J. Cosmet. Sci., 54, 1-7 (January/February 2003)
Evaluation of preservative systems in a sunscreen
formula by the linear regression method
NA´ DIA A. BOU-CHACRA, TEREZINHA DE JESUS A. PINTO, and MITSUKO
TABA OHARA, Department of Pharmacy, Faculty of Pharmaceutical
Sciences, Sa˜o Paulo University, Sa˜o Paulo, SP, Brazil 66355.
Accepted for publication, May 29, 2002. Poster presented
at the XIII Congreso Latino-Americano e Ibe´rico de Quý´micos
Cosme´ticos, Acapulco, Mexico, September 1997.
Synopsis
A sunscreen formula with eight different preservative
systems was evaluated by linear regression, pharmacopeial, and
the CTFA (Cosmetic, Toiletry and Fragrance Association) methods.
The preparations were tested against Staphylococcus aureus,
Burkholderia cepacia, Shewanella putrefaciens, Escherichia coli,
and Bacillus sp. The linear regression method proved to be useful
in the selection of the most effective preservative system used
in cosmetic formulation.
J. Cosmet. Sci., 54, 9-20 (January/February 2003)
Skin hydration effects, film formation time,
and physicochemical properties of a moisture mask containing
Monostroma nitidium water-soluble mucilage
RONG HUEI CHEN and WEEI YUU CHEN, Department of Food Science,
National Taiwan Ocean University, Taiwan.
Accepted for publication May 3, 2002.
Synopsis
The objectives of the study were to explore the effects
of using the water-soluble mucilage of Monostroma nitidium to
replace the humectant and half of the thickening agent on the
rheological properties, color, storage stability, water-holding
capacity, and film formation time of moisture masks thus prepared.
Results showed that moisture masks containing water-soluble
mucilage were pseudoplaxtic fluids. The apparent viscosity of
these moisture masks decreased with increasing shear rate but
increased with increasing concentration of the aqueous extracts
used. The water-holding capacity of moisture masks containing
1% aqueous extracts and 1% hydroxyethyl cellulose (HEC) were
similar to those containing 2% HEC and 5% 1-3 butadiene (humectant)
but better than those containing 2% methyl cellulose (MC) and
5% humectant. The film formation time of moisture masks containing
different concentrations of aqueous extracts decreased with
increasing concentration of the aqueous extract used. The storage
stability of a moisture mask containing 1% aqueous extract and
1% HEC was similar to that containing 2% HEC and 5% humectant
and better than those containing 2% MC and 5% humectant. The
safety test resulted in no erythema based on the Draize score
test. The pH was between 7.1 and 7.5 for all moisture masks
studied.
J. Cosmet. Sci., 54, 21-27 (January/February 2003)
Analysis of DNA in hair fibers
DANIELLA M. HEYWOOD, RICHARD SKINNER, and PAUL A. CORNWELL,
Hair Group, Unilever Research, Port Sunlight, Quarry Road East,
Bebington, Wirral, CH63 3JW, United Kingdom.
Accepted for publication September 6, 2002.
Synopsis
The extraction and identification of deoxyribonucleic
acid (DNA) from human hair shafts is described, along with the
effects of hair treatments on levels of DNA and suggestions
of DNA location within the shaft. DNA was present at low levels
in the hair shaft, and was identified using polymerase chain
reaction amplification of the human leukocyte antigen (HLA)-DQA1
locus. The use of cleanup columns aided the success of PCR amplification.
DNA appears to reside in the cuticle portion of the hair shaft.
Levels of DNA were found to be higher at the root-end compared
to the tip-end of hair and were also found to be lower after
permanent colorant treatment. DNA was found to be lost with
surfactant washing, with increased loss occurring with prolonged
or an increasing number of washes. These results suggest that
small amounts of residual DNA remain after differentiation and
add to our knowledge of the constituents of hair.
J. Cosmet. Sci., 54, 29-46 (January/February 2003)
Challenging the surfactant monomer skin penetration
model: Penetration of sodium dodecyl sulfate micelles into the
epidermis
PETER N. MOORE, SUDHAKAR PUVVADA, and DANIEL BLANKSCHTEIN,
Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, MA 02139 (P.N.M., D.B.), and Unilever
Home and Personal Care NA, Trumbull, CT 06611 (S.P.).
Accepted for publication November 15, 2002.
