Corneometiy measurements to evaluate skin dryness in the modified soap chamber test.
OBJECTIVE
Patch test procedures have been developed to compare the irritation potential of surfactant-based products. Skin changes due to product application are usually assessed visually by a trained evaluator using standard scoring scales or instrumentally. This study has been carried out to optimize the assessment of skin dryness in the Modified Soap Chamber Test both by visual scoring and Comeometer measurement, with transepidermal water loss as an additional measure.


METHODS
Products were applied, under occlusion, to the skin, for 2 successive periods of 24 and 21 h; skin reactions were evaluated 3 h after removal of each series of patches, and followed up to 7 days after patches had been removed.


RESULTS
Skin dryness progressively develops after patch removal, and reaches a maximum 3 to 5 days later. Capacitance measurements correlate the best with visual scoring of dryness when waiting 5 days after patch removal before assessment.


CONCLUSIONS
Comeometer is an useful instrument to quantify observed dryness only when transepidermal water loss has recovered a value close to its baseline value. For both visual and instrumental assessments of skin dryness, waiting 3 to 5 days after patch removal in the Modified Soap Chamber Test will provide the most valuable results.
Colgate-Palmolive R&D, Inc., Liege, BelgiumColgate-Palmolive Technology Center, Piscataway, NJ, USA.
M
M
Paye
Colgate-Palmolive R&D, Inc., Liege, BelgiumColgate-Palmolive Technology Center, Piscataway, NJ, USA.
D
D
Van de Gaer
Colgate-Palmolive R&D, Inc., Liege, BelgiumColgate-Palmolive Technology Center, Piscataway, NJ, USA.
B M
BM
Morrison
Comeometer; Soap chamber test; capacitance; dryness; skin