Organogels for cosmetic and dermo-cosmetic applications

FORMULATION
Kirilov Plamen
KIRILOV PLAMEN1*, LE CONG ANH KHANH1, DENIS ALICE1, RABEHI HALIMA1,
RUM SILVIA2, VILLA CARLA2, HAFTEK MAREK1,3, PIROT FABRICE1,4
* Corresponding author
1. Université Claude Bernard Lyon 1, EA 4169 "Aspects fondamentaux, cliniques et thérapeutiques de la
fonction cutanée", SFR Lyon-Est Santé, INSERM US 7, CNRS UMS 3453
Laboratoire de Pharmacie Galénique Industrielle, ISPB, 8 Avenue Rockefeller 69737 Lyon Cédex 08, France
2. Dipartimento di Scienze Farmaceutiche dell’Università, Viale Denedetto XV, Genova, Italia
3. Université Claude Bernard Lyon 1, EA 4169 "Aspects fondamentaux, cliniques et thérapeutiques de la
fonction cutanée", SFR Lyon-Est Santé, INSERM US 7, CNRS UMS 3453
Laboratoire de Dermatologie, ISPB, 8 Avenue Rockefeller, F-69737 Lyon, Cédex 08, France
4. Groupement Hospitalier Eduard Herriot, Service Pharmaceutique, Fabrication et contrôles des
médicaments, Pavillon X, Place d’Arsenal, 69437 Lyon, Cédex 03, France
Organogels for cosmetic
and dermo-cosmetic applications
Classification, preparation and characterization of
organogel formulations - PART 1
KEYWORDS: organogel, organogelator, LMOG, formulation, cosmetic product, dermo-cosmetic application.
Abstract
Organogels are semi-solid systems in which an organic liquid phase is immobilized by a three-dimensional
network composed of low molecular weight or polymeric components. Recently, they have raised an
increasing interest in the pharmaceutical, cosmetic and food industry. Numerous cosmetic products based on organogels
formulations are marketed. Many studies now focus on new applications of organogels and therefore, aim to develop novel systems
of organogels and new generations of organogelators.
In this review, methods of preparation and characterization of organogel will be described, as well as different classifications and
current applications in the cosmetic field, more particularly in dermo-cosmetics.
INTRODUCTION
Along with the rising customers’ incomes and their
interest% in beauty, cosmetic and dermo-cosmetic industry
has continuously been developing for the last century.
According to l’Oréal, results in 2013 showed this industry is
particularly dynamic which is valued about 172 billion euros
and experienced an annual increase of 3.8%. Among 6
main categories of cosmetic industry, the skincare sector
makes up the largest part of the global cosmetic market,
accounting 33.8% in 2012 and is also leading in terms of
growth potential with an expected increase of 6% by 2025
(1, 2). In addition to identify attractive active ingredients
and new pharmacological targets, an important strategy
of developing cosmetic products for skin care is to design
more effective delivery systems for cosmetic agents.
The skin has been known as an advantageous route of
administration for numerous active pharmaceutic and
cosmetic ingredients. It offers the possibility for a noninvasive delivery which is controllable, without the risk of
gastrointestinal degradation or first-pass liver metabolism
of active ingredients. However, as a complex organ
designed to isolate the organism from the environment, the
skin is a barrier limiting the penetration and absorption of
active ingredients and thus represents a challenge to the
pharmaceutical and cosmetic development of carrier. In
principle, it is essential to choose the appropriate delivery
vehicle for each active ingredient, depending on its
physicochemical properties and the targeted site.
In the cosmetic field, several strategies have been
considered to protect active ingredients whose stability
could be altered, either by the dispersion medium or
the manufacturing process, and also to vectorize them
to a specific receptor site. Penetration and permeation
through different layers of skin can also be improved by
using suitable vehicles. Many of the solutions suppose the
incorporation or encapsulation of the active components
in particles of various sizes and constitutions, such as
liposomes, ethosomes, nanoparticles, etc.
