Originally Posted by SuzanneSLO
I think that you have actually stated the rule: You cannot put a 4 oz contact lens solution in your quart bag but you can take it in your carryon if you declare that you have it as an essential medicine as an exception to the no liquids rule. Remember that it is all about form and not about substance and that should help.
But why would you "declare" it at all when you can probably easily hide it in your carryon?