Lecithins
Lecithins are mixtures of several polar lipids and their accompanying substances consisting of neutral and nonpolar lipids. Since decades lecithins are used in the food industry, pharmacy, medicine
and in cosmetic formulations. Behind this demand is their unique effect and diversity which can
be shown by their biological function and chemical constitution.
O
O
R
O CH2
R
O CH
O
CH3
O
R
O CH2
R
O CH
O
CH2 O P O CH2 CH2 +N CH3
Biological function
CH2 O P O CH2 CH2 NH2
CH3
O-
O-
Phosphatidylcholine
Lecithins are a natural component with important functions in living cells of humans, animals and
plants. Our cells are separated into compartments by bio membranes. Their unique composition
is needed for the complex processes in each cell. Human membranes mainly consist of membrane lipids which form the double layer surface of all cells. These lipids are so called phospholipids
which have one water soluble end formed by a polar head group (phosphate group) and a lipid
soluble end formed by a nonpolar tail (fatty acids). Within membranes polar ends point outwards,
whereas unpolar ends point inwards. In this way they form the fluid mosaic model proposed by
Seymour Jonathan Singer und Garth Nicolson (fig 1.)
Phosphatidylethanolamine
O
O
R
O CH2
R
O CH
O
O
O
CH2 O P O
O-
OH
O CH2
R
O CH
O
OH
OH
OH
R
O
CH2 O P O CH2 CH COOH
O-
NH2
OH
Phosphatidylinositol
Phosphatidylserine
Carbohydrates
Figure 2: The four most important types of phospholipids consist of a glycerol backbone. Two nonpolar fatty acids (grey) and
one polar head group (blue) are attached to this backbone.
polar
heads
nonpolar
tails
Phospholipids
polar
heads
Proteins
Figure 1: Schematically layout of a bio membrane. Integral proteins penetrate or span the phospholipid bilayer and carbohydrates are bound to the surface.
The flexibility of a membrane is based on phospholipids. Besides phospholipids membranes also
consist of integral and peripheral proteins as well as carbohydrates. The individual ratio of these
components influences the flexibility and biological activity of a membrane. All of them are essential for cell metabolism.
Chemical composition
Cosmetic relevance
Lecithins are natural products and thus, bio-degradable and toxicologically harmless. These characteristics combined with their numerous positive effects make them the ultimate choice for
modern cosmetic applications and open a broad range of opportunities.
Caused by their amphiphilic structure they tend to form lamellar structures in an aqueous environment, which are influenced by temperature as well as water and the phospholipid concentration.
Lecithins are natural, skin analog (Co-)emulsifiers, which avoid a separation of water and lipid phases
in formulations. Therefore, they increase the stability of water in oil or oil in water emulsions. In
contrast to typical respectively synthetic emulsifiers lecithins have no defined HLB-value (hydrophilic-lipophilic balance) because their composition as natural product varies. With the help of
modern processes we are still able to influence their composition and thus, to group them in HLB
ranges. This allows you to specifically select one lecithin or to combine two of them in order to get
a defined HLB value similar to the usage of typical emulsifiers.
The best way to understand the diversity of lecithins is the knowledge of their chemical composition. Phospholipids are the value-determining component of lecithins, whereas the accompanying
substances (triglycerides, fatty acids, sterols and glycolipids) are less important. The group of phospholipids mainly consists of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and
phosphatidylinositole.
All of them are composed of a polar head group and two nonpolar fatty acids esterified at the carbon
atoms one and two. The backbone is formed by glycerol. This so called amphiphilic structure (polar
and nonpolar part within one molecule) causes a higher polarity by contrast to the accompanying
substances. Therefore, phospholipids are also called acetone-insolubles because the accompanying
substances are soluble in the relatively nonpolar solvent acetone, whereas phospholipids are not.
2
3
W/O
1
2
3
W/O or O/W
4
5
Cosphaderm®
SF-S
6
7
O/W
8
Cosphaderm®
SF-D
SF-50
9
10
HLB
11
12
Cosphaderm®
SF-75
SF-90
SF-75H
SF-90H
E NGM
E NGM 50
E 100 E IP
Figure 3: Rough classification of the lecithins based on their HLB range.
Furthermore, phospholipids have a positive effect on the moisture balance of skin and hair by
forming a protective layer which is still present after washing. In this way they protect the natural
fat layer. By contrast to silicones lecithins do not cover the hair with a plastic foil which is longterm harmful. Hair consists of three layers: cuticula, cortex and medulla. The cortex is the main
component of hair and consists of keratins (scaffold protein). Environmental influences, heat and
chemicals damage the amino acids of keratins, resulting in a curvature of the outer layer (cuticula).
