But here's the problem... It's no secret that Pfizer wants to split its Established Products and Innovative Products segments into two separate entities, and it only makes sense to pair the Innovative segment with Allergan for the reasons outlined above. By carving out the Innovative Products business via a merger with Allergan, though, Pfizer's Established Products business would be left in no man's land. As I mentioned previously, this particular segment is experiencing double-digit sales declines because of falling sales for drugs likeCelebrex and Zyvox.