Besides, the desirable properties of a formulation for
cutaneous application are the acceptability and the
feasibility; it should be non-toxic, non-irritation, easy to
use and allow a good skin feeling. Typical formulations
for cosmetics are: gels, creams, lotions, ointments, sticks,
emulsions, powders, etc.
Gels are vehicles that have been proved to be favorable
for topical drug delivery or for the localized drug action
on the skin and other topical routes such as ophthalmic,
H&PC Today - Household and Personal Care Today Vol. 10(3) May/June 2015
15
rectal, vaginal (3-5). They are rigid and elastic materials
and are widely used in cosmetics, medicines, biomaterials
and food technologies. They are also found in numerous
daily products, such as soap, shampoo, toothpaste, hair
gel and contact lenses. Gels mainly consist of a fluid solvent
with a gelator as the minority component: in general, a
gelling agent such as a carbomer or a natural gum (i.e.
xanthan gum) is dispersed in the solvent (6). Despite high
concentration of liquids in the composition of gels, they are
defined as a semi-solid formulation, showing a hydrophobic
or hydrophilic external solvent phase, thus immobilizing
active ingredients within the spaces available of a threedimensional network structure (7, 8). In comparison to
cream and ointment, gel formulation may provide better
application properties and stability. Thanks to a high solvent
content, gels appear to be great vehicles for the dissolution
of drugs and also enhance permeation through the skin.
Moreover, the incorporation of the active ingredient in
a gel matrix allows to control its release rate, increasing
the application time and the efficacy. Gels also show
protective action and skin hydration properties by limiting
the transepidermal water loss (5, 6).
Organogels (also called oleogels) are a specific type of
gels in which organogelators swell and retain organic
solvents in a three-dimensional network. They consist in a
non-crystalline, unglossy, thermoreversible solid material
and viscoelastic system. The organogelators can be either
low-molecular-weight components or polymers forming
the network which entrap the solvent, by non-covalent
bonds such as Van der Waals forces and hydrogen bonds,
or covalent bonds (6, 9). In general, gelators can function
as relatively low concentrations, typically inferior to 15 wt%.
In some cases, the amount required has been reported
to be as low as 0.1 wt% (11). This simplifies the cosmetic
formulation due to the reduction of the required amount
of rheological additives, as well as reduces potential side
effects. The gels obtained from low concentrations of
gelators are also very transparent and stable (5). Besides,
the capacity of organogelators to form a fibrillar structure
and retain significant concentrations of oils attracts the
interest of researchers. They also provide a pleasant
texture and stabilize many heterogeneous systems. Being
thermodynamically stable, the structural integrity of
organogels is maintained for longer time periods. They are
resistant to microbial contamination: the external phase
is non-aqueous; therefore, the internal aqueous phase
within organogels is well protected (6, 10). Not only easy to
prepare as they have auto-assembly properties, organogels
can also boost drug permeation through the stratum
corneum thank to their lipophilic nature. Many components
known as permeation enhancer such as fatty acids,
surfactants, glycols, essential oils and terpenes are used
for the preparation of organogels. Moreover, organogel
formulations can play a solubilizing role, maximizing the
partitioning of active ingredients into the skin tissue (10,
12-15). They have been proved to be advantageous
carriers for both hydrophobic and hydrophilic compounds.
Recently, lecithin organogels turned out to be a topical
vehicle of interest, particularly in skin aging treatments,
as the lecithin itself provides skin protection against UV,
it shows potential and could be even more effective if
combined to active agents against skin aging. Regarding
pharmaceutical uses, numerous active ingredients such as
vitamins, hormones, NSAIDS, peptides, amino acids, local
16
anesthetics and antifungal agents have been entrapped
in lecithin organogels for topical or transdermal delivery
assays and presented efficient skin permeation and
distribution (12-15).
Possessing numerous advantages, organogels have
been invested for a wide range of applications including
cosmetics, pharmaceutical and medical fields, food
industry, cleaning or light emitting materials, etc. (9, 11, 16,
17). In this review, we focus on their cosmetic and dermocosmetic applications and on providing a global view of
their classification, preparation and characterization.
