J. Cosmet. Sci., 55, 1-12
(January/February 2004)
The stabilization of L-ascorbic acid in aqueous
solution and water-in-oil-in-water double emulsion by controlling
pH and electrolyte concentration
JONG-SUK LEE, JIN-WOONG KIM, SANG-HOON HAN, IH-SEOP CHANG,
HAK-HEE KANG, OK-SUB LEE, SEONG-GEUN OH, and KYUNG-DO SUH, Amore
Pacific Corporation R&D Center, 314-1, Bora-ri, Giheung-eup,
Yongin-si, Gyeonggi-do 449-729 (J.-S.L., J.-W.K., S.-H.H., I.-S.C.,
H.-H.K., O.-S.L.), and Division of Chemical Engineering, College
of Engineering, Hanyang University, Seoul 133-791 (S.-G.O.,
K.-D.S.), Korea.
Accepted for publication September 11, 2003.
Synopsis
This study presents a new approach that can stabilize effectively
L-ascorbic acid in water-in-oil-in-water (w/o/w) double emulsions.
Basically, the behavior of L-ascorbic acid in the aqueous phase
was observed, considering its molecular deformation. Then, it
was found that the stability determined in the aqueous phase
by high-performance liquid chromatography (HPLC) showed that
the collapse of ionization of L-ascorbic acid played a crucial
role in protecting the molecular deformation. Then, the stable
aqueous system was incorporated into the internal aqueous phase
of the double emulsions. From the HPLC analysis, it was observed
that the L-ascorbic acid in an appropriate system showed high
molecular stability for a long time. Moreover, in the measurement
of in vitro skin permeation, the L-ascorbic acid stabilized
in this study showed considerable skin permeation ability, indicating
its potential applicability in pharmaceutics and cosmetics.
J. Cosmet. Sci., 55, 13-27
(January/February 2004)
Effects of thermal treatments with a curling
iron on hair fiber
S. B. RUETSCH and Y. K. KAMATH, TRI/Princeton, Princeton, NJ
08542.
Accepted for publication October 2, 2003.
Synopsis
The effect of curling hair with a curling iron has been
investigated. Possibilities of thermal damage with repeated
curling according to, and in violation of, the manufacturer's
specifications have been studied. The propensity of hair surface
to damage depends on the moisture content of the hair, and these
experiments have been conducted in both wet and dry conditions,
with and without application of tension, and with short or prolonged
times. Scanning electron microscopic (SEM) examination revealed
that fibers treated under the dry condition (50% RH) show radial
and axial cracking along with scale edge fusion. Similar thermal
treatment on wet hair resulted in severe damage of the type
described above, as well as bubbling and buckling of the cuticle
due to the formation and escaping of steam from the fiber. Fibers
subjected to repeated curling in the dry condition show slight
increases in tensile mechanical properties, characteristic of
a crosslinked fiber. Fibers treated with conditioners show an
improvement in characteristic life, especially in the case of
low-molecular-weight conditioners, such as CETAB, which can
penetrate into the hair fiber (shown by TOF-SIMS analysis).
J. Cosmet. Sci., 55, 29-47
(January/February 2004)
Optical properties of hair-Detailed examination
of specular reflection patterns in various hair types
R. MCMULLEN and J. JACHOWICZ, International Specialty Products,
International Specialty Products, Wayne, NJ.
Accepted for publication September 11, 2003.
Synopsis
Details of the specular reflection of curved hair tresses,
resulting from illumination with a collimated incident light
source, were examined both qualitatively and quantitatively
using high-resolution photography and image analysis. The reflections
were found to consist of a multitude of light dots aligned with
the fibers and typically separated by a distance of 81-145 µm.
The contrast between the dots (specular reflection) and the
darker regions (diffuse reflection) of the entire reflection
band was found to increase with increasing pigmentation of hair.
Highly pigmented Oriental hair provided more contrast within
the specular reflection band than unpigmented natural white
hair. A quantitative description of the light reflection patterns
within the specular reflection band included two-dimensional
distribution of luminosity, histograms of the frequency of appearance
for peak maxima and minima in luminosity distribution plots,
and histograms of absolute maxima and minima of luminosity along
the length of the fibers. Specular reflection from African hair,
which consists of many curls that provide multiple and randomly
distributed reflection centers, have also been investigated.
Using microscopy software, Image Tool 2.0, and a method termed
image threshold, the number of reflection sites and their shapes
could be quantified. For example, treatment of African hair
with synthetic sebum was shown to significantly affect the reflection
patterns, resulting in a decrease in the overall hair luster.
Comparison of reflection patterns from Caucasian frizzy, very
curly, and curly hair is also discussed.
J. Cosmet. Sci., 55, 49-63
(January/February 2004)
Studies of light scattering from ethnic hair
fibers
K. KEIS, K. R. RAMAPRASAD, and Y. K. KAMATH, TRI/Princeton,
P.O. Box 625, Princeton, NJ 08542.
Accepted for publication October 16, 2003.
Synopsis
One of the most desirable hair attributes to consumers,
irrespective of ethnic background, is hair shine. The light
reflected from a fiber has two components, specular and diffuse.
The specular fraction of reflected light from the front surface
of the fiber is generally recognized as a contributor to high
luster. The distinction between specular and diffuse reflection
is, however, not always clearly defined. In this study an attempt
has been made to differentiate between specular and diffuse
reflectance by analyzing mathematically goniophotometric curves
of light reflected from unaltered single hair fibers from European,
African, and Asian ethnic groups. The effect of macroscopic
characteristics of the hair fibers, such as fiber diameter,
cross-sectional shape, and curvature on luster is demonstrated.
