Dear Fathima,
Yes, you can take admission to pharmacy courses after B. Sc but for that you must have biology in 10+2 examination.
But I suggest you to not waste your time for doing B. Pharma as it will be two graduations. After doing B. Sc you could go for M. Sc and also after B. Pharma you could go for Masters. So you will waste both your time and efforts.
You can't go for M. Pharma without pursuing a course in B. Pharm. If you interested in pharmacy course then you can opt for PG course in clinical research. It's a better option for you.

All the best for your future!!!