Cosmetic
Testing Equipment: Device and Types of Equipment for Dermatological Evaluation for
Women’s Skin
Arushi Saloki1,
Taranjeet Kukreja1, Sarita Gaikwad1, Arvind Kumar1,
Ayush Parker1, Bhavana Dowand1, Chetna Sahu1,
Damini Mali1, Swarnlata Saraf1*
1University
Institute of Pharmacy, Pandit Ravishankar Shukla University, Raipur 492010,
Chhattisgarh, India.
Abstract:
There are many different equipment and
techniques for an aesthetic skin evaluation, efficacy testing, claim support,
and objective measurements of women’s skin parameters for all applications.
Women have softer skin than men. Nothing commercially available in terms of
moisture, oiliness, color, texture, etc existed over 20 years ago. Fortunately,
several cost-effective ways are available to quantify these characteristics and
compare them before and after a treatment or application. Before distributing
the finished product to outside testing facilities for the final validation,
the cosmetic business conducts these tests at different stages of product
development to determine the product’s direction. In this review, we have summarized the C+K devices that are
acknowledged as industry-standard tools for assessing efficacy in the fields of
cosmetics and the types of equipment used for the cosmetic evaluation of the
skin.
Keywords: Cosmetic
equipment, types of equipment, evaluation, skin parameters, dermatology.
Introduction
Cosmetics
must be examined during production to ensure that they meet product
specifications, are safe, and are made economically. Sensory approaches have
been used from the earliest to establish sensory evaluation methods for
objectively understanding users' impressions. Although the only instrumental
method cited was a spectrometer to detect sunscreen chemicals, an article on
dermatologically efficacy testing was published in the Society of Cosmetic
Chemists' first publication, which was published in 1947. 1956 was the year
that the first instrumental method of measuring the static charge on human hair
was published. The in-vitro method using radioisotopes to measure absorption by
hair was also published in the same journal. The development of the means of
measuring cosmetic effects is driven by increasing pressure on cosmetic
companies to provide solid evidence to support claims made for products. The
development of the means of measuring cosmetic effects is driven by increasing
pressure on cosmetic companies to provide solid evidence to support claims.
Claims associated with several of the signs of aging such as reduced facial
wrinkling are often subjected to intense scrutiny. Other claims include
increased moisture level in the skin, improvements in skin texture, elasticity,
and, smoothness, and of regulation of sebum. (Ctplus 2022)
The
C+K devices are recognized as industry-standard methods for evaluating efficacy
in the sectors of food, nutritional supplements, personal care products, raw
materials, medications, and cosmetics. The devices are easy and quick to use,
thus perfectly suitable to study the product properties on the skin in each
phase of the development process. The C+K equipment is used by CROs and
external testing labs all over the world to conduct final product tests for
documentation.
Cutometer
Since
the cutometer Probes are modular, we can assemble them anyway we need to. They
are made up of probes and a basic apparatus. By selecting a simple device that
satisfies our needs, such as one with a display, one that can only be connected
to software, or even one that can wirelessly communicate measurement
information to software. Selecting the measurement parameters that are
necessary for your work. The basic gadget and the probes will work together to
create your measuring center. (Does et al. 2017)
Fig 1: Cutometer® dual MPA 580 Device
The
Cutometer Probe Family
The
Cutometer probes are digital and contain all calibration information. Thus,
they can be simply connected to a basic unit. A variety of probes are available
to measure different parameters on the skin:
A.
Corneometer®
CM 825: Skin surface hydration
B.
Sebumeter®
SM 815: On the skin's surface, sebum
C.
Skin-pH-Meter
PH 905: pH-measurement
D.
Mexameter®
MX 18: Melanin & erythema
E.
Tewameter®
TM 300: Transepidermal water loss measurement
F.
Indentometer
IDM 800: Mech. Properties
G.
Elastometer
EM 25: Viscoelasticity by suction
H.
Skin-Thermometer
ST 500: Body heat
I.
Skin
Glossymeter GL 200: Appearance of skin and hair gloss
J.
Skin-Colorimeter
CL 400: Skin and hair colors
Frictiometer
FR 700
Friction
readings on the skin using the Frictiometer FR 700.
The
MPA Systems (Multi Probe Adapter) It's modular to use the Multi Probe Adapter
System. It consists of probes and a basic device.
·
The
user selects a basic device that meets his needs. The probes are digital
containing all calibration data. Therefore, they can be connected to any of
them.
·
The
probes provide a high degree of flexibility and stability and can be easily
serviced.
·
Operation
with the overall MPA CT plus software for all devices and probes (with cables).
·
The
accuracy of the probes can always be checked with a check calibration function.
·
The
measurements include the room temperature and relative humidity from the sensor
RTH 100.
·
The
perfect solution for efficacy testing, claim support, various scientific
investigations, and field trials.
