In Vitro Depigmentation & Skin Lightening Analysis
RHPE — Reconstructed Human Pigmented Epidermis
Evaluate the efficacy of depigmenting and whitening active ingredients using validated 3D human pigmented skin models. Quantitative, reproducible results that support cosmetic claims and accelerate your product development.
Phototype II
Phototype IV
Phototype VI
The RHPE Skin Model
The Reconstructed Human Pigmented Epidermis (RHPE) is a 3D tissue model cultivated at the air-liquid interface in chemically defined medium. Normal human keratinocytes are cultured in the presence of melanocytes, forming fully differentiated epidermal tissue that faithfully reproduces the pigmentation characteristics of human skin.
3D co-culture of keratinocytes and melanocytes at the air-liquid interface
Available in 3 phototypes (II, IV, VI) representing different skin tones
Chemically defined medium — no animal-derived components
Fully differentiated epidermis with functional melanin units
Validated for depigmentation and pigmentation modulation assays
Quantitative endpoints: colorimetry (CIELab), UV-Vis reflectance, melanin extraction
Download the EPISKIN RHPE Data Sheet
Download PDF
Available Phototypes
Phototype II
Light skin — ideal for evaluating skin brightening in fair complexions
Phototype IV
Medium skin — the most versatile model for general depigmentation studies
Phototype VI
Dark skin — suited for evaluating strong whitening agents and ethnic-specific formulations
Depigmentation Analysis Services
Six specialized services for comprehensive evaluation of depigmenting and skin lightening active ingredients using the RHPE model.
Skin Lightening Assessment
Quantitative evaluation of depigmenting effect by instrumental colorimetry (CIELab). Measures L* (lightness), a* (red-green), b* (yellow-blue) and ITA° (Individual Typology Angle) parameters under D65 illuminant.
Technique
Colorimetry (CIELab / ITA°)
Endpoints
- L* (lightness)
- a* (red-green axis)
- b* (yellow-blue axis)
- ITA° (Individual Typology Angle)
Claims Supported
Melanin Index Quantification
Non-destructive quantification of melanin content by UV-Vis reflectance spectrophotometry in the 400–800 nm range. Provides Melanin Index (MI) for objective comparison between treated and control tissues.
Technique
UV-Vis Reflectance Spectrophotometry (400–800 nm)
Endpoints
- Melanin Index (MI)
- Reflectance spectra (400–800 nm)
Claims Supported
Absolute Melanin Quantification
Destructive extraction of total melanin from the epidermal tissue followed by spectrophotometric dosage. Quantifies absolute melanin content (µg/tissue) for definitive efficacy assessment.
Technique
Melanin Extraction + Spectrophotometric Dosage
Endpoints
- Total melanin content (µg/tissue)
- Melanin reduction (%)
Claims Supported
Dose-Response Depigmenting Efficacy
Evaluation of the product at 3 concentrations to establish a dose-response relationship. Determines optimal concentration and therapeutic window for the depigmenting active ingredient.
Technique
Multi-concentration colorimetric analysis
Endpoints
- Dose-response curve
- EC50 estimation
- Optimal concentration range
Claims Supported
Mechanism-Specific Depigmentation Study
Investigation of the depigmentation mechanism by tyrosinase activity assay (DOPA oxidation) combined with histological analysis of melanosome distribution (Fontana-Masson staining). Differentiates between tyrosinase inhibition and melanosome transfer disruption.
Technique
Tyrosinase assay (DOPA) + Fontana-Masson histology
Endpoints
- Tyrosinase activity (%)
- Melanosome distribution score
- Mechanism classification
Claims Supported
Complete In Vitro Depigmentation Study
Comprehensive package combining all analytical endpoints: CIELab colorimetry, UV-Vis melanin index, absolute melanin quantification, dose-response at 3 concentrations, and mechanism of action study. Provides a complete scientific dossier for regulatory submission and marketing claims.
Technique
Combined multi-technique protocol
Endpoints
- All endpoints from COS-101 to COS-105
- Integrated scientific report
- Statistical analysis (ANOVA)
Claims Supported
Technical Specifications
Ready to Evaluate Your Depigmenting Active?
Our team of experts will design a customized in vitro study using the RHPE model to generate the scientific evidence your product needs. From single-endpoint screening to comprehensive efficacy dossiers.