Liquid Hand Wash Soap

Ingredients

Component	INCI / Chemical Name	Function	% w/w
Sodium laureth sulfate (27 % active)	Sodium Laureth Sulfate	Primary surfactant, foaming	25.93
Cocamidopropyl betaine (30 % active)	Cocamidopropyl Betaine	Co-surfactant, mildness	7.83
Glycerin 99.5 %	Glycerin	Humectant, moisturizer	3.00
Sodium chloride 25 % solution	Sodium Chloride	Thickener (viscosity adjustment)	2.40
Sodium benzoate / potassium sorbate blend	Sodium Benzoate, Potassium Sorbate	Preservative system	1.00
Sodium citrate	Sodium Citrate	Buffer	0.10
Citric acid 20 % solution	Citric Acid	pH adjustment (to 5.0–5.5)	q.s.
Fragrance	Parfum	Sensory attribute	0.25
Deionized water	Aqua	Solvent	59.49
Total			100.00

Addition Order & Process

Procedure: Dissolve sodium citrate in deionized water. Add SLES 27 % and mix for 10 minutes. Add CAPB 30 % and mix for 10 minutes. Add glycerin and the preservative blend. Adjust pH to 5.0–5.5 with citric acid 20 % solution. Add sodium chloride 25 % solution gradually while monitoring viscosity until the target range of 3{,}000–5{,}000 mPa·s (Brookfield RV, spindle 4, 50 rpm, 20 °C) is reached . Add fragrance last and mix for 5 minutes.

Formulation Notes

Liquid hand wash formulations pair anionic and amphoteric surfactants. Sodium laureth sulfate (SLES) provides primary detergency and foam volume, while cocamidopropyl betaine (CAPB) reduces irritation potential and stabilizes foam through mixed-micelle formation . Glycerin replenishes moisture stripped during cleansing.

Formulation Card FC-11.5-M: Liquid Hand Wash Soap

The pH of 5.0–5.5 matches the skin’s isoelectric point and minimizes damage to the stratum corneum lipid barrier . The SLES:CAPB ratio of approximately 3:1 maximizes foam volume while minimizing the Zein test irritation score . Sodium chloride thickens via electrolyte-induced micellar elongation; excessive salt (> 3 %) can cause salting-out of the surfactant . The final active surfactant matter (ASM) is approximately 8.7 %.