j.1468-2494.2008.00416.x

Review Article

Novel cosmetic delivery systems: an application

update

V. B. Patravale and S. D. Mandawgade

Department of Pharmaceutical Sciences and Technology, University Institute of Chemical Technology, Mumbai 400

019, India

Received 20 February 2007, Accepted 27 September 2007

Keywords: cosmetic delivery systems, encapsulation, nutracosmetics, personal care, skin care

Synopsis

World consumers are nowadays more focused on

their health and appearance. This trend is creating

heightened demand for products formulated with

natural and nutraceutical ingredients. Functional

ingredients and innovative delivery systems are

driving the new product development in the field

of cosmetics. A significant number of innovative

formulations are now being used in personal care

with real consumer-perceivable benefits and opti-

mized sensory attributes, resulting in an economic

uplift of cosmetic industry. In fact, the U.S. market

alone for novel cosmetic delivery systems has been

projected to be more than $41 billion for the year

2007. Novel cosmetic delivery systems reviewed

here possess enormous potential as next-genera-

tion smarter carrier systems.

Resume

Les consommateurs du monde entier portent

aujourd’hui une plus grande importance a leur

sante et a leur apparence. Cette tendance creee une

demande accrue de produits formules avec des

ingredients naturels et nutraceutiques. Les ingredi-

ents fonctionnels et les systemes de liberation

innovants sont a la base du developpement de nou-

veaux produits dans le domaine des cosmetiques.

Un nombre significatif de formulations innovantes

sont maintenant utilisees dans les soins personnels

avec un benefice consommateur reellement percu et

des attributs sensoriels optimises, ce qui conduit a

un accroissement economique de l’industrie cosme-

tique. En fait, le seul marche US pour les nouveaux

systemes de liberation a ete estime a plus de 41

milliards de $ pour 2007. Les nouveaux systemes

de liberation cosmetique presentes ici possedent un

potentiel enorme en tant que prochaine generation

de systemes vecteurs plus sophistiques.

Introduction

World consumers are now focused on their

health, well-being and appearance more than

ever before. Terms such as ‘natural’, ‘organic’,

‘no artificial preservatives’ and ‘no animal ingre-

dients’ are drawing formidable attention. This

trend is creating heightened demand for products

formulated as cosmeceuticals with natural and

nutraceutical ingredients. Functional ingredients

and innovative delivery systems are driving the

new product development arena. Nutracosmetics

is an emerging class of health and beauty aid

products. They combine the benefits of nutraceu-

tical ingredients with the elegance, skin feel and

delivery systems of cosmetics. Nutracosmetics

and cosmeceuticals thus differ in the origin of

their functional ingredients. Nutraceutical ingre-

dients formulated in cosmetic delivery systems

Correspondence: Vandana B. Patravale, Reader in Phar-

maceutics, Department of Pharmaceutical Sciences and

Technology, University Institute of Chemical Technology

(UICT), N. P. Marg, Matunga, Mumbai 400 019, India.

Tel.: +91 022 24145616 Extn. 425; fax: +91 022

24145614; e-mail: [email protected]

International Journal of Cosmetic Science, 2008, 30, 19–33

ª 2008 The Authors. Journal compilation

ª 2008 Society of Cosmetic Scientists and the Societe Francaise de Cosmetologie 19

constitute nutracosmetics, whereas cosmeceuti-

cals are cosmetics formulated with pharmaceuti-

cal-type ingredients.

Today, consumers worldwide are looking for

personal care products that supply multiple bene-

fits with minimal efforts. They also expect the lat-

est technology advances to be incorporated into

innovative formulations. Faced with these trends,

formulators strive to develop highly differentiated

multifunctional products that focus on treatment

as well as aesthetics. A significant number of novel

products are based on a new generation of active

ingredients. With these emerging actives, come a

range of formulation challenges that includes sta-

bility control and the complications of combining

several actives into a single cosmetic product. As a

discipline that concerns with the treatment of

non-pathological skin, modern cosmetology is

increasingly alternating with dermatology.

To obtain skin care formulations with real con-

sumer-perceivable benefits and to optimize sensory

attributes, formulators are resorting to technology

that until recently was exclusively used in phar-

maceutical products. These special delivery sys-

tems are now being used in personal care

formulations. In cosmetics, the main concern is to

reach cutaneous cell while limiting the passage

into the blood circulation. The objectives of topical

therapy can therefore be classified into two major

areas:

1. To modulate or assist the barrier function of skin;

2. To administer an active ingredient to one or

more skin layers or compartments while mini-

mizing systemic involvement.

Depending on the composition, a vehicle is used

to exert mainly five types of effects on the skin

cleansing, decoration, care, hydration and protec-

tion. Delivering active substance to the targeted site

requires the right concentration of actives in the

formulation to achieve the optimal release rate and

desired distribution of active substances between

the vehicle and target site. A cosmetic care product

has to be developed and whenever this is the case,

various issues and aspects have to be considered

such as site and area of application, sensory and

optical properties, state of matter, actives and final

product storage stability and packaging.

Cosmetic delivery systems

Encapsulation techniques are most widely used in

the development and production of improved deliv-

ery systems. Some of the important novel cosmetic

delivery systems are discussed.

Vesicular systems

Following are the promising vesicle delivery sys-

tems in cosmetics:

• Liposomes;

• Silicone vesicles and matrices;

• Multi-walled delivery systems.

Liposomes

Liposomes are the most widely known cosmetic

delivery systems. These are artificial spherical sub-

microscopic vesicles with diameter between 25

and 5000 nm. Vesicles are composed inevitably of

amphiphilic molecules. Their centre consists of an

aqueous cavity, which is encapsulated by one or

more bimolecular phospholipid sheets, each sepa-

rated from each other by aqueous layers. The

polar head group forms the interface at both the

external and internal surfaces of liposomal bilay-

ers. The phosphatidyl moiety consists of two fatty

acids, which are ester bridged to glycerol phos-

phate. The chain length of fatty acids (mainly

C14, C16 and C18) and the degree of unsatura-

tion (one or two bonds) may vary. The polar head

group may be zwitterionic, negatively or positively

charged [1, 2].

The intensity of the mechanical mixing needed

to form liposomes from lipid bilayer sheets deter-

mines the dimensions and number of vesicle bilay-

ers. Such liposomes are multilamellar, small

unilamellar and large unilamellar vesicles. The

type of head group and fatty acid nature of phos-

pholipids determine physical stability of liposomes.

Natural lecithins (egg or soyabean lecithin) or syn-

thetic lecithin (di-palmitoyl lecithin) are mostly

used. The most common lecithin is mixture of

phosphatidylcholine, phosphatidylethanolamine,

phosphatidylinositol, phophatidylserine and phos-

phatidic acid. Depending on the nature of compo-

nents, which form their envelope, whole series of

name other than liposome have been given to the

commercial products [3, 4].

Liposomes are artificial phospholipid mem-

branes that can facilitate the passage of active

principles across the stratum corneum. After the

fortuitous observation that phospholipids exhibit a

marked affinity for some classes of flavonoids,

a new series of compounds denominated as


ª 2008 Society of Cosmetic Scientists and the Societe Francaise de Cosmetologie

International Journal of Cosmetic Science, 30, 19–3320

Novel cosmetic delivery systems V. B. Patravale and S. D. Mandawgade

‘phytosome’ has been developed by complexation

with polar botanical derivatives such as catechin,

quercetin, escin and glycyrrhetinic acid. From the

chemical viewpoint, phytosomes are complexes

between a pure phospholipid and pure active

principles.

Niosomes are non-ionic surfactant vesicles fabri-

cated from polyoxyethylene alkyl ether, polyoxy-

ethylene alkyl ester or saccharose diester. The oil

spreads uniformly over the surface of the skin; ves-

icles penetrate the stratum corneum in fractioned

form while the water of continuous phase evapo-

rates. The result is a special sensation to touch,

freshness, even essence, hydration and a feeling of

protection because of the oily film. If the envelope

is made of sphingolipids, vesicles are named

sphingosomes [5–7].

