Expanding the Range of Possible Skin Effects from Moisturizing Body Washes
KD Ertel, PhD; HL Focht, BChE; DD Watson, BS; RA Bacon, BS; AL Newman, BS The Procter & Gamble Company, Cincinnati, OH
Literature from the past several decades contains numerous examples of studies comparing the skin compatibility of cleansing bars having different formula compositions, and dermatologists are aware of the broad range of potential irritant effects these different bar formulations have on skin. Liquid personal cleanser forms such as body washes are a more recent market introduction and are not as widely studied. Body washes have fewer formulation constraints than bars and offer new formulation possibilities, initially for improving skin compatibility (compared to bars) and more recently for developing products that deposit benefit agents on skin to improve skin condition. As a result body washes, like cleansing bars, are expected to produce a range of skin effects, although these often involve skin improvement rather than irritation. We developed a new petrolatum-depositing body wash technology that delivers a greater amount of this benefit agent to the skin than was previously possible, without compromising product stability or in-use aesthetics.
To assess the dry skin improvement potential of the new petrolatum-depositing body wash and to compare its clinical performance to that of other moisturizing body wash products
• A randomized, blinded leg wash study was used to compare the new petrolatum-depositing body wash (PDBW), 2 marketed moisturizing body washes (MBW), and a water control. •Healthy adult females gave informed consent and entered a 7 day pretreatment phase. Moisturizer application to the legs and other activities that could impact leg skin condition were prohibited. Leg shaving was restricted. Sixty-three subjects with sufficient dry leg skin entered the treatment phase. •Controlled leg washing was conducted once daily for 7 days.1 •Subjects acclimatized in a controlled environment room for at least 30 minutes at each evaluation. Expert visual and instrumental (Corneometer CM-825, Vapometer) evaluations were made at baseline, before the seventh wash, and 3 hours after the seventh wash. Subjects also self-assessed their leg skin condition at the pre-wash evaluation. •Data were analyzed using mixed model techniques adjusting for study design parameters.
•The new PDBW improved dry skin condition better than the control at both evaluations on day 7. The PDBW provided greater dry skin improvement than MBW #1. MBW #2 did not improve dry skin condition and in fact worsened dry skin relative to control at the pre-wash evaluation (Figure 1). •Results from subject self-assessment conducted at the day 7 pre-wash visit for "noticing improvement in how moisturized skin looks" followed the same trend as the expert dryness scores. (data not shown) •Skin capacitance measurements were consistent with expert dryness scoring. The new PDBW and MBW #1 provided a skin hydration benefit compared to control. Conversely, MBW #2 had a marked drying effect on the skin (Figure 2). •The new PDBW and MBW #1 were not irritating under this clinical protocol. Erythema is generally not an issue with once daily application but, surprisingly, MBW #2 produced marked irritation under these conditions (Figure 3). •Transepidermal water loss (TEWL) measurements were consistent with expert erythema scoring. The new PDBW and MBW #1 improved barrier function compared to control, while MBW #2 compromised the stratum corneum barrier (Figure 4).
A broad range of skin effects is possible from moisturizing body washes. Some products, such as the new petrolatum-delivering body wash, can markedly improve skin condition while other ‘moisturizing' body washes can cause further drying and irritation. This outcome highlights the importance of understanding a moisturizing body wash product's potential to impact skin condition before recommending it to patients with dry skin care needs.