Overview on Applications of Nanoparticles in Cosmetics

Full text

ISSN: 2249-2135
======================
Asian Journal of
Pharmaceutical Sciences
and Clinical Research
=======================
www.pharmaboon.org
Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
REVIEW ARTICLE
OVERVIEW ON APPLICATION OF NANOPARTICLES
IN COSMETICS
Anuradha Patel
1
*, Parixit Prajapati
1
, Rikisha Boghra
1
1
Department of Pharmaceutics, Smt. B.N.B. Swaminarayan Pharmacy College, Vapi, Gujrat-India
Received 14 July 2011, Accepted 05 October 2011
Abstract
The present review aims to study a promising area of Nanoparticles used in various cosmetic
products like Deodorant, Soap, Toothpaste, Shampoo, Hair conditioner, Anti-wrinkle cream,
Moisturizer, Foundation, Face powder, Lipstick, Blush, Eye shadow, Nail polish, Perfume and
After-shave lotion etc. In particular, NLCs have been identified as a potential next generation
cosmetic delivery agent that can provide enhanced skin hydration, bioavailability, stability of the
agent and controlled occlusion. Nanoparticles are synthesized by various techniques are Sol–gel
Method, Vacuum Deposition Method, Ball Milling Method, Pyrolysis etc. Characterization of
Nanoparticles is must necessary in order formulate Nanocosmeticeuticals. Many methods are
used for their evaluation and they are High-Resolution Transmission Electron Microscopy
(HRTEM), but the core dimensions can also be determined using Scanning Tunneling
Microscopy (STM), atomic force microscopy (AFM), Small Angle X-ray Scattering (SAXS), a
Laser Desorption Ionization Mass Spectrometry (LDI-MS), and X-ray Diffraction, Transmission
Electron Microscopy etc. The studies proved that the developed Nanoparticles in cosmetics have
potential in term of industrial feasibility.
Keywords: Nanoparticles, Nanocosmeceuticals, Sol-gel Method
Introduction:
Nanotechnology, from the Greek “nano” for dwarf, consists of manipulating materials
at the atomic and molecular levels to create new molecular structures known as “Nano
materials” having unique and new characteristics that differ from those of the
* Corresponding author. Tel: +919913051223
E-mail address: anupatel03@gmail.com (Anuradha Patel)
© Pharmaboon. All rights reserved.
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
original materials they are derived from. A Nanomaterial is defined as a “material with
one or more external dimensions, or an internal structure, on the nanoscale, which could
exhibit novel characteristics compared to the same material without nano scale
features”.
[1]
Nanoparticles (NP) are a subset of NM and were defined as single particles
with a diameter below 100 nm, although their agglomerates may be larger.
Figure 1: Nano size / Nanoparticles
Nature depends fundamentally on structures and processes operating at the nanoscale,
from simple colloids such as milk to highly sophisticated proteins. Free Nanoparticles
also occur naturally as by-products of combustion and cooking. In some sense,
nanoscience and nanotechnologies are not new: size-dependent properties have been
exploited for centuries. For example, Au and Ag nanoparticles (particles of diameter
less than 100 nm) have been used as colored pigments in stained glass and ceramics
since the 10th century AD.
[2]
Nanotechnologies have been used to create the features on
computer chips for the past 20 years. However, through the invention of imaging
techniques like the Scanning Tunneling Microscope and the Atomic Force Microscope,
our understanding of the nano world has improved dramatically
The Working Party on Manufactured Nanomaterial (WPMN) of the Organization for
Economic Cooperation and Development (OECD) has selected a list of representative
manufactured Nanomaterial considering those materials which are
[3]
• Single-Walled Carbon Nanotubes (SWCNTs)
• Multi-Walled Carbon Nanotubes (MWCNTs)
• Silver Nanoparticles
• Nan clays
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
• Iron Nanoparticles
• Carbon Black
• Titanium Dioxide
• Aluminum Oxide
• Cerium Oxide
• Silicon Dioxide
• Polystyrene
• Dendrimers
Nanotechnology and NP in Cosmetics and Sunscreens
Nano-emulsions are commonly used in certain cosmetic products, such as conditioners
or lotions. Nanoemulsions combine traditional cosmetic ingredients, such as water, oils
and surfactants, in a two-phase system in which droplets sized 50–100 nm are dispersed
in an external (aqueous) phase. The small droplet size renders nano-emulsions
transparent and pleasant to the touch, their texture and rheological properties have yet
to be obtained by other formulation methods.