CLASSIFICATION OF ORGANOGELS
Organogel is a system composed of an organic liquid and
a gelator. The organogel classification can be based on
the nature of the organic liquids, gelators used as well as
their intermolecular interactions.
Nature of the organic liquid
Organogelator are capable to jellify a broad range
of organic liquids. However, it remains difficult to
predict the organic liquid appropriate for a particular
gelator. Generally, the discovery of gelators is still today
spontaneous and is usually followed by investigative
screening of different solvent systems potentially suitable
with gelation (6, 11). Based on polarity of organic liquids,
we can classify them in two main groups: polar and apolar.
A variety of polar organic liquids has been studied for the
preparation of organogels such as 1,2-dichloroethane,
dichloromethane, chloroform, ether (diethyl ether, diphenyl
ether), 1-4-dioxane, esters (ethyl formate, ethyl acetate,
ethyl maloate), ketones (acetone, methyl ethyl ketone),
amides (N,N-dimethylformamide, N,N-dimethylacetamide),
dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetonitrile,
carboxylic acids, acetic anhydride, amines,
trimethylchlorosilane, trifluoroethanol, glycerol, propylene
glycol (18, 19).
Besides polar liquids, apolar liquids are also good solvents
for organogel obtaining. These liquids include alkanes,
cycloalkanes, aromatic compounds, natural or synthetic
oils. Among them, oils are the most frequent used organic
solvent for cosmetic products because of their availability,
low price, compatibility, emollient property and high
spreading ability. Some examples are vegetable oils, such
as jojoba, avocado, sweet almond, soybean, apricot, olive,
pumpkin seed, soybean, karanja, castor and liquid fraction
of shea butter; mineral oils such as vaseline oil; synthetic
oils such as triglycerides (for example caprylic/capric
triglycerides), isopropyl myristate, 2-ethylhexyl palmitate,
cetearyl octanoate hydrogenated isoparaffin, isononyl
isononanoate; volatile or nonvolatile silicone oils and
fluorinated oils (20-24).
Nature of organogelators
Organogelator can be classified into two groups based on
their molecular weight: low molecular-mass organogelators
(LMOGs) and polymer organogelators (POGs).
LMOGs
A LMOG corresponds to a relatively small organic molecule
with molecular weight of less than 2000 g/mol, and more
particularly less than 500 g/mol, capable of gelling organic
H&PC Today - Household and Personal Care Today Vol. 10(3) May/June 2015
Figure 1. Schematic representation and scanning electron microscopy (SEM) micrographs of HSA
(intermolecular hydrogen bonds, Van der Waals interactions) and DBS (intra- and intermolecular hydrogen
bonds, π-π stacking) organization in organic medium (25, 28).
liquids, forming a supramolecular three-dimensional
network (16). Their potential advantages over POGs could
be their biocompatibility, lower toxicity, easy to prepare,
strong physical stability, greater flexibility of use and gelling
capacity even in very small quantities (> 1 wt%) (6, 11, 25).
The LMOGs can be separated into “classes” according
to chemical structure, including: alkanes, derivatives
of fatty acids, steroid derivatives, anthryl derivatives,
amino acid types, amide or urea compounds, inorganic
and organometallic compounds. Derived from these
categories, several chemical compounds are widely used
as organogelators for cosmetic formulations for example,
12-hydroxystearic acid (HSA), 1,3: 2,4-di-O-benzylidèneD-sorbitol (DBS), sterols, lecithin, mono- and diglycerides,
lecithin mixtures with sorbitan esters, fatty acids, fatty
alcohols, waxes and wax esters. In these cases, the gelled
organic liquids are usually vegetable, animal or mineral and/
or synthetic oils or waxes (26, 27).
