External lipid function in ethnic hairs.

Objective: The main aim of this study is to characterize the external lipids of different ethnic hairs and to study the contribution of the exogenous lipids on their physicochemical properties.

Methods: On the extraction procedure, sebaceous lipids from the exterior of the fiber are removed. The influence of those free lipids on the hair properties, such as contact angle, mechanical characteristics, and sorption of water, will be evaluated to determine permeation characteristics of the keratin fibers.

Caffeine delivery in porcine skin: a confocal Raman study.

Confocal Raman microscopy is a novel optical method for studies of pro-drug and drug delivery. This method is a promising technique that enables non-destructive measurement of the permeation profile through skin layers. Peaks of compounds are usually normalised to skin peaks (amino-acid and amide I) for semi-quantitative evaluation.

In vitro penetration through the skin layers of topically applied glucocorticoids.

Corticoids are actives widely used in the treatment of skin diseases. This work aims to study the penetration of 3 corticoids (betamethasone, clobetasol, and flurandrenolide), their relationship with their Log D values and the effects of the vehicles. The 3 compounds were applied on a Franz-type diffusion cell in propylene glycol solution and their respective commercial creams and ointments.

Skin permeation and antioxidant efficacy of topically applied resveratrol.

The permeation of resveratrol was assessed by in vitro and in vivo experiments 24 h after topical administration. The in vitro profile of resveratrol was assessed by Raman spectroscopy. Human skin permeation was analysed in vivo by the tape stripping method with the progressive removal of the stratum corneum layers using adhesive tape strips.

Skin penetration and antioxidant effect of cosmeto-textiles with gallic acid.

In this work, the antioxidant gallic acid (GA) has been encapsulated in microspheres prepared with poly-ε-caprolactone (PCL) and incorporated into polyamide (PA) obtaining the cosmeto-textile. The topical application of the cosmeto-textile provides a reservoir effect in the skin delivery of GA. The close contact of the cosmeto-textile, containing microsphere-encapsulated GA (ME-GA), with the skin and their corresponding occlusion, may be the main reasons that explain the crossing of active principle (GA) through the skin barrier, located in the stratum corneum, and its penetration into the different compartments of the skin, epidermis and dermis.

The influence of hair lipids in ethnic hair properties.

Objective: Biochemical studies have mainly focused on the composition of hair. African hair exhibited lower moisturization and less radial swelling when flushing with water compared with Asian or Caucasian hair, and they assumed a possible lipid differentiation among human populations. This study consists in the lipid characterization of different ethnic hairs (Caucasian, Asian and African hairs) and the influence of these lipids in different hair properties such as humidity and mechanical properties.

Skin delivery of antioxidant surfactants based on gallic acid and hydroxytyrosol.

Objectives: The aim of this study has been to investigate the dermal absorption profile of the antioxidant compounds gallic acid and hydroxytyrosol as well as their derivatives, hexanoate (hexyl gallate and hydroxytyrosol hexanoate) and octanoate (octyl gallate and octanoate derivative) alkyl esters (antioxidant surfactants). Previously, the scavenging capacity of these compounds, expressed as efficient dose ED50, has also determined.

Methods: The percutaneous absorption of these compounds was obtained by an in vitro methodology using porcine skin biopsies on Franz static diffusion cells.

Cosmetotextiles with gallic Acid: skin reservoir effect.

The antioxidant gallic acid (GA) has been incorporated into cotton (CO) and polyamide (PA) through two different vehicles, that is, liposomes and mixed micelles, and their respective absorption/desorption processes have been studied. Moreover, in vitro percutaneous absorption tests of different cosmetotextiles have been performed to demonstrate antioxidant penetration within the layers of the skin. When GA was embedded into the cosmetotextiles, it always promoted a reservoir effect that was much more marked than that observed for polyamide.

Antioxidant cosmeto-textiles: skin assessment.

Resveratrol, a natural product, has been reported to have antioxidant activities such as the scavenging of free radicals. This compound could be used in the dermocosmetic field to protect the skin from oxidative stress. In this work, the percutaneous profile of resveratrol in ethanol solutions through pig skin was determinated by an in vitro methodology.

Damaged hair retrieval with ceramide-rich liposomes.

Lipids from human hair consist mainly of cholesterol esters, free fatty acids, cholesterol, ceramides, and cholesterol sulfate. They are structured as lipid bilayers in the cell membrane complex (CMC) and make a large contribution to diffusion, cell cohesion, and mechanical strength. The loss of these lipids could impair the integrity of the hair, leading to deterioration in its tensile properties.