An antiaging skin care system containing alpha hydroxy acids and vitamins improves the biomechanical parameters of facial skin

Figures & data

Figure 1 Skin surface curve obtained with a profilometer depicting R_y (wrinkle depth) and R_a (mean surface roughness).

Notes: R_y represents the maximum peak height of the profile minus the minimum valley of the profile, R_y = peak (maximum) − valley (minimum). R_a represents the area that the profile deviates above and below an average line generated to run through the center of the profile, R_a=1/ℓ₀∫^ℓ|y(x)|dx, where ℓ is the scan length and |y(x)| is the absolute value of the location of the profile relative to the mean profile height.

Figure 2 Skin deformation curve obtained with a cutometer depicting the immediate deformation or skin extensibility (U_e), delayed distension (U_v), final deformation (U_f), immediate retraction (U_r), total recovery (U_a), and residual deformation at the end of the measuring cycle (R).

Table 1 Self-assessment questionnaire showing the percentage of positive responses from volunteers following an antiaging skin care regimen for 7, 14, and 21 days (n=52)

Question	7 days	14 days	21 days
Have you seen a reduction in fine lines?	40.4	67.3	73.1
Have you seen a reduction in skin pigmentation?	32.7	46.2	55.8
Have you seen an improvement in the skin firmness of your neck?	57.7	67.3	75.0
Have you seen a reduction in fine lines around your eyes?	40.4	67.3	73.1
Have you seen a reduction in wrinkles?	11.5	50.0	57.7
Does your skin look rejuvenated?	78.9	82.7	90.4
Have you seen an improvement in the skin elasticity of your neck?	57.7	71.2	76.9
Have you seen a reduction in wrinkles around your mouth?	13.5	34.6	46.2
Does your skin look younger?	59.6	63.5	76.9
Have you seen a reduction in “bags” around your eyes?	34.6	55.8	57.7
Does your skin look regenerated?	75.0	84.6	88.5
Do you look more refreshed?	80.8	86.5	86.5
Have you seen a reduction in fine lines around your mouth?	30.8	46.2	53.9
Have you seen an improvement in skin appearance around your eyes?	50.0	76.5	82.7
Do you look less tired?	57.7	71.2	80.77
Have you seen an improvement in skin tone?	57.7	76.9	84.6
Have you seen a reduction in skin roughness?	78.9	84.6	88.5
Have you seen an improvement in skin elasticity?	69.2	76.9	84.6
Does your skin feel rejuvenated?	78.4	86.5	88.5
Have you seen an improvement in skin firmness?	67.3	80.8	84.6
Do you feel younger?	46.2	55.8	57.7
Have you seen an improvement in the skin tone of your neck?	46.2	69.2	75.0
Does your skin look more radiant?	78.9	86.3	88.2
Have you seen a reduction in wrinkles around your eyes?	17.3	51.9	65.4
Have you seen an improvement in skin clarity?	73.1	82.4	88.5
Have you seen an improvement in the skin radiance of your neck?	50.0	64.6	75.5
Did you like the texture of each product?	86.3	86.5	86.5
Do you feel more refreshed?	75.0	82.7	86.5
Do you feel more beautiful after regular use of the range?	65.4	72.6	75.0
Have you seen an improvement in skin softness?	82.7	92.3	92.3
Have you seen a reduction in skin redness?	36.5	48.1	53.9
Would you recommend this range to your friends?	68.6	82.7	78.9
Do you look younger?	48.1	61.5	71.2
Have you seen an improvement in skin texture?	80.8	86.5	86.5
Is your complexion more youthful?	55.8	69.2	76.9
Have you seen a reduction in puffiness around your eyes?	36.5	55.8	61.5
Have friends commented on the appearance of your skin?	30.8	50.0	57.7
Have you seen a reduction in skin coarseness?	71.2	86.5	88.5
Does your skin feel regenerated?	80.4	86.5	90.2
Have you seen a reduction in dark circles around your eyes?	31.4	44.2	60.0
Does your skin feel rehydrated?	86.3	92.3	92.3
Would you continue to use this range if able to?	88.5	90.4	88.5
Have you seen an improvement in skin smoothness?	84.6	90.4	90.2

Note: Relevant performance questions pertaining to skin texture and smoothness are highlighted.

Figure 3 The percentage reduction in R_y (wrinkle depth) and R_a (mean surface roughness) versus time (days).

Notes: The reduction was determined by skin surface profilometry for the crow’s feet area of volunteers following an antiaging skin care regimen for 21 days (n=15). Results are presented as mean ± SEM. *P<0.0001 versus t=0, **P<0.001 versus t=0.
Abbreviation: SEM, standard error of mean.

Table 2 Characterization of skin surface topography of the crow’s feet area antiaging

Time (days)	Ry (wrinkle depth) (μm)	Ra (average skin roughness) (μm)
0	37.2±2.2	7.4±0.6
7	30.9±2.1**	5.7±0.4**
14	27.9±1.9*	4.8±0.4*
21	25.1±2.1*	4.1±0.4*

Notes: Parameters R_y (wrinkle depth; μm) and R_a (average skin roughness; μm) were measured by skin surface profilometry at day 0 (pre-application), and following a daily antiaging skin care regimen for 7, 14, and 21 days. Results are presented as mean ± SEM.

* P<0.0001 versus t=0;

** P<0.001 versus t=0.

Figure 4 The percentage increase in skin elasticity parameters R2 (gross elasticity), R5 (net elasticity), R6 (viscoelastic portion), and R7 (recovery after deformation) versus time (days).

Notes: The increase was determined by cutometer for facial skin of volunteers following an antiaging skin care regimen for 21 days (n=52). Results are presented as mean ± SEM. *P<0.0001 versus t=0, **P<0.05 versus t=0.
Abbreviation: SEM, standard error of mean.

Table 3 Characterization of facial skin elasticity antiaging

Time(days)	R2	R5	R6	R7
0	0.645±0.014	0.416±0.015	0.314±0.007	0.326±0.011
7	0.683±0.011*	0.444±0.013**	0.310±0.006	0.338±0.009
14	0.696±0.001*	0.447±0.010**	0.287±0.007**	0.348±0.007**
21	0.726±0.008*	0.446±0.011**	0.254±0.005*	0.344±0.008

Notes: Parameters R2 (gross elasticity), R5 (net elasticity), R6 (viscoelastic portion) and R7 (recovery after deformation) (arbitrary units) were calculated by using cutometer at day 0 (pre-application), and following a daily antiaging skin care regimen for 7, 14, and 21 days Results are presented as mean ± SEM.

* P<0.0001 versus t=0;

** P<0.05 versus t=0.