LMOGs are often used for the formulation of physical
gels. In contrast to chemical gels, in which the network
is maintained by covalent bond, physical gels of LMOGs
are thermoreversible, appearing as a gel below a
critical temperature, such as sol-to-gel phase transition
temperature (gelation temperature, Tgel), and as a solution
above it. The driving force for the initiation of gelation and
formation of their networks can be weak, non-covalent
interactions like Van der Waals interactions, π-π stacking,
intermolecular hydrogen bonds, ionic or organometallic
bonds or (almost always) a combination of these
interaction (25, 28) (Figure 1).
Based on the kinetic properties of aggregates, organogels
of LMOGs can be classified into two groups: “strong”
organogel (solid fiber network) and “weak” organogel (fluid
fiber network) (Figure 2).
of gelator molecules
in the organic medium
results in the formation
of aggregates. The
junction zones, crystallized
microdomains, are
responsible for the highly
non-Newtonian behavior
of “strong” physical
gels (Figure 2a) (11, 29).
“Strong” organogels can be
obtained by using different
LMOGs with appropriate
solvents: fatty and amino
acids, organometallic
compounds, steroids,
amide- or urea compounds,
alkanes (11).
“Weak” organogels
“Weak” organogels (flux-matrix organogels) are made of
transient three-dimensional networks exhibiting a liquid-like
“Strong” organogels
“Strong” organogels are materials made of permanent
three-dimensional networks exhibiting a solid-like,
viscoelastic, mechanical behavior as a result of their
thermoreversibility or the existence of Tgel and Tmelt
(melting temperature or gel-to-sol phase transition
temperature). They are generally prepared by dissolving
the gelator in a heated solvent, following a decrease
in temperature below the gelator solubility limit.
Consequently, cooperative intermolecular interactions
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2A
2B
Figure 2. Nature of organogel networks structure. 2a “strong”
organogel with a permanent solid-like network where
junction points are spatially extended (pseudo) crystalline
microdomains. 2b “weak” organogel with transient networks in
which the junction points are entanglements or spatially limited
organized microdomaines, characterized by chain breaking/
recombination (11).
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viscoelastic behavior. Fluid matrices are formed as a result
of the reorganization of surfactant molecules into monoor bilayer cylindrical aggregates upon the incorporation
of polar solvents into organic solutions of surfactants. The
transient networks are characterized by the continuous
breaking and recombination of the constituent rods, and
are also referred to as “worm-like” or
“polymer-like” networks (Figure 2b). Some typical examples
for this system are lecithin and sorbitan monostearate,
glyceryl fatty acid ester which have gained an increasing
interest in pharmaceutical science (11).
POGs
POGs are high molecular-mass molecules which are
capable of gelling organic solvents by the formation
of physical supramolecular crosslinking points. Such
crosslinking points are formed by a conformational
change in the polymer backbone or by the addition
of crosslinking agents. In comparison to LMOGs, POGs
are just of a limited number and their organogelation
abilities are relatively lower. However, gels developed
by polymeric organogelators generally have lower Tgel
and comparatively higher gel strength when compared
with organogel obtained with LMOGs (30). Recently,
interest arises in development of a novel class of
polymer organogelator, where LMOGs are combined
to conventional polymers, forming supramolecular selfassembling polymer organogelators. According to Suzuki
et al., POGs can be classified into three categories:
supramolecular crosslinkable polymers, polymer-crosslinking
agent organogelators and LMOG-incorporated polymer
organogelators (25).
Supramolecular crosslinkable polymer organogelators
The polymer chains naturally entangle, forming a threedimensional network which immobilizes the solvent. In this
structure, physical crosslinking points are usually maintained
by helical conformations due to their relatively strong
interactions. This is the case of polyethylene in mineral
oil (Plastibase®), poly(methyl methacrylate) in propylene
glycol, polystyrenes in chloroform, carbon tetrachloride or
benzene, etc. (11, 25).
Polymer-crosslinking agent organogelators
The polymer itself is not a gelator of the organic liquid.
