Basically just try to be yourself. I found out that the Professor would have considered me with a C in chem because I was jammy enough to come acorss quite well in my interview.
Basically, if you have put down in your personal statement that you have read any scientific journals then make sure you at least memories one interesting thing to say about it. I memorised a piece about MRSA and how a new antibiotic could help destroy the bacterial cross links... yada yada... It shows that you take an interest in science as a whole.
If you mentioned anything about work experience you did during the summer, talk about all the things that you did and how you found it interesting.
At every interview I had I was asked exactly the same question:
'why do you want to study pharmacy at [insert uni here] ?'
Try and give some good responses, even if it is just an insurance. Mention that you have heard that the uni has a good reputation and a high quality of teaching. But dont just go on about that, also mention that you like the surrounding areas and campus as well. One of the Professors who interviewed me stated that he also wanted applications who were here for the whole experience of the local area as well as the course.
Another thing I got asked was how I got interested in Pharmacy as a whole. That was a common question.
Most importantly, I found that it was extremely handy to come across as a passionate individual who likes to work hard. I emphasised how much pharmacy was my dream and how interested I found the topic, and equally how excited I would be to study this at degree level. If you come across as sincere and a personal with a drive to do well in the subject, that is what really counts. Schools of Pharmacy want students who are passionate about Pharmacy, and not those who 'put down pharmacy because they might not get into medicine'....
Anyway, good luck and I am sure you will do well!
Come across as passionate and genuine and you will be fine! But then again if you are passionate about Pharmacy (which I guess you must be to want to do it), then my advice is just common sense!
Lastly... ENJOY YOURSELF! Having an interview is not just about whether the Uni wants to give you an offer, it is also a very important indication to you about whether you will be happy studying at that institution. It is just as much about them judging you as it will be you judging the uni. So dont think that you are the only one who should be feeling nervous.