·
The
Multi Probe Adapter Systems can feature up to 10 different probes and are
connected directly to the software (no display on the device).
·
Measurement
system that is ideal for your needs and can grow as you go.
·
The
brand-new, cutting-edge programme MPA CT plus is used to operate the MPA
systems.
·
The
measurements are saved along with the information from the RHT ambient
condition sensor.
·
The
system may be well-suited through all upcoming cutometer probes.
Available
models:
·
With
the exception of the Cutometer®, the Multi Probe Adapter MPA 6 supports up to
five probes and has an integrated Sebumeter®.
·
A
built-in Sebumeter® and the possibility to connect any probes with an external
power source are features of the Multi Probe Adapter MPA 10 (up to 9, excluding
Cutometer®).
·
The
Cutometer® dual MPA 580 has a built-in Sebumeter® and the capacity to connect
up to four additional C+K-probes, and it uses a vacuum pump inside the device
to induce suction in order to measure the viscoelasticity of the skin.
·
The
tool comes with one Cutometer® probe (2 mm standard opening), extras, and
software. Another alternative is to connect and use more than one Cutometer®
probe simultaneously. Connect any two in MPA 2 (aside from the Frictiometer and
Cutometer®), there is no need for an additional power source; simply connect
the device with the system through USB. (Does et al. 2017)
A.
Corneometer® CM 825
The
most popular instrument that measures skin hydration in the world is Corneometer®
CM 825 Over the course of 35 years. The Corneometer® has made it possible to
consistently and precisely determine the degree of moisture on the skin's
surface (stratum corneum). The fact that the term "corneometry" is
used in so many scientific publications and that measures of skin moisture
depend on one another is proof of this. Other hydration measurement devices on
the market are always compared to the Corneometer® standard to determine their
accuracy. (Anon 2017)
Fig 2: Corneometer® CM 825(Anon n.d.-l)
The
Corneometer indicates hydration of the superficial layers of the skin (stratum
corneum) via measurement of skin dielectric properties. The measurements are
performed by the application of a probe to the skin surface. Upon contact, an
electric field passes through the stratum corneum and the dielectric constant
is obtained. The amount of skin hydration is exactly proportional to the value
of the dielectric constant (in arbitrary units). The Corneometer has given the
most popular and reliable method for calculating the degree of moisture of skin
surface for more than 35 years (stratum corneum). The numerous scientific
publications that use the terms "corneometry" and "skin
hydration measures" interchangeably serve as evidence for this. Other
hydration measurement devices on the market are always compared to the
Corneometer standard to determine their accuracy. The measuring of skin
moisture with corneometry is a common technique. It measures the relative
permittivity of the upper skin layers using a capacitive sensor. The measured
value serves as a metric because these depend on the skin's level of moisture
level of the skin. The German trademark Corneometer is where the name
corneometry originates. Under this name, the first commercial skin hydration
measurement device was released in 1979.
Fig 3: Hydration level detected on the stratum
cornea (outermost skin layer) (Skin Hydration
Measurement by Dr. Jonathan Crowther Via SpecialChem • Skinob , Cosmetic
Testing, n.d.)
Measurement principle
A
capacitance measurement of a dielectric material, in this case skin, is the
foundation of the Corneometer measurement. The dielectric constant of the skin
is measured using fringing field capacitance sensors. Skin's dielectric
constant will alter depending on how much water is present. This enables the
precision measuring capacitor to detect any changes in skin moisture. These
variations in the stratum corneum's water content are transformed into
arbitrary hydration units. On the probe head there is a fine piece of glass to
ensure that only the capacitance changes due to water content are identified.
Even small changes in water can be detected.
The measurement time is short at only 1 second minimizing occlusion
effects. The stratum Corneum, at a depth of 10–20 m, prevents deeper layers of
skin from influencing the measurement.
Application areas
I. Ideal for product
development, supporting claims, and efficacy testing
II. Can be utilized
for unbiased clinical evaluation can be used to keep track of treatments
provide details on the course of treatment
III. For use in medical
surveys Various scientific applications that involve evaluating hydration
Benefits
of a Corneometer
1.
To
avoid blockage, the probe enables very quick measurement (1 s).
2.
Optionally,
measurements over a longer time span might be done continuously ("dynamic
occlusion").
3.
Due
to capacitance measurement, substances on the skin (such as salts or product
residues from topically applied goods) have very little impact.
4.
To
avoid contamination, measurement depth is quite shallow (10–20 m of the stratum
corneum).
5.
For
simple handling and measurement on all body sites, the probe is compact and
lightweight (e.g., lips, etc.). The probe head's spring keeps the pressure on
the skin constant for precise, repeatable results. It is simple to evaluate the
Corneometer® probe's accuracy and the scatter field's penetration depth at any
moment.
6.
It
takes little time to clean the probe head after each measurement. With a wide
spectrum of investigations, "corneometry" is widely recognised.
