I agree with 99.9% of what young skywalker said. In the research area, you would need a PhD to be respected. However, it is not so much the type of degree you should get, the but number of publication, the quality of your publication, the area you are doing research in (is it hot, is it cutting edge), and who you choose to be your advisor.
There are some positives I can see with getting a pharmD/PhD. Free tuition, better chance at a faculty position, more job opportunities (clinical and research jobs), better understanding of how the drug works.
If you are just interested in pure theoretical research, then I agree with young skywalker, go just for the PhD. The pharmD is very clinical oriented.
You don't have to do research in pharmacology. Many things are drug related in which you can go into. Proteinomics, immunology, physical biochemistry, pharmacuetics, and etc. You can either take a basic science research class as an elective or just talk to a faculty memember and ask him/her if you can work with them on your free time. You will just have to work out a schedule with the faculty memember.
For me, I am working on computer modeling of various mutant DNA structure. No chemicals and no drug involve. However, it does cut into my study time. Between health fair, work, and school work, you will have to decide is this what you really want to try or do. For me, it was since I plan to work in industry after this.