ECO-FRIENDLY CLEANSING MILK FORMULATION USING JOJOBA AND BLACK SEED OIL IN SELF-EMULSIFYING MICROEMULSION SYSTEMS

The need for natural and sustainable personal and skin care products has enabled novel formulations to develop that respond to the dual concerns of efficacy and skin acceptability. The goal of this study was to develop and study a new self-emulsifying micro-emulsion cleansing milk formulation containing natural active ingredients, Jojoba oil and Black seed oil. Two oil blends were prepared: Blend A (jojoba: black seed oil, 90:10 w/w) and Blend B (80:20 w/w). Both formulations used PEG-40 hydrogenated castor oil (HLB 13.1) as the emulsifier. Pseudo-ternary phase diagrams were created in an effort to identify the stable micro-emulsion region. The Physicochemical characterization consisted of droplet size, pH, conductivity and stability. Results indicated that both oil blends produced stable micro-emulsions (74.2 - 189.7 nm) with good droplet dispersion. Blend A was more efficient at forming micro-emulsions and stability than blend B as it formed mostly oil in water (O/W) micro-emulsions with smaller droplet sizes (90.5 and 101.4 nm), higher conductivity (234.1 and 334.2 μS/cm). All formulations were stable to thermodynamic testing. The final cleansing milk formulations had an appropriate viscosity (515.5 - 698.9 cps), skin compatible pH (6.5-6.8), and all formulations were homogeneous. This research successfully demonstrates the feasibility of combining natural oils with self-emulsifying micro-emulsion technology to create stable, effective, and environmentally friendly cosmetic cleansing products that offer an alternative to conventional synthetic formulations.