In yesterday's post, Shampoo - how does it work", we took a look at how a shampoo works to clean our hair. Today, let's take a look at how one would formulate a shampoo, then at the ingredients we might find in one.
So what makes a shampoo a shampoo" We want to formulate a shampoo that will remove sebum and soil from our hair and scalp, remove residue of styling products, leave hair in good condition, and deposit lovely things like panthenol, conditioning agents, and so on.
How do we achieve these goals" We want to include between 15% to 40% surfactants in our mix to remove soil, sebum, and styling product residue. To leave hair in good condition, we'll choose a surfactant mix that is mild to hair and scalp as well as add a few things that might help leave our hair conditioned. And we can use all kinds of lovely ingredients like conditioning agents, panthenol, extracts, and so on to make our hair feel nice when we've rinsed it off.
The concentration of your surfactants will vary, but I usually go for the higher amount (around 40%) because not only is it easier to thicken higher amounts of surfactants, but it's more concentrated, so I don't have to use a lot to get some serious lather!
A basic shampoo would look something like this...
15% to 40% surfactants (mix of anionic and cocamidopropyl betaine)
0.5% to 1% preservative
1% fragrance or essential oil
up to 3% Crothix (liquid) to thicken or use salt at up to 3%
water to 100%
Why are we including each ingredient"
Water: Well, that's a given right" We need to include water in a shampoo to decrease the concentration of the surfactants and act as a solvent for the other ingredients.
Surfactants: We always want to include cocamidopropyl betaine in our mixtures to increase the mildness and thickening of the mix. We can choose surfactants suitable for our skin types - dry, normal, and oily - and use those for our hair types. Some good choices m...