Volume XXVI - Nr.2 - December 2011
SAFE AND EFFECTIVE LIPIDS
For new mineral oil- and lanolin-free formulations
Oils, waxes and their derivatives constitute a very large and important class
of basic cosmetic and pharmaceutical raw materials. They are used mainly as
vehicles and emollients for a very wide range of creams, lotions, ointments,
lipid gels, oils, pastes and soaps.
Lanolin, mineral oil, petrolatum and isopropyl esters are the raw materials most
often found in topical ointments and emulsions. As it has been largely
demonstrated in the past years all these lipid components present not
neglectable drawbacks which suggest their total or partial substitution with
safer raw materials having the same effectiveness.
Vevy Europe will present the results of research studies regarding the
formulation of “alternative” ointments, absorption bases and emulsions
containing no mineral oil, petrolatum, lanolin and IPM or IPP, but safe and
effective raw materials for dermatological and cosmetic application.
Here follows a brief review on the properties but also the inconveniences of the
traditional substances found in topical products.
Lanolin has been one of the most extensively used ingredients in topical
preparations throughout the centuries. Indeed the use of lanolin was known to
the ancient Greek since 700 B.C. It is the lipid secretion of the sebaceous
glands of the sheep and chemically it is a complex mixture of esters, di-esters
and hydroxyesters of high MW, lanolin alcohols and acids.
Lanolin is an effective emollient. It softens and improves dry skin by retarding
TEWL with a milder occlusive effect compared to petrolatum. However, apart from
the pesticides content issue, the incidence of allergy and sensitization to
lanolin and its derivatives has been reported in several papers.
Petrolatum, also known as petroleum jelly or vaseline, is a purified yellowish
to light amber or white complex mixture of semisolid hydrocarbons, chiefly of
the methane series having carbon numbers predominantly greater than C25.
Actually petrolatum is a colloid system of non straight chain saturated
crystalline hydrocarbons and high-boiling liquid hydrocarbons.
White mineral oils are viscous liquid derived also from petroleum. They are
complex mixtures of saturated hydrocarbons, having carbon numbers in the range
of C15 to C50. The chemical and physical properties of white mineral oils are
defined by a number of national and international standard setting groups
dealing with food, pharmaceutical and cosmetic specifications.
Petrolatum and white mineral oils have been used in topical preparations since
the beginning of this century. They are excellent moisturizers and emollients
and found very quickly markets in cosmetics and pharmaceuticals, e.g. baby oils,
sunscreens and suntan oils, emollient creams and lotions, bath oils, lipsticks,
makeups, makeup removers, hair care formulations, etc.
In pharmaceuticals petrolatum and white oils provide a convenient anhydrous base
for topical products, while the higher viscosity white oils are also used as
laxatives.
Later we shall discuss more data on mineral oil and petrolatum safety,
remembering Butcher's studies showing acanthosis and parakeratosis (hypertrophy
of the stratum corneum with imperfect cornification) following repeated
application of mineral oil.
Isopropyl esters are used to produce a light, non-greasy, emollient skin feel.
Results presented by Lanzet show that all isopropyl esters, but mainly
myristate, linoleate and lanolate, are comedogenic.
Alternative raw materials
To overcome traditional formulation and the side effects connected to the
traditional lipids , to improve anhydrous cosmetics appearance, skin feel,
stability, etc. we have performed several formulation studies substituting
petroleum derivatives, lanolin, isopropyl esters and also vegetable oils with
suitable Vevy Europe raw materials.
We also replaced natural vegetable oils because they may develop rancidity and
malodour due to their content in unsaturated fatty acids. Nesatol (Vevy codex
03.0197) is a reconstituted vegetable-based oil containing saturated fatty acids
resistant to oxidation, having good solubilizing properties, imparting a soft
feel and having a low skin irritation potential. Moreover some authors found
that capric/caprylic triglyceride, peach kernel oil, sweet almond oil, grape
seed oil, etc. exhibit comedogenic effects.
PME(Vevy codex 03.0775), and also newer PME-1 (Vevy codex 03.3392) are non
occlusive substitute for petrolatum; Syntesqual (Vevy codex 03.1133) substitutes
mineral oil; Lanolide (Vevy codex 02.0911) and Lanolide-Extra (Vevy codex
02.2390) replace lanolin; Isostearene (Vevy codex 03.0373) replaces IPM and
Lipocerite (Vevy codex 03.0465) replaces vegetable butters.