Thus, the state of the cuticula indicates the health of hair. Phospholipids are able to attach to
keratins between the cuticula, neutralize them and form a natural, antistatic and conditioning
protective layer. The combability increases and the silky gloss is restored. Furthermore, the affinity
of lecithins to the skin surface can be used to increase the adhesion of pigments from lip sticks and
make-ups to the skin. Additionally tocopherols as a part of lecithins show an antioxidative effect.
Split and
dry hair
Healthy and
shiny hair
Lecithins are characterized by their high skin tolerance which is typical for a natural part of the
membrane. Additional characteristics are their ability to form structures similar to cell membranes and to the lipid layer of the Stratum corneum (top layer of the epidermis) and their affinity to
natural skin lipids. They improve the skin smoothness and litheness. The choline group of phospholipids is effective against cornification disorders. In biochemical terms, phosphatidylcholine
intervenes in the ceramide metabolism by transferring its phosphocholine group to the ceramides.
In this way the living epidermis can be restored, whereas phosphatidylcholine converts to a diaglycerole.
Ceramides
(corneal layer)
Sphingomyelins
(living epidermis)
Figure 5: Effects of lecithins to hair
O
R
O CH2
R
O CH
O
O
CH3
CH2 O P O CH2 CH2 +N CH3
O-
Phosphatidylcholine
Phosphocholine group
CH3
Diaglycerine
Figure 4: The ceramide metabolism describes the cornification of cells caused by ceramide formation. This process is reversible
by transferring the phosphocholine group to the ceramide.
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Phosphatidylcholin-enriched (fractionated) lecithins are of high interest because of their tendency to form liposomes. Liposomes are spherical vesicles composed of lamellar phase lipid
bilayers which are able to encapsulate cosmetic
actives. These encapsulated actives are released consistently to the skin. Thus, they are very
compatible with conventional systems and can
be applied in lower dosages in comparison to Figure 6: Liposomes that have encapsulated actives are able
conventional systems. Experiments showed that to merge with the membrane. In this way actives can be better,
deeper and consistently transported into the skin.
for this purpose a phosphatidylcholine amount
of 70-75 % is best suitable. Also empty liposomes are highly efficient because of their increased
content of linoleic acid. Linoeic acid shows a strong efficiency against skin impurities and light acne
which is based on their important role by the production of ceramide 1. The lipid ceramide 1 highly
influences the formation of the barrier function.
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Cosphaderm® Lecithin types
We offer a broad range of lecithins to cover the whole spectrum for cosmetic applications. All of
our lecithins are NON GMO. They are derived from soy bean or sunflower. The big advantage of
sunflower lecithins is their lower allergenic potential and that a GMO discussion is unnecessary.
Standard lecithins (Cosphaderm® SF-S) consist of the value-determining phospholipids (acetone-insolubles) and their accompanied substances. They have a characteristic odor and a typical
brown color.
Deoiled lecithins (Cosphaderm® SF-D) mainly consist of the value-determining phospholipids
(acetone-insolubles) because nearly all of the accompanied substances get removed. This process
also goes along with a decrease of the odor and color. Furthermore, the water solubility increases.
Lysolecithins (Cosphaderm® E NGM; E NGM 50; E 100 E IP) are characterized by a high water
solubility. They are best suited for cosmetic formulations with high water content. The water solubility increases by an enzymatic treatment with phospholipase. The phospholipase separates one
of the fatty acids. The nonpolar part decreases whereas the polar increases. Once 50 % is reached
the emulsifying properties cannot rise further.
Fractionated lecithins (Cosphaderm® SF-50; SF-70; SF-90) are the royal class of lecithins. In a
first step they are de-oiled to increase the value determining content (phospholipids) and in a second step the phosphatidylcholin is being enriched because it is known as particularly revitalizing
and best suited to form liposomes. Fractionation with ethanol increases the amount of phosphatidylcholine. Depending on the number of fractionating steps different phosphatidylcholineenriched lecithins can be produced.
Fractionated and hydrogenated lecithins (Cosphaderm® SF-75H; SF-90H) are similar to the
fractionated lecithins but additionally they get hydrogenated. In this step the unsaturated fatty
acids of the phospholipids get saturated. Resulting products are characterized by high temperature
stability and by contrast to the non-hydrated they can be stored at room temperature. As a last
step they are carefully bleached leading to a white powder of lecithins which are best suited for
brilliant white formulations.
Listed below are the most important characteristics of our lecithins.
