SUSTAINABILITY
vectorisation protects the molecule from being either degraded or metabolised by the microbiome before it could penetrate the skin. After two hours, the total amount of biotin
delivered into the skin is twice the amount (+109%, p<0.02) with the vectorisation compared to free biotin that is rapidly metabolised or degraded (Figure 3). The penetration flux of biotin was also
determined within the first ten minutes and the next 30 minutes (Table 1). These results express the quantity of biotin that diffused to deeper layers and indicate that the tested liposomal natural biotin increases the biotin penetration flux 8.7 times compared to free biotin within the first ten minutes after the application and liposomal natural biotin increases the biotin penetration flux three times compared to free biotin between 10 and 40 minutes after the application. This study shows the interest of vectorising
natural biotin in a stable liposomal structure. Liposomal natural biotin allows a gradual delivery of higher amounts of natural biotin into the skin and reduces immediate biotin degradation that may be due to microbiome metabolism to support its diffusion to deeper layers.
Synthesis of endogen ceramides and lipids The formation of a competent epidermal permeability barrier requires an approximately equal molar ratio of cholesterol, free fatty acids and ceramides, which are synthesised in the endoplasmic reticulum of the stratum spinosum keratinocytes within the epidermis. Deficiencies in any of these lipids can result in a defective epidermal permeability barrier. Studies have shown that the aged stratum
corneum displays a >30% reduction in total lipid content in comparison to young stratum corneum, due to reduced epidermal lipid synthesis.3
The level of lipids in the stratum
corneum is thus a relevant marker of ageing. A clinical study was performed on ten volunteers who applied on the face a cream
100 80 60 40 20 0
V1 V2
65
Eraglow Beautin ■ Biotin ■
0.20 0.15 0.10 0.05 0.00
Figure 2: Penetration of vectorised biotin versus free biotin
TABLE 1: PENETRATION FLUX OF BIOTIN IN THE STRATUM CORNEUM
Penetration flux (µg/cm2 Free biotin EraGlow beautin
0 to 10 minutes 0.0002 0.0006
/h)
10 to 40 minutes 0.0011
0.0096
containing 20% liposomal natural biotin for 28 days. The amount of ceramides/fatty acid levels were evaluated by confocal Raman spectroscopy using the Gen2 SCA Ultimate at a wavelength of 785 nm. The results of the measurements of
ceramides and fatty acid levels after 28 days of treatment with a face cream containing liposomal natural biotin showed that endogen ceramides and fatty acid levels were increased very significantly by 20.3%, up to 50.4% and that
Eraglow Beautin ■ Biotin ■ 81.2% 38.9%
100% of the volunteers presented an increase (Figure 4). Lipids and ceramides are primarily produced
in the spinous layer at about 30 µm depth and are externalised from the outermost stratum granulosum cells to form the epidermal brick and mortar impermeable structure.4 Confocal Raman spectroscopy allows to
directly measure the ceramide and fatty acid levels in the skin in different depth layers, from the stratum corneum to the dermis. It is then possible to visualise the effect of biotin in liposomal form on the increase in ceramide and fatty acids synthesis as a function of the epidermis depth on a graph (Figure 5). Results shows that the liposomal biotin
increases the ceramide and fatty acid levels up to a depth of 18 µm. As expected, it is possible to see the settlement of these lipids in the layers of the stratum corneum where they are externalised from the outermost layers of keratinocytes. At the level of the most superficial corneocyte layers, the amount of ceramides and fatty acids has increased by more than 30%. Under 18 µm depth, lipids detected by confocal Raman spectroscopy are mostly constitutive of the cellular membrane.
V3 V4 V6 Figure 3: Total amount of absorbed biotin for each volunteer
www.personalcaremagazine.com V1 V2 V3 V4 V6
Reinforcing the epidermis to lock in moisture The human stratum corneum is a layer only about 10 to 20 µm thick in most body regions however this thin layer functions as the main evaporation barrier. Because of its the brick- and-mortar structure, water domains are mainly present within the corneocytes and not in the lipidic intercellular regions. It has been shown that vertical corneocyte swelling increases linearly with the hydration level, thus impacting stratum corneum thickness.5 Studies describe the water gradient from about 15% to 25% at the skin surface to a constant level of about 70% in the viable
October 2024 PERSONAL CARE
Absorbed Biotin (µg/cm2
SC)
Biotin level (µg/cm2
SC)
Baseline 1 minute 10 minute 20 minute 40 minute 120 minute
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 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108