Formulations
a. Anhydrous cosmetics
To increase ointments, lipid gels, pastes and oils stability, skin feel and
spreadability were performed formulation studies with alternative raw materials
and results were compared with classic-formula anhydrous cosmetics.
First we studied the simple mixture of PME and Syntesqual to duplicate the
texture of petrolatum/mineral oil combinations. The 60:40, 50:50 and 40:60
ratios are the most comparable to the hydrocarbons , with a viscosity of
100,000, 60,000 and 20,000 cPs respectively); higher levels of the ether
increase too much the hardness characteristics, while its lower percentages
yield very low viscosity values (down to 500 cPs).
Systems (50:50) with PME and Syntesqual or Nesatol compared to similar
petrolatum and mineral oil systems gave increased spreadability, stability and
better texture.
By adding 10% Lipocerite to a 25:65 PME: Syntesqual or Nesatol we have
comparable or even better results than with a 25:65 petrolatum: mineral oil
mixture.
b. Absorption bases
They have water-absorbing and emulsifying properties and are usually mixtures of
mineral oil, petrolatum, lanolin, hydrocarbon waxes and alcohols,
lanolin-derived or from other sources, or sorbitan derivatives.
They are mainly used in W/O emulsions or as vehicles for pharmaceutical and
cosmetic ointments.
We have determined that 100 g of each mixture based on PME: Syntesqual:
Sitostene (Vevy codex 13.0983) [ratio 30:60:10 and 30:65:5] absorbs respectively
100 g and 150 g of water and therefore may effectively replace the petrolatum:
lanolin mixtures.
By adding 5% Ixolene 8 to the 30:60:5 and 10:80:5 mixtures of PME: Syntesqual:
Sitostene we obtain respectively a four-time and a three-time water absorption
indicating the suitability of these systems as absorption bases for W/O
emulsions. The 10:80:5:5 ratio, shows the greater spreadability.
c. Emulsions
Results obtained formulating different emulsions with Isostearene suggest its
suitability as isopropyl esters replacement.
Conclusions
Effective and safe raw materials can be used to replace petroleum derivatives,
lanolin and isopropyl esters which have repeatedly shown safety drawbacks.
Pharmaceutical and cosmetic formulations can be improved by combining advanced
lipid substances safe on the skin.
Oils, waxes and their derivatives constitute a very large and important class
of basic cosmetic and pharmaceutical raw materials. They are used mainly as
vehicles and emollients for a very wide range of creams, lotions, ointments,
lipid gels, oils, pastes and soaps.
Lanolin, mineral oil, petrolatum and isopropyl esters are the raw materials most
often found in topical ointments and emulsions. As it has been largely
demonstrated in the past years all these lipid components present not
neglectable drawbacks which suggest their total or partial substitution with
safer raw materials having the same effectiveness.
Vevy Europe will present the results of research studies regarding the
formulation of “alternative” ointments, absorption bases and emulsions
containing no mineral oil, petrolatum, lanolin and IPM or IPP, but safe and
effective raw materials for dermatological and cosmetic application.
Here follows a brief review on the properties but also the inconveniences of the
traditional substances found in topical products.
Lanolin has been one of the most extensively used ingredients in topical
preparations throughout the centuries. Indeed the use of lanolin was known to
the ancient Greek since 700 B.C. It is the lipid secretion of the sebaceous
glands of the sheep and chemically it is a complex mixture of esters, di-esters
and hydroxyesters of high MW, lanolin alcohols and acids.
Lanolin is an effective emollient. It softens and improves dry skin by retarding
TEWL with a milder occlusive effect compared to petrolatum. However, apart from
the pesticides content issue, the incidence of allergy and sensitization to
lanolin and its derivatives has been reported in several papers.
Petrolatum, also known as petroleum jelly or vaseline, is a purified yellowish
to light amber or white complex mixture of semisolid hydrocarbons, chiefly of
the methane series having carbon numbers predominantly greater than C25.
Actually petrolatum is a colloid system of non straight chain saturated
crystalline hydrocarbons and high-boiling liquid hydrocarbons.
White mineral oils are viscous liquid derived also from petroleum. They are
complex mixtures of saturated hydrocarbons, having carbon numbers in the range
of C15 to C50. The chemical and physical properties of white mineral oils are
defined by a number of national and international standard setting groups
dealing with food, pharmaceutical and cosmetic specifications.
