Challenging The Personal Cleanser Paradigm

Keith Ertel, PhD; Heather Focht, BChE; Janyl Plante, MS; Robert Bacon, BS; Amanda Newman, BS;

The Procter & Gamble Company, Cincinnati, OH

Introduction

Personal cleansing products are a useful adjuvant in dermatologic therapy, not only as an aid to removing dirt and other soils from the skin's surface but also by helping to maintain or increase patients' confidence and sense of wellbeing. Personal cleansers are generally viewed as agents that can dry or irritate skin and disrupt the stratum corneum barrier. To minimize such effects patients are recommended to use cleansers based on synthetic detergents (syndets). A leave-on lotion is frequently added to this recommendation to help relieve dry skin. Personal cleanser technology has advanced in recent years and evidence suggests that newer personal cleanser forms such as petrolatumdepositing body washes might provide skin benefits beyond simple cleansing and dry skin improvement.1 

Objective

To assess the potential for a next generation, high-depositing petrolatum-containing body wash to effect clinical improvement in skin condition and its potential to impact consumers' perceptions of their skin condition under in-use conditions. 

Methods

Clinical Effects

• A randomized Latin square design was used to compare a high-depositing petrolatum-containing body wash (HDPCBW), a regimen comprising a regular body wash (RBW) followed by a dermatologist-recommended leave-on body lotion, and a control (water only treatment).
• Healthy adult females with dry leg skin entered treatment. Subjects provided written informed consent.
• Controlled leg washing was conducted once daily over 21 days.2 In the case of the regimen the leg was washed and patted dry, then the leave-on lotion was applied (1µL/cm2) and rubbed into the skin with a cotted finger.
• Expert visual evaluations were made at baseline and 3 hours after the final study wash. Skin capacitance measurements (Corneometer CM-825) and transepidermal water loss measurements (DermaLab evaporimeter) were made at baseline, before the final wash (about 24 hours after the previous wash), and 3 hours after the final wash. Subjects acclimated in a room with controlled environmental conditions for at least 30 minutes prior to evaluation. The grader and instrument operators were blind to study treatments and assignments.
• Data were analyzed using mixed model techniques adjusting for study design parameters.

Microscopic Clinical Effects

• A home use study was conducted to study the effect of the HDPCBW on intercellular lipid organization in the outer stratum corneum.
• Healthy adult females with dry leg skin entered treatment. Subjects provided written informed consent.
• Subjects used the HDPCBW each day in the shower.
• Tape strip samples were taken from designated areas of the leg at baseline and after 21 days. These samples were prepared as described previously and analyzed by TEM.3

Results

• The HDPCBW provided greater improvement in visible dry skin than the combination of RBW plus leave-on body lotion (P=0.07). Both treatments improved dry skin compared to the control (P<0.01). The HDPCBW also increased stratum hydration compared to the control (pre- and post-final wash) and the RBW plus leave-on body lotion (post-final wash).
• Petrolatum is reported to permeate the stratum corneum and speed barrier repair.4 TEM photos obtained after 21 days of using the HDPCBW show a marked improvement in the intercellular lipid structure of the outer stratum corneum.5 This result, coupled with the sustained improvement in TEWL, suggests that the HDPCBW improves stratum corneum health.
• The HDPCBW improved stratum corneum barrier function relative to the control pre- (P=0.08) and post- (P=0.07) final wash. An improved stratum corneum barrier should reduce the penetration of potential irritants and improve moisture retention. In contrast the combination of RBW plus leave-on body lotion did not improve the barrier relative to the control.
• The clinical improvements found in these studies translate into consumer noticeable skin benefits. High percentages of consumers enrolled in a home use test who noted specific problems with their skin at baseline judged an improvement in these skin conditions after using the HDPCBW for 2 weeks.

Conclusion  

The next generation, high-depositing petrolatum-containing body wash improved visible dry skin condition, increased stratum corneum hydration, and improved barrier function relative to control and even when compared to a regimen that included a dermatologist-recommended leave-on body lotion. Such changes are indicative of improved skin health. Importantly, this body wash also yielded noticeable skin improvements under in-use conditions. Taken together, these results indicate that the high-depositing petrolatum-containing body wash is an excellent option for dermatologists to recommend to their patients with special skin care needs.