Prediction of chemical absorption into and through the skin from cosmetic and dermatological formulations.

Background: To date, risk assessment following topical exposure to cosmetic/dermatological formulations cannot be precisely evaluated.

Objectives: To provide a tool for optimization of active permeation into/through skin and for risk assessment.

Methods: A predictive model was developed for estimating the cumulative mass of a chemical absorbed into and across the skin from a cosmetic/dermatological formulation.

Human percutaneous absorption of a direct hair dye comparing in vitro and in vivo results: implications for safety assessment and animal testing.

Although in vitro skin absorption studies often detect small residues of applied test material in the epidermis/dermis, it is uncertain whether the residue is within the living skin. We studied the dermal absorption of a hair dye hydroxyanthraquinone-aminopropyl methyl morpholinium methosulphate (HAM) in human skin in vivo and in vitro. In vivo, skin (back and scalp) received 0.

Improvement of the experimental setup for skin absorption screening studies with reconstructed skin EPISKIN.

Percutaneous penetration studies are usually performed in human skin samples set up in a Franz cell device. The ability to perform these studies may depend on the availability of skin samples. Reconstructed skin models are an interesting alternative to overcome such limitations but are less easily mounted in diffusion cell devices.

Grey goo on the skin? Nanotechnology, cosmetic and sunscreen safety.

Many modern cosmetic or sunscreen products contain nano-sized components. Nanoemulsions are transparent and have unique tactile and texture properties; nanocapsule, nanosome, noisome, or liposome formulations contain small vesicles (range: 50 to 5000 nm) consisting of traditional cosmetic materials that protect light-or oxygen-sensitive cosmetic ingredients. Transdermal delivery and cosmetic research suggests that vesicle materials may penetrate the stratum corneum (SC) of the human skin, but not into living skin.

Organization of stratum corneum lipids in relation to permeability: influence of sodium lauryl sulfate and preheating.

The role of the structural organization of intercorneocyte lipids in the barrier function of human stratum corneum was evaluated by treatment with heat and sodium lauryl sulfate. Measurement of transepidermal water loss in treated samples was used to quantify variations in stratum corneum permeability. Thermodynamic transition of lamellar lipids and their degree of organization were evaluated by differential scanning calorimetry and small-angle X-ray diffraction, respectively.