Marinosomes� (Bordeaux, France) are liposomes

based on a natural marine lipid extract containing

high ratio polyunsaturated fatty acids like, eicosa-

pentaenoic acid (EPA, 20:5n-3) and docosahexae-

noic acid (DHA, 22:6n-3). They are not present in

normal skin epidermis. However, they are metabo-

lized by skin epidermal enzymes into anti-inflam-

matory and anti-proliferative metabolites that are

associated with a variety of benefits with respect

to inflammatory skin disorders [8]. In one study,

Marinosomes� were prepared and characterized in

conditions that mimic topical application in terms

of pH and temperature. Further, preliminary

freeze-fracture TEM observations concerning Mari-

nosomes� formulations in oil-in-water (O/W)

emulsion showed that the membrane structures

were mostly preserved even in the presence of sur-

factant. In parallel, the first toxicology file indi-

cated a good skin and eye tolerance towards

Marinosomes�. All these results allowed consider-

ing Marinosomes� as potential candidates for cos-

meceutical in view of the prevention and

treatment of skin diseases [9].

Other related small vesicles having size around

20 nm, formed by a gellified polysaccharide

hydrophilic core capable of capturing the active

substances in the link of a network are termed

as ‘supramolecular biocarriers’. Their central core

is surrounded by crown of fatty acids attached

to the core by a covalent bond. The whole is

covered by an external sheet of phospholipids

attached to the lipid crown by hydrophobic

interaction with their polar heads facing the

periphery. The hydrophilic actives are attached

to the heart of the core, whereas the active

lipophilic substances penetrate through the dou-

ble lipid membrane [10].

Some important liposomal preparations having

cosmetic potential are discussed [11, 12]. The

skin care preparations with empty or moisture-

loaded liposome or niosome reduce the transder-

mal water loss and are suitable for the treatment

of dry skin. They also enhance the supply of lipids

and water to stratum corneum. Liposomal formu-

lations would have an advantage that the active

ingredient would be distributed optimally in the

horny layer and also would acquire a certain

water resistance. This has been illustrated by lip-

osomally encapsulated radical scavenger tanning

agents such as tyrosine and creams containing

aloevera, a-hydroxy acids (glycolic acid), sun-pro-

tection formulations with UV absorbers. Liposome

with anti-ageing complex such as ‘face capture’

contains thymus extracts, collagen and elastin.

Capture increases the cellular activity and rejuve-

nates the cells. Capture containing proteins and

peptides form a part of the connective tissue and

enhance the strength and tone of the skin. ‘Les

vitamins’ is a day cream with liposome containing

vitamin A, vitamin B2, vitamin B5 and vitamin

E. The cream assists in the skin regenerative pro-

cess and is helpful in removing the visible signs of

ageing.

Liposome stability may be referred to in terms of

leakage of contents, presence of oxidation products

or change in particle size because of aggregate for-

mation and fusion. Enclosing them in a gel matrix

can protect liposomes. The stability of liposome in

gellified aqueous or hydro-alcoholic environment

ranges between 2 and 3 years at a temperature

4–25�C. Stable liposomes can also be prepared by

polymerization of phospholipids, coating them with

a mixture of collagen and polysaccharide, albumin

or c-globulin. Polyethylene glycol (PEG) polymer

chains of various lengths can be covalently cou-

pled to lipids. Such liposomes are called stealth

liposomes or sterically stabilized liposome. Degra-

dation of liposomes is largely related to oxidation

and hydrolysis. Oxidation of liposome can be

avoided by using phospholipids with fully satu-

rated acyl chains (hydrogenated soyabean). Hydro-

lysis of the ester groups can be avoided by keeping

the pH values near 4.5–6.5. However, they remain

stable only for a few months, if dispersed in a

lipid-rich solution containing surfactant [13].

Some of the specialized liposomal preparations are

as follows.



International Journal of Cosmetic Science, 30, 19–33 21


Ultrasomes

Ultrasomes are specialized liposomes encapsulating

an endonuclease enzyme extracted from Micrococ-

cus luteus; the enzyme recognizes the sun damage

to the skin and initiates removal of damaged DNA.

Photosomes

Photosomes are incorporated in sun-care product

to protect the sun-exposed skin by releasing a

photo-reactivating enzyme extracted from a mar-

ine plant, Anacystis nidulans. Photosomes on light

activation reverse the cell DNA damage, reducing

immune suppression and cancer induction.

AOCS liposome

Asymmetric oxygen carrier system (AOCS) lipo-

somes are designed to carry oxygen into the skin.

These vesicles are composed of perfluorocarbon

core surrounded by a monolayer of phospholipids,

followed by a bilayer system. Perfluorocarbons are

excellent carriers of oxygen and so this system is

used to transport molecular oxygen into the skin.

Yeast-based liposomes

Yeast cell derivatives repair, soothe and oxygenate

the skin. In its liposomal form, it stimulates dermal

fibroblasts and provides a feeling of well-being.

Incorporation of vitamin C into the cell increases

significantly when liposomes are used as a vehicle

[4, 14].

Silicone vesicles and matrices

Silicones in physical association with various

active ingredients can function as delivery vesicles

for the actives. In the most basic example of this

concept, aluminium zirconium tetrachlorohydrex

GLY, an active ingredient used in anti-perspirant

applications was suspended in a vesicle based on

volatile silicones. The anhydrous vesicles reduce

stickiness and protect the activated salts from

hydrolysis. The active is released when the volatile

silicone evaporates. This approach has been

expanded to ingredients such as fragrances and

conditioning ingredients. Based on in vitro and in

vivo sun protecting factor (SPF) evaluations, it was

determined that stearyl dimethicone contributed to

increased SPF compared with the formulations

without stearyl dimethicone. High values of thixot-

ropy for the stearyl dimethicone allow the product

to be evenly distributed on the skin, improving

sun protection by forming uniform homogenous

film. Silicones have a long history of use in hair

care, where they are recognized for their ability to

provide improved conditioning, shine, manageabil-

ity, reduced flyway and number of other benefits.

The polymer based on hydroxyl ethyl cellulose cat-

ionic modified and hydroxyl propyl guar hydroxyl

propyl trimonium chloride have various benefits

including wet combing and hair manageability.

The addition of certain silicone polymers to the

above-mentioned systems has been found to

improve conditioning performance. However, the

synergy between these two types of materials has

been only recently demonstrated. Several silicone-

based technologies illustrate the synergistic proper-

ties of silicones with a variety of personal care

actives via physical association. These technologies

offer a wide scope for a range of innovative per-

sonal care applications [15, 16]. Induction of sili-

cone polyether into nanomicron- to submicron-

sized vesicular structures provides excellent stabil-

ity in aqueous medium. These are called ‘assem-

bly-required’ vesicles. Actives that can be delivered

by silicone-based vesicles are [17]:

1. Conditioning agents such as vitamin A, vita-

min E acetate and lanolin oil, humectants such

as lanolin alcohol, cetearyl octanoate and

sodium stearoyl lactylate, colorants;

2. Emollients such as mineral oil, jojoba oil and

polydimethyl siloxane.

Common silicone fluids such as dimethicone

are well known to cosmetic formulators. A gen-

eral property of silicone polymers is their high

permeability. The permeability of silicones makes

them suitable for controlled release applications

and for this reason they are used widely in trans-

dermal delivery systems. Cross-linked silicones

such as elastomers and adhesives are a relatively

new class of cosmetic raw materials that have

utility in delivery systems for active ingredients

[18].

Silicone elastomers are cross-linked and the

interconnections between polymer chains make

the elastomers solid material. Because of this struc-

ture, an active ingredient can be trapped in the

matrix and will not separate even if the active

ingredient is not soluble in the elastomer matrix.

Most of the active ingredients now can be loaded

into an elastomer matrix. Formation of silicone

polymer systems is based on different cross-linking

schemes, viz.

1. Condensation of a silica derivative with hydro-

xyl-terminated silicone polymer;





2. Mixing the active ingredient with the silicone

polymers before cross-linking;

3. Swelling the cross-linked silicone matrix with a

suitable solvent and using this solvent to carry

the active ingredient into the matrix.