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Cosphaderm®
Cosphaderm®
SF-S
SF-D
SF-50
SF-75
SF-75H
SF-90
SF-90H
Lecithin type
Standard
De-oiled
Fractionated
Fractionated
Fractionated
and
hydrogenated
Fractionated
Fractionated
and
hydrogenated
Soy bean
Origin
Sunflower
Sunflower
Sunflower
Sunflower
Sunflower
Sunflower
Sunflower
liquid
powdery
Consistency
liquid
powdery
waxy
waxy
powdery
waxy
powdery
tan to amber
tan to amber
yellowish to beige
Color
dark brown
brownish
yellowish to
brownish
yellowish to
brownish
white yellowish
yellowish to
brownish
white yellowish
typical
typical
typical
Odor
typical
weak
weak
weak
odorless
weak
odorless
min 56 %
min 56 %
min 95 %
min 60 %
min 95 %
-
-
-
-
-
10 %
10 %
12 %
Acetoninsoluble
(polar lipid
content)
PC amount
12-18 %
20-27 %
min 45 %
min 70 %
min 70%
min 90 %
min 90 %
-
-
max 6 %
max 6 %
max 6 %
max 5 %
max 5 %
Emulsifier
yes
yes
yes
yes
yes
yes
yes
Skin care
yes
yes
yes
yes
yes
yes
yes
Hair care
yes
yes
yes
yes
yes
yes
yes
Foam stabilizer
no
no
no
no
no
no
no
Antioxidant
yes
yes
yes
yes
yes
Liposome
formation
no
no
yes
yes
yes
yes
yes
Consistency
builder
low
low
low
low
strong
low
strong
HLB-value
4-6
6-8
7-9
9-12
9-12
10-12
10-12
Rec. conc.
0.5-12.0 %
1-10 %
0.5-6.0 %
0.5-6.0 %
0.5-6.0 %
0.5-6.0 %
0.5-6.0 %
E NGM
E NGM 50
E 100 E IP
Lyso
Lyso
Lyso
Soy bean
Soy bean
liquid
Color
Odor
Product
Lecithin type
Origin
Consistency
Aceton-insoluble
(polar lipid content)
PC amount
Lyso content
25 %
50 %
Product
30 %
Lyso content
Emulsifier
Skin care
Hair care
Foam stabilizer
Antioxidant
Liposome formation
Consistency builder
HLB-value
Rec. conc.
yes
yes
yes
yes
no
no
low
9-12
1-6 %
yes
yes
yes
yes
no
no
low
10-12
1-6 %
yes
yes
yes
yes
no
no
low
10-12
1-6 %
Table 1: Characteristics and composition of Cosphaderm® soy lecithins
Table 2: Characteristics and composition of Cosphaderm® sunflower lecithins
The content was created with great care. For the accuracy, completeness and timeliness of the content we accept no liability.
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Application hints
The composition of the individual lecithins differs. Thus, small deviations in the application process
are required. To simplify the usage of our lecithins please follow our application hints.
Cosphaderm® SF-S (standard lecithin) is used in concentrations of 5-20 %, as a co-emulsifier
0.5-3 % are enough. It is water dispersible. Rich formulations (for example baby cosmetic) that
consists of a aqueous phase <50 % result in W/O emulsions. If the water phase is >65 %, O/W
emulsions are formed. Cosphaderm® SF-S is suitable for hot (max 70° C) and cold emulsification.
You can apply it to the aqueous and lipid phase or additionally to the finished formulation. It is
a weak consistency builder. The final viscosity is formed after 1-2 days. Depending on the target
consistency often an additional thickener is needed.
Cosphaderm® SF-D (de-oiled lecithin) is used in concentrations of 3-5 %. For shampoos and conditioners we suggest using 1-2 %, for bath bombs 5-10 %. It is water dispersible and tends to form
W/O and mixed emulsions. Cosphaderm® SF-D is suitable for hot (max 70° C) and cold emulsification. You can apply it to the aqueous and lipid phase or additionally to the finished formulation.
If you mix it with water in a ratio of 1:1 and let it soak at room temperature for 20 min, processing
will be easier. It is a weak consistency builder. The final viscosity is formed after 1-2 days. Depending on the desired consistency an additional thickener may be needed. A pH-value of 5-6 for the
finished formulation is advisable.