[4]
Liposomes and Niosomes are globular vesicles with diameters between 25 and 5,000 nm
and are composed of amphiphilic molecules which associate as a double layer
(unilamellar vesicles) or multiple double layers (multilamellar vesicles). Liposomes are
mainly composed of phospholipids, whereas niosomes use non ionic surfactants, such as
polyoxyethylene alkyl ethers or esters.
[5]
The ultra structure of these vesicles is quite
similar to that of mammalian milk, which contains nano-sized fat droplets surrounded
by the milk fat globular membrane.
[6,7, 8]
Vesicle formulations are important in cosmetic
applications because they may improve the stability and skin tolerance of ingredients,
such as unsaturated fatty acids, vitamins or anti-oxidants and thereby contribute to the
safety of cosmetics.
Sunscreens contain insoluble, mineral-based materials whose performance depends on
their particle size. Mineral particles, such as TiO
2
, reflect and scatter UV light most
efficiently at a size of 60–120 nm.
[12]
The surface of these particles is frequently treated
with inert coating materials, such as aluminium oxide or silicon oils, in order to
improve their dispersion in sunscreen formulations. Sunscreen products containing
mineral UV filters protect consumers from the harmful effects of UV exposure,
including skin ageing, herpes as well as skin and lip cancers.
[9,10 ,11]
The transparency of
man-sized particles of titanium or zinc oxides results in better consumer
acceptance/compliance and thus improves the protection of human skin against UV
induced damage.
Some nanotechnology enabled products are already on the market and enjoying
commercial success. For example, self-cleaning windows use a 15 nm thick coating of
activated TiO
2
engineered to be highly water-repellent, so that rainwater just flows off
the surface, washing away the dirt.
[12]
Studies so far on TiO
2
nanoparticles suggest that
they do not penetrate beyond the epidermis.
[13]
However, as both cosmetics and
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
sunscreens are intended for use on undamaged skin, few studies appear to have looked
at whether or not nanoparticles in cosmetic preparations can penetrate skin that has
been damaged previously, perhaps by severe sunburn or common complaints like
eczema.
Nanoparticles of silver are now used in toothpastes, soaps and face creams, food
packaging, clothing, household appliances, disinfectants and wound dressings. Silver
nanoparticles have a potent ability to kill bacteria.
[14]
.Other examples of nano cosmetic
products on the market include body firming lotion, bronzer, exfoliant scrub, eye liner,
and styling gel. Friends of the Earth as far as starting that “[their] research
demonstrates that nanoparticles have entered just about every personal care product on
the market, including deodorant, soap, toothpaste, shampoo, hair conditioner, anti-
wrinkle cream, moisturizer, foundation, face powder, lipstick, blush, eye shadow, nail
polish, perfume and after-shave lotion.
[15]
Physical and chemical properties of nanoparticles that may influence skin uptake and
that require investigation are: particle size and shape, surface characteristics including
the presence of coatings, electronic charge and dose. Encapsulation techniques have
been proposed for carrying cosmetic activities. Nan crystals and Nanoemulsions are
also being investigated for cosmetic applications.
[16]
EXAMPLES O F SOME NANOPARTICLES USED IN COSMETICS
Figure: 2 TiO
2
Nanoparticles Figure: 3 silver Nanoparticles
Figure: 4 Padalium Nanoparticles Figure: 5 Gold Nanoparticles
(TEM images of Nanoparticles)
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
Advantages:-
1. Use of nanotechnology in cosmetics is aimed to make fragrances last longer,
sunscreens more effective and anti-ageing creams.
2. To optimize manufacturing conditions for skin care formulation, a multicomponent
system.
3. To prevent hair from turning grey and also for prevention of in treatment of hair loss
& used to preserve active ingredients, such as vitamins and anti-oxidants, and their
lightness and transparency.
4. To improve the UV protection in combination with organic sunscreens such as 2-
hydroxy-4-methoxy benzophenone this allows a reduction of the concentration of the
UV absorber.
Disadvantages:-
1. Smaller particles have a greater reactivity, are more chemically reactive and produce
greater numbers of reactive oxygen species.
2. It may result in oxidative stress, inflammation, and consequent damage to proteins,
membranes and DNA.
3. Nanomaterial has proved toxic to human tissue and cell cultures, resulting in
increased oxidative stress and cell death.
