Choosing Gelling Agent for Cold-Process Facial Cleanser Gel
Question
What dry powder gelling agent dissolves quickly in cold water to form a non-sticky, non-slippery, easy-to-rinse gel for an oil-removing facial cleanser, compatible with SLS and alkaline surfactants? Considering Carbopol, Xanthan Gum, and Methylcellulose, which is best for fast dissolution and desired texture/rinsability?
Answer
Choosing a Gelling Agent for Cold-Process Facial Cleanser
Based on your requirements for a dry powder gelling agent that dissolves quickly in cold water to form a non-sticky, non-slippery, easy-to-rinse gel for a facial cleanser with SLS and alkaline surfactants, here's a comparison of the options you mentioned:
Hydroxypropyl Methylcellulose (HPMC): Specifically, the HPMC ColdMix™ type is designed to dissolve in cold water without heating. It is a non-ionic polymer, which generally results in a smoother, less sticky feel and can be easier to rinse off compared to anionic polymers. It is also compatible with electrolytes and works well in alkaline pH ranges, making it suitable for your formula with SLS and alkaline surfactants. You will need to disperse it in cold water first, and then adjust the pH to alkaline (around 8.5-9.0) to achieve thickening.
Carbomer (Carbopol): Carbomer Ultrez grades (like U10, U21, Ultrez 30) are designed for easy dispersion in cold water. They form clear gels and are compatible with electrolytes and wide pH ranges (including alkaline). However, Carbomers are anionic after neutralization, which might give a slightly different feel or rinsability compared to non-ionic HPMC. They also require neutralization with an alkali to thicken.
Xanthan Gum: Xanthan Gum dissolves in cold water, especially finer mesh sizes or easy-dispersing grades. It is compatible with electrolytes and works over a wide pH range. However, Xanthan Gum gels can sometimes have a slightly slimy or stringy texture depending on the grade and concentration, which might not meet your requirement for a non-slippery feel.
Recommendation:
For a quick-dissolving powder in cold water that provides a non-sticky, non-slippery feel and is easy to rinse, HPMC ColdMix™ appears to be the most suitable option among those you listed. Carbomer Ultrez grades are also good alternatives, particularly if a very clear gel is desired, but the feel might differ slightly from HPMC.
Remember to follow the specific mixing instructions for the chosen gelling agent to ensure proper dissolution and gel formation.
