HAIR CARE
Difference test as appropriate. Two-way ANOVA was used to further review the ∆E values between the variables. Probability results of 95% (p<0.05) were considered statistically significant.
Results and discussion The co-surfactant screening results for colour fading are presented in Figure 1. From the tested co-surfactants, DSL demonstrated the strongest capacity to remove colour, while CAPB and CG induced 50% less colour fading. The presence of SLES increased the total colour loss for the milder anionic, non-ionic and amphoteric co-surfactants, due its high solubility and free availability in solution. This effect was not noted with the SLES combination with the commercial surfactant blend. Further to the surfactant screening tests,
CAPB and CG were selected for the further investigation, as they demonstrated good potential for colour retention when tested individually, and for mitigating the colour fading induced by the primary surfactant SLES. The results for the total colour changes
(∆E) and the corresponding colour protection values for all test formulation variables and controls are presented in Figures 2 and 3, respectively. The formulations containing CAPB outperformed those containing CG, showing smaller colour difference of hair tresses before and after the wash-and-dry cycle (Fig. 1) and larger colour protection values (Fig. 2). When comparing the conditioning additive effect on the reduction on red colour fading, it has been shown that dimethicone was superior to the cationic polymers, offering better colour protection, irrespective of the co-surfactant effect. Statistical analysis performed on the results revealed the following:
One-way ANOVA tests Comparison of the ∆E values of the test formulations in the CAPB group produced p<0.05, therefore showing a significant difference in total colour change between the formulations in the CAPB group; Comparison of % colour retention
of the variables in the CAPB group has also produced p<0.05, confirming the conclusion of different colour protection efficacy.
Tukey HSD test There was statistically significant difference within each pair the CAPB group, with dimethicone/PQ-28 showing the lowest p value of 0.001. However, there was no statistically
significant difference for the ∆E and % colour retention between the variables within the CG group.
48 PERSONAL CARE September 2015
10 8 6 4 2 0
9.09 7.59 5.59 4.69 8.12 6.76 8.77
n Cocoamidopropyl Betain n Coco-Glucoside
6.51
Control
PQ-55
PQ-28 Conditioning additives
Figure 2: Total colour changes in hair tresses treated with the formulations containing SLES, one of the two co-surfactants (CAPB or CG) and one of the conditioning additives (PQ-55, PQ-28 or dimethicone) vs. control formulations without conditioning additives.
Two-way ANOVA tests Comparison of the ∆E values of conditioning additives and co-surfactant variables has produced p<0.05, indicating statistically significant difference between the efficacy of the CAPB and the CG group of formulations. The statistical analysis confirmed the co-
surfactant effect on colour fading of dyed hair induced by shampooing. Specifically, the amphoteric surfactant (CAPB) demonstrated more effective colour retention capacity when combined with SLES, than that of the selected non-ionic surfactant – CG. Furthermore, the study demonstrated
that the positive effect of CAPB on colour retention is enhanced by the presence of other hair substantive materials such as polycationics and silicone polymers. In particular, dimethicone alone offered superior colour retention compared to polycationics. PQ-55 also delivered significant colour
protection value when combined with CAPB and better than that of PQ-28. This superior efficacy can be explained by the PQ-55 hydrophobicity, thus enhanced
45 40 35 30 25 20 15 10 5 0
n Cocoamidopropyl Betain n Coco-Glucoside
26.37
substantively to hair (Fig. 4). These effects could be enhanced via further optimisation of the polymer/surfactants ratio.
Conclusion This investigation demonstrated that certain ingredients can improve the colour retention of red oxidative dye coloured hair during shampooing. The choice of co-surfactant was shown
to have an effect on the reduction of the colour fading induced by SLES. The amphoteric co-surfactant cocoamidopropyl betain, in particular, was proven to offer statistically significant colour protection efficacy in shampoo formulations. This effect could be further enhanced
by the addition of appropriate conditioning materials. Dimethicone was identified as the most effective conditioning additive in this study, providing superior colour protection in combination with both CAPB or CG, followed by polyquaternium-55 mixed with CAPB. Further investigations of the optimal concentration ratios of co-surfactants and conditioning additives could lead to
38.24 28.38
Dimethicone
10.68
10.97 3.55 PQ-55 PQ-28 Conditioning additives
Figure 3: Colour protection values of hair tresses treated with SLES-based shampoos with different co-surfactants and one of the three conditioning additives.
Dimethicone
Percentage
Delta E
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 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92