7.
The
condition of the skin of the astronauts aboard the International Space Station
was evaluated using the Corneometer® (ISS). The most recent recommendation for measuring
skin water by the experts of EEMCO (European group on efficacy measurement and
assessment of cosmetics and other products) is to use the Corneometer®. (Skin
Research & Technology, 2018, 24, p. 351-358).
8.
The
Corneometer CM 825 is existing as an individual instrument, derma section SSC
3, connectable to the MPA systems, or as a wireless probe.
Available
formats
1.
Multiprobe Adapter System
The
Corneometer CM 825 probe can be plugged in to all of the computer driven MPA
devices (MPA 2, MPA 6, MPA 10 & Cutometer dual MPA 580)
2.
Multi Display Device Mdd 4
The
Corneometer CM 825 is available as a stand-alone device through the MDD 4.
Supplied with a room condition sensor may be likely to add a further two
measurements. In addition to the color screen for displaying results the MDD 4
can be connected to a computer and measurements recorded using the MPA
software.
3.
Wireless Probe
Radio
waves are used to transmit measurements to the diminutive RR 200 receiver unit,
which is connected via a USB port to the computer. The values can be
transmitted over a 5–10 m distance. The values are collected using special MPA
Wireless software. The probes are battery operate.
Technical
Information
Length:
11 cm, Weight: approx 41g,
Measuring
surface: 49mm2,
Measuring
principle: capacitance, Measurement frequency: 0.9-1.2 MHz, Accuracy: ±3% Technical
changes may be made without prior notice.
Benefits
1)
Repeatable
and since 1980,
2)
Precise
measurements of skin hydration.
3)
Brief
measurement period
4)
Constant
pressure for repeatable measurements that are accurate and unaffected by skin.
5)
Taking
measures at each skin spot makes individual and continuous measurements
possible not frequently, intricately, or laboriously require calibrating Data
on calibration kept in the probe Check To ensure the accuracy of measurements, test
the calibration.
6)
A shallow depth measurement
7)
The
moisture content of the stratum corneum affects a number of skin
characteristics, including its mechanical qualities and barrier function.
As a
result, measuring hydration is now among the most significant and widely
utilised metrics. Other hydration instruments are constantly evaluated and
contrasted with the Corneometer®, which is the most popular hydration
assessment device in the world. High-quality electronics in the probe ensure
temperature stability in addition to preventing fluctuations from interfering
with the measurement. The probe's light weight and small measurement area
(49mm2) make it simple to use measurements across the entire body.
Methods
The
experimental apparatus included a combination of cellulose and saline to
simulate the SC and polyethylene foil to simulate the underlying skin layers
that contain a lot of water. Following the application of three different skin
formulations, base, base plus salt (2 wt% NaCl), and base plus salt and
glycerine (5 wt%), the hydration of the SC of the volar forearm was assessed in
eight healthy volunteers using the Moisture Meter SC-2 and Corneometer CM 825.
In the sorption-desorption test, a drop of water was applied to the skin, and
both instruments monitored the skin's dehydration for two minutes.
SM
815 Sebumeter
Sebaceous
gland secretions, keratinous layer fat, and sweat remnants all contribute to
the heterogeneous components of sebum. Glycerides, free fatty acids, wax
esters, squalene, cholesterol esters, and cholesterol are only a few of the
lipids that make up sebum, which is a complex and changeable mixture. There are
various kinds of instruments available for measuring sebum production. Sebumeter®
provides the furthermost prevalent technique for reliably and accurately
determining the sebum level for 35 years and plus of the skin's surface, the
scalp, and the hair. The numerous occurrences of these terms in scientific
literature serve as evidence for this. Sebum measurements and
"sebumetry" go hand in hand.(S 2022)
Fig 4: Measuring sebum on skin
Measurement
of sebum
Lipids
are synthesized at a constant rate in sebaceous gland and secreted onto the
skin surface an average of eight days after synthesis. Therefore, by
measuring the sebum content of a skin specimen with a known surface area, it
should be possible to determine the sebum production rate that had been
occurring in vivo. According to a study on men, the average rate of scalp sebum
production is 1.45 mg.
Fig 5: Demonstrates the sebum production averages
from human skin.
Measurement
Principle
Grease
spot photometry is the foundation for the measurement. The skin or hair comes
into contact with the Sebumeter SM 815 mat tape. Depending on the amount of
sebum on the measurement area's surface, it turns translucent. A photocell then
tests the device's transparency and aperture after inserting the tape inside.
Transmission is an example of a light Sebum content.
Fig 6: Optical
diagram of sebumeter
The Probe (Cartridge)
A 64 mm2 measuring section of the mat
tape is visible through the measuring head of the cartridge. For a measurement
the tape is moved forward by a trigger at the side of the cartridge to expose a
new section of tape. The used tape is rewound inside the cartridge. 400
measurements can be made with one cartridge. How much of the tape is still
unutilized is shown on the trigger by the scale from 1-0.
