See IAS IPS is not a way to earn only but also a responsibility. So If you aren't very much passionate about it then it will be hard for you to compete in UPSC.

A Pharmacy business will give you a lot of money which will not be fixed nor certain.

So its up to you what you want to do? If you care for only money then go business but If you feel like serving your nation then go for UPSC CSE. Pharmacy business is also a great work for the society but its not like Civil Services.

I hope you got my point.