One example of controlled release that has been

used commercially is the incorporation of fra-

grance into a silicone elastomer that is highly

swollen with silicone fluid. The use of such a sili-

cone elastomer blend to modulate the release rate

of fragrance has been reported [19]. Combining

the active ingredient with a silicone surfactant can

increase the release rate.

Multi-walled delivery systems

The multi-walled delivery system (MDS) is based

on a combination of structured vesicle-forming

materials and high shear processing. It provides

exceptional long-term stability to cosmetic skin

treatment products. MDS is analogous to the struc-

ture of membrane lipid found in the intracellular

matrix and made up of non-phospholipid amphi-

philic molecules (oleic acid, derivatives of polygly-

cerols, amino acid residues). Stability of these

types is predicted by zero-order kinetics. When

they are produced, MDS vesicles form five to seven

bilayer walls. MDS gives stability to liposomes but

by combining hydration and delivery, MDS also

nourishes and protects the skin, bringing the for-

mulator closer to optimizing product performance

[20].

Derivatives of essential fatty acids (EFAs) and

ceramides define today’s MDS [21]. EFAs bind

large volumes of water and form flexible mem-

branes that smoothen the stratum corneum.

MDS can be engineered to permeate the stratum

corneum or to remain on top of the stratum cor-

neum, offering a truly delayed release effect as the

multiple bilayers release their contents in response

to decreasing levels of moisture on the skin. This

forms effective delivery of sunscreens. Mixture of

glyceryl distearate, polyoxyethylene stearyl ether

and cholesterol could be used as a wall-forming

material to prepare MDS vesicles. These cyclo-

methicone-loaded MDS are stable over a period of

time and ready for incorporation into any desired

number of formulations. A 30% w/w petrolatum

MDS was prepared. At this concentration, petrola-

tum is a skin protectant. The MDS allows for pet-

rolatum to be applied without occluding the skin.

Small amino acid peptide chains have been encap-

sulated using MDS approach and formulated into

a cream. Encapsulated peptide fraction showed no

degradation over a period of 70 days and was also

found to enhance the percutaneous absorption of

peptide in human skin [22].

Emulsions

Following are the different emulsion delivery sys-

tems used in cosmetics:

• Microemulsions;

• Liquid crystals;

• Multiple emulsions;

• Nanoemulsions;

• Pickering emulsions.

Microemulsions

Microemulsions are stable, transparent (or translu-

cent), dispersions of oil and water stabilized by an

interfacial film of surfactant molecules and having

diameter <100 nm. Microemulsion formation usu-

ally involves a combination of three to four

components – water, oil, surfactant/s and co-sur-

factant/s. The surfactants chosen are generally

those in the non-ionic group because of their good

cutaneous tolerance and balanced lipophilic and

hydrophilic property. The most important role of

co-surfactant in the formation of microemulsions

is to increase interfacial fluidity and to modify the

Hydrophilic-Lipophilic Balance (HLB) of surfactant

to optimal value. Thus, their combination is more

effective than a single surfactant. Factors affecting

stability of microemulsions include interfacial ten-

sion, interfacial curvature, entropy and fluidity.

In microemulsions, the active is solubilized

rather than suspended as in the vesicles and is

available for immediate absorption, generally more

rapidly and effectively. Microemulsions are easy to

manufacture as they form spontaneously without

high shear equipments. Their optical transparency

and low viscosity ensure that they are of good

appearance, easy to handle and pack. Microemul-

sions are preferred to be used in moisturizing for-

mulation because they provide occlusivity and

fulfil criteria for aesthetic appearance, ease of

removal from container, ease of application and

adherence to treated area without tackiness. Car-

otenoids formulated in a microemulsion are

employed for treatment in skin cancers. Cosmetic

microemulsion containing di-decanoyl glycerol is

used to increase melanin content of melanocytes





thereby increasing pigmentation of skin. Moisturiz-

ing effect and penetration of vitamin E is enhanced

when employed in a microemulsion. The efficiency

of tri-decyl salicylic acid was increased when

incorporated in microemulsion as an anti-ageing

composition. Benzotriazoles, bisesorecinyl triazine

and S-triazine have been incorporated in micro-

emulsion for photo-protective efficacy. Microemul-

sion containing ascorbyl palmitate effectively

prevents UV-A-induced lipid peroxidation [23, 24].

A new multifunctional silicone quaternary poly-

mer microemulsion for hair care offers condition-

ing as well as protection from heat, improved

colour retention, enhanced body and volume and

also the product clarity [16].

Liquid crystals

Liquid crystalline phase is thermodynamically sta-

ble and represents a state of incomplete melting.

Liquid crystals are mainly of two classes – thermo-

tropic liquid crystals (smetic and nematic type)

and lyotropic liquid crystals. Liquid crystals exhibit

birefringence and dichromism and hence enhance

the cosmetic appeal because of the coloured

appearance of the preparations into which they

are incorporated. Liquid crystals form multilayers

around the emulsion droplets, decreasing the van

der Waal’s energy and increasing the viscosity

which increases the emulsion stability. These mul-

tilayers act as rheological barriers to coalescence.

Lipophilic materials such as vitamins, incorporated

into liquid crystalline matrix, are protected from

both thermal and photo-degradation. Emulsions

containing liquid crystals have been observed to

have a rate of active release much slower than those

without this stabilizing component. This effect is

because of multilayer structure of liquid crystalline

material around droplet, which effectively reduces

the interfacial transport of the dissolved actives from

within the droplet. For example, timed release of

vitamin A palmitate containing liquid crystals

dispersed in water-based gel [25].

Multiple emulsions

Multiple emulsions are emulsions in which glob-

ules of the dispersed phase encapsulate smaller

droplets, which in most of the cases are identical

with continuous phase. The two major types of

multiple emulsions are W/O/W in which internal

and external aqueous phases are separated by an

oil layer and O/W/O in which water separates the

two oil phases. In cosmetics, the most widely used

type is W/O/W. Although multiple emulsions espe-

cially W/O/W systems have potential applications

in controlled release systems for delivery of the

active ingredient, their use has been limited by

lack of stability. Multiple emulsions consist of W/O

and O/W emulsions and requires at least two sta-

bilizing surfactants, a low HLB one forming pri-

mary emulsion and a second, higher HLB

surfactant to achieve the secondary emulsification.

Primary emulsifiers are decaglycerol decaoleate,

mixed triglycerol trioleate and sorbitan trioleate.

Secondary emulsifiers include polysorbates and

poloxamers for W/O/W emulsion [26].

Multiple emulsions are thermodynamically

unstable systems. Principal modes of emulsion

breakdown involve coalescence of internal or

external droplets, expulsion of internal droplets,

osmotic swelling or shrinking [27]. Stability of the

multiple systems can be improved by forming a

polymeric gel in either the internal or external

aqueous phase. Two principle hypotheses were

proposed for the mechanism of transport of solute

from multiple systems. In the first hypothesis, the

active substance is released in the internal phase

by virtue of the rupture of multiple oily globules.

This rupture takes place either by shearing

(induced by rubbing the preparation on the skin)

or by swelling of internal phase. In the second

hypothesis, the encapsulated active substance dif-

fuses through the oily membrane. This would be

dependent on several factors like partitioning of

actives, its permeability and diffusion rate through

oily membrane, viscosity and thickness of interfa-

cial film, presence or absence of liquid crystals,

particle size and its distribution [28–30]. In cos-

metics, multiple emulsions are useful when one

wishes to prepare sustained release aerosol fra-

grances, prolonged skin moisturizers and pro-

tection of sensitive biologicals, personal care

formulations for perfumes, skin lipids, vitamins

and free radical scavengers [31–33].

Polyaphrons are three liquid-phase dispersions,

the internal phase being stabilized by encapsula-

tion in a thin aqueous soapy film. Polyaphrons

exhibit foam-like character in which the oil-encap-

sulated cells aggregate to form stable polyhedral

structures. Dispersions containing 97% of dis-

persed oil phase within a continuous structure

that contains only 3% water could be achieved

[28]. In another example, a five-phase novel emul-





sion consists of water, perfluorinated oil and liquid

crystal dispersed in a continuous silicone phase

along with coarsely dispersed aqueous gel phase.