Results indicate that broadening of the specular peak reduces
luster values, and is related to these characteristics. Thus,
specular peak broadening is one of the important features to
take into account when evaluating luster. Therefore, a new method
for luster evaluation from goniophotometric curves is proposed.
Additionally, we present the general model for light scattering,
showing how scattering by surface roughness of different origin
and magnitudes, and the scattering and absorption processes
by the hair's interior, affect the position of the specular
reflectance peak and its broadening.
J. Cosmet. Sci., 55, 65-80
(January/February 2004)
Targeted delivery of salicylic acid from acne
treatment products into and through skin: Role of solution and
ingredient properties and relationships to irritation
LINDA RHEIN, BHASKAR CHAUDHURI, NUR JIVANI, HANI FARES, and
ADRIAN DAVIS, GlaxoSmithKline Consumer Healthcare, Parsippany,
NJ (L.R., H.F., A.D.), and Bertek Corporation, Foster City,
CA (B.C., N.J.).
Accepted for publication October 18, 2003.
Synopsis
Salicylic acid (SA) is a beta hydroxy acid and has multifunctional
uses in the treatment of various diseases in skin such as acne,
psoriasis, and photoaging. One problem often cited as associated
with salicylic acid is that it can be quite irritating at pH
3-4, where it exhibits the highest activity in the treatment
of skin diseases. We have identified strategies to control the
irritation potential of salicylic acid formulations and have
focused on hydroalcoholic solutions used in acne wipes. One
strategy is to control the penetration of SA into the skin.
Penetration of the drug into various layers of skin, i.e., epidermis,
dermis, and receptor fluid, was measured using a modified Franz
in vitro diffusion method after various exposure times up to
24 hours. A polyurethane polymer (polyolprepolymer-15) was found
to be an effective agent in controlling delivery of SA. In a
dose-dependent fashion it targeted delivery of more SA to the
epidermis as compared to penetration through the skin into the
receptor fluid. It also reduced the rapid rate of permeation
of a large dose of SA through the skin in the first few hours
of exposure. A second strategy that proved successful was incorporation
of known mild nonionic surfactants like isoceteth-20. These
surfactants cleanse the skin, yet due to their inherent mildness
(because of their reduced critical micelle concentration and
monomer concentration), keep the barrier intact. Also, they
reduce the rate of salicylic acid penetration, presumably through
micellar entrapment (either in solution or on the skin surface
after the alcohol evaporates). Cumulative irritation studies
showed that targeting delivery of SA to the epidermis and reducing
the rapid early rate of penetration of large amounts of drug
through the skin resulted in a reduced irritation potential.
In vivo irritation studies also showed that the surfactant system
is the most important factor controlling irritancy. SA delivery
is secondary, as formulations with less SA content reduced the
rate of delivery to the receptor and yet were some of the most
irritating formulations tested, presumably due to the action
of the specific anionic surfactant on the barrier. Alcohol content
also did not appreciably affect irritation and SA delivery;
formulations with considerably lower alcohol content but containing
anionic versus nonionic surfactant systems exhibited considerably
higher irritancy. Thus the surfactant type was again the predominant
factor in those studies, although arguably alcohol plays some
role (solubilization of SA). Results showed that both polymers
and mild surfactants work in concert to provide the optimal
formulation benefits of targeted delivery and reduced irritation.
Synergistic relationships among hydroalcoholic formulation components
will be discussed along with the mechanisms likely involved
in controlling delivery of SA to skin.
J. Cosmet. Sci., 55, 81-93 (January/February 2004)
Analyzing the laser-light reflection from human
hair fibers. II. Deriving a measure of hair luster
F.-J. WORTMANN, E. SCHULZE ZUR WIESCHE, and B. BOURCEAU, DWI,
German Wool Research Institute, Veltmanplatz 8, 52062 Aachen
(F.-J.W.), Schwarzkopf GmbH, Hohenzollernring 127-129, 22763
Hamburg (E.S.z.W.), and Fiantec GmbH, Technologiezentrum, Europaplatz,
52068 Aachen (B.B.), Germany.
Accepted for publication October 8, 2003.
Synopsis
Hair shine or luster is perceived as an important, though
analytically somewhat elusive, attribute of beauty, primarily
associated with clean and healthy hair. Principles for the assessment
of hair luster are developed that are consistent with the practical
situation. These principles are related to the components of
light, specularly and diffusely reflected from single hair fibers,
as measured by laser-based, multiangle goniophotometry, presented
in Part I. Considering various definitions of gloss, their tradition,
practical implementation, and their inherent limitations for
testing hair, the gloss index as a physically consistent measure
of hair luster is derived from the ratio of the integral intensities
of the light components. Changes of the parameter values along
hair length, namely their decrease, are analyzed for hairs of
different color and ethnic origin. The correlation with shine
evaluations of hair tresses by panels, based on literature data,
is analyzed and ascertained.
J. Cosmet. Sci., 55, 95-113
(January/February 2004)
Review of the current understanding of the effect
of ultraviolet and visible radiation on hair structure and options
for photoprotection
VITTORIA SIGNORI, BASF Corporation, 1705 Route 46 West, Ledgewood,
NJ 07852.
Accepted for publication June 18, 2003.
Synopsis
This article describes the current understanding of the
effect of ultraviolet (UV) radiation and visible light on the
structure and integrity of human hair fibers; furthermore, it
discusses current and past approaches to the protection of hair
from UV rays. Relevant literature is reviewed.
J. Cosmet. Sci., 55, 115-137
(January/February 2004)
Papers Presented at the 2003 Annual Scientific
Meeting and Technology Showcase
(Thursday's Program)
December 4-5, 2003
New York Hilton
New York, NY
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