4. Photo-activated Nanoparticles titanium dioxide has been demonstrated to cause
oxidative damage to DNA in cultured human fibroblasts.
5. Photo-activated titanium dioxide nanoparticles were toxic to skin fibroblasts and
nucleic acids and to human colon carcinoma cells.
6. Inhaled ultrafine particles induce pulmonary inflammation when the particles are
quartz, minerals, dust, coal, silicate, and asbestos. These can induce pulmonary fibrosis,
cytotoxicity, and even malignancy.
Discussion
Routes of Exposures
[ 17]
:-
A. Dermal absorption:-
Three pathways of penetration across the skin have been identified: intercellular,
transfollicular and transcellular. The passive transport of nanoparticles through intact
stratum corneum is considered highly unlikely because of the matrix of corneocytes,
lipid bilayers within the intercellular spaces and the physiological environment below
the stratum corneum containing high levels of proteins. If the skin is damaged, and the
normal barrier disrupted, then the probability of entry of particles may be substantially
increased. Follicular openings are compatible with particulate dimensions.
B. Respiratory tract:-
The alveolar macrophages reside as free cells within the alveolar air spaces, from where
they may migrate to the bronchioles and then, via the mucociliary escalator, to the
lumen of the conducting airways. The alveolar macrophage plays an important role in
the response of the lung to inhaled dusts and in the development of inflammatory
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
lung disorders. Their essential function is phagocytosis and clearance of particulates
and micro-organisms. The type II cell is a secretary cell and is considered to be the
progenitor cell for type I cells
C. Intestinal tract:-
Particulate uptake occurs not only in the gut-associated lymphoid tissue (GALT), but
also in the normal intestinal enterocytes.
D. Eye:-
The eye only provides only a small surface area for potential exposure but be indirect
exposure to Nanomaterial may occur through it by cosmetics intended for use in the
vicinity of the eye or from other types of cosmetic products.
Figure: 6 the Eye
Methods for the preparation of nanoparticles:-
A. The sol–gel method
B. Vacuum deposition method
C. Ball milling method
D. Pyrolysis
E. Other methods like Arc (DC) plasma, Laser Processes, Wire electrical explosion,
Sputtering, Droplet-to-Particle Conversion, Flame synthesis.
A. The sol–gel method
[ 18]
:-
Silver nanoparticles; for example, is prepared by mixing the AgNO
3
solution with
tetraethylorthosilicate, ethanol and water then with a few drops of HNO
3
as a catalyst.
The mixed solution was dispersed and dried. The dried gels were reduced at a
temperature of 400 co for 30 min in hydrogen gas. The Ag particles have a size of about
5-10 nm with a profile distribution in the form of lognormal distribution. The
nanoparticles are embedded in silica glass in well separated and protected matrix. The
preparation of iron nanoparticles embedded in glass can be prepared with the same
method by substituting FeC
l3
for the silver salt
[19 , 20, a nd 21]
. The sol–gel method has
advantages of yielding high purity, isotropic, and low temperature annealing while with
shortage of cracking after dried by heavy doping. The free water absorbed in the porous
gel and the H-O bonds desorbed on the porous surface.
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
B. Vacuum deposition method
[ 22]
:-
The presence of inert gas in vacuum chamber and lowering down the substrate
temperature to liquid nitrogen temperature during thermal evaporation can reduce the
momentum of the evaporated metallic atoms or clusters by collision with gas to obviate
their further aggregation on the substrate. The evaporated metal atoms condensed just at
where they reached without migration to the potential minimum thereby lose Vander
wall attraction between particles. The resulting smokes can be collected from the
substrate or walls of the evaporation chamber with the particle sizes can be easily
controlled between 30-1000 Å depending on the gas pressure, the evaporation speed,
the type of gas used, and the substrate temperature. Direct (DC) or radio frequency (RF)
sputtering with the structure of deposited films mostly to be amorphous without
substrate heating can successfully deposit refractory metals and alloys.
C. Ball milling method:-
Hard and brittle ceramic materials can be ball-milled into nanoparticles to produce
nanocrytals, noncrystals, and pseudo crystals. Powders of 500 nm sizes can be milled
into several nm by strong vibrations when mixed with tungsten-carbide spheres. The
shortages of ball milling are the surface contamination of the products and non
uniformity of the structure but are a simple method.