Lipophilic actives can be incorporated into the

liquid crystalline phase; hydrophilic actives can be

dissolved in either of the two aqueous phases.

Such systems can be used to incorporate two

incompatible hydrophilic actives in different aque-

ous phases.

Nanoemulsions

Nanoemulsions consist of very fine oil-in-water dis-

persions, having droplet diameter smaller than

100 nm. Compared with microemulsions, they are

in a metastable state and are very fragile systems

by nature. Their structures depend on the process

used to prepare them. They can be prepared by

spontaneous emulsification such as phase inver-

sion temperature (PIT) emulsification or phase

inversion composition, or by using a high shear

device, which allows a better control of the droplet

size and large choice of compositions. The nano-

emulsions are easily valued in skin care because of

their good sensorial properties (rapid penetration,

merging textures) and their biophysical properties

(especially, hydrating power). They lead to a large

variety of products from water-like fluids to ring-

ing gels. Lotions, transparent milks, crystal-clear

gels with different rheological behaviours, visual

aspects, richness and skin feel are allowed with

nanoemulsions. A significant improvement in dry

hair aspect (after several shampoos) is obtained

with a prolonged effect after a cationic nanoemul-

sion use. Hair becomes more fluid and shiny, less

brittle and non-greasy [34].

A great deal of effort is currently being put into

the development of aqueous-based nail lacquers.

The nail lacquers are based on aqueous polymer

emulsion and contain in addition, oxyalkylene gly-

cols and selected oils, as plasticizers. These nail

lacquers reportedly adhere well to the nails, are

characterized by good gloss, exhibit good water

resistance after drying and do not have any sol-

vent odour [35]. According to a patent application

assigned to Advanced Genetic Technologies Corp.,

protein-adherent polymers with hydroxyl-substi-

tuted aromatic groups can be used to increase the

adhesiveness and durability of nail polish composi-

tions [36]. Nails are not porous although they per-

mit the penetration of externally applied materials

through nail plate, including moisture that helps

maintain flexibility [37, 38]. The moisture content

of nails is less than half that of the stratum corne-

um and total lipid content is <1%. Considerable

efforts are being made in Japan to develop water-

containing nail enamels to address the dry/brittle

nail problem. In a work by Yamazaki et al. [39]

on the development of new water-in-oil (W/O)

emulsion type nail enamel using human sections,

a series of model experiments were performed con-

firming that moisture is essential for flexible and

non-brittle nails. The researchers developed a new,

nitrocellulose containing W/O emulsion nail

enamel, which kept the nails in good condition.

Ultraset Limited Corp. has come up with a quick-

drying, photo-reactive nail polish coating composi-

tion that cures quickly on exposure to natural

light. The resulting product is compatible with

commercially available nail polish of any colour. It

is also compatible with every-day chores because

it is insoluble in water [40].

Pickering emulsions

Pickering emulsions have been a laboratory curi-

osity since their discovery almost a century ago.

Recent technological advances in this field have

resulted in the introduction of amphipathic nano-

particles that enable the production of surfactant-

free, particle-stabilized emulsion. It has been

revealed that ‘the emulsifier-free’ O/W pickering

emulsion can be formed in which the stabilizing

particles are zinc oxide or titanium dioxide that

have been coated with aluminium stearate or

dimethicone and aluminium hydroxide or silicon

dioxide [41–43]. The ultra-fine amphiphilic parti-

cles are defined as having particle sizes <200 nm.

The specifications of the patents disclosed that

these formulated emulsions are characterized by

excellent skin tolerability and exhibit higher effec-

tiveness in sunscreen formulations. The inventors

also reveal that these particle-stabilized emulsions

are remarkably stable in the presence of electro-

lytes and this makes it possible to design systems

containing both astringents and anti-microbials.

These stable compositions can also contain non-

amphiphilic pigments such as hydrophobically

modified titanium dioxide [44, 45]. Polymeric

moisturizers can also be included [46]. One draw-

back of particle containing emulsion is dull or dry

impression on the skin, which can be overcome by

the addition of cyclodextrin preferably b- and

a-cyclodextrin [47–49].





Particulate systems

The particulate delivery systems used in cosmetics

include:

• Microparticulates;

• Porous polymeric systems;

• Nanoparticulates;

• Cyclodextrin complexes.

Microparticulate systems

Microparticles are solid polymeric particles falling in

the range of 0.1–1000 lm and include microcap-

sules and microspheres. In general, microparticles

are used in cosmetics to avoid incompatibility of

substance, reduce odour of actives and for protec-

tion of substances prone to oxidation or action by

atmospheric moisture. Listed below are some of the

applications of microcapsules in controlled delivery.

1. Microcapsules containing sun filters such as

octyl methoxycinnamate, octyl salicylate;

2. Depilatory pastes containing microencapsulated

enzyme for protection against surface active

agents. (e.g. Sodium Lauryl Sulphate (SLS));

3. Skin tanning agent containing dihydroxyace-

tone (DHA) and glycerine in separate compart-

ments within a microcapsule;

4. Microcapsule with encapsulated oils like, min-

eral oil, vegetable oil, isopropyl myristate, isopro-

pyl palmitate contained in cleansing creams;

5. Skin depigmentation products containing micro-

encapsulated anti-oxidants such as tocopherols,

which will prevent lipid peroxidation in the skin.

Nylon microspheres are being used in cosmetic

make-up and skin care products because of the feel

and skin adhesion they impart, because of their

particle size and narrow particle size distribution.

Chemical inertia of nylon microspheres allows

them to hold hydrophilic and lipophilic ingredients

including vitamins, sun filters, moisturizers, fra-

grances and many other actives such as retinyl

palmitate, d-panthenol, ascorbic acid, tocopheryl

acetate and dimethicone. Nylon microspheres con-

taining 40–50% water can function as a delivery

system when incorporated in a moisturizing lip-

stick. It can also avoid exudation observed in lip-

sticks. DHA-impregnated nylon microspheres as a

self-tanning formulation showed increased stabil-

ity. Microspheres loaded with vitamin E showed

enhanced concentration of vitamin E in the epider-

mis because of continued contact with skin and

microspheres, slow release of vitamin from the

particles and protection of vitamin E from chemi-

cal interactions before absorption. The nylon micr-

ospheres can be used in combination with either

or both organic chemical and particulate mineral

sun filters to reduce filter concentration while

retaining effectiveness [50].

Egg albumin microspheres of size 222 lm, con-

taining vitamin A (15.7 ± 0.8%) were used to pre-

pare O/W creams. The in vitro and in vivo drug

release of a microencapsulated vitamin A cream

was studied and compared with a non-microen-

capsulated vitamin A cream. The in vitro study

showed a prolonged release of vitamin A, the rela-

tive bioavailability of the microencapsulated for-

mulation being 78.2 ± 7.3% [51].

LipoPearl� (Lipo Chemicals Inc., Paterson, NJ,

USA) represents standardized line of pearlescent

beads containing emollient oils and vitamins that

enhance the tactile and visual appearance of cos-

metic and personal care products. The average size

is 1000–2800 lm. A variety of LipoPearl� prod-

ucts are readily available. Agar LipoSphere� (Lipo

Chemicals Inc., Paterson, NJ, USA), derived from a

renewable marine source, offers a wide range of

encapsulation possibilities. These spheres provide

the visual effects, which were previously available

only with gelatin capsules while offering the same

ease of formulation. Agar LipoSphere� leaves little

or no residue upon rubout. The average size is

between 500 and 4000 lm. Lipobead� (Lipo

Chemicals Inc., Paterson, NJ, USA) is a uniform

spherical semi-solid matrix of lactose, microcrystal-

line cellulose and hydroxypropyl methylcellulose,

coloured by pigments. Lipobead� (Lipo chemicals

Inc., Peterson, NJ, USA) is an ideal, simple carrier

system for active ingredients in creams, lotions,

gels, body cleansers, shampoos, conditioners, hair

gels and foot care products, where an exciting

visual effect is desired (www. lipochemicals.com).