For hygienic reasons, the cartridge is
simply replaced when it runs out.
Positive aspects of the Sebumeter
§ The unique tape solely reacts to the content of skin sebum
and is independent of water.
§ It enables very quick and simple measurement to prevent
occlusion.
§ A zero calibration before each measurement provides
highest accuracy.
§ For simple handling and measurement on all body locations,
the probe is compact and light.
§ Precision and repeatability are made possible by the
cartridge's spring, which maintains consistent pressure on the skin.
§ It is simple to check the device's accuracy at any time
using a particular test tool with a predetermined value.
Fig 7: Cartridge on head
Fig 8: Cartridge on cheek
Application Areas
The sebum content is important in
several application areas, including:
§ For all types of cosmetic and pharmaceutical products,
claim support and efficacy testing are crucial (especially cleansers, anti-acne
products, shampoos and hair care, products for oily skin).
§ Typical claims (examples) supported by the Sebumeter
include protection from oily skin, hair, and scalp, cleaning/purifying, against
impurities, oil restoring, anti-dandruff, anti-acne, calming, nourishing,
opulent, balancing, normalising, safeguarding, and pore activity
decreasing, among other things.
§ It is beneficial in a typical in dermatological basic
research in humans and animals.
Fig 9: Sebumeter basic
efficacy testing face wash
Fig 10: Sebumeter basic
device in cosmetic research
Technical
Data:
A.
Cartridge only
Dimensions:
8.5 x 11.3 x 2.3 cm, Measuring surface: 64 mm², Weight: 65 g,
Units:
Sebumeter® units from 0-350 (approximated to μg/cm2 in a certain range),
measurement uncertainty: ± 5%
A
single cartridge provides about 400–450 measurements. Expired cartridges must
be replaced.
B.
Skin-pH-Meter PH 905
Skin-pH-Meter
PH 905 used to measure the pH of the skin and scalp. For quickly, easily, and
affordably measuring the pH on the scalp or skin surface, use the Skin-pH-Meter
PH 905 device. The H+ ion and one housing each include a sensitive electrode
and an extra reference electrode, which are measured using a high-quality
combination electrode. It is connected to the measurement electronics found on
a probe handle.(Courage+Khazaka electronic GmbH 2022)
Fig 11: Measurement of skin pH(Anon n.d.-e, Anon n.d.-h)
C.
Mexameter® MX 18
The
Mexameter® MX 18 is a very simple, quick, and affordable tool for measuring
erythema. The two substances primarily responsible for the skin's colour,
melanin and reflecting haemoglobin (erythema). Changes in skin tone are
relevant in a wide range of application areas. The instrument is well-known and
widely used in scientific research. It is essential for supporting efficacy
claims and testing for cosmetics and pharmaceutics.
A Mexameter is a
tool that helps in measuring amount of melanin or erythemal that is present in
the person’s stratum corneum who being tested. This help in understanding If
someone is afflicted with from deficiency or excess of these two components. The
measurements are performed by the application of a probe to the skin surface.
The probe has a 5 mm aperture that emits radiations. These radiations are
reflected by the skin and captured back by the same probe.(Anon 2022b). The results are
expressed as index value for each parameter (melanic index and erythematic
index) in arbitrary units on a scale from 0 to 999.
Fig 12: Mexameter® MX 18 (Anon n.d.-c)
Measurement principle
Absorption/reflection
is the foundation of the measurement. The Mexameter® MX 18 probe emits three
distinct light wavelengths. The receiver measures the light reflected by the
outermost layer. After the light emitted amount is determined, the amount of on
the skin, light absorption can be calculated. Two distinct wavelengths are used
to measure the melanin (red: 660 nm and near infrared: 880 nm) was chosen to
match various pigment absorption rates. In the t wo distinct wavelengths are
used to measure erythema: green (568 nm) and red (660 nm), which corresponds to
the haemoglobin spectral absorption peak, and to prevent other colours
have an impact (e. g. bilirubin).
Benefits
·
Measuring erythema and melanin in a reliable and accurate manner
·
Extremely rapid measurement time
·
The constant pressure provided by spring has no impact on the
skin.
·
Low weight provides easy handling
·
Do not need regular, complex and time-consuming recalibration
·
Data on calibration kept in the probe
·
Verify calibration to ensure measurement accuracy.
Fields of Applications
Skin colour are of interest in various
fields. Many international scientific studies demonstrate its benefits in all
important dermatological basic research in humans and animals and cosmetic
application fields.
1.
It is indispensable in efficacy testing and claim
support for cosmetics and pharmaceuticals
2.