Petrolatum and white mineral oils have been used in topical preparations since
the beginning of this century. They are excellent moisturizers and emollients
and found very quickly markets in cosmetics and pharmaceuticals, e.g. baby oils,
sunscreens and suntan oils, emollient creams and lotions, bath oils, lipsticks,
makeups, makeup removers, hair care formulations, etc.
In pharmaceuticals petrolatum and white oils provide a convenient anhydrous base
for topical products, while the higher viscosity white oils are also used as
laxatives.
Later we shall discuss more data on mineral oil and petrolatum safety,
remembering Butcher's studies showing acanthosis and parakeratosis (hypertrophy
of the stratum corneum with imperfect cornification) following repeated
application of mineral oil.
Isopropyl esters are used to produce a light, non-greasy, emollient skin feel.
Results presented by Lanzet show that all isopropyl esters, but mainly
myristate, linoleate and lanolate, are comedogenic.
Alternative raw materials
To overcome traditional formulation and the side effects connected to the
traditional lipids , to improve anhydrous cosmetics appearance, skin feel,
stability, etc. we have performed several formulation studies substituting
petroleum derivatives, lanolin, isopropyl esters and also vegetable oils with
suitable Vevy Europe raw materials.
We also replaced natural vegetable oils because they may develop rancidity and
malodour due to their content in unsaturated fatty acids. Nesatol (Vevy codex
03.0197) is a reconstituted vegetable-based oil containing saturated fatty acids
resistant to oxidation, having good solubilizing properties, imparting a soft
feel and having a low skin irritation potential. Moreover some authors found
that capric/caprylic triglyceride, peach kernel oil, sweet almond oil, grape
seed oil, etc. exhibit comedogenic effects.
PME (Vevy codex 03.0775), and also newer PME-1 (Vevy codex 03.3392) are non
occlusive substitute for petrolatum; Syntesqual (Vevy codex 03.1133) substitutes
mineral oil; Lanolide (Vevy codex 02.0911) and Lanolide-Extra (Vevy codex
02.2390) replace lanolin; Isostearene (Vevy codex 03.0373) replaces IPM and
Lipocerite (Vevy codex 03.0465) replaces vegetable butters.
Formulations
a. Anhydrous cosmetics
To increase ointments, lipid gels, pastes and oils stability, skin feel and
spreadability were performed formulation studies with alternative raw materials
and results were compared with classic-formula anhydrous cosmetics.
First we studied the simple mixture of PME and Syntesqual to duplicate the
texture of petrolatum/mineral oil combinations. The 60:40, 50:50 and 40:60
ratios are the most comparable to the hydrocarbons , with a viscosity of
100,000, 60,000 and 20,000 cPs respectively); higher levels of the ether
increase too much the hardness characteristics, while its lower percentages
yield very low viscosity values (down to 500 cPs).
Systems (50:50) with PME and Syntesqual or Nesatol compared to similar
petrolatum and mineral oil systems gave increased spreadability, stability and
better texture.
By adding 10% Lipocerite to a 25:65 PME: Syntesqual or Nesatol we have
comparable or even better results than with a 25:65 petrolatum: mineral oil
mixture.
b. Absorption bases
They have water-absorbing and emulsifying properties and are usually mixtures of
mineral oil, petrolatum, lanolin, hydrocarbon waxes and alcohols,
lanolin-derived or from other sources, or sorbitan derivatives.
They are mainly used in W/O emulsions or as vehicles for pharmaceutical and
cosmetic ointments.
We have determined that 100 g of each mixture based on PME: Syntesqual:
Sitostene (Vevy codex 13.0983) [ratio 30:60:10 and 30:65:5] absorbs respectively
100 g and 150 g of water and therefore may effectively replace the petrolatum:
lanolin mixtures.
By adding 5% Ixolene 8 to the 30:60:5 and 10:80:5 mixtures of PME: Syntesqual:
Sitostene we obtain respectively a four-time and a three-time water absorption
indicating the suitability of these systems as absorption bases for W/O
emulsions. The 10:80:5:5 ratio, shows the greater spreadability.
c. Emulsions
Results obtained formulating different emulsions with Isostearene suggest its
suitability as isopropyl esters replacement.
Conclusions
Effective and safe raw materials can be used to replace petroleum derivatives,
lanolin and isopropyl esters which have repeatedly shown safety drawbacks.
Pharmaceutical and cosmetic formulations can be improved by combining advanced
lipid substances safe on the skin.