Synopsis
The penetration of sodium dodecyl sulfate (SDS) into
the epidermis was measured using 14C-radiolabeled SDS. It was
found that, at surfactant concentrations that exceed the critical
micelle concentration (CMC) of SDS, the concentration of SDS
measured in the epidermis increased as the total SDS concentration
in the solution contacting the skin increased, thus demonstrating
that micellar SDS contributes to the penetration of SDS into
the epidermis. The observed SDS dose-dependent response contradicts
the widely accepted view that only surfactant monomers penetrate
into the skin, while surfactant in micellar form does not contribute
to surfactant penetration into the skin. Nevertheless, this
finding is consistent with previously unexplained observations
of a dose-dependent damage to the skin induced by SDS at concentrations
above the CMC. When poly(ethylene oxide) (PEO) was mixed with
SDS, SDS micelles bound to PEO did not contribute to the concentration
of SDS in the epidermis, while SDS in free SDS micelles did.
Dynamic light-scattering measurements revealed an average hydrodynamic
radius of 20 Å for the SDS micelles, and a larger radius of
25 Å for the PEO-bound SDS micelles. A comparison with typical
aqueous pore radii in the stratum corneum measured in the literature
(10-28 Å) suggests that the SDS micelles may be able to penetrate
into the skin, while the PEO-bound SDS micelles may be sterically
hindered from penetrating into the skin.
J. Cosmet. Sci., 54, 47-52 (January/February 2003)
Determination of methylparaben in o/w emulsions
by solid-phase extraction and high-performance liquid chromatography
NONGNUCH PONGCHAROENKIAT, ARUNEE WITTAYANUKULLUK, and STANLEY
L. HEM, Department of Industrial and Physical Pharmacy, Purdue
University, W. Lafayette, IN 47907.
Accepted for publication April 29, 2002.
Synopsis
A simple, fast, and accurate solid-phase extraction (SPE)
using a 1-cc Oasis HLB cartridge for sample clean-up followed
by an HPLC analysis for the assay of methylparaben (MP) in an
o/w emulsion is described. One milliliter of methanol followed
by 1 ml of 10% methanol in water was used to activate the cartridge
sorbent. The sample was loaded into the cartridge and MP was
then separated from oil-soluble excipients by washing the cartridge
with 1 ml of 10% CH3CN in water. MP was finally eluted from
the cartridge with mobile phase, acetonitrile and water (60:40),
and quantified by HPLC analysis on a Nova-pak_ C-18 column at
254 nm.
J. Cosmet. Sci., 54, 53-62 (January/February 2003)
Scalp hair length. I. Hair length in Florida
theme parks: An approximation of hair length in the United States
of America
CLARENCE ROBBINS and MARJORIE GENE ROBBINS, Clarence Robbins
Technical Consulting, 12425 Lake Ridge Circle, Clermont, FL
34711.
Accepted for publication May 15, 2002.
Synopsis
Ten hair length studies were conducted (January through
May of 2001) at theme parks in central Florida, by observing
and counting people with different lengths of hair with reference
to specific anatomical sites. We observed 13.20% of the 24,300
males and females with hair shoulder-length or longer and 2.43%
with hair down to the bottom of the shoulder blades or longer.
We observed only 77 persons or 0.32% with hair waist-length
or longer. Only three of these 77 persons were men. We observed
22 men with hair shoulderlength or longer or about 0.18%, among
men only. Only four women, representing 0.0165% of this population,
had hair reaching to the bottom of the buttocks. Hairstyles
such as buns, topknots, or other styles of wearing hair bound
to the head did interfere with our estimate of shorter lengths
but not the longer ones (waist-length or longer). Head covers,
e.g., caps, hats, scarves, etc., did not interfere with these
estimates.
J. Cosmet. Sci., 54, 63-83 (January/February 2003)
The role of cationic conditioning compounds
in reinforcement of the cuticula
SIGRID B. RUETSCH, Y. K. KAMATH, and H.-D. WEIGMANN, TRI/Princeton,
P.O. Box 625, Princeton, NJ 08542.
Accepted for publication April 3, 2002.
J. Cosmet. Sci., 54, 85-111 (January/February 2003)
Papers Presented at the 2002 Annual Scientific
Meeting and Technology Showcase (Thursday's Program) December
5-6, 2002 New York Hilton New York, NY
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