AMA Laboratories, Inc.

Bringing Testing, Claims Substantiation and Marketing Together

Skin Moisturization and Hydration

Electroconductivity via Novameter – Nova® Dermal Phase Meter, Model DPM 9003 (NOVA Technology Corp., Gloucester, Mass.) is used to obtain measurements of skin surface impedance to determine electroconductivity of the treatment sites. This meter provides a relative measure of the retained water content of the skin as a function of the skin’s dielectric value. Skin impedance is recorded automatically when equilibrium is achieved.

Capacitance via Corneometer® – The Corneometer® (Courage and Khazaka Electronic GmbH, Köln, Germany) provides a method to reproducibly and accurately determine the hydration level of the skin surface. Analysis of moisture retention capacity of the skin is based on the dielectric constant of water and measured in the superficial layers of the stratum corneum (as deep as 10-20 µm to ensure that the measurement is not influenced by capillary blood vessels).

Skin Barrier Protection and Film Integrity

Transepidermal Water Loss (TEWL) via DermaLab Evaporimeter – Transepidermal Water Loss (TEWL), the low level of moisture that constantly transpires through the skin, is measured with a computerized Evaporimeter using the DermaLab System (cyberDERM, Inc. Cortex Technology, Penn.). A built-in A/D (analog-to-digital) converter streams data for analysis. A reduction in TEWL generally indicates proportionately high film (barrier) integrity and/or wound closure in wound healing studies.

Wrinkle Reduction, Skin Smoothness, Roughness, and Scaling

Surface Evaluation of Living Skin (SELS) via Visioscan® – Visioscan® (Courage + Khazaka Electronic GmbH) takes a direct image of the living skin non-invasively. The Visioscan software automatically calculates skin smoothness, skin roughness, scaliness and wrinkle parameters by creating a mathematical interpretation of skin surface topography. The measuring head contains a CCD-camera and two halogen lamps to evenly illuminate the measuring field on the skin. In the image, gray level distribution corresponds to different phenomena. (White pixels represent desquamation on the skin; dark pixels represent lines and wrinkles, etc.)

Skin Elasticity and Firmness

Cutometer® – A Cutometer® (Courage + Khazaka Electronic GmbH) is used to measure skin firmness and elasticity based on a suction method. The resistance of skin drawn into the probe by negative pressure (firmness) and its ability to return to its original position (elasticity) are displayed as curves. From these curves, measurement parameters for viscoelastic properties of skin are calculated.

Skin Sebum Content

Sebumeter SM 810 PC – A Sebumeter SM 810 PC (Courage + Khazaka Electronic GmbH) is used to obtain skin sebum measurements (skin surface lipids). To accomplish this, a special-purpose film within the cartridge measuring head is applied for 30 seconds to the relevant skin area. The cartridge is then inserted into the Sebumeter SM 810 PC to determine variations in film transparency, spectrophotometrically. The instrument presents the result as μg/cm2.

Skin Color Evaluations

Minolta Chromameter and IMS SmartProbe – This evaluation method is ideal for skin lightening/whitening/brightening studies as well as tan accelerator evaluations and erythema suppression (counter irritation, anti-inflammatory). Instrumental color measurements corroborate visual analysis. They are performed using a Minolta Chromameter, SmartProbe 400, IMS Inc. or the equivalent. The Minolta CR-200 Chromameter interfaced with a DP-100 Color Computer System (Minolta CR-200) detects subtle changes in color by a 3D profile of hue, value, and chroma. These characteristics are then translated into Munsell color coordinates (L*, a*, b*). Any increase in the L* values indicates lightening of the skin color. The a* values represent relative red-to-green changes, and b* values represent relative blue-to-yellow changes.

Skin Scaliness and Surface Debris

D-SQUAME™ skin sampling discs – Adhesive discs take the trial-and-error out of sampling cells of the superficial stratum corneum (top layer of skin). These crystal clear polymer discs provide the required rigidity and adhesion to uniformly sample a fixed area of skin surface. The discs give optimum visibility of adhering skin cells and allow staining by many histological preparations.

Itch Relief Testing

WEST-itch™ Esthesiometer – The Weinstein Enhanced Sensory Test™ (WEST) is used to evaluate the effectiveness of itch relief treatments. It enables In-Vivo evaluation of antipruritics on mild itch such as dry skin, winter itch, insect bites or fiber-induced itch. The WEST-itch™ esthesiometer induces a controlled, reliable itch stimulus, and In-Vivo itch intensity is rated by test subject using a continuous ten-point scale.

Skin Reflectance

The Skin-Glossymeter GL 200 – Gloss measurement is important in the efficacy testing of skin care, hair care and decorative cosmetics (lipsticks, make-up, etc.). The Skin-Glossymeter GL 200 (Courage + Khazaka Electronic GmbH) assesses the gloss of the skin surface by measuring reflectance. The probe measures both the portion of directly reflected light mirrored from the surface, which is related to the gloss and the scattered portion as well.

This is important because skin not only varies in structure and brightness, but also in color. With Diffuse Scattering Correction (DSC), these variations are taken into account and almost eliminated, making it easy to accurately compare gloss measurements across different skin types.