Aim, materials and methods – Depigmentation Activity – PG6 active AA-BET C ®
The tested product is an active product, called PG6 ACTIVE AA- BETC ®. The raw material was tested at 2% in a cream with the following INCI: Aqua, Paraffinum Liquidum, Glyceryl Stearate, Cetearyl Alcohol, Glycerin, Cetyl Alcohol, Polyglyceryl-6 Azelaiate Betaine, Ceteareth -20, Phenoxyethanol, Dimethicone, Stearamidopropyl Dimethylamine, Citric Acid, Sodium Dehydroacetate, Benzoic Acid, Lecithin, Dehydroacetic Acid, Ethylhexylglycerin, Tocopherol, Ascorbyl Palmitate.
For this study, female volunteers, aged between 30 and 50, were enrolled, with hyperpigmentation spots such as pregnancy and non-chloasma, age spots and
accumulations of melanin caused by photo damage to the skin and post-inflammatory hyperchromic spots. All the volunteers had the following characteristics: good state of health, absence of cutaneous pathologies and topical or systemic pharmacological treatments in place, negative history for atopy and DAC. The following have been excluded: pregnant or lactating women and minors. Each subject, informed of the modalities of the test, signed a written consent before the treatment.
It was a single-blind study where 15 volunteers applied facial cream twice daily, in the morning and in the evening, as usual facial lightening treatment, for a total of 30 days.
At the time of inclusion (t0), after 15 (t15d), 30 (t30d) days the cutaneous status of the volunteers was assessed through:
a) COLORIMETRIC MEASUREMENT performed instrumentally, as colorimetric index M, using the Mexameter MX16 of Courage & Khazaka Electronic GmbH (Cologne, Germany).
This probe has a hole of about 4 mm in diameter. For each volunteer, 4 measurements were made with a circular pattern always on the same spot expressed in units of me lanina (parameter M) where the minimum value corresponds to 500.
The principle of measurement of skin color is based on a light source, with three specific wavelengths, whose radiation is absorbed by the skin and diffusely reflected. A sensor analyzes the reflection spread by the skin: the more the skin is rich in melanin, the more the M value is increased. As a consequence, it is possible to evaluate the lightening effect before and after a topical application with the measurement of the value of melanin. The probe itself is used as well as to quantify the degree of skin tanning also to determine the reddening of the skin (erythema)
b) SUBJECTIVE DERMATOLOGICAL CLINICAL EXAMINATION using the Scaling Severity Score (SSS) for the evaluation of the degree of pigmentation of the spots hyperchromics present on the face according to a scale of 5 degrees (0 = absent, 1 = mild, 2 = medium, 3 = relevant, 4 = noticeable).
c) PSYCHORHEOLOGICAL TEST – At the end of the experimentation, all the volunteers of each group responded to a test psychoreological to evaluate the cosmetic properties and the action on the skin of the product used. The score on, for each question, was graded as: “for nothing”, “poor”, “indifferent”, “quite” and “very”.
All results were compared, with baseline measurement at every time, using the Student’s t test for paired data or a non-parametric test (Wilcoxon signed rank test) when the difference in the averages did not present 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. In particular: p <0.05 (*) = significant, p <0.01 (**) = very significant 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).