D. Pyrolysis:-
In pyrolysis, a vaporous precursor (liquid or gas) is forced through an orifice at high
pressure and burned. The resulting solid (a version of soot) is air classified to recover
oxide particles from by-product gases. Pyrolysis often results in aggregates and
agglomerates rather than single primary particles. The thermal plasma temperatures are
in the order of 10,000 K, so that solid powder easily evaporates. Nanoparticles are
formed upon cooling while exiting the plasma region. The main types of the thermal
plasma torches used to produce nanoparticles are dc plasma jet, dc arc plasma and radio
frequency (RF) induction plasmas.
Methods for preparation of Solid Lipid Nanoparticles
[ 23]
:-
a) High shear homogenization and ultrasound
b) High pressure homogenization
c) Solvent emulsification /evaporation
d) Micro emulsion based SLN preparations
a) High shear homogenization and ultrasound
High shear homogenization and ultrasound are dispersing techniques which were
initially used for the production of solid lipid nano dispersions. Both methods are wide
spread and easy to handle. However, dispersion quality is often compromised by the
presence of micro particles. Furthermore, metal contamination has to be considered if
ultrasound is used. A Lak Tek rotor–stator homogenizer (Omni International,
Gainesville, USA) to produce SLN by melt–emulsification [56].
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
They investigated the influence of different process Para meters, including
emulsification time, stirring rate and cooling conditions on the particle size and thezeta
potential. Lipids used in this study include trimyristin, tripalmitin, tristearin, a mixture
of mono-, di- and triglycerides and glycerol behenate , poloxamer 188 was used as
steric stabilizer (0.5 w%). ForWitepsoleW35 dispersions the following parameters were
found to produce the best SLN quality: stirring for 8 min at 20 000 rpm, the optimum
cooling conditions: 10 min at 5000 rpm at room temperature. In most cases, average
particle sizes in the range of 100–200 nm were obtained in this study.
b) High pressure homogenization
High pressure homogenization (HPH) has emerged as a reliable and powerful technique
for the preparation of SLN. Homogenizers of different sizes are commercially available.
HPH has been used for years for the production of Nanoemulsions for parenteral
nutrition. High pressure homogenizers push a liquid with high pressure (100–2000 bar)
through a narrow gap (in the range of a few microns). The fluid accelerates on a very
short distance to very high velocity (over 1000 km/h). Very high shear stress and
cavitation forces disrupt the particles down to the submicron range. Typical lipid
contents are in the range 5–10% and represent no problem to the homogenizer. Even
higher lipid concentrations (up to 40 %!) have been homogenized to lipid Nano
dispersions.
There are generally two methods
1.Hot Homogenization
2.Cold Homogenization
Figure: 7 Schematic procedures of hot and cold homogenization techniques for SLN production.
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
c) Solvent emulsification /evaporation
In this method lipophilic material is dissolved in a water-immiscible organic solvent (e.g.
cyclohexane) that is emulsified in an aqueous phase. Upon evaporation of the solvent
Nanoparticles dispersion is formed by precipitation of the lipid in the aqueous medium. The
mean diameter of the obtained particles was 25 nm with cholesterol acetate as model drug and by
using a lecithin /sodium glycocholate blend as emulsifier. The cholesterol acetate nanoparticles
prepared by such method has particles size of 29 nm.The nanoparticles of tripalmitin prepared by
dissolving the triglyceride in chloroform. This solution was emulsified in an aqueous phase by
High Pressure Homogenization. The organic solvent was removed from the emulsion by
evaporation under reduced pressure (40–60 mbar). The mean particle size ranges from
approximately 30 to 100 nm depending on the lecithin/co-surfactant blend. Particles with
average diameters as small as 30 nm were obtained by using bile salts as co-surfactants. Very
small particles could only be obtained with low fat loads (5 w %) related to the organic solvent.
With increasing lipid content the efficiency of the homogenization declines due to the higher
viscosity of the dispersed phase. The advantage of this procedure over the cold homogenization
process described before is the avoidance of any thermal stress.
d) Micro emulsi on based SLN preparations
Micro emulsions are two-phase systems composed of an inner and outer phase (e.g. o/w-micro
emulsions). They are made by stirring an optically transparent mixture at 65–70
o
c which is
typically composed of a low melting fatty acid (e.g. stearic acid), an emulsifier (e.g. polysorbate
20, polysorbate 60, soy phosphatidylcholine, and taurodeoxycholic acid sodium salt), co-
emulsifiers (e.g. butanol, sodium monooctylphosphate) and water. The hot micro emulsion is
dispersed in cold water (2–38C) under stirring. Typical volume ratios of the hot micro emulsion
to cold water are in the range of 1:25 to 1:50. The dilution process is critically determined by the
composition of the micro emulsion. The droplet structure is already contained in the micro
emulsion and therefore, no energy is required to achieve submicron particle sizes.