Typical claims (examples) substantiated
with the Mexameter®: sun protecting, whitening/brightening, skin
tone correcting, concealing, soothing, micro circulation increasing,
vitalising, anti-allergic, anti-irritation, safe, for sensitive skin,
anti-pollution, improves healing, anti-aging, against dark-spots/age-spots/dark-circles,
anti-photosensitive and many more.
3.
In occupational health the skin irritation (erythema value) is of
special interest to show the necessity of skin protection measures
4.
Ideal for product
development, supporting claims, and efficacy testing
5.
It is used for patch
testing, allergy testing, and objective clinical assessment.
6.
Used keep track of
treatments
7.
Measurement of melanoma
and scar tissue
8.
Suitable for medical
surveys
9.
Assessing melanin and
erythema in a range of research applications
Benefits of Mexameter®
§ Measurement
is rapid and easy (1 second for the results: melanin index and erythema index).
§ Continuous
measurements over a longer time span are optional.
§ The
highly sensitive measurement provides results for melanin and erythema on a
wide scale (0-999), making even the smallest variations in colour traceable.
§ It is
lightweight and tiny enough to be handled easily and measured on all body
regions.
§ A spring
within consistent pressure from the probe head on the skin enables precise,
repeatable measurements.
§ The accuracy of the Mexameter® probe
easily checked at any time.
§ The
probe head can easily be cleaned after each
measurement.
§ Worldwide
established and used in many scientific studies.
Technical Data
Probe only:
Dimensions: 13 cm x 2.4 cm Ø,
Measuring
surface: Ø 5 mm ≈ 19.6 mm²,
Cable
length: approx. 1.3 m,
Weight: 85 g (incl. cable)
Measurement
principle: absorption/reflection,
Nominal wavelengths: 3 colour measuring system
green: λ
peak = 568 nm,
red: λ peak
= 660 nm,
near
infrared: λ peak = 880 nm,
Units: arbitrary Mexameter® units (0-999 for
melanin and erythema),
Measurement
time: 1 s,
Measurement
uncertainty: ± 5%
B.
Tewameter® TM 300
Measurement
of Transepidermal Water Loss and Skin Barrier Function
The
Tewameter® TM 300 (the predecessor to the Tewameter® TM Hex) is the most widely
used measuring tool for the estimation of Transepidermal Water Loss because of
its "open chamber" principle(TEWL). This is a crucial variable for
determining how well the water barrier function of the skin and a fundamental
measurement for all applications. Even the slightest damage in the skin water
barrier can be determined at an early stage.(Anon n.d.-j)
Fig 13: Tewameter TM 300 probe(Anon n.d.-j)
What
Does It Measure?
The
Tewameter® TM 300 is the most widely used instrument for monitoring
transepidermal water loss (TEWL). The evaluation of the skin's barrier function
is based on this factor the most.
The
most used tool for monitoring transepidermal water loss is the Tewameter® TM
300. (TEWL). This information is essential for figuring out how efficient the
skin is as a barrier. Due to its "open chamber" approach, the
Tewameter® TM 300 (the Tewameter® TM's predecessor Hex) is the measurement
device that is used the most frequently worldwide (TEWL).
This
is a fundamental measurement used in all kinds of applications and a crucial
parameter for assessing the skin's ability to act as a water barrier. Early
detection of even the smallest skin water damage was possible.
Measurement
Theory
Water
from the skin always evaporates to some extent as part of natural skin
metabolism. However, the water loss will accelerate the moment the skin's
barrier function is even slightly compromised (even with the smallest damages
invisible to the human eye). As a result, this assessment serves as the basis
for all cosmetic and dermatological research. The two sets of sensors inside
the hollow cylinder (temperature and relative humidity) allow the Tewameter®
probe to indirectly measure the density gradient of skin water evaporation.
This
is an “open chamber” measurement. The TEWL can only be constantly assessed
using this method without changing its microenvironment. In g/h/m2,
the measured values represent the evaporation rate.
A = surface [m2]
m = water transported [g]
t = time [h]
D = diffusion constant [= 0.0877
g/m(h(mmHg))]
p = vapor pressure of the
atmosphere [mm Hg]
x = distance from skin surface to
point of measurement [m]
Fields
of Application
· Indispensable in
formulation, efficacy testing and claim support for cosmetics and
pharmaceuticals, regarding improvement of the skin barrier function.
· Safety tests for
products as even slight deficiencies in the skin barrier can be detected.
· Dermatological
basic research.
· Studies on sweat (antiperspirant
efficacy testing).
· Measures used in
occupational health education to inform people about the need for
· products that
protect the skin.
· Zoology and
veterinary medicine.
· Also, for the
textile, food, packaging and paper/ tissue industry, the measurement is of
interest.
Advantages
· The open chamber
measurement is the only method to assess the TEWL continuously, which is
necessary for most applications, without influencing the skin surface.
· Numerous studies
available.
