MSc Psychology or Master of Science in Psychology is a 2 year full-time postgraduate course  .

For pursuing the MSc Psychology course the candidate should have a BA/BSc in Psychology degree with minimum of 50% in their undergraduation.

Students holding any other degree such as Bachelor of Social Work (BSW), BA Sociology, B.Sc. Home Science, B.A. Philosophy or B.Ed. with Psychology Papers are also eligible to apply for this course.

The colleges see to it that the student who is seeking admission   in this course has psychology in their UG course.

Having said this since you have opted for  B.Pharm  there is a very rare possibility for you to get admission in this postgraduation course of MSc Psychology.

I also see that you have a interest in Research so you can either do M.Pharm or MSc in clinical research and change the direction of your career towards in clinical research. Its also a 2 year Post graduation course , helping you to develop knowledge in advancement and doing new innovation for productions of medicines and vaccines.

Thank you & All the Best