However, upon the addition of the low molecular
weight crosslinkers, the supramolecular crosslinking
junction is formed rapidly. One example for this system
is poly(allylamine) (PAA) which cannot jellify any
tested organic liquids, but shows to be an excellent
organogelator for alcohols ROH (R = C1–C8) and 1-methyl2-pyrrolidonealcohols when CO2 was bubbled into this
solution. The organogels obtained were stable for more
than two months. In this case, through the interaction
between PAA and CO2, the allylammonium (NH3+) and
allylcarbamate (NHCO2-) moieties were formed, and they
functioned as crosslinking points (25). Another example is
photoreversible and thermoreversible supramolecular gels
consisting of poly(tri-methylene iminium trifluorosulfonimide)
(PTMI) as the polymer and a bifunctional
benzoxazylpyridine (bzpybox) ligand with an azobenzene
group as the crosslinker, mediated by complementary
hydrogen bonds. The suspension of PTMI and the crosslinker
in acetonitrile forms a homogenous clear solution as
18
heated up, and transforms into a transparent gel upon
cooling to the room temperature (25).
LMOG-incorporated polymer organogelators
Self-assembling polymer has been designed by
introducing LMOGs into conventional polymers. LMOGs
function as a gelation-causing segment form the
supramolecular polymer, while the polymer backbone
inhibits crystallization of the gelator and provides large
spaces for the immobilization of solvents. Introduction
methods for LMOGs into polymers are achieved by two
strategies: copolymerization and polymer reaction. For
example, L-Ile-PDMS obtained by the copolymerization
of poly(dimethylsiloxaneco-hydridomethylsiloxane)
(polymer) with allyl-containing Lisoleucine LMOG,
presented a good organogelation ability for many organic
liquids, such as alkanes, alcohols (methanol, ethanol,
1-propanol, 2-propanol, 1-butanol), ethyl acetate, ketones,
aromatic solvents, polar solvents (dimethylformamide,
dimethylacetamide, dimethylsulfoxyde, pyridine) (25).
Nature of interaction
In literature, organogels are divided into two categories
based on the nature of organogelator intermolecular
interactions: physical organogels and chemical organogels.
Physical organogels
Physical organogels are three-dimensional networks which
are held together by non-covalent bonds such as hydrogen
bonds, π-π stacking, Van der Waals, electrostatic and
coordination interactions. They are thermoreversible, which
means there is Tgel, above which the system is a solution of
polymer in organic liquid, whereas cooling the hot solution
phase results in gel phase (21-29). All of the organogels
of LMOGs and the majority of the organogel of POGs are
physical gels (25).
Chemical organogels
Chemical organogels are formed by entrapment of organic
liquid in a chemical crosslinking network structure. The
network is maintained by covalent bond; therefore it is more
robust and resistant to physical deformations. Recently,
different chemical organogels have been developed
based on copolymers, especial copolymers of acrylic acid,
including polymeric organogels based on acrylic acid (AA)
and sodium allyl sulfonate (SAS) (31), polymeric organogels
based on acrylic acid and sodium styrene sulfonate (SSS)
(32), organogels of N-tertiary butyl acrylamide–acrylic acid
copolymer (33) and organogels of metalloporphyrin-based
conjugated microporous polymer (34).
PART II OF THIS REVIEW WILL BE PUBLISHED IN
H&PC Today VOL 10 NR 4
REFERENCES AND NOTES
1.
2.
3.
4.
Statistics and Facts on the Cosmetic Industry: http://www.
statista.com/topics/1008/cosmetics-industry.html (last checked
on Feb. 6th 2015).
Dermo-cosmetics Global Market: http://www.loreal.com/
beauty-in/beauty-in-active-cosmetics/the-dermocosmeticsglobal-market.aspx (last checked on Feb. 10th 2015).
Allan, S. H. “Hydrogels for Biomedical Applications”, Advanced
Drug Delivery Reviews, 64, 18-23, 2012.
Otto, W., Drahoslav L. “Hydrophilic Gels in Biologic Use”, Nature,
H&PC Today - Household and Personal Care Today Vol. 10(3) May/June 2015
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
185, 117-118, 1960.