Cosphaderm® E NGM (lysolecithin with a lyso content of approx. 25 %) is used in concentrations
of approx. 1-6 %. The higher the concentration the higher are the skin-smoothing properties. Lysolecithin has a high water affinity. It can be used for O/W and W/O emulsions depending on the
amount of the lipid phase (18-70 %). However, the best concentration amount of the fat phase is
20-45 %. It is suitable for hot (70° C) and cold emulsifications. You can apply it to the aqueous and
lipid phase or additionally to the finished formulation. It is a weak consistency builder. The final
viscosity is formed after 1-2 days. Depending on the desired consistency an additional thickener
may be needed.
Cosphaderm® E NGM 50 (lysolecithin with a lyso content of approx. 50 %) is used in concentrations of approx. 1-6 %. The higher the concentration the higher are the skin-smoothing properties.
Lysolecithin has a high water affinity. It can be used for O/W emulsions and is suitable for hot (70° C)
and cold emulsifications. You can apply it to the aqueous and lipid phase or additionally to the
finished formulation. It is a weak consistency builder. The final viscosity is formed after 1-2 days.
Depending on the desired consistency an additional thickener may be needed.
Cosphaderm® SF-50, SF-75 and SF-90 (fractionated lecithins) are used in concentrations of
approx. 0.5-3.0 %. If particularly high skin-smoothening properties are required, it should be used
in concentrations of up to 6 %. It is suited for water-based formulations, is water dispersible and
tends to form W/O emulsions. It is suitable for hot (max 60° C) and cold emulsifications. You can
apply it to the aqueous and lipid phase or additionally to the finished formulation. Avoid unnecessary long heat terms. Solubilizers like ethanol or diols (Cosphaderm® Propanediol natural or
Pentiol natural) facilitate the application. Fractionated lecithins are best suited as penetration
enhancer because they tend to form liposomes. To obtain concentrated suspension of liposomes
loaded with actives, add in a first step a concentrated solution/suspension of active ingredients in
demineralized water. Simultaneously prepare the pre-solution of liposomes consisting of aqueous
ethanol and/or glycerin and phospholipids. In a second step add the active pre-solution to the proliposome solution. The ratio of the amount of proliposome solution to the aqueous active solution
must be kept by 1:1 or maximum 1:2. In a third step gradually dilute the obtained concentrate to
the final volume with demineralized water or aqueous solution (ratio 2:8 or 3:7 respectively). If you
use fractionated non hydrogenated lecithin, the operation temperature will be room temperature.
Cosphaderm® SF-75H and SF-90H (fractionated und hydrogenated lecithins) are used in concentrations of approx. 0.5-3.0 %. If particularly high skin-smoothing properties are required, it should
be used in concentrations up to 6 %. It is suited for water-based formulations, is water dispersible
and tends to form W/O emulsions. It is suitable for hot (max 70° C) and cold emulsifications.
You can apply it to the aqueous and lipid phase or additionally to the finished formulation. Long
heat terms are possible because the lecithins are hydrogenated. Solubilizers like ethanol or diols
(Cosphaderm® Propanediol natural or Pentiol natural) facilitate the application. Alternatively let it
soak in the whole aqueous phase for 20 min. at 70° C. Soaking increases the consistency-forming
properties. Fractionated lecithins are best suited as penetration enhancer because they tend to
form liposomes. To obtain concentrated suspension of liposomes loaded with actives, add in a first
step a concentrated solution/suspension of active ingredients in demineralized water. Simultaneously prepare the pre-solution of liposomes at 65° C consisting of aqueous ethanol and/or glycerin
and phospholipids. In a second step add the active pre-solution to the proliposome solution at 65°
C. The ratio of the amount of proliposome solution to the aqueous active solution must be kept by
1:1 or maximum 1:2. In a third step gradually dilute the obtained concentrate to the final volume
with demineralized water or aqueous solution (ratio 2:8 or 3:7 respectively) at room temperature.
Cosphaderm® E 100 E IP (de-oiled lysolecithin with a lyso content of approx. 25 %) is used in
concentrations of 1-6 %. The higher the concentration the higher are the skin-smoothing properties. Lysolecithin has a high water affinity. It can be used for O/W and W/O emulsions depending
on the amount of the fat phase (18-70 %). However, the best concentration amount of the lipid
phase is 20-45 %. It is suitable for hot (70° C) and cold emulsifications. You can apply it to the
aqueous and lipid phase or additionally to the finished formulation. It is a weak consistency builder.
The final viscosity is formed after 1-2 days. Depending on the desired consistency an additional
thickener may be needed. In comparison to Cosphaderm® ENGM it can be used to achieve a lighter
color of the final formulation.
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2015
Cosphatec GmbH | Drehbahn 7 | 20354 Hamburg
Tel. +49 40 3501669-0 | Fax +49 40 3501669-10
[email protected] | www.cosphatec.com