I am working on a roll-on formulation and I am using HEC as a thickener at 0.9% in nothing but both at cold and warm water (50 'C) but I couldn't dissolve it. I mixed it with mechanical stirrer at 500 rpm sometimes even more. Is it beacause my chemicals or my methode ? I used two different HEC but ı couldn't dissolve both anyway. To conclude if you have any suggestions I would be so glad, thanks in advance.