· A stable measurement
is achieved quickly; the next measurement can be done without waiting time.
· The small size of
the probe head reduces the impact of air turbulence inside the probe.
· Its light weight
ensures easy handling and has no impact on the skin's structure.
· Easy check
calibration with a small chamber.
· Offset of probe by
the user possible for compensation of “aging effects “of the sensor.
· Special
calculations i.e., Skin Surface Water Loss (the skin ‘s water holding capacity
after occlusion).
· Available as a
standalone device (MDD) and wireless probe for C+K MPA-systems (operation with
MPA Wireless software).
Skin
temperature is 30°C or higher, while the sensors of the probe typically operate
at room temperature (20–22°C). As the amount of evaporating water measured with
the device is extremely small (healthy skin 8-15 g/h/m² → 0.000001333 -
0.00000025 g/minute/cm²), the sensors inside the probe should reach skin
temperature to measure this small amount exactly and stable. The Probe Heater
PR 100 continuously raises the probe head's temperature to a temperature
getting very quickly accurate and stable and being close to skin temperature
results.
Special
Accessories for Tewameter® TM 300
Disinfectable steel rings are
available when measuring on special surfaces. They can be mounted on the
measuring head and after the measurement taken off the probe and be cleaned.
Technical
Data
Cable probe only:
Dimensions: Measuring Chamber: Height: 2 cm, Ø 1 cm, Probe: Length
17 cm, Cable length: approx. 1.3 m, Weight: 75
g (incl. cable), Resolution: Humidity: ± 0.01 % RH, Temp.: ±
0.01 °C, TEWL: 0.1 g/h/m²
Operating
conditions: T:
10-40° C, RH: 30-70 % RH
Specified
measurement conditions: 10° C to 40° C and TEWL-values lower
than 70 g/h/m²
TEWL: ± 10 % of the measured value plus ± 0.8 g/h/m² for RH ≥ 30 %;
± 1.3 g/h/m² for RH ≤ 30%
Temperature (T): ± 0.5 °C
Rel. humidity (RH): ± 1.5 % for RH between 30 % and 90 %, ± 2.5 %
for RH values outside this range
Probe Heater PR 100: Power supply: external 100-240
VAC, 47-63 Hz, DC 12V/4A, Dimensions: 10 x 11 x 10.5 cm, Weight: 470
g
Other Available
TEWL probes:
1.
Tewameter® TM Hex:
The ultimative TEWL
measurement with one head (NEW). The
Tewameter® TM Hex assesses the Transepidermal Water Loss (TEWL essential
component for the evaluation of the performing as a water barrier, the skin,
with a revolutionary accuracy and reproducibility. 30 sensors inside the probe
“see” temperature and relative humidity like a camera. The high amount of data
allows the user not only to highly accurately measure inside the probe but can
show results also for the areas right outside the probe, namely skin surface
and ambience above the probe. (Anon 2021)
Fig 14: Tewameter® TM Hex
2.
Tewameter® TM Nano: Ultra-Small
TEWL Measurement Probe for Special Skin Sites
With
its exceptional small measuring chamber (only 2 mm Ø), the Tewameter® TM Nano
allows to measure the Transepidermal Waterloss (TEWL) in g/h/m² on small, or
difficult to reach sites, e.g., nails, scalp with hair, lips, etc. (Anon 2021)
Fig 15: Tewameter® TM Nano
3.
Tewameter® Triple TM
330T: TEWL measurement probe with three flexible
measurement heads. Tewameter® Triple TM 330T The probe follows the
worldwide acknowledged open chamber measurement of the Tewameter®. It does so
by using two sets of sensors (temperature and relative humidity) inside the
hollow cylinder to indirectly measure the gradient of water evaporation from
the skin. A microprocessor analyses the values. It is very suitable device to
reduce the measuring time as with its three probe heads it supplies three
measurements at the same time. (Anon 2021)
Fig 16: Tewameter® Triple TM 330T
4. Invitro
Tewameter® VT 310: TEWL
measurement directly on Franz cells. A special
probe for the measurement of the TEWL, perfectly suited to fit on a Franz cell.
The probe emulates completely the upper part (donor chamber, standard is 15 mm
Ø, other sizes on request). A convenient way to study skin permeability and
dermal absorption necessary for safety & efficacy testing.(Anon 2021)
Fig 17: Invitro Tewameter® VT
310
5.
Tewitro® TW 24: TEWL
measurement on up to 24 cultured skin wells simultaneously. The Tewitro® TW 24 is the only device to
measure the water evaporation from cultured tissue sets (wells in a
plate with medium) in up to 24 wells simultaneously with the
worldwide most used “open chamber” measurement of the Tewameter®.
Fig 18: Tewitro® TW 24
C.
