52, 155-161 (May/June 2001)
Direct evidence for bioconversion of vitamin
E acetate into vitamin E: An ex vivo study in viable human skin
W. BASCHONG, C. ARTMANN, D. HUEGLIN, and J. ROEDING, M.
E. Mueller Institute at the Biozentrum, University of Basel,
Klingelbergstrasse 50-70, CH-4056 Basel, Switzerland (W.B.),
PhaCos GmbH, Munich, Germany (C.A.), Ciba Specialty Chemicals,
P.O. Box 1266, D-79630 Grenzach-Wyhlen, Germany (D.H.), and
Mica Products GmbH, Zoellinplatz 4, D-79410 Badenweiler, Germany
(J.R.). Accepted for publication March 15, 2001.
Synopsis
For better stability, vitamin E is commonly used as the non-active
esterified pro-drug. Such esters are postulated to be hydrolyzed
to the free active form by skin-related esterases. So far, successful
conversion of esterified vitamin E to free vitamin E (tocopherol)
has been mainly delineated from observed biological effects.
Quantitative evidence in human skin is poor. In vitro and in
vivo studies on human and animal skin have proved ambiguous.
Formulation-based effects may have added to this controversy.
In the present study, comparable amounts of vitamin E acetate
(i) in oil (Mygliol-812N), (ii) surfactantsolubilized in water,
(iii) encapsulated in liposomes, or (iv) encapsulated in Nanotopes™
were applied to human skin mounted in modified Franz-perfusion
chambers that permit emulation of both open or occlusive conditions.
The distribution of vitamin Etotal (vitamin E acetate + vitamin
E) was assessed on the skin surface, in the horny layers, and
in the underlying skin by high-pressure liquid chromatography
(HPLC), with a recovery higher than 90%. Vitamin E acetate in
Mygliol deposited exclusively on the surface and in the stratum
corneum. In contrast, solubilized or encapsulated vitamin E
acetate deposited also in the underlying skin. Nanotopes™ performed
best, followed by liposomes and solubilized vitamin E acetate.
Non-occlusive application favored deposition in the skin relative
to occlusive application. Conversion of vitamin E acetate to
vitamin E was not observed on the skin surface or in the horny
layers, while in the underlying skin up to 50% of the vitamin
Etotal was deacetylated.
52, 163-167 (May/June 2001)
Abrasiveness evaluation of silica and calcium
carbonate used in the production of dentifrices
I. M. C. CAMARGO, M. SAIKI, M. B. A. VASCONCELLOS, and D.
M. A´ VILA, Instituto de Pesquisas Energe´ticas e Nucleares,
Centro de Quý´mica e Meio Ambiente, IPEN/CNEN-SP, Caixa Postal
11049, ZIP 05422-970, Sa˜o Paulo, SP, Brazil. Accepted for publication
March 15, 2001.
Synopsis
Our purpose was to apply a radiometric method to an abrasiveness
evaluation in samples of silica and calcium carbonate used as
an abrasive in a dentifrice, to help in a prudent selection
of materials by dentifrice producers. The results of RDA (radioactive
dentin abrasion) abrasiveness indices obtained for these compounds
varied from 136 to 19. The relative standard deviations of these
RDA results varied from 5.9% to 11.8%, showing a good precision
in the method. Also, the results obtained indicated that the
abrasiveness indices increase with the particle size of the
material. A comparison between different abrasives with similar
particle sizes showed that silica presents higher RDA values
than calcium carbonate.
52, 169-184 (May/June 2001)
Secondary ion mass spectrometric investigation
of penetration of coconut and mineral oils into human hair fibers:
Relevance to hair damage
S. B. RUETSCH, Y. K. KAMATH, AARTI S. RELE and R. B. MOHILE,
TRI/Princeton, Princeton, NJ 08540 (S.B.R., Y.K.K.), and Marico
Industries Ltd., Andheri, Mumbai 400 058, India (A.S.R., R.B.M.).
Accepted for publication March 15, 2001.
Synopsis
An attempt has been made to show the difference in the penetrability
of coconut oil and mineral oil in human hair. We have used secondary
ion mass spectrometry (SIMS) in combination with a time-of-flight
(TOF) mass spectrometer. Characteristic ions formed by the pure
components when bombarded with gallium ions have been identified
with their m/z values. The distribution of the ion, characteristic
of the particular treatment, has been established in the cross
sections of hair treated with coconut and mineral oils. The
results show that coconut oil penetrates the hair shaft while
mineral oil does not. The difference may be due to the polarity
of the coconut oil compared to the nonpolar nature of the mineral
oil. The affinity of the penetrant to the protein seems to be
the cause for this difference in their behavior. This study
also indicates that the swelling of hair is limited by the presence
oil. Since the process of swelling and deswelling of hair is
one of the causes of hair damage by hygral fatigue, coconut
oil, which is a better penetrant than mineral oil, may provide
better protection from damage by hygral fatigue.
52, 185-193 (May/June 2001)
Mechanical extension of human hair and the movement
of the cuticle
M. FEUGHELMAN and B. K. WILLIS, Department of Fibre Science,
University of New South Wales, Sydney, NSW 2052 (M.F.), and
Reckitt and Colman, P.O. Box 138, West Ryde, Sydney, NSW 2114
(B.K.), Australia. Accepted for publication March 15, 2001.
Synopsis
Goniophotometry has enabled measurement of the angle that
the surface of the cuticle (the scales) of a human hair fiber
makes with the axis of the hair shaft. This measuring technique
has been used to obtain the change of this scale angle with
extension of a hair fiber under fixed conditions of temperature
and relative humidity. Based on a simple model of overlapping
scales of the hair cuticle, analysis shows that, for hair fibers
extended to strains above 10% at 35% relative humidity and at
35°C, overlapping scales become progressively detached from
each other. This scale detachment has been suggested to result
from the mechanical failure of the endocuticle layer in the
scale structure. This endocuticle layer is low in disulfide
cross-linking, which would result in a lowered stiffness and
greater extensibility, as indicated by the higher swelling of
the layer in water as against the highly cross-linked exocuticle
layers. The greater extensibility of the endocuticle would also
explain the greater distortion of this layer under stress, but
it would not follow that endocuticular failure under stress
should result. An alternative mechanism of failure of adhesion
between overlapping scales in the cuticle is suggested, based
on the involvement of the hydrophobic upper-b-layer with its
surface of 18-methyleicosanoic acid (18- MEA), which may provide
mobility and a reduction in adhesion between scales. This potential
failure of the cementing of the overlapping scale structure
due to the 18-MEA is discussed, with particular reference to
the standard permanent setting procedure of human hair.
52, 195-198 (May/June 2001)
Abstracts Journal of the Society of Cosmetic Chemists
Japan Volume 34, No. 1, 2000
BACK