Well, after many failed attempts using a Carbomer to thicken up a formula I finally decided to take a look at Cellulose Thickeners. More specifically I've been working with MethylCellulose and Hydroxyethylcellulose. I am using 1% Cellulose with 1% Triethanolamine to thicken and getting great results. No more air bubbles or stringy flow!!
My only question is really with regards to stability and preservation. We normally use a DMDM to preserve, but a few years back had a bad batch due to excessive use of Xantham Gum. Do the cellulose thickeners need any special preservation techniques? Or anything else which help enhance a formula's stability.