Botanical microspheres such as ‘Elespher’ of nat-

ural origin are composed of algae extract, which

forms spheres containing a system of internal

canals. Release of actives occurs by diffusion from

sphere or by breaking when applied to the skin.

They can be even coloured to achieve a pleasing

visual effect [52].

Unispheres are an alternative to liposomes in

preparations like shampoos containing high con-

centration of surfactants. These are small, coloured

cellulose beads that hydrate and swell in aqueous

media and disappear when rubbed into the skin

leaving behind no shell.





Porous polymeric systems

Porous polymeric systems utilize microentrapment

technology wherein the particles have an open,

porous structure compared with the continuous

shell structure associated with microencapsulation,

which results in sustaining the activity of the

active ingredients over longer periods of time.

The spheres can be programmed to release the

entrapped active ingredient to the skin in a con-

trolled time release pattern or a pre-programmed

manner through the use of several different trig-

gers such as rubbing or pressing the system after

it has been applied to the skin, elevating the skin

surface temperature, introducing solvents such as

water, alcohol, perspiration for the entrapped

material.

Entrapment systems can control the release of

actives onto the epidermis with assurance that the

actives remain primarily localized and do not enter

the systemic circulation in significant amounts,

thus reducing toxicity while maintaining efficacy.

They have high pay load capacity and can hold

up to 50–60% of solid, semisolid or liquid material,

which can comprise aqueous hydrophilic mate-

rial as well as oils and lipophilic materials.

Sorption-based polymer systems provide optimal

medication over a moderate period of time and

hence overcome the problems like rashes or other

energic responses. Significant reduction in undesir-

able properties such as, oiliness, greasiness, tacki-

ness, stickiness or undesirable odour and feel of

ingredients was also seen. Shelf-life and product

stability can be prolonged without the use of

chemical preservatives as bacteria are too large to

enter the entrapped material.

Microsponges are polymeric delivery systems

consisting of porous microspheres, each micro-

sphere consisting of a myriad of interconnecting

voids within a non-collapsible structure with a

large porous surface. The porous sphere polymers

vary in diameter from 5 to 300 lm. A 25 lm

sphere can have up to 3000 mm of pore length

providing a total pore volume of about 1 ml g)1.

The highly compartmentalized nature of these

materials lends them a very high internal surface

area and high-level payload. Depending upon their

particle size, these porous systems can be divided

into microporous microbeads (particle below

50 lm) and microporous macrobeads (particle

range of 100–200 lm). These porous sphere poly-

mers consist of a polymeric membrane that holds

together the solid nanoparticles, which compose

the core of the sphere. The outer membrane is

interrupted by a multitude of pores that allow

entrapped active to flow out of the sphere [53].

Microsponge particles are made by free radical sus-

pension polymerization technique. This approach

involves the synthesis of a dispersed phase made

up of a monomer, cross-linkers, an initiator, water

immissicible active ingredient/s and surfactants to

promote suspension. Once polymerization is com-

pleted, the resultant solid particles are recovered

from suspension. Release rate and diffusion of

entrapped material from such system can be modi-

fied by altering the particle size, pore diameter, vol-

ume and monomer composition [54]. These

systems have a myriad of applications.

Melanosponge-a containing genetically engi-

neered melanin is designed to distribute melanin

over the skin surface, providing full spectrum sun

protection by blocking UV-B and UV-A light. In

anti-acne formulations, a reduction in the skin

irritation potential with increased efficacy was

observed when benzoyl peroxide was entrapped in

a microsponge system. Anti-inflammatory activity

of hydrocortisone could be sustained with reduc-

tion in skin allergy responses and dermatoses.

In anti-dandruff products, the unpleasant odour

of zinc pyrithone and selenium sulphide was

reduced. Irritation was lowered, whereas safety

and efficacy were found to be extended. All day

treatment and symptomatic relief of fungal prob-

lem have been achieved through such systems.

Reduced allerginicity was observed when insensi-

tizing ingredients are entrapped in microsponge

systems, as in the case of cinnamic aldehyde [55].

Another polymeric sorption system prominent

in cosmetic delivery is ‘Polytrap’. These are highly

cross-linked methacrylate copolymer powders,

which are capable of sorbing up to four times their

weight of lipophilic and hydrophilic liquids while

maintaining flowable powder form. The systems

can sorb liquid dispersions, emulsions and solids

that can stay long enough to be sorbed by and in

the form of polymer aggregate [1, 53].

Chronospheres are polyurethane/acrylate poly-

mer (PAP)-based powders. PAP powders with

pre-loaded actives represent a finished topical

product with controlled/sustained release capabili-

ties. By adding the active at the liquid oligomer

precursor stage and then converting the molecu-

lar solution to a solid microparticulate matter

without using heat or solvents, consistent active





levels are assured and the degradation of sensitive

material is avoided. Such powders are currently

available containing benzocaine, glycerine,

allantoin, salicylic acid and collagen as active

ingredients [56].

Nanoparticulate systems

Nanoparticulate systems include nanospheres and

nanocapsules and can be defined as submicron

colloidal systems having a mean particle diame-

ter of 0.003–1 lm. Nanocapsules differ from

nanospheres in that the former is a reservoir

type of system, whereas the latter is a matrix

system. Polymer composition for both is identical

and includes biodegradable synthetic polymers

like polyamides, cross-linked polysiloxanes or

modified natural products such as, gelatin and

albumin. The active ingredient in nanocapsules

and nanospheres can be incorporated in different

patterns; dissolved in the nanosphere matrix,

adsorbed at the nanosphere surface, dissolved in

the liquid-phase nanocapsules, adsorbed at the

nanocapsules surface. In case the active is

adsorbed on the carrier surface, the active release

from polymeric nanoparticles is biphasic with an

initial burst phase followed by sustained release.

An ideal delivery system for water-based skin

product would be a product that is completely

washable with water; yet, the functional ingredi-

ents remain in contact with the skin to perform

their pharmacological action. These two com-

pletely opposite performance criteria can be

achieved by applying a delivery system that incor-

porates bio-adhesive nanospheres. The nano-

spheres can be surface modified to promote

adhesion and hence deposition on body surfaces in

rinse-off products. High cationic charge density

improves the deposition of the nanospheres onto

the target site and prevents them from being

diluted or washed off during the rinse process.

Such delivery technology enhances adhesion

mostly because of the fact that the functional

ingredient is retained in a solid structure that has

a high surface area per volume with presence of

charges and moieties on the nanospheres surfaces.

The sustained release of fragrance at 0.5% was

tested with free and encapsulated in highly cat-

ionic nanospheres. The results indicated that three

times as much fragrance remained on the skin

after 2 h, when the fragrance was encapsulated

inside the nanospheres [57].

Another important system is solid lipid nanopar-

ticles (SLNs). These represent a particulate disper-

sion of solid spherical particles consisting of

hydrophobic core of triglycerides or fatty acid

derivatives surrounded by a layer of phospholipids.

The advantage of SLNs over polymeric nanopartic-

ulate systems is the absence of harmful additives

required for polymerization and biodegradability of

physiological lipids. When compared with lipo-

somes, they have better stability against coales-

cence because of the solid nature and reduced

mobility of incorporated active molecules, prevent-

ing the active leakage from the carrier. SLNs pos-

sess some features, which make them promising

carriers for cosmetic applications:

1. The protection of labile compounds against

chemical degradation (e.g. for retinol and toc-

opherols).

2. Depending on the produced SLNs type, con-

trolled release of the active ingredients is possi-

ble. SLNs with a drug-enriched shell show

burst release characteristics whereas SLNs with

a drug-enriched core lead to sustained release.

3. SLNs act as occlusive, they can be used to

increase the water content of the skin.

4. SLNs show a UV-blocking potential. They act

as physical sunscreens on their own and can

be combined with molecular sunscreens to

achieve improved photo-protection.

It can be remarked that SLNs with a desired

degree of occlusion can be produced when the par-

ticle size is taken into account. The dependence of

the occlusive effect on the particle size of SLNs is

because of film formation. An in vivo study showed

that addition of 4% SLNs to a conventional O/W

cream leads to an increase in skin hydration by

31% after 4 weeks. The application of SLNs as

physical sunscreens and as active carriers for

molecular sunscreens has also been investigated.