Characterisation of nanoparticles:-
The most common characterization technique is High-Resolution Transmission Electron
Microscopy (HRTEM), but the core dimensions can also be determined using Scanning
Tunneling Microscopy (STM), atomic force microscopy (AFM), Small Angle X-ray
Scattering (SAXS), a Laser Desorption Ionization Mass Spectrometry (LDI-MS), and
X-ray Diffraction.
Following are method for characterization of Nanoparticles
[24]
:-
A. Transmission Electron Microscopy (TEM):-
A TEM image of the prepared silver nano particles is shown in the fig. The Ag nano
particles are spherical in shape with a smooth surface morphology. The diameter of the
nano particles is found to be approximately 16 nm. TEM image also shows that the
produced nano particles are more or less uniform in size and shape.
B. Scanning Tunneling Spectroscopy (STS):-
Scanning tunneling spectroscopy (STS) had been used to observe Coulomb blockade in
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
metal nanoparticles. The tunneling current is induced by an applied voltage and leads to
the charging of a metal particle with at least one single electron. Electrostatic trapping
(ET) is a technique used to investigate isolated nanosize metal particles. It is based on
moving a polarized particle in an electric field to the point of strongest field, which is
the position between two electrodes (dipped in a solution of the particles) at a distance
comparable to the particle diameter.
Figure 08: TE M image of Ag nanoparticles
C. UV& IR Spectroscopy:-
The UV-visible and IR spectra provide an identification of the ligand that is also
confirmed by NMR spectroscopy, except that the ligand atoms close to the core give
broad signals. This latter phenomenon is due to (i) spin-spin relaxational (T 2)
broadening (main factor), (ii) variations among the sulfur bonding sites around the
particle, and (iii) a gradient in the packing density of the thiolate ligands from the core
region to the ligand terminus at the periphery. The NMR spectra are very informative,
as for all molecular compounds, for the part of the ligand remote from the core. The
latter can also be more fully analyzed, if desired, after oxidative decomplexation using
iodide.
IR spectroscopy shows that, the thiolate ligands of NPs are essentially in all-trans
zigzag conformations, with 5-25% of gauche defects at both inner and terminal
locations. IR and NMR spectroscopy allow, together with Differential Scanning
Calorimetry (DSC), the detection of order-disorder transitions in NPs in the solid state.
The temperature of the transition increases with the chain length and FTIR shows the
increasing amount of gauche defects. Variable-temperature deuterium NMR in the solid
state shows that the disorder materialized by the increased proportion of gauche bonds
propagates from the chain terminus toward the middle of the chain but not further to the
ligand atom and causes chain melting. Calorimetric measurements led to the
determination of the formation enthalpy of NPs in a water/sodium bis(2-ethylhexyl)
sulfosuccinate/n-heptane micro emulsion. The results indicated that the energetic states
and the dimensions of the NPs were influenced by the concentrations of the reversed
micelles.
D. Capillary Zone Electrophoresis:-
Capillary zone electrophoresis in acetate buffer showed that the mobility of NPs with a
given core diameter decreased with decreasing ionic strength. At the highest ionic
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
strength investigated (6 mmol/ L) a good linear dependence of the mobility on the
reciprocal of the core radius allowed the characterization of the size of the NPs.
E. XRD Analysis
[2 5,2 6]
:-
The structure of prepared silver nanoparticles has been investigated by X-Ray
Diffraction (XRD) analysis. Typical XRD patterns of the sample, prepared by the
present chemical method are shown in the Fig.3.
Figure 09: X-ray diffraction pattern of Ag nano particles.
Table 1 shows the experimentally obtained X-ray diffraction angle and the standard
diffraction angle of Ag specimen.
Table1. Experimental and standard diffraction Angles of Ag specimen
Expe rime nta l dif fra ctio n
angle [2 θ in deg ree s]
Standard diff ract ion
angle [2 θ in deg ree s]
45 44.3
From this study, considering the peak at 45 degrees, average particle size has been
estimated by using Debye-Scherrer formula.