Intendometer IDM 800
Assessing Skin Mechanical Skin Properties from
a Different Angle
The
Indentometer IDM 800 is a quick, easy and economical tool to look at the skin
softness/stiffness. Probes with 3 different pin diameters (2, 3 and 5 mm Ø) are
available, suitable for various skin sites. The smaller the diameter, the
deeper the pin goes into the skin when using the same force as the contact area
with the skin is smaller. The Indentometer is connectable to the MPA systems.(Anon n.d.-k)
Fig 19: Intendometer IDM 800 (Anon n.d.-b, Anon n.d.-k)
D.
Skin-Glossymeter GL 200
Measuring
Gloss on Skin, lips and Hair
When
evaluating the effectiveness of skin care, hair care, and decorative cosmetics,
gloss measurement is crucial (lipsticks, make-up, etc.). Skin and hair should
have a luminous, natural sheen without looking greasy.(Anon 2022a)
Fig 20:Skin-Glossymeter GL 200 (Anon n.d.-i)
E.
Skin-Colorimeter CL 400
An
Economical Way to Look at Skin & Hair Colour
The
colour of the skin is specifically measured by the Colorimeter CL 400.It can be
applied to hair as well. Coordinates in the colour space are used to express
measurement values.
(Or
as RGB - red/green/blue) space L*a*b*(Anon n.d.-f)
Fig 21: Skin-Colorimeter CL 400 (Anon n.d.-f)
F.
Skin-Thermometer ST 500
Microcirculation
and Skin Temperature Evaluation A quick, simple, and affordable tool for
measuring skin temperature—which is a sign of the microcirculation of the
skin—is the Skin-Thermometer ST 500.
Fig 22: Skin-Thermometer ST 500 (Anon n.d.-d)
G.
Elastometer EM 25
Determination of Skin Aging with Elasticity Measurement EM 25
The elasticity measurement
probe with display and interpretation chart that is most frequently used
worldwide. The biological skin age (elasticity of the skin) is measured quickly
and easily by (Skin's resistance/firmness compared to its capacity to
return to its initial state) suction position). The outcome is presented as a
percentage, and a chart links the measurement to the age of a person.
Fig 23: Elastometer EM 25 (Anon n.d.-a)
PRINCIPLE-
The
principle is based on a mechanical deformation of the skin via the suction
method. A negative pressure is created in the device and the skin is drawn into
the 2 mm aperture of the probe. The device develops a negative pressure, which
draws the skin into the probe's 2 mm aperture. The skin is drawn into the
probe's aperture by the device's pressure, which is then released after a predetermined
amount of time.
Fig 24: Suction hand and released hand
A
non-contact optical measuring system inside the probe uses the Cutometer
principle to determine the penetration depth. The components of this optical
measuring system are a light source, a light receptor, and a light is projected
from the transmitter to the receptor by two prisms facing each other. The depth
of the skin's penetration affects light intensity. The skin's resilience to the
firmness of the negative pressure and its capacity to revert to its initial
position(elasticity) are shown in real-time as curves (penetration depth in
mm/time). The different forces of elastin and collagen in the skin are what
give human skin its typical shape of a curve. Elastin is in charge of the Cutometer
collagen vs elastin-flexibility of the skin whereas collagen’s main task is to
keep the skin in shape.
The
first, very straight part of the curve is shaped by the proportion of elastin
in the skin as it easy to displace and very flexible. Collagen has taken over
when skin starts to "creep" inside the probe. It is more durable and
better able to withstand mechanical force. As soon as the device's
pressure has stopped, the collagen begins to bring skin back to life returning
to its initial form. Consequently, in youthful skin with new collagen, the skin
immediately compared to older skin, it reverts to its original position more
closely. Finally, the eventual Elastin ensures that the skin heals
completely.
Fig
25: Elastometer typical curve collagen
vs elastin
Measurement
Parameters
The
user can adjust the MPA CTplus software's settings to suit various applications
(such as suction time, relaxation time, pressure/pressure rate, repetitions,
etc.). The programme enables the calculation of numerous fascinating
parameters from variousthe suction and recovery portions of the measurement
curve. The majority of measurements in the literature have been made using mode
1 (full suction then through total relaxation). Here a short overview:
R-Parameters
–
· R0: Uf
firmness/pliability mm (amplitude at the end of the suction phase)
· R1/R4: Skin's
capacity to return to its original state (remaining deformation in mm after
recovery)
· R2: (resistance to
mechanical force versus capacity for recovery) viscoelasticity in percent
· R3/R9/R10: Fatigue
effects in mm are evident for continuous suction/recovery circles.
· R5: net elasticity
in %: Ur/Ue = elastic part of the suction phase \svs.\simmediate recovery
during relaxation phase
· R6: Uv/Ue Portion
of the Curve's Viscoelasticity During the Suction Phase in %
· R7: Ur/Uf ratio of
the instantaneous recovery to the amplitude following suction in%
· R8: Ua Total
recovery in millimetres following the loss of pressure
Area
Parameters (F):
· F1: The region
above the curve when suction is occurring. There is less area the more elastic
the material.