Incorporation of molecular sunscreens in SLNs

leads to synergistic UV-blocking effects. The

amount of molecular sunscreen could be decreased

by 50% while maintaining the protection level

comparable with a conventional emulsion [58].

Dingler et al. reported that the incorporation of

vitamin E into SLNs enhances the stability. The

ultra-fine particles possess an adhesive effect. This

leads to a formation of fine adhesive film on the skin

leading to occlusion and subsequent hydration.

Hydration of the skin promotes penetration of

actives and enhances their cosmetic efficiency [59].

In a 1997 patent, De Vringer showed that the size





of particles could change the occlusion factor. Lipoid

microparticles are greatly inferior to lipoid nanopar-

ticles in their occlusive effect and the addition of

lipoid microparticles in a cream lowers the cream’s

occlusivity, whereas the addition of lipoid nanopar-

ticles in a cream raises the cream’s occlusivity.

Nanospheres containing b-carotene and a blend of

UV-A and UV-B sun filters were prepared. The

results clearly show that the synergistic effect result-

ing from the combination of nanospheres and filters

has an inhibitory effect on tyrosinase by cinnamic

nature of the UV-B screening agent [60].

Cyclodextrin complexes

Cyclodextrins (CDs) are cyclic oligosaccharides

containing a minimum of six d-(+)-glucopyranose

units attached by a (1 fi 4) glucosidic bonds. The

three natural CDs are a, b and c which differ in

their ring size and solubility. Most of the molecules

fit into the internal CD cavity forming a complex

and the resulting structure is called CD clathrates

or inclusion complexes. a-CD typically forms inclu-

sion complexes with both aliphatic hydrocarbons

and gases. b-CD forms complexes with small aro-

matic molecules. c-CD can accept more bulky

compounds like vitamin D.

Complexation with CDs can bring about stabil-

ization of the active ingredient against oxidative,

photolytic and thermal degradation. It can keep

the molecules in a more rigid form, inhibit occur-

rences of reactive confirmation (e.g. vitamin E and

vitamin C phosphate included in hydroxylated

cyclodextrin showed improved light stability com-

pared with un-complexed form of the compound),

isolates the molecules from environment and

diminishes the incompatibilities (decreasing skin

penetration of guest molecules by CD encapsula-

tion thereby reducing undesirable side effects).

Complexation with CD can mask the smell of

mercaptan, inherent to many wave products, by

reducing volatility of the thiol groups. The self-tan-

ning agent di-hydroxyacetone with tyrosine,

which increases production of melanin in the skin

is an unpleasantly scented substance. Including

CD in the formulation can eliminate this problem

[61]. Empty CD complexes with polyunsaturated

fatty acids in sebum prevent their oxidation and

inhibit the free radical formation. It has therefore

proved to be an efficient anti-acne agent, also

reducing the infections and inflammation. Aque-

ous solubility of minoxidil (compound stimulating

keratinocyte growth and promote hair growth)

can be increased through complexation with a-CD

[62, 63].

Delivery devices

Following different delivery devices in the cosmetic

delivery are discussed.

• Iontophoresis;

• Cosmetic patches.

Iontophoresis

Iontophoresis is a virtually painless procedure that

uses a mild electric current to deliver water solu-

ble, ionized compounds into the intact skin and

the underlying tissue. Iontophoresis has gained a

great deal of attention during the last two decades

for both systemic and topical delivery. It is particu-

larly attractive for the delivery of low-molecular-

weight (<1000) hydrophilic solutes at the site of

action [64]. It has been observed that for ionic

molecules, the major contribution to the overall

flux is because of iontophoretic delivery, whereas

diffusive delivery and electro-osmosis make a rela-

tively smaller contribution to ion flux [65–67].

Iontophoresis is an active means to deliver active

agent into the skin and to achieve enhanced cos-

metic benefits in a variety of skin disorders. Use of

appropriate composition of electrical current and

the active agent can provide superior results in

the treatment of hyper-pigmentation, melasma,

aged skin, acne scars [68], hypertropic scars [69,

70], cellulite and many other aesthetic disorders of

the skin. A typical iontophoresis device consists of

an electrical power source, electrodes and the

active agent in an appropriate carrier (solution,

gel or cream). There are several examples of uses

of iontophoresis and electro-osmosis in cosmetics.

Vitamin C is known to inhibit both melanin for-

mation and oxidized melanin. However, vitamin C

does not easily penetrate the skin. A controlled

human study was carried out for 6 weeks with

enhancer patch and magnesium ascorbyl phos-

phate (MAP) 3% gel. The data revealed a 50%

mean reduction in spot size and a 60% decrease in

pigment intensity within 42 days. In addition, sig-

nificant effects were noticeable after only 7 days of

treatment. This effect was 300% better than the

results attained by applying the MAP 3% passively

onto the face without using micro-electronic cur-

rents [71].





Schmidt et al. [72] have reported on treatment

of post-acne scars using iontophoresis with

0.025% tretinoin gel. Tretinoin iontophoresis was

found to be effective, non-invasive treatment of

atrophic acne scars without causing disturbing

side effects.

Cosmetic patches

The influence of the pharmaceutical technology is

apparent in the case of the cosmetic patches, not

as simple cosmetic forms but as cosmetic delivery

systems. Cosmetic patches today represent a con-

venient, simple, safe and effective way for cosmetic

applications, using one of the most acceptable,

modern and successful delivery techniques. In the-

ory, cosmetic patches can be applied in most cases

for the same use as classical cosmetic products, for

example, wrinkles, ageing, dark rings, acneic con-

ditions, hydration of specific areas, spider veins

and slimming. In practice, several of the aforemen-

tioned applications have been investigated with

very positive results and a high degree of accept-

ability from the consumers. There are several ways

to categorize a cosmetic patch. It can be character-

ized from the patch form (matrix, reservoir), appli-

cation for expected results (moisturizing, anti-

wrinkles), structural materials (synthetic, natural

and hybrid), the duration of application (over-

night, half-hour patch). Categories of functional

cosmetic patches are anti-blemish patch, pore

cleansers, pimple patch, eye-counter patch, anti-

ageing patch, anti-wrinkle patch and lifting patch

[73].

Power paper micro-iontophoretic patches

equipped with integrated electrical cell and a

hydrogel interphase are intended for use on skin

wrinkles. Human clinical study has shown that a

single 20-min treatment using the patch resulted

in a visible reduction of the number and depth of

wrinkle under the eye and lasted for several hours.

The short-term effect can be explained by the

occurrence of a slight, sub-clinical inflammatory

response, which resulted in skin smoothening. The

longer-term rejuvenation effects may have resulted

from tissue stimulation, enhanced blood flow,

improved respiration and increased cell turnover

[74].

Future trends in cosmetic delivery

Through the efforts of the cosmetic industry, lipo-

somal and nanoparticle formulations for the skin

have definitively been an economic success. Molec-

ular biology has provided us with tools to identify

and build genetic materials that can be used for

the treatment of hereditary diseases. The efforts

made to obtain a better understanding concerning

the mechanisms of the novel formulations at the

molecular and supramolecular level have led to

new formulation processes and could open new

prospects in the area of active delivery by means

of encapsulated system. Controlled release will

continue to play a large part in the efficacy of cos-

metics. Some trends that the consumers are likely

to see in the future include improved systems that

release their actives via pH and temperature mod-

ulation. The liposomal dispersions have proved not

only to be innovative and effective cosmetic deliv-

ery systems but also very successful for preventing

and treating several skin diseases. Liposomes and

nanoemulsions do not disturb the integrity of the

Table I Summary of commercially available delivery systems

Name Supplier Application

Natipide II Liposome Rhone-Poulenc Reinforces skin’s own moisture retention capabilities

Ultrasome Applied Genetics Sun-care products

Photosome Applied Genetics Sun-care products

Catezomes Collaborative Labs Versatile active delivery

Elespher Laboratories Serobiologiques Natural, botanical vehicle; pleasing visual effect

Microsponge Advanced Polymer System High payload; improves cosmetic elegance of liquid

Elesponge Laboratories Serobiologiques Entraps a wide range of actives whilst softening skin

LipoCD-SA Lipo chemicals Able to deliver oils in powder form

Unispheres Induchem Less sensitive to pH and surfactants; pleasing visual effect

Orgasol Elf Atochem Improves skin feel and adhesion, offers controlled delivery

and protection to variety of hydrophilic, lipophilic substances





skin lipid bilayers and are not washed out while

cleansing the skin. So, these formulations are

believed to have a great future in the cosmetic sci-

ence. The evolution of cosmetic patches is some-

thing expected after the warm acceptance of new

cosmetic delivery systems by the consumers. Non-

passive cosmetic patches like, iontophoretic ones

will find in future several applications for more

sophisticated cosmetic actives and ingredients.