Luis, S. V., Burguete, M. I., Martí-Centelles, V., Rubio, J.
“Pseudopeptidic Compounds for Biocompatible Gels: a
Review”, Cosmetics & Toiletries, 127 (4), 282-290 (2012).
Weiss, R. G., Terech, P. “Molecular Gels: Materials with SelfAssembled Fibrillar Networks”, Kluwer Academic: Norwell, MA,
2005.
Terech P., Weiss R. G. “Low Molecular Mass Gelators of Organic
Liquids and the Properties of Their Gels”, Chemical Reviews, 97
(8), 3133-3159, 1997.
Van Esch, J. H., Feringa, B. L. “New Functional Materials Based
on Self-Assembling Organogels: from Serendipity towards
Design”, Angewandte Chemie International Edition, 39 (13),
2263-2266, 2000.
Gupta, R., Gupta, M. K., Sharma Hemant K. “A Review on
Organogels and Fluid Filled Method”, Journal of Scientific
Research and Reviews, 3 (2), 278-288 (2014).
Nigar, K. M., Sangramsinh, L. G., Veerendra, C. Y. “Organogel:
Factors and its Importance”, International Journal of
Pharmaceutical, Chemical and Biological Sciences, 4 (3), 758773, (2014).
Vintiloiu, A., Leroux, L. C. “Organogels and Their Use in Drug
Delivery – a Review”. Journal of Controlled Release, 125, 179192 (2008).
Sushi, l. R., Santosh, S. B., Vaibhav, U. “Lecithin Organogel: a
Unique Micellar System for the Delivery of Bioactive Agents in
the Treatment of Skin Aging”, Acta Pharmaceutica Sinica B, 2,
8-15, 2012.
Rajiv, K., Om, P. K. “Lecithin Organogel as a Potential
Phospholipidstructured System for Topical Drug Delivery: a
Review”, AAPS PharmaSciTech, 6, 298-310, 2005.
Shaikh, I. M., Jadhav, K. R., Gide, P. S. “Topical Delivery of
Aceclofenac from Lecithin Organogels: Preformulation study”,
Current Drug Delivery, 3 (4), 417-427, 2006.
Willimann, H., Walde, P., Luisi, L. “Lecithin Organogels as Matrix
for Transdermal Transport Drugs. Journal of Pharmaceutical
Sciences, 81 (9), 871-874, 1992.
Carretti, E., Dei, L., Weiss, R. G. “Soft Matter and Art
Conservation. Rheoreversible Gels and Beyond”, Soft Matter, 1,
17-22, 2005.
Ayyappanpillai, A., Chakkooth, V., Vakayil K. P. “White Light
Emitting Organogel and Process Thereof”, U. S. Patent,
US8529790B2, 2013.
Shchipunov, Y. A., Shumilina, E. V. “Lecithin Organogels: Role of
Polar Solvent and Nature of Intermolecular Interactions”,
Colloid journal, 58 (1), 117-125, 1996.
Shchipunov, Y. A., Shumilina, E. V. “Lecithin Bridging by
Hydrogen Bonds in the Organogel”, Material Science and
Engineering C, 3 (1), 43–50, 1995.
Kirilov, P., Lukyanova, L., Franceschi-Messant, S., Perier, V.,
Perez, E., Rico-Lattes, I. “A New Type of Colloidal Dispersions
Based on Nanoparticles of Gelled Oil”, Colloids and Surfaces A:
Physicochemical and Engineering Aspects, 328, 1-7 (2008).
Kirilov, P., Franceschi –Massant, S., Perez, E., Rico-Lattes, I.,
Bordat, P. “Novel Organogel Particles, Method for the
Preparation Thereof and Cosmetic Uses Thereof”, W. O. Patent,
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
H&PC Today - Household and Personal Care Today Vol. 10(3) May/June 2015
US2008037697A1, 2008.