· F2/F3/F4: "Skin
Fatigue"
Fig 26: Area parameters
Q-Parameters:
The
scientist Di Qu (Senior Research Scientist, R&D Skin Care, Amway
Corporation, Ada, Michigan, USA) created a set of parameters that display
intriguing correlations. The relationship between skin age and the curves'
elastic and viscous recovery
· Q0: Area of
maximum recovery
· Q1: Total recovery
(overall elasticity) - (QE + QR)/Q0
· Q2: Elastic
recovery - QE / Q0
· Q3: Viscoelastic
recovery - QR / Q0
Fig 27: Age and the elastic and viscous recovery of
the curves are correlated.
*From: D. Qu et al., Correlating Age and Quantifying
Product Efficacy on Human Skin Using Novel Viscoelastic Parameters.
Technical Data
Device: Dimensions: 24 x 20 x 7 cm,
Weight: approx. 2.2 kg, External power supply: 100-240 VAC/12VDC.
CONCLUSION
This review attempts to demonstrate the convenience that some basic or sophisticated
techniques often already applied to other purposes could provide for the quality monitoring of cosmetic products for
dermatological use in women. Due to the
significant contribution that the C+K
probe devices may make to the
cosmetic industry, they have drawn attention. The C+K probe family is
now being used in a completely new way thanks to this updated software, which
also includes several useful new capabilities. The technique most frequently used worldwide to measure capacitance-based
skin surface moisture, oiliness, activity
of the sebum glands, redness
and melanin measurements are useful for determining skin sensitivity, elasticity and biological age of the skin an
important tool for all kinds of skin and body care goods. One second is
all it takes to perform the quick and simple measurement. Most of the
measurement is done using a probe devices with an integrated measurement probe.
Cutometer® dual MPA 580 has an integrated multi probe adapter system and
can connect up to eleven C+K-probes. The devices are claimed to support
cosmetics, pharmaceuticals, raw materials, household/personal care products,
detergents, as well as food and food supplements. They are used as standard
instruments in efficacy testing across the globe. Women have softer skin as
compared to men. Thus many scientists provide new discoveries in dermatology
and cosmetology.
Acknowledgment
We
would like to express our sincere gratitude to the head of the
Phyto-formulation, Cosmetic, and Nano Drug Laboratory at the University
Institute of Pharmacy, Pt. Ravishankar Shukla University in Raipur,
Chhattisgarh, for their efforts in creating this manuscript.
Conflicts of Interest
The authors declare no conflict
of interest related to the submission of this manuscript and the manuscript is
approved for publication by all author.
References:
Anon. 2017. “Cm 825 - T.” 49(0):50829.
Anon. 2021. “T Ewl M.”
49(0):50829.
Anon. 2022a. “G l 2 0 0 -
M.” 50829.
Anon. 2022b. “Mx 18- A.”
50829.
Anon. n.d.-a. “Courage +
Khazaka Electronic, Köln - Elastometer EM 25 (E).”
Anon. n.d.-b. “Courage +
Khazaka Electronic, Köln - Indentometer IDM 800 (E).”
Anon. n.d.-c. “Courage +
Khazaka Electronic, Köln - Mexameter® MX 18 (E).”
Anon. n.d.-d. “Courage +
Khazaka Electronic, Köln - Skin-Thermometer ST 500 (E).”
Anon. n.d.-e. “Hanna
Instruments India.”
Anon. n.d.-f. “Skin
Colorimeter CL 400 - An Economical Way To Look | Medisa.”
Anon. n.d.-g. “Skin
Hydration Measurement by Dr Jonathan Crowther Via SpecialChem • Skinobs ,
Cosmetic Testing.”
Anon. n.d.-h. “Skin PH
Level - Balance | Skin Science, Skin Care Business, Organic Skin Care Routine.”
Anon. n.d.-i. “Skin Test
Institute - Services.”
Anon. n.d.-j. “Tewameter
TM 300.”
Anon. n.d.-k. “The
Indentometer, An Alternative Approach to Assess Skin Mechanical Properties by
Courage+Khazaka • Skinobs , Cosmetic Testing.”
Anon. n.d.-l.
“Wetenschappelijk Onderzoek - CK Technology - Skin Technology Devices.”
Courage+Khazaka
electronic GmbH. 2022. “Prospekt PH-Meter.” 49(0):50829.
Ctplus, M. P. A. 2022. “C
+ k M.” 1–2.
Does, What, It Measure,
The Cutometer, The Multiprobe Adaptor, The Measuring, Principle The,
Application The, and Microsoft Excel. 2017. “Mpa 580 - M.” 49(0):90–91.
S, S. 2022. “Sm 815 - D.”
50829.