Patches of potent ingredients or extracts are

expected to have a wide acceptance to achieve a

very fast and effective action. Microsponges and

microemulsions are also gaining good market

value. Acceptability of microemulsions, however,

would be governed by the use of safer surfactants,

which do not appreciably change the permeability

of membrane over repeated use. As research and

development costs are on the rise, efficacy and

safety are essential to assure a product’s sustain-

ability in the market and repetitive purchases. This

has created increased interest in delivery systems.

In fact, the U.S. market for delivery systems has

increased from $19 billion in 2000 to more than

$41 billion projected for the year 2007. Some of

the commercially available novel cosmetic delivery

systems are summarized in Table I.

Summary

Novel cosmetic delivery systems reviewed here

possess the potential to develop as the ‘new genera-

tion smarter carrier systems’ after the liposomes.

The technical, economic and sensory aspects should

be taken into consideration while selecting an

appropriate type of delivery system to enhance the

safety, stability, extended efficacy and to enhance

the aesthetic appeal of the final product.

However, despite the fact that the use of dis-

cussed delivery carriers for topical administration

is very promising and highly attractive application

area, further basic research needs to be carried out

for a better understanding of the reasons for lipid

modifications, the effect of surfactants used for

these modifications and their transition during

storage. Also, a better understanding is needed of

how such systems modify the diffusion of actives

into the skin, how lipid particles interact with the

lipids of the stratum corneum and then how they

affect penetration. Definitely, more human studies

need to be carried out to have a ‘real life’ data.

After all, a delivery system is effective only, if it

appeals to a consumer who is willing to use it and

is founded on the ‘no skin care without bioactivity’

principle.

Acknowledgements

The authors of this manuscript would like to

express their thanks to the Institute of Chemical

Technology for extending technical support during

the preparation of this manuscript. In addition,

the authors are thankful to Charbhuja Trading &

Agencies, India, and Kamani Oil Industries, India,

for their discussions during the compilation of this

article and also to Sunder Medical Agencies, India,

for their financial support.

References

1. Redziniak, G. and Perrier, P. Cosmetic applications of

liposomes. In: Microencapsulation: Methods and Indus-

trial Applications (Benita, S., ed.), pp. 577–579.

Marcel Dekker Inc., New York (1996).

2. Nacht, S. Encapsulation and other topical delivery

systems. Cosmet. Toil. 110, 25–30 (1995).

3. Citernesi, U. and Sciacchitano, M. Phospholipid/

active ingredient complexes. Cosmet. Toil. 110, 57–

68 (1995).

4. Suzuki, K. and Sakon, K. The applications of lipo-

somes to cosmetics. Cosmet. Toil. 105, 65–78 (1990).

5. Junginger, H.E., Hofland, H.J. and Bouwstra, J.A.

Liposomes and niosomes: interaction with human

skin. Cosmet. Toil. 106, 45–50 (1991).

6. Peschka, R., Dennehy, C. and Szoka, F.C., Jr. A sim-

ple in-vitro model to study the release kinetics of lipo-

somes encapsulated material. J. Control. Release 56,

41–51 (1998).

7. Imbert, D. and Wickett, R.R. Topical delivery with

liposomes. Cosmet. Toil. 110, 32–45 (1995).

8. Ziboh, V.A., Miller, C.C. and Cho, Y. Metabolism of

polyunsaturated fatty acids by skin epidermal

enzymes: generation of anti-inflammatory and anti-

proliferative metabolites. Am. J. Clin. Nutr. 71,

361S–366S (2000).

9. Moussaoui, N., Cansell, M. and Denizot, A. Marino-

somes� marine lipid-based liposomes: physical char-

acterization and potential applications in cosmetics.

Int. J. Pharm. 242, 361–365 (2002).

10. Benita, S., Martini, M.C. and Seiller, M. Cosmetic

applications of vesicular delivery systems. In: Micro-

encapsulation: Methods and Industrial Applications

(Benita, S., ed.), pp. 587–631. Marcel Dekker Inc.,

New York (1996).

11. Hayward, J.A. Potential of liposomes in cosmetic

science. Cosmet. Toil. 105, 47–54 (1990).

12. Magdassi, S. and Touitou, E. Cosmeceutics and deliv-

ery Systems. In: Novel Cosmetic Delivery Systems





(Stanzl, K., ed.), pp. 1–8. Marcel Dekker Inc., New

York (1999).

13. Lasic, D.D. Stealth liposomes. In: Microencapsulation:

Methods and Industrial Applications (Benita, S., ed.),

pp. 297–328. Marcel Dekker Inc., New York (1996).

14. Lautenschlager, H. Liposomes in dermatological prep-

arations: Part II. Cosmet. Toil. 105, 63–72 (1990).

15. Newton, J. and Stoller, C. Silicone technologies as

delivery systems via physical associations. Cosmet.

Toil. 119, 69–78 (2004).

16. Ostergaard, T., Gomes, A., Quackenbush, K. and

Johnson, B. Silicone quaternary microemulsion: a

multifunctional product for hair care. Cosmet. Toil.

119, 45–52 (2004).

17. Newton, J., Postiaux, S., Stoller, C. et al. Silicone-

based vesicle delivery systems. Cosmet. Toil. 119, 53–

60 (2004).

18. Victor, A.R., Gerald, K.S. and Starch, M. Controlled

release of active ingredients from cross-linked sili-

cones. Cosmet. Toil. 120, 69–72 (2006).

19. Newton, J., Postiaux, S., Stoller, C. et al. Silicone

elastomer delivery systems. Cosmet. Toil. 119, 24–31

(2004).

20. Birman, M. and Lawrence, N. Liposome stability via

multi-walled delivery systems. Cosmet. Toil. 117, 51–

58 (2002).

21. Mathur, R. Glucoside paucilamellar vesicles. US Patent

6 251 425. Igen Inc., Wilmington, DE, USA (2001).

22. Weiner, N. Influence of non-ionic liposomal composi-

tion on topical delivery of peptide drugs into piloseha-

ceous units. Cosmet. Derm. 10, 1186–1190 (1997).

23. Eccleston, G.M. Microemulsions. In: Encyclopedia of

Pharmaceutical Technology (Swarbrick, J. and Boylan,

J.C., eds), pp. 375–421. Marcel Dekker Inc., New

York (1994).

24. Osborne, D.W., Ward, A.J.I. and O’Neill, K.J. Surfac-

tant association colloids as topical drug delivery

vehicles. In: Topical Drug Delivery Formulations (Os-

borne, D.W. and Amann, A.H., eds), pp. 349–380.

Marcel Dekker Inc., New York (1990).

25. Cioca, G. and Calvo, L. Liquid crystals and cosmetic

applications. Cosmet. Toil. 105, 57–62 (1990).

26. Tadros, T.F., Dederen, C. and Taelman, M.C. A new

polymeric emulsifier. Cosmet. Toil. 112, 75–86

(1997).

27. Florence, A.T. and Whitehill, D. Some features of

breakdown in W/O/W multiple emulsion. J. Colloid

Interface Sci. 79, 243–256 (1981).

28. Rosoff, M. Specialized pharmaceutical emulsions. In:

Pharmaceutical Dosage Forms: Disperse Systems

(Lieberman, H.A., Rieger, M.M. and Banker, G.S.,

eds), pp. 1–42. Marcel Dekker Inc., New York

(1998).

