Everywhere I've read said it doesn't (not sure about sweetener though), but whenever I mix in my creatine with my protein I just FEEL like it's not getting to my muscles at all because of how it's diluted. Even if the "science" said that it's fine to take that way, I'd still rather just take the 5g in my mouth directly and wash it down with a drink. Feels better.
I take supplements with food if possible and when applicable. Sometimes actual food contains other molecules that help with absorption of the given nutrient.
I take CLA with beef/chicken/eggs, because those things contain naturally occuring CLA. Our body is used to absorbing CLA with those nutrient profiles.
I take a multivitamin with a meal containing proteins, fats, and vegetables. Especially vegetables. Some of these vitamins are typically found in nature along with different cofactors and molecules that actually help with absorption.
I take creatine with juice or protein, as this has been shown to help absoption vs taking creatine by itself.
I take a fiber supplement by itself, but shortly before eating carbs, because fiber helps slow the absorption of sugars into the blood, which tames insulin response.
I take cinnamon and turmeric before eating a meal because it lowers blood triglycerides after eating.