Where 'λ' is wave length of X-Ray (0.1541 nm), 'W' is FWHM (full width at half
maximum), 'θ' is the diffraction angle and 'D' is particle diameter (size). The average
particle size is calculated to be around 14 nm. Table 2 gives the diffraction planes, d
spacing, and average size.
Table2. Size, diffraction plane, d spacing of Ag sample
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55
Diffract ion
angle
[degree]
FWHM
[radians ]
d
spac ing
[n m]
Diffract ion
plan e
Size
[n m]
45 0.011 0.1788 200 14

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
F. Electroluminescence:-
Figure displays the room temperature electroluminescence spectra of silver
nanoparticles when the silver nanoparticles (assembly of Nanoparticles) are biased with
ac supply voltage. This experiment reveals that unlike fluorescence (FL), silver
nanoparticles also exhibit electroluminescence (EL). Radioactive recombination of
electron hole pairs between d-band and sp-conduction above the Fermi level produces
FL emission, which occurs practically at 480 nm when biased with ac voltages. Also,
the absorbed linoleic acid during the formation of silver nanoparticles further enhances
the intensity of emission
[27,28]
.
Figure 10: Electroluminescence spectra of Silver Nanoparticles
PROPERTIES OF NANOPARTICLES
[ 29, 30 , 3 1 , 32]
:-
• They are effectively a bridge between bulk materials and atomic or molecular
structures.
• A bulk material should have constant physical properties regardless of its size,
but at the nano-scale size-dependent properties are often observed.
• For bulk materials larger than one micrometer (or micron), the percentage of
atoms at the surface is insignificant in relation to the number of atoms in the
bulk of the material.
• The high surface area to volume ratio of nanoparticles provides a tremendous
driving force for diffusion, especially at elevated temperatures. Sintering can
take place at lower temperatures, over shorter time scales than for larger
particles.
• Suspensions of nanoparticles are possible since the interaction of the particle
surface with the solvent is strong enough to overcome density differences, which
otherwise usually result in a material either sinking or floating in a liquid.
• Nanoparticles also often possess unexpected optical properties as they are small
enough to confine their electrons and produce quantum effects. For example gold
nanoparticles appear deep red to black in solution.
• Nanoparticles with one half hydrophilic and the other half hydrophobic are
termed Janus particles and are particularly effective for stabilizing emulsions.
They can self-assemble at water/oil interfaces and act as solid surfactants.
• The photo catalytic activity of the nanoparticles must not lead to a self-
destruction of the composite system, and it is essential to check this point before
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
fixing a combination of polymer matrix and nanoparticles.
• A higher concentration of ferrite particles clearly increases optical absorption.
Furthermore, the strong increase in absorption for shorter wavelengths is shifted
significantly to shorter wavelengths when the concentration is reduced. This blue
shift may be attributed to a smaller particle size or surface phenomena on the
band gap.
Applications of nanoparticles in cosmetics:-
1. Sunscreens:-
UV filters, such as titanium dioxide and zinc oxide, are used in nano form rather than
bulk form to make the sunscreen transparent rather than white. It is also claimed that
they are more effective when used in nano form.
`
2. Breast cream:-
St Herb Nano Breast Cream claims it is a combination of “nanotechnology and the
timeless Thai herb, Pereira Mirifica” and that niosomes “expands the cellular
substructure and development of the lobules and alveoli of the breasts”, with increased
size from one to three cups
33
.
3. Hair care:-
RBC Life Science’s Nanoceuticals Citrus Mint Shampoo and Conditioner are made with
Nano Clusters TM, “nanoclusters to give your hair a healthy shine”.
4. Make-up:-
Serge Lutens Blusher’s Nano Dispersion technology “creates an extremely fine and
light powder with extraordinary properties: excellent elasticity, extreme softness and
light diffusion”
5. Moisturizers/anti-wrinkle creams:-
Lancôme Hydra Zen Cream with “nano-encapsulated Triceramide renew skin’s healthy
look”; L’Oreal Revitalift Double Lifting anti-wrinkle cream is their “first double-action
cream that instantly re-tautens the skin and reduces the appearance of wrinkles”, and
contains Nanosomes of Pro-Retinol A.