29. Couvreur, P., Couarraze, G., Devissaguet, P.J. and

Puisleux, F. Nanoparticles: preparation and charac-

terization. In: Microencapsulation Methods and Indus-

trial Applications (Benita, S., ed.), pp. 183–211.

Marcel Dekker Inc, New York (1996).

30. Westesen, K. and Siekmann, B. Biodegradable colloi-

dal drug carrier systems based on solid lipids. In:

Microencapsulation Methods and Industrial Applications

(Benita, S., ed.), pp. 213–258. Marcel Dekker Inc,

New York (1996).

31. Liebowitz, M. and Brandli, E.H. Polish. US Patent 4

013 475. Colgate-Palmolive Company, New York

(1977).

32. Fox, C. An introduction to multiple emulsion. Cos-

met. Toil. 101, 101–112 (1986).

33. Bevacqua, A.J., Konstantinos, M.L., Lahanas, M.

et al. Liquid crystals in multiple emulsion. Cosmet.

Toil. 106, 53–56 (1991).

34. Sonneville-Aubrun, O., Simonnet, J.T. and Alloret, F.L.

Nanoemulsions: a new vehicle for skin care products.

Adv. Colloid Interface Sci. 108–109, 145–149 (2004).

35. Fox, C. Cosmetic and pharmaceutical vehicles: skin

care, hair care, makeup and sunscreens. Cosmet. Toil.

113, 45–56 (1998).

36. EP 605,951. Advanced Genetics Technologies, Pitts-

burg, PA, USA.

37. Schlossman, M.L. Trends in nail care technology.

Cosmet. Toil. 96, 51–54 (1981).

38. Barnett, J.M. and Scher, R.K. Nail cosmetics. Int. J.

Dermatol. 31, 675 (1992).

39. Yamazaki, H. Novel O/W type nail enamel. Fragrance

J. 20, 86–88 (1992).

40. Valenty, V.B. Quick-drying nail coating method and

composition. US Patent 5 456 905. Ultraset Limited

Partnership, Scottsdale, AZ (1995).

41. Gers-Barlag, H. and Muller, A. Emulsifier-free finely

dispersed systems of the water-in-oil type. US Patent 6

379 680. Beiersdorf AG, Hamburg (2002).


dispersed systems of the oil-in-water type. US Patent

Application 20030017184 A1. Beiersdorf AG, Ham-

burg (2003).


disperse systems of the oil-in-water and water-in-oil

type. US Patent Application 20030175221. Beiers-

dorf AG, Hamburg (2003).

44. Gers-Barlag, H. and Muller, A. Emulsifier-free finely dis-

perse systems of the oil-in-water and water-in-oil type. US

Patent 6 579 529. Beiersdorf AG, Hamburg (2003).


disperse systems of the oil-in-water and water-in-oil type.

US Patent 6 692 755. Beiersdorf AG, Hamburg (2004).





disperse systems of the oil-in-water and water-in-oil type.

US Patent 6 703 032. Beiersdorf AG, Hamburg

(2004).






disperse systems of the oil-in-water- and water-in-oil-

type. US Patent Application 20030003122 Al.

Beiersdorf AG, Hamburg (2003).




50. Parison, V. Active delivery from nylon particles.

Cosmet. Toil. 108, 97–100 (1993).

51. Torrado, S., Torrado, J.J. and Cadorniga, R. Topical

application of albumin microspheres containing vita-

min A: drug release and availability. Int. J. Pharm.

86, 147–149 (1992).

52. Rogers, K. Controlled release technology and delivery

systems. Cosmet. Toil. 114, 53–60 (1999).

53. Gans, E.H. Polymer developments of cosmetic inter-

est. Cosmet. Toil. 103, 94–98 (1988).

54. Nacht, S. and Katz, M. The microsponge: a novel

topical programmable delivery system. In: Topical

Drug Delivery Formulations (Osborne, D.W. and

Amann, A.H., eds), pp. 300–310. Marcel Dekker

Inc., New York (1990).

55. Nacht, S. and Katz, M. The microsponge: a novel

topical programmable delivery system. In: Topical

Drug Delivery Formulations (Osborne, D.W. and

Amann, A.H., eds), pp. 322–323. Marcel Dekker


56. Siciliano, A.A. and Szycher, M. Controlled release

using polyurethane/acrylic polymers. Cosmet. Toil.

107, 123–129 (1992).

57. Shefer, A., Ng, C. and Shefer, S. Nanotechnology

enhances bio-adhesion and release after rinse-off.

Cosmet. Toil. 119, 57–60 (2004).

58. Wissing, S.A. and Muller, R.H. Cosmetic applications

for solid lipid nanoparticles (SLNs). Int. J. Pharm.

254, 65–68 (2003).

59. Dingler, A., Hildebrand, G., Niehus, H. and Muller,

R.H. Cosmetic anti-aging formulation based on vita-

min E-loaded SLNs. Proc. Int. Symp. Control Rel. Bio-

act. Mater. 25, 433 (1998).

60. De Vringer, T. Topical preparation containing a suspen-

sion of solid lipid particles. US Patent 5 667 800.

Yamanouchi Europe B.V., Zoetermeer, the Nether-

lands (1997).

61. Amann, M. and Dressnandt, G. Solving problems

with cyclodextrins in cosmetics. Cosmet. Toil. 108,

90–95 (1993).

62. Citernesi, U. and Sciacchitano, M. Cyclodextrins in

functional dermocosmetics. Cosmet. Toil. 110, 53–61

(1995).

63. Duchene, D., Wouessidjewe, D. and Poelman, M.C.

Cyclodextrins in cosmetics. In: Novel Cosmetic Deliv-

ery Systems (Duchene, D., ed.), pp. 275–278. Marcel

Dekker Inc., New York (1999).

64. Preat, V. and Vanbever, R. Topical delivery by ionto-

phoresis. In: Handbook of Cosmetic Science and Technol-

ogy (Barel, A.O., Paye, M. and Maibach, H.I., eds),

pp. 211–219. Marcel Dekker Inc., New York (2001).

65. Schultz, S.G., ed. Basic Principles of Membrane Trans-

port. Cambridge University Press, New York (1980).

66. Marro, D., Kalia, Y.N., Delgado-Charro, M.B. and

Guy, R.H. Contributions of electro-migration and

electro-osmosis to iontophoretic drug delivery.

Pharm. Res. 18, 1701–1708 (2001).

67. Srinivasan, V., Higuchi, W.I., Sims, S.M. et al. Trans-

dermal iontophoretic drug delivery: mechanistic

analysis and applications to polypeptide delivery.

J. Pharm. Sci. 78, 370–375 (1989).

68. Schmidt, J.B., Binder, M., Macheines, U.V. and Biegl-

mager, C. New treatment of atrophic acne scars by

iontophoresis with estriol and tretinoin. Int. J. Derma-

tol. 34, 57–62 (1995).

69. Shigene, S., Murakami, T., Yata, N. and Ikuta, Y.

Treatment of keloid and hypertrophic scars by ionto-

phoretic transdermal delivery of tranilast. Scand. J.

Plast. Reconstr. Surg. Hand Surg. 31, 151–154

(1997).

70. Zhao, L., Hung, L. and Choy, T. Delivery of medica-

tion by iontophoresis to treat post-burn hypertrophic

scars: investigation of a new electronic technique.

Burns 23, S27 (1997).

71. Tamarkin, D. Using iontophoresis to enhance cos-

metic delivery. Cosmet. Toil. 119, 63–74 (2004).

72. Schmidt, J.B., Donath, P., Hannes, J. et al. Tretinoin-

iontophoresis in atrophic acne scars. Int. J. Dermatol.

38, 149–153 (1999).

73. Fotinos, S.A. Cosmetic patches. In: Handbook of Cos-

metic Science and Technology (Barel, A.O., Paye, M.

and Maibach, H.I., eds), pp. 233–243. Marcel Dekker


74. Tamarkin, D. Enhancing cosmetic efficacy by orders

of magnitude using thin and flexible microelec-

tronic patches. Health Beauty America 1, 9–10

(2003).





Documents

j.1468-2494.2008.00416.x