This is actually a 6 year course. It is called Doctor of Pharmacy. You can directly apply for PhD if you do PharmaD. You are also eligible to have  Dr. before your name. This is a PG course. You can enter into Pharma D if you- 

• pass 10+2 with Physics, chemistry and Maths / Biology. 
• Complete D.pharma from PCI approved institution
• any other qualification approved by PCI 

After your B.Pharm also you can admit into Pharma D. It will be a 3 year course that time. You need to have completed B.Pharm from a PCI approvved Institute. It is wuivalent to Lateral entry to Pharm-D.

Hope this helps your query. 

Good Luck.