Personal care products are necessities in peopleâs daily life, especially cosmetic creams and lotions. Cosmetic creams are semi-solid emulsions, most of which are normally at a thermodynamically metastable state, thus surfactants play a key role in the formulation. Most industrially applied surfactants are chemically synthesized, which are poorly biodegradable and biocompatible. With the increase in concern for environment protection, considerable attention has been given to biosurfactants due to their environmentally friendly merits and higher surface activity. This project aims to study the preparation of cosmetic cream formulated with biosurfactants, compared to a system of containing cetyl alcohol (CA), glycerol monostearate (GM) and sodium lauryl ether sulfate (SLES) with paraffin in water. Instead of applying the petroleum-based surfactants, the cream will be reformulated with microbial-derived surfactants, e.g. sophorolipids (SLs) and mannosylerythritol lipids (MELs). Key parameters for the performance of the cream are analysed to allow understanding of the production process and the effect of replacing the surfactant. Droplet size analysis was performed using a Mastersizer 3000. The d3,2 of the distributions were used to determine the dependencies of the surfactant concentrations, the rotor speed, and the mixing time used to manufacture the cream. Rheological properties of the cream were also examined, e.g. shear stress sweep, and linked to the droplet size distributions. As a result, structural mixture of SLs mainly consisting of diacylated acidic SLs of C18:1, diacylated acidic SLs with C20:1 and diacylated lactonic SLs with C18:1, that extracted from c. bombicola cultivation consuming glucose and rapeseed oil as substrates, was successfully incorporated with fatty alcohols for cream formulation in replacement of anionic surfactant SLES. In this study, bio cream with 6 wt% SLs exhibited smooth texture with sufficient stiffness, reflecting as an average maximum viscosity of approximate (2±0.7)Ã105 Pa·s. And a primary creep was obtained from creep test, indicating a solid behaviour of the system. Also higher concentration of SLs formulated in cream system led to better result with good performance. Vegetable oils that formulated as alternatives to mixed paraffin oils were well emulsified in water with surfactant system containing SLES and fatty alcohols, especially coconut oil. In addition, 2 wt% MELs incorporating with cetyl alcohol and glycerol monostearate formulated with coconut oil in water could prepare cream with average maximum viscosity of (1.18±0.8)Ã105 Pa·s which is comparable to that of system with 2 wt% SLES instead.
Formulation of personal care products with bio-surfactants
Zhang, C. (Author). 1 Aug 2021
Student thesis: Phd