He told CNBC's "Halftime Report" on Thursday that while it's likely there will come a day where the pharmaceutical company sells a lot of its non-core assets, Bausch & Lomb will not be one.
In fact, Ackman says it's possible that in the future, the brand could become "an even more dominant part of the franchise." He said Valeant may someday even rename itself Bausch & Lomb.
"Bausch & Lomb has a very low tax basis relative to what we believe it is worth. We think it's a great franchise. We think it's a franchise that you build on and it's really the core of the company," he said.
Ackman's hedge fund, Pershing Square Capital Management, has had a tough year, hit in particular by its stake in Valeant. Earlier this year, Ackman said that "of course" he regrets his initial investment in the embattled pharmaceutical company.
CNBC reported Wednesday that J. Michael Pearson, former CEO of Valeant Pharmaceuticals, unloaded more of his personal holdings than originally thought. The founder and CEO of Pershing Square said that "it's kind of sad that he was forced to sell out at this price."
U.S.-listed shares of Valeant traded near $22.40 on Thursday, a fraction of its all-time intraday high of $263.81.
According to documents not made public yet but obtained by CNBC, Pearson sold nearly 5 million shares and options for a total of $96.8 million. The news came on the same day that the Sequoia Fund revealed it is completely out of the stock. Sequoia was at one time the largest Valeant shareholder.
Also Wednesday, short seller Andrew Left said that Valeant's stock could be headed to zero, sinking share prices.