Home Facilities Facility Service of Dermocosmetic Assesment
Services

 

The Skin Absorption group deals with the knowledge and quantitation of the skin absorption of a given compound topically applied. Using an in vitro methodology officially adopted by the OECD (2004), the distribution of a chemical in the different skin compartments (stratum corneum, epidermis and dermis) can be detected and quantified.

 
Test methodologies

A percutaneous absorption protocol depends on a number of experimental factors such as exposure time, presence or absence of occlusion, formulation type and frequency of use. 


Some tests are:

Conventional in vitro tests using porcine or human skin (exposure time: 24h).

Conventional compartment kinetics (stratum corneum, epidermis, dermis and receptor fluid) of a compound or a cosmeto‐textile topically applied.

In vitro compartmental distribution of a topically applied compound or cosmeto‐textile.

Skin penetration kinetics (receptor fluid) of a topically applied compound or cosmeto‐textile.

Simulation of the percutaneous absorption using in vitro skin previously modified ("stripping", solvents or SLS).

The behaviour of impaired skin (psoriatic, eczematous) during the percutaneous absorption may be simulated.

Dermatopharmacokinetic tests using the in vivo stripping technique as a bioequivalence approach for topically applied compounds.

In vitro release test through different synthetic membranes using FDA Guidelines. 

 

The Skin Efficacy group deals with the experimental design, evaluation and objective diagnostic of the skin efficacy and tolerance of cosmetic and dermatologic formulations topically applied by the use of non-invasive biophysical techniques. Evaluation and diagnosis of other keratinized tissues such as human nails are also evaluated. 

  

Test methodologies

In vivo skin efficacy

Studies are conducted with Caucasian panellists with skin phototype III-IV in a conditioned room at 22ºC and 50% RH. Some of these protocols are also used on nails.

Hydration capacity of skin or nails due to topically applied formulations (Corneometer).
Water Sorption-Desorption test on skin (Corneometer).
Barrier Function of skin and/or nails (Tewameter).Protection capacity of the barrier function of skin and/or nails in front of surfactants, solvents or stripping (Tewameter, Corneometer).
 
Repair capacity of damaged skin or nails in front of surfactants, solvents or stripping (Tewameter, Corneometer).

Melanin typology assesment and erythema detection (Mexameter).

Firming effect on skin elasticity (Cutometer).
 
Assessment of skin surface pH (Skin-pHmeter).

Determination of fat content of the skin (Sebumeter).
 
Assessment of skin surface topography with silicon resin (Visioline)
 

In vitro skin efficacy 

Separation, extraction and lipid analysis of epidermis and dermis (TLC-FID).
 
Antioxidant effect of cosmetics on skin, by an “ex vivo” test on skin lipoperoxidation (TBARS).

Degradative treatments of nails: acetone, hydration/dehydration cycles.

Absorption/desorption kinetics to determine the permeability of stratum corneum and/or nails (DVS). Servicio de Ánalisis Térmico (SAT)

Skin Eficacy TARIFF (2017) 

 

The Hair Efficacy group deals with the experimental design and evaluation  of the in vitro efficacy of cosmetic formulations applied to the hair.

 

Test methodologies

Degradative treatments of hair, permanent, bleaching, relaxed, UV photodegradation, etc.

Extraction and analysis of hair lipids (TLC/FID).

Surface hidrophobicity/hydrophilicity. Contact angle determination (electrobalance KSV Sigma 70).

Moisture content. Thermogravimetric analysis (TGA TG-50). Servicio de Ánalisis Térmico (SAT)

Absorption/desorption kinetics (DVS) to determine hair permeability (Thermobalance TA ). Servicio de Ánalisis Térmico (SAT)

Thermotropic evaluation with Differential Scanning Calorimetry (DSC) to determine thermal stability of hair’s major morphological components (DSC-821). Servicio de Ánalisi Térmico (SAT)

Mechanical properties of human hair such as elasticity, extension and energy at break, etc. (Dinamometer Instron 5500R).

Capilar surface visualization by Scanning Electron Microscopy (SEM) in collaboration with the Service of Microscopy of the Barcelona University (UB). 

Colour determination (Color-Eye 3000 Macbeth).

Protein degradation after UV irradiation (colorimetric Bradford Test).

Free radical evaluation formed in the oxidative process (Electronic Paramagnetic Resonance Spectrometer (EPR) EMX-Plus 10/12 Bruker BioSpin). Magnetic Resonance Service

Hair Lipid peroxidation. Malonilaldehide content determination using barbituric acid test (TBARS).

Hair gloss evaluation (Glossmeter Micor-TRI-gloss).

Tryptophan degradation (Spectrofluerimetric assess).