Nope, not allowed. The best way to decide if something is going to work in a carryon, and is larger than 3.4oz (100ml), is to see if it holds it's shape when taken out of it's container. Obviously, those ice packs are not going to hold their shape.
You can pack them in your checked bags though. What a lot of folks do is to freeze a bag of corn and use that to keep things cool in their carryon. Or freeze grapes...yum!!