On the index, Torrent Pharma, Lupin, Biocon and Dr Reddy's were top underperformers, slumping between 1.5-2%.
Divis Lab and Alkem Laboratories plunged by 1% each. Cipla recorded a marginal drop.
Sun Pharma and Aurobindo Pharma were lead gainers, surging by 1% each. Cadila Healthcare advanced marginally.
In the latest development, it is being known that US-based Pfizer Inc and its group companies have filed a petition against Aurobindo Pharma Ltd and Dr Reddy’s Laboratories in a US court.
Pfizer alleges that the two Indian pharma companies planned to come out separately with their generic version Ibrance which is also called as palbociclib, before the expiration of its patent.
Notably, the US drugmaker filed a patent infringement case against Aurobindo in the US District Court for the District of Delaware, while a case is filed against Dr Reddy's in the New Jersey court.