Materials and Methods – Efficacy in dermatitis treament – MULTI FEEL
The tested product, called MULTI FEEL®, was added to 2% in a cream. The active has the following INCI: Polyglycerin-6, Aqua, Propanediol, Centella Asiatica Leaf Extract, Scutellaria Baicalensis Root Extract, Hylocereus Undatus Fruit Extract, Camellia Sinensis Leaf Extract, Glycyrrhiza Glabra Root Extract, Berberis Vulgaris Root Extract, Rosmarinus Officinalis Leaf Extract
The cream tested has the following INCI: AQUA, CAPRYLIC / CAPRIC TRIGLYCERIDES, ETHYL HEXYL STEARATE, GLYCERYL STEARATE, CETEARYL ALCOHOL, GLYCERIN, CETYL ALCOHOL, CETEARETH-20, PHENOXYETHANOL, DIMETHICONE, CITRIC ACID, SODIUM DEHYDROACETATE, BENZOICACID, LECITHIN, ETHYLHEXYLGLYCERIN , TOCOPHEROL, ASCORBYL PALMITATE.
SELECTION OF VOLUNTEERS
For this study, 20 female and / or male subjects were selected with irritative dermatitis of the hands caused by external agents or hyper-use of water.
All volunteers had to have the following inclusion and exclusion criteria: age between 20 and 50, good state of health, absence of skin diseases, absence of topical or systemic pharmacological treatments in progress, and a negative history of DAC. Were excluded: pregnant women, nursing mothers and minors.
Each volunteer was given a form by completing and signing which he gave free consent to the test and stated that he was not in any of the exclusion conditions from the test.
The effectiveness in improving irritated skin was assessed instrumentally by measuring the degree of hydration, evaporimetry and colorimetry through the sensors of a Multiprobe Adapter System MPA5 of Courage & Khazaka Electronic GmbH (Cologne, Germany).
Evaluation of the skin hydration index
Measurement of skin hydration was assessed using the internationally recognized Corneometer method. The measurement is based on the evaluation of the dielectric constant of the water. The measuring probe shows changes in the water content of the sample to be measured. A diffuse electric field, generated by the probe head, penetrates the first layers of the skin and determines the dielectricity.
In particular, the CORNEOMETER® CM825 (Courage + Khazaka, electronic GmbH) has been used for the instrumental assessment of the moisturizing capacity of the products.
It allows the measurement of skin hydration by means of capacitance measurements between the horny layer and the sensor probe of the device. By pressing the front surface of the sensor on the skin, a number appears on the computer monitor: this number is related to the level of hydration on the skin surface. The measurement was performed on a cutaneous area, as flat as possible, taking care to exert a constant pressure for a time set by the instrument itself. The sensor has been kept clean from time to time. A healthy skin in conditions of about 20 ° C of temperature and about 40-60% of environmental humidity should, in the monitored region, have a hydration index> 45.
The water evaporation index from the epidermis (TEWL) of the treated skin area was measured using the TEWAMETER® TM300. The skin constantly loses water in the form of steam and TEWL is the most important parameter to evaluate the efficiency of the water barrier function of the skin. The measurement of water evaporation is based on the principle of diffusion in an open chamber and the physical basis of measurement is the law of diffusion discovered by Adolf Fick in 1855. This tool allows to evaluate the flow of water vapor through a specific unit of surface by changes in water concentration and temperature in the atmosphere near the stratum corneum. The measuring probe is a shallow cylinder (diameter 10 mm and 20 mm length) in order to minimize the influences due to air turbulence inside the probe. It consists of two pairs of sensors that measure humidity and temperature gradients in two different distances. After detecting the resulting humidity and temperature gradients, the TEWL is automatically calculated and shown on the computer monitor.
The effect on the redness reduction was assessed using the Mexameter MX 18 probe (Courage + Khazaka Electronic GmbH). This probe has a hole of about 4 mm in diameter. Four measurements were taken, at the corners of an area bounded with tape, for each volunteer expressed in units of hemoglobin (parameter E) where the minimum value corresponds to 500. The principle of measurement of skin reddening is based on a source of light, with three specific wavelengths, whose radiation is absorbed by the skin and diffusely reflected. A sensor analyzes the reflection diffused by the skin. If the skin is well vascularized, the hemoglobin value is also increased. As a result, stimulation of microcirculation can be assessed before and after topical application with hemoglobin measurement. The probe itself is used as well as to quantify the reddening of the skin (erythema) also to determine the degree of tanning of the skin (melanin).
An in vivo blind, single blind trial has been carried out. 2% cream was applied according to its characteristics of use, twice a day on irritated skin. Its effectiveness was assessed in both Short and Long Term Test lasting 14 days. The area used for the test was the dorsal region of the hand at the metacarpal or digital level. The corneometric measurements were four around a point marked with a dermographic pen. TEWL and colorimetry was evaluated with a single measurement at the center of the study area. Before the measurements all the volunteers remained for 30 minutes at rest in the clinic, to acclimatize the skin to the temperature and humidity of the air-conditioned room in which the tests were carried out.
The instrumental evaluations were made at the time t0 (value baseline), after 60 minutes (t1h) in the Short Term Test and after 7 days (t7d) and 14 days (t14d) of continued application of the product in the Long Term Test. Before the t0 each volunteer was asked not to cleanse the hand, for at least 3 hours before the
experiment. After this period the baseline values of corneometry were measured. If, after the acclimatization phase, at least two very different hydration values were observed (greater than ± 5 corneometric units), more time was expected before proceeding with instrumental evaluations. The volunteers who even after this precaution still showed differences in constant reading and above ± 5 u.c., were discarded.
Following the hydration measurements, the cutometric and vaporimetric measurements were carried out. After the basal hydration values were measured, colorimetry and TEWL was the product for the Short Term Test. At the end of the Short Term Test the cremai was delivered for the Long Term Test.
For the evaluation of tolerability were registered all the undesirable local events, immediate or delayed, occurred during the study, evaluating its severity, onset time, duration and possible relationship with the treatment.
All results were compared, with baseline measurement at each time, using the Student test for paired data or with a non-parametric test (Wilcoxon signed rank test) when the difference in averages did not present the characters of normality verified using the Shapiro-Wilk test. The same parametric techniques were used for group comparison. Results were considered significant if p <0.05 (95% Confidence Level) and were calculated using a Microsoft® Excel spreadsheet. All data were presented as mean ± standard deviation and in addition to the measured value they were also reported as differences vs. baseline (difference and percentage value).