6. Toothpaste:-
Sangi’s Apagard claims to be the world’s first ‘remineralizing’ toothpaste, promoting
oral health by supporting natural healing, using “Nanoparticles hydroxyapatite”, “the
same substance as our teeth”; Ace Silver Plus Nano silver toothpaste is manufactured
and available in Korea.
7. Fullerenes:-
New types of materials can be produced using nanotechnology, such as carbon
fullerenes. It is claimed that these tiny carbon spheres have anti-aging properties.
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
8. Others
a) Nano emulsions and nanosomes – used to preserve active ingredients, such as
vitamins and anti-oxidants, and their lightness and transparency.
b) Other materials used in nano size – a whole range of materials can be used in
nano size in order to give them different properties when compared with their
larger form. We found, for example, an ‘energizing’ moisturizer using nano gold
and products using nano silver because of its anti-bacterial properties
[33, 3 4]
.
c) SLN can act as a physical UV blocker them and are able to improve the UV
protection in combination with organic sunscreens such as 2-hydroxy-4-methoxy
benzophenone which allows a reduction of the concentration of the UV absorber
[35]
.
d) Nanogold Facial Mask
[3 6]
Conclusion
Nanotechnology is a rapidly expanding and potentially beneficial field with tremendous
implications for Society, Industry, Medicine, and Cosmeceuticals. Nanomaterial has been
incorporated into a number of skin care products to take advantage of the unique properties of
matter on a nanoscale. It is critical for dermatologists intimately involved with the health of the
skin to be aware of this new technology, to educate our own colleagues about it, and to play an
active role in evaluating this technology and setting policies and guidelines for its safe and
fruitful use.
References
1. SCCP (Scientific Committee on Consumer Products), 18 December 2007, Safety of
Nanomaterial in cosmetic products, p.10.
2. Ricardo Molins, “Opportunities and Threats from Nanotechnology in Health, Food,
Agriculture and the Environment” Comuniica-fourth year, Second phase, Jan-April-2008.
3. Organization for Economic Co-operation and Development, Series on the safety of
manufactured nanomaterials, number 6, List of manufactured nanomaterials and list of
endpoints for phase one of the OECD testing programme, 2008, accessed on 13
November 2008.
4. Sonneville-Aubrun O, Simonnet JT, L’Alloret F, “Nanoemulsions: a new vehicle for
skincare products” Adv Colloid Interface Sci 2004; 108/109: 145–149.
5. Junginger HE, Hofland HEJ, Bouwstra JA, “ Liposomes and niosomes: interactions with
human skin” Cosmet Toiletries 1991; 106: 45–50.
6. Van den Bergh BAI, Vroom J, Gerritsen H, Junginger HE, Bouwstra JA, “ Interactions of
elastic and rigid vesicles with human skin in vitro: electron microscopy and two-photon
excitation microscopy” Biochim Biophys Act 1999; 1461: 155–173.
7. Alvarez-Roman R, Naik A, Kalia YN, Guy RH, Fessi H, “ Enhancement of topical
delivery from biodegradable nanoparticles” Pharm Res 2001; 21: 1818–1825.
8. Popov AP, Lademann J, Priezzhev AV, Myllyla R, “ Effect of size of TiO
2
nanoparticles
embedded into stratum corneum on ultraviolet- A and ultraviolet-B sun-blocking
properties of the skin” J Biomed Optics 2005; 10: 1–9.
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
9. Gelis C, Girard S, Mavon A, Delverdier M, Paillous N, Vicendo P, “ Assessment of the
skin photoprotective capacities of an organo-mineral broad-spectrum sunblock on two ex
vivo skin models” Photodermatol Photoimmunol Photomed 2003; 19:242–253.
10. Nohynek GJ, Schaefer H, “ Benefit and risk of organic ultraviolet filters” Regul Toxicol
Pharmacol 2001; 33: 285–291.
11. World Health Organization: INTERSUN: The Global UV Project. Protection against
Exposure to Ultraviolet Radiation. Geneva, World Health Organization, 1998.
http://www.who.org.
12. Kroto, H. W., et al., Nature 1985; 347, 354.
13. 13.www.europa.eu.int/comm/health/ph_risk/committees/sccp/docshtml/sccp_out
135_en.htm.
14. Salata O “Applications of nanoparticles in biology and medicine”. Journal of
Nanobiotechnology 2:3; So ndi I and Salopek-Sondi B 2004. “Silver nanoparticlesas
antimicrobial agent: a case study on E. coli as a model for Gram-negativebacteria”.
