Hydrating effects of moisturizer active compounds incorporated into hydrogels: in vivo assessment and comparison between devices.
BACKGROUND
Water is an important factor on the appearance and function of the skin and, when dehydrated, it becomes rough and flaky. The measurement of stratum corneum hydration is widely employed to verify the moisture effect of topical products.


OBJECTIVE
This study has evaluated in vivo the stratum corneum hydration, by the electrical measurements of skin, after treatment with different moisturizers presented in gel base. MoistureMeter and Corneometer were used as bio-instruments. Urea, the herbal extract (Imperata cylindrical), the NMF components and the carbohydrate derivate compound (xylityglucoside, anhydroxylitol, and xylitol) were used as the active substances.


METHODS
The study protocol was carried out according to the three-factor factorial design. The gels were applied on both forearms of eight female volunteers. However, each volunteer had one untreated skin area as the skin moisture control. The electrical capacitance of the skin was measured by both instruments in different times: after application (0 time), 30, 60, 120, 240 and 360 min.


RESULTS
Gel base, gel containing herbal extract, and gel containing NMF components statistically have equal moisture effect measurements, according to both bio-instruments. However, the values obtained for urea, carbohydrate derivate compound, and untreated skin (control) have statically different results in both devices.


CONCLUSIONS
The gel containing urea and the carbohydrate derivate compound gel have promoted the most intense moisture effect compared with the other formulations. The measurements of hydration between the devices generated different absolute values; however, the statistical analysis has shown similar precision among the measurements.
Leite e Silva
Vânia Rodrigues
VR
Department of Pharmacy, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil.
Schulman
Marcelo Ariel
MA
Ferelli
Cibeli
C
Gimenis
Janine Mailho
JM
Ruas
Gabriele Wander
GW
Baby
André Rolim
AR
Velasco
Maria Valéria Robles
MV
Taqueda
Maria Elena
ME
Kaneko
Telma Mary
TM
D000279:Administration, Cutaneous; D000328:Adult; D000704:Analysis of Variance; D001834:Body Water / Q000187:drug effects; D002626:Chemistry, Pharmaceutical; D016001:Confidence Intervals; D025802:Electric Capacitance; D055664:Electrochemical Techniques / Q000379:methods*; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005542:Forearm; D005712:Galvanic Skin Response; D006801:Humans; D020100:Hydrogels / Q000378:metabolism / Q000494:pharmacology*; D011336:Probability; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D012869:Skin Absorption / Q000187:drug effects* / Q000502:physiology; D055815:Young Adult
D020100:Hydrogels