The Chemistry of Shampoo
How are Shampoos Made?
Shampoos are formulated by combining a surfactant (surface active agent aka detergent), such as sodium lauryl sulfate or sodium laureth sulfate, with a co-surfactant, such as cocamidopropyl betain, along with salt (sodium chloride – to adjust viscosity aka thickness), preservative(s) – to prolong shelf-life, fragrance, and other cosmetic and/or medicated ingredients, plus water. Most shampoos consist of anywhere between 75% – 95% water. Obviously, the higher the water content, the less of other beneficial ingredients, such as detergents, are being used.
How do Surfactants Work?
Surfactants are composed of a “head and a tail,” if you will. The first, a hydrophobic tail (not water-friendly – allows dirt, oil, and grime to attach), while the second, the hydrophilic head (water-friendly, allows the H2O to wash away the hydrophobic tail and all its attached contents).
Negatively charged (think shampoos and laundry detergent) – strips down hair
Positively charged (think conditioners and laundry softener) – builds up hair
3. Zwitterrionic & Amphoteric
Not charged (think baby shampoo)
Classification of Pet Shampoo & Sprays
Moisturizing shampoos specifically designed to make the external layers of skin, the epidermis, softer & more pliable. Emollients are fats and oils such as coconut, olive, lanolin, paraffin, etc.
Like emollients, humectants also help to moisturize the hair the skin. However, humectants work by attracting H2O molecules, (they contain many hydrophilic groups), then binding and trapping them against the epidermis. Common humectants found in pet products are propylene glycol and glycerin. They also help with anti-static & anti-frizz.
A shampoo which contains two or more liquids that are normally unmixable, for example, essential oils, and water. To ensure emulsion stability, we use our IKA homogenization pump to spontaneously solubilize oil molecules within a mixture of surfactants, co-surfactants, and suspending agents.
These shampoos usually contain pyrethrin or pyrethroids (such as permethrin – which cannot be used on cats), and are used to kill fleas & ticks and treat parasitic infections.
Designed for pets with scales, skin flakes (dandruff), or those with excessively oily skin covered with flaky scales or crust. Products to treat, usually contain sulfur, salicylic acid and coal tar (can’t be used on cats.)
Used to treat bacterial infections with commonly used ingredients such as chlorhexidine, benzoyl peroxide, triclosan, or natural tea tree oil, etc.
Used on pets with ringworm or yeast infections. Common antifungals include: miconazole, ketoconazole, chlorhexidine, or natural neem and tea tree oils.
Intended to provide relief of itching due to allergies and other conditions. Usually contains colloidal oatmeal, hydrocortisone, aloe vera, menthol, salicylic acid, etc.