Clinical research

Please refer to the link provided below for an exhaustive list of colleges which offer courses in clinical research in Mumbai. You should be able to navigate to a college of your choice using the filters on the web page. Additionally, you can download their brochure which contains important information regarding admissions, reviews and placements.
https://www.shiksha.com/medicine-health-sciences/paramedical/colleges/clinical-research-colleges-mumbai

Ph.D is a doctorate degree which can only be done after post graduation. Since D.Pharma is a Diploma so you will not be able to pursue Ph.D. You can pursue Ph.D only after post graduation like M.Pharma, M.Sc, etc. Clinical Research is a very good field and has great scope in India in coming times.

Pursuing MD in Canada or USA will launch you into a luxury career, so that would be the best option. If you are interested in further studies in your related field or MBA in hospital management, it can be a good option too, but you may face a lot of competition from management students and http://www.timesjobs.com/candidate/careerresources/htmls/clinical_research.jsp that link will help you with clinical research and it's benefits in future.

Hi, if you have graduated from India you must clear the licensing exam, the Foreign Pharmacy Graduate Equivalent Exams (FPGEE) . Check the respective website for clarity.Since you are already there in US you should have an upper hand in gaining access to first hand information on such rules, so make use of your stay there.