Aim, Methods and Materials – Moisturizing and Purifying activity – IN&OUT DETOX®
AIM OF THE STUDY
In this research, non-invasive techniques were used to evaluate the normalizing effects on the seborrheic skin of a cosmetic product for the face.
MATERIALS AND METHODS
IN&OUT DETOX® :
Polyglycerin-6, Propanediol, Solanum Melongena (Eggplant) Fruit Extract, Bioflavonoids (Nobiletin), Brassica Oleracea Italica Fruit Extract. In this experimentation the active was used at 2% in a detergent with the following INCI formula: Aqua, Sodium Myreth Sulfate, Glycerin, Cocamidopropyl Hydroxysultaine, Steareth-10 Allyl Ether Acrylates Copolymer, Phenoxyethanol, Decyl Glucoside, Benzyl Alcohol, Sodium Hydroxide, Tetrasodium Glutamate Diacetate, Hydrolyzed Wheat Protein.
SELECTION OF VOLUNTEERS
For this study a standard female sample was selected with the following inclusion criteria: age between 20-40 years, with normal skin impure tenderness, good state of health, absence of skin diseases, absence of topical pharmacological treatments or systems in place, a negative history of atopy and DAC.
The exclusion criteria were: pregnant and lactating women, minors. All subjects were informed about the study procedures and signed an informed consent.
The effectiveness of the product has been evaluated:
A) instrumentally measuring the degree of hydration, of sebum through the sensors of a Multiprobe Adapter System MPA5 of Courage & Khazaka Electronic GmbH (Cologne, Germany); the degree of skin desquamation through the Corneofix F20 (Courage & Khazaka Electronic GmbH, Cologne, Germany);
B) subjectively through dermatological clinical examination to evaluate the safety parameters after application of the product.
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 evaluation of the moisturizing capacity of the products. It allows the measurement of skin hydration by means of capacitance measurements between the stratum corneum and the probe 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 sebometric index was evaluated using the sebumeter method which for over 25 years has been the most widely used method for determining the level of sebum of the cutaneous surface as well as of the scalp is accurate and reproducible. It consists of a direct measurement of the level of lipids present on the surface of the skin. The principle of the method used is photometric. A special opaque tape, in a special cartridge applicator, rests on a delimited area of the skin surface, from which it absorbs the superficial sebum and becomes all the more transparent the more abundant the sebum is. The tape is then inserted into a photocell instrument: a light beam is passed through the tape, reflected on the mirror placed in the cartridge on the back of the tape and is picked up by the receiving probe. The intensity of the radius will be greater the more transparent the tape and therefore the amount of sebum absorbed. The data are displayed on computers and are expressed in micrograms of sebum / cm2 and derive from a comparison between the initial transparency of the tape (measured before contact with the skin) and the values after application on the skin. A strip section of 64 mm² is used for each measurement. A trigger located on one side of the tape cassette allows access to a new measurement. The used ribbon is rewound in the cassette. The life of the cassette is around 450 measurements. For reasons of hygiene, when the tape is applied in its entirety, only the cassette is replaced.
The values found can be very different depending on the area of the face, and in general they are higher in the so-called “T zone” which includes the forehead, nose and chin, more rich in sebaceous glands. The lateral areas of the face (high and low cheekbones, cheek and external eye contour), less rich in sebaceous glands and less induced by hormonal stimuli secrete less sebum and have lower sebometric values.
Evaluation of the desquamation index
The scaling degree of scalp was measured using CORNEOFIX F20. The Corneofix F20 (Courage & Khazaka Electronic GmbH, Cologne, Germany) is a transparent adhesive tape, which is pressed on the surface of the skin with a light pressure for 5 seconds. Pressing with the thumb the corneocytes present in the desquamating lesion adhere to the tape so that it is possible to analyze the number and the dimensions of the scales. These strips were subsequently analyzed with the VISIOSCAN® VC 98 chamber which, by analyzing the light absorbed differently depending on the number and thickness of the corneocytes, will create digital images with corresponding dark pixels with variable gray values. The entire image and the measured parameters are automatically saved.
The most important parameters obtainable with this technique are:
PA – Percentage area (the percentage of total surface covered by adherent corneocytes);
Area in mm2 (the total area covered by adherent corneocytes expressed in mm2);
DI – Desquamation index (which is calculated from the distribution of the different corneocytes for five categories). The Visioscan was calibrated before each measurement.
The study was performed in single-blind mode without control or placebo. The moisturizing effectiveness was evaluated in the Short Term Test lasting 4 hours. The area used for the test was, randomly for the side, the forehead for biometric measurements and the mandibular angle for corneometric and skin desquamation measurements. Clinical-instrumental evaluations were performed at time t0 (baseline value) and after 1 hour (t1h) and 4 hours (t4h).
Before the measurements the subjects remained for 30 minutes in the medical clinic, to acclimatize the skin to the temperature and humidity of the air-conditioned room in which the tests were carried out. After the basal values were detected, the product was applied. At each study time a dermatological examination was performed to evaluate any side effects.
The hydration index was obtained through 4 measurements performed along the mandibular angle. In each study period, if, after the acclimatization phase, at least 2 very different hydration values were observed (greater than ± 5 corneometric units), more time was expected before proceeding with the evaluation. The sebometric and desquamation index were performed with a single measure.
For the evaluation of tolerability all undesirable local events, immediate or delayed, occurred during the study, evaluating their severity, time of onset, duration and possible relationship with the treatment.
All results were compared, with baseline measurement at any time, using Student’s ttest for paired data or a non-parametric test (Wilcoxon signed rank test) when the difference in averages did not show the characters of normalcy verified using the Shapiro-Wilk test.
The 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 basal (difference and percentage value).