Journal of Colloidal Interface Science 275(1) 2004; 177-182.
15. Foresight Guidelines on Molecular Nanotechnology.
16. Sayes C, Fortner J, Guo W, Lyon D, Boyd A, Ausman K, Tao Y, Sitharaman B,Wilson
L, Hughes J, West J, Colvin V “The differential cytotoxicity of water soluble fullerenes”.
Nanolett. 4, 2004; 1881-1887.
17. Adnan Nasir, ”Nanotechnology and dermatology: Part II—risks of nanotechnology”
ELSEVIER, Clinics in Dermatology 2010 28, 581–588.
18. S. K. Ma and J. T. Lue, Solid State Commun. 1996; 97, 979.
19. W. Stober, A. Fink, and E. J. Bohn, J. Colloid Interf. Sci. 1968; 26, 62.
20. S. P. Mukherjee, “Sol–Gel Technology for Thin Films, Fibers, Preforms, Rlrctronics and
Specialty Shapes” (I. C. Klein, Ed.). Noyes Pub., Park Ridge, New York, 1988.
21. T. Lopez, J. Mendez, T. Z. Mudio, and M. Villa, Mater. Chem. Phys. 1992; 30, 161.
22. R. E. Cavicchi and R. H. Silsbee, Phys. Rev. Lett. 1984; 52, 1453.
23. Wolfgang Mehnert, Karsten Mader, “Solid lipid nanoparticles Production,
characterization and applications” ELSEVIER, Advanced Drug Delivery Reviews 47
;2001 165–196.
24. Marie C. D. et al., “Gold Nanoparticles: Assembly, Supramolecular Chemistry,
Quantum-Size-Related Properties, and Applications toward Biology, Catalysis, and
Nanotechnology, Molecular Nanosciences and Catalysis”. Chem. Rev.2003;104.
25. Nath S. S., Chakdar D., and Gope G., “ Synthesis of CdS and ZnS quantum dots and their
applications in electronics, Nanotrends- A journal of nanotechnology and its
application”2007;203.
26. Nath S. S., Chakdar D., Gope G., and Avasthi D. K., “Effect of 100 Mev Nickel Ions on
Silica Coated ZnS Quantum Dot, Journal of Nanoelectronics and Optoelectronics” 3,
2008,1-4.
27. A. Bouheiler, M. R. Beversluis, and L. Novonty, "Characterization of nano plasmonics
structures by locally excited Photoluminescences," Applied physics letters, 2003,83.
28. S. Kalele, A. C. Despande, S. B. Singh, and S.K. Kulkarni, "Tuning luminescences
intensity of RHO6G dye using silver nano particles," Bull. Mater. Sci. 31(3), pp. 2008
541-544.
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55

Asian Journal of Pharmaceutical Sciences and Clinical Research (AJPSCR) Vol. 1, Issue 2 (2011), 40-55
29. Dieter Vollath, ”Nanomaterials-An Introduction to Synthesis, Properties and
Application” Environmental Engineering and Management Journal November/December
2008, Vol. 7, No.6, 865-870.
30. Limin Sun, Laurence C. Chow, Stanislav A. Frukhtbeyn” Preparation and Properties of
Nanoparticles of Calcium Phosphates With Various Ca/P Ratios” J. Res. Natl. Inst.
Stand. Technol., Volume 115, Number 4, July-August 2010; 115, 243-255.
31. Adrina Zelenakova, Vladimir Zelenak, “The iron-gold magnetic nanoparticles:
preparation, characterization and magnetic properties” Advanced Study Center Co. Ltd.
Rev.Adv.Mater.Sci. 18 2008; 501.
32. Juh Tzeng Lue, “Physical Properties of Nanomaterials” Encylopedia of Nanoscience and
Nanotechnology.
33. www.aspbs.com/enn.
34. www.wilsoncenter.org/nano.
35. http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_mi_009.pdf
36. Jana Pardeike, Aiman Hommoss, Rainer H. Müller” Lipid nanoparticles (SLN, NLC) in
cosmetic and pharmaceutical dermal products” International Journal of Pharmaceutics
366 200; 170–184.
37. 36. http://www. B2b-beautycare.com/facial mask (viewed on 12 March 2010).
Patel Anuradha et al.: Asian Journal of Pharmaceutical Sciences and Clinical Research, Vol.1, Issue 2 (2011), 40–55