Boudier, A., Kirilov, P., Franceschi-Massant, S., Belkhelfa, H.,
Hadioui, E., Roques, C., Perez, E., Rico-Lattes, I. “Evaluation of
Biocompatible Stabilized Gelled Soybean Oil Nanoparticles as
New Hydrophobic Reservoir”, Journal of Microencapsulation,
27 (8), 682-692, 2010.
Kirilov, P., Tourrette, A., Cazalbou, Boudier, A., FranceschiMessant, S., Perez, E., Rico-Lattes, I. “Self-Assembled Organogel
Dispersed Systems: New Materials for Cosmetic and
Pharmaceutical Applications” 8th Meeting of Pharmaceutics,
Biopharmaceutical and Pharmaceutical Industry, March 19-22,
2012, Istanbul, Turkey.
Kirilov, P., Roul, A., Gilbert, E., Roussel, L., Salmon, D., Abdayem,
R., Colomb, E., Salvi, J.-P., Serre, C., Boulieu, R., Haftek, M., Pirot,
F. “Caractérisation Physico-Chimique et Rhéologique
d’Organogels à Base d’OFPM et d’Huiles d’Intérêt Cosmétique
et Dermo-Cosmétique”, CoBiP, Matrix Edition, 2014.
Suzuki, M., Hanabusa, K. “Polymer Organogelators That Make
Supramolecular Organogels through Physical Crosslinking and
Self-assembly”, Chemical Society Reviews, 39 (2), 455-463
(2010).
Nogueira, C., da Silva Pacheco, C. R., Arellano, D. L. B.,
Botega, D. C. Z., Mathias, N. M. L. “Structuring of Cosmetic
Composition Using Organogels”, WO2014147447A2, 2014.
Yoo, H. O., Kim, J. C., Kwak, J. H., Choi, E. K., Park, D. K. “Oil-inWater form Organogel Cosmetic Composition Having Variable
Transparency”, U. S. Patent, WO2014065536A1, 2014.
Lukyanova, L., Franceschi-Messant, S., Vicendo, P., Perez, E.,
Rico-Lattes, I., Weinkamer, R. “Preparation and Evaluation of
Microporous Organogel Scaffolds for Cell Viability and
Proliferation”, Colloids and Surfaces B: Biointerfaces, 79 (1), 105112 (2010).
Kirilov, P., Gauffre, F., Franceschi-Messant, S., Perez, E., RicoLattes, I. “Rheological Characterization of a New Type of
Colloidal Dispersion Based on Nanoparticules of Gelled Oil”,
Journal of Physical Chemistry B, 113 (32), 11101-11108, 2009.
Garg, T., Bilandi, A., Kapoor, B., Kumar, S., Joshi, R. “Organogels:
Advanced and Novel Drug Delivery System”, International
Research Journal of Pharmacy, 2 (12), 15-21 (2011).
Kabiri, K., Azizi, A., Zohuriaan-Mehr, M. J., Marandi, G. B.,
Bouhendi, H. “Alcohophilic Gels: Polymeric Organogels
Composing Carboxylic and Sulfonic Acid Groups”, Journal of
Applied Polymer Science, 120 (6), 3350-3356 (2011).
Kabiri, K., Azizi, A., Zohuriaan-Mehr, M. J., Marandi, G. B.,
Bouhendi, H. “Poly(Acrylic Acid–Sodium Styrene Sulfonate)
Organogels: Preparation, Characterization, and Alcohol Super
Absorbency”, Journal of Applied Polymer Science, 119 (5),
2759-2769, 2011.
Bera, R., Dey, A., Chakrabarty, D. “Studies on Gelling
Characterstics of N-Tertiary Butyl Acrylamide-Acrylic Acid
Copolymer”, Advances in Polymer Technology, 33 (2), 1-12
(2014).
Wu, K., Guo, J., Wang, C. “Gelation of Metalloporphyrin-Based
Conjugated Microporous Polymers by Oxidative Homocoupling
of Terminal Alkynes”, Chemistry of Materials, 26 (21), 6241-6250,
2014.
19