COLOUR COSMETICS 29
formulators aiming to achieve superior stability and flawless application in pigmented cosmetic systems.
ColorEst - pigments suspended in esters In the case of pigment dispersions, a highly refined ester system derived from byproduct of olive oil as the dispersion medium has been selected (EMotion Light). Composed of Triolein, representing the triglyceride fraction, and Glyceryl Dioleate, corresponding to the diglyceride fraction, it is a result of upcycling approach of non-edible olive fruit fractions. Both components are obtained through the extraction and purification of fatty acids naturally present in olive oil. Following purification, the fatty acids are esterified in accordance with green chemistry principles, prioritizing low environmental impact and controlled processing conditions. From a formulation standpoint, the combination
of triglyceride and diglyceride fractions provides an optimal balance between fluidity, polarity, and pigment affinity. Triolein contributes to excellent pigment wetting and dispersion stability, while glyceryl dioleate enhances interfacial interactions at the pigment surface, supporting long-term homogeneity and reducing the risk of agglomeration or sedimentation. This synergistic ester system allows pigments to remain uniformly dispersed while maintaining low viscosity and good flow properties, facilitating easy incorporation during R&D and manufacturing processes. Parameters such as polarity, viscosity and
wetting ability has been evaluated to understand how the ester can improve technical and sensorial features of pigments.
Polarity
Among the chemical attributes investigated, polarity emerged as a pivotal criterion for selecting esters as dispersion agents. To characterize the upcycled ester, its polarity was classified using HPLC. This analysis was performed on an Agilent 1100 system equipped with a reverse-phase gradient setup, utilizing a Phenomenex Gemini C18 column as the stationary phase. The mobile phase consisted of a binary gradient: (A) water with 0.1% formic acid and (B) methanol. This method
700 600 500 400 300 200 100 0
30 25 20 15 10 5 0
27.17 20.84 15.54 16.60 20.95 21.13
Dibuty Adipate
Dibuty Sebacate Caprylic/Capric Triglycerides
High Polarity (Short RT)
C12-15 Alkyl Benzoate
Medium Polarity (Medium RT)
Figure 4: Polarity scale comparison of olive oil esters based on HPLC retention times
allows for the precise categorization of emollients based on their relative affinity for the non-polar stationary phase versus the polar mobile phase (Figure 4). The upcycled ester shows a low polarity. In
a pigment dispersion, low-polarity oils serve as a critical functional complement to the coating process. While medium-polarity esters ensure the initial wetting of the particles, low-polarity components provide a dry, non-greasy sensory profile and significantly improve the “slip” during application. Due to their high hydrophobicity, they enhance the water resistance and long-wear properties of the final product.
Viscosity To further characterize the upcycled ester, a comprehensive viscosity assessment was conducted. The dynamic viscosity was measured using a Brookfield viscometer, a standard rotational method that ensures high precision and reproducibility. To establish a clear performance benchmark,
several industry-standard emollients were analysed under identical experimental conditions. This evaluation is fundamental for understanding the flow behaviour of the emollient, as viscosity directly influences both the processability of pigment dispersions and the final sensory
685 386 80.4 34
Caprylic/Capric Triglycerides
EMotion Glow
Dimethicone (350)
Castor Oil
Figure 5: Comparative dynamic viscosity values (mPa·s) of various emollients
www.personalcaremagazine.com
100 80 60 40 20 0
experience on the skin (Figure 5). The analytical outcomes indicate that the
upcycled ester possesses a moderate viscosity profile, which offers significant advantages for both formulation and production. This balanced rheological behaviour ensures excellent glide and spreadability upon application, preventing an overly greasy feel. From a manufacturing perspective, this
viscosity range is highly beneficial as it optimizes the dosing and handling stages; it is fluid enough to be easily pumped and metered, yet structured enough to maintain stability. Consequently, the upcycled ester facilitates a more efficient production workflow while ensuring the final pigment dispersion remains easy to incorporate and apply.
Wetting ability To assess the dispersion efficacy of the upcycled ester, its wetting ability was evaluated. This property was quantified using the flow point parameter, defined as the minimum amount of ester required to fully wet a specific mass of pigment until the mixture reaches a fluid state (Figure 6). Remarkably, the upcycled ester demonstrated
superior wetting properties compared to castor Oil, traditionally regarded as the industry gold
% Pigment ■ % Emollient ■ 49.0 56.8
Castor Oil
EMotion Glow
Low Polarity (Long RT)
51.0 43.2
EMotion Glow
Castor Oil
Figure 6: Dispersion efficiency of olive oil esters compared to castor oil, expressed as the pigment-to-ester ratio required to reach the flow point
July 2026 PERSONAL CARE MAGAZINE
mPas
RT (mins)
FP (%)
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72
