Development of shampoo formulations using plant/microbial biosurfactants as an alternative to shampoos formulated with harsh synthetic surfactants

The presence of harmful chemical surfactants such as sodium lauryl sulfate (SLS) in healthcare products is a challenge that world is facing today. The present study aimed to formulate novel green shampoos using rhamnolipid and saponin instead of chemical surfactants, and comparison with commercial shampoos. Biosurfactants were confirmed by thin layer and high-performance liquid chromatography, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and their performance was evaluated by zone inhibition and critical micelle concentration (CMC). The saponin and rhamnolipid reduced the surface tension (ST) of water from 72 to 40 and 30 mN/m at their CMCs, respectively. Four novel shampoo formulations were made with SLS, rhamnolipid, saponin, and a mixture of rhamnolipid and saponin. The green shampoos were evaluated with tests of color, odor, transparency, pH, ST, detergency, solid content, foam type, foam volume, wetting time and microbial contamination standard to determine the physicochemical properties. The green formulations with rhamnolipid, saponin and mixture of rhamnolipid and saponin were clear and transparent with a good odor. Low ST (34.13, 38.83, and 31.73 mN/m), good detergency (63.87%, 57.74%, and 64.45%), comparable solid contents (25.11%, 26.95%, and 27.50%), good wetting time (160, 165, and 153 s), and good foam stability even after 60 min were observed for three green shampoos, respectively. Based on the results, it can be concluded that these green shampoos can compete with commercial shampoos and be a suitable alternative to chemical shampoos containing sulfate and sulfate-free, especially for children, people with eye and skin sensitivities and with oily hair.