Dishwashing Soap with Bioactive Compound for Sensitive Skin

Chemical and Environmental Engineering (CHEE), Malaysia-Japan International Institute of Technology, Jalan Sultan Yahya Petra, Universiti Teknologi Malaysia, 54100 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur

^* Corresponding author: chia@graduate.utm.my

Abstract

Conventional dishwashing liquids containing synthetic surfactants often raise environmental and dermatological concerns, causing skin irritation and pollution. To overcome these issues, a plant-based dishwashing liquid was developed via saponification of coconut oil using potassium hydroxide (KOH) with addition of glycerin, aloe vera and chamomile extract at 0.5, 2 and 4%. The formulations were characterized by fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) spectroscopy and saponification value (SV) analysis to verify the compositions and presence of bioactive compounds. Physiochemical assessments including pH, foaming power, and cleaning efficiency were also evaluated. The calculated SV was 157.14 mg KOH/g oil, lower than the theoretical value. This indicated unsaponified lipid fraction may function as an occlusive agent to support skin hydration by minimizing transepidermal water loss (TEWL) and lipid barrier disruption. UV-Vis confirmed the bioactive compounds. FTIR detected the flavonoids and polysaccharides functional groups. Higher extract content improved foaming and cleaning abilities while maintained skin-friendly pH of 9. The formulation with 2% of each extract showed optimal performance and balance on cleaning, stability and safety. These findings highlight the potential of plant-based formulations as sustainable alternatives to conventional dishwashing liquids.