Tolerance of fragranced and fragrance-free facial cleansers in adults with clinically sensitive skin

Although mild, fragrance-free, nonfoaming cleansers generally are recommended for individuals with sensitive skin, many consumers choose fragranced foaming cleansers. The addition of hydrophobically modified polymers (HMPs) to mild facial cleansers has been shown to improve product tolerability in individuals with sensitive skin while facilitating foaming. The objective of the 2 studies reported here was to assess the tolerability of a mild, HMP-containing, foaming facial cleanser with a fragrance that was free of common allergens and irritating essential oils in patients with sensitive skin. In the first study, 8 participants with clinically diagnosed fragrance sensitivity used a gentle foaming HMP-containing facial cleanser with or without fragrance for 3 weeks. Both cleansers improved global disease severity, irritation, and erythema with similar cleansing effectiveness. The second study was a 3-week, prospective, double-blind, randomized, 2-center study of 153 participants with clinically diagnosed sensitive skin. In this study, the fragranced gentle foaming cleanser with HMP was as well tolerated as a benchmark gentle, fragrance-free, nonfoaming cleanser. Itching, irritation, and desquamation were most improved from baseline in both groups. The participant-rated effectiveness of the cleanser with HMP was similar or better than the benchmark cleanser after 3 weeks of use. In conclusion, the gentle facial cleanser with HMPs and a fragrance offers a new option for adults with sensitive skin who may prefer, and commonly use, a fragranced and foaming product.

Hydrophobically modified polymers can minimize skin irritation potential caused by surfactant-based cleansers

Introduction

The addition of hydrophobically modified polymers (HMPs) to cleansers that contain surfactants can create polymer–surfactant complexes that are less irritating to the skin than commercially available mild cleansers. Our objective was to compare the tolerability and efficacy of a test foaming liquid facial cleanser containing HMPs with a commercial liquid nonfoaming facial cleanser in women with sensitive skin.

Methods

In this randomized, prospective, double-blind, comparative study, women (n = 20 per group) with mild-to-moderate atopic dermatitis (AD), eczema, acne, or rosacea used a test gentle foaming liquid facial cleanser containing HMPs or a commercial gentle liquid nonfoaming facial cleanser daily for 3 weeks. Investigators assessed irritation and skin condition. Study subjects also assessed their skin properties and the performance of each cleanser.

Results

Clinicians as well as study subjects consistently rated the test cleanser as effective or slightly more effective at improving symptoms than the commercial cleanser, although no significant differences between groups were observed. At weeks 1 and 3, respectively, more users of the commercial cleanser reported irritation (20% and 10%) than users of the test cleanser (5% and 5%). In addition, subject self-assessments of skin condition and cleansing properties were slightly more improved with the test cleanser than with the commercial cleanser.

Conclusions

Both the test foaming cleanser containing HMPs and the commercial nonfoaming cleanser were effective and well accepted by most women in the study. Improvements were observed by both clinicians and subjects in the group using the test cleanser containing HMPs in all evaluated skin categories.

A broad spectrum high-SPF photostable sunscreen with a high UVA-PF can protect against cellular damage at high UV exposure doses

BACKGROUND

Advances in sunscreen technologies have yielded broad spectrum sunscreens at high-sun protection factor (SPF) and ultraviolet A protection factor (UVA-PF) levels that are photostable and powerful in protecting skin from erythema. Questions arise whether these sunscreens protect proportionally against cellular skin damage caused by high ultraviolet exposures.

OBJECTIVE

The objective of this study is to evaluate if high-SPF sunscreen can protect skin at a cellular level under UV exposure doses [>50 minimal erythema dose (MED)] similarly to the SPF value.

METHODS

Sunburn cells, Langerhans cells, thymine dimers, protein 53 (p53), and matrix metalloproteinase (MMP)-1 and MMP-9 endpoints were evaluated in biopsies from 12 subjects following four treatments: unprotected exposed to 0, 1 and 3 MED and sunscreen (SPF 55) protected exposed to 55 MED of UV radiation.

RESULTS

All the markers showed significantly more damage for the 3 MED-untreated sites when compared with non-irradiated control, and majority of the markers showed marked damage following unprotected 1 MED exposure. After 55 MEDs, sunscreen-protected sites showed significantly less p53 and MMP-9 (keratinocyte) staining than the 1 MED-exposed unprotected sites, while all the other biomarkers in sunscreen protected sites showed no statistical differences from 1 MED-exposed unprotected sites.

CONCLUSIONS

A high-SPF photostable sunscreen with high UVA-PF can provide proportionately high protection against multiple cellular damage markers.

High-SPF sunscreens (SPF ≥ 70) may provide ultraviolet protection above minimal recommended levels by adequately compensating for lower sunscreen user application amounts

BACKGROUND

The manner in which consumers apply sunscreens is often inadequate for ultraviolet protection according to the labeled sun protection factor (SPF). Although sunscreen SPFs are labeled by testing at an application density of 2 mg/cm(2), the actual protection received is often substantially less because of consumer application densities ranging from 0.5 to 1 mg/cm(2). High-SPF sunscreens may provide more adequate protection even when applied by consumers at inadequate amounts.

OBJECTIVE

We sought to measure the actual SPF values of various sunscreens (labeled SPF 30-100) applied in amounts typical of those used by consumers.

METHODS

Actual SPF values were measured on human volunteers for 6 sunscreen products with labeled SPF values ranging from 30 to 100, applied at 0.5, 1.0, 1.5, and 2.0 mg/cm(2).

RESULTS

There was a linear relationship between application density and the actual SPF; sunscreens with labeled SPF values of 70 and above provided significant protection, even at the low application densities typically applied by consumers. Sunscreens labeled SPF 70 and 100 applied at 0.5 mg/cm(2) provided an actual SPF value of, respectively, 19 and 27.

LIMITATIONS

The study was conducted in a laboratory setting under standardized conditions and results are extrapolated to actual in-use situations.

CONCLUSION

Sunscreens with SPF 70 and above add additional clinical benefits when applied by consumers at typically used amounts, by delivering an actual SPF that meets the minimum SPF levels recommended for skin cancer and photodamage prevention. In contrast, sunscreens with SPF 30 or 50 may not produce sufficient protection at actual consumer usage levels.

Ranking of aqueous surfactant-humectant systems based on an analysis of in vitro and in vivo skin barrier perturbation measurements

We propose that skin electrical current measurements can be used in vitro to effectively rank aqueous solutions containing surfactants and humectants (the enhancer) contacting the skin, relative to a PBS aqueous solution (the control) contacting the skin, based on their ability to perturb the skin aqueous pores. Specifically, we develop an in vitro ranking metric using the increase in the skin electrical current induced by an enhancer relative to the control. Aqueous contacting solutions containing (i) surfactants [SDS (sodium dodecyl sulfate)] and C(12)E(6) [dodecyl hexa (ethylene oxide)], (ii) humectants (glycerol and propylene glycol), and (iii) a control (PBS) were studied. Utilizing the new in vitro ranking metric, these aqueous contacting solutions were ranked as follows (from the mildest to the harshest): glycerol < propylene glycol < PBS < C(12)E(6) < SDS. In order to further develop this ranking methodology, which can potentially lead to the reduction, or elimination, of costly and time-consuming procedures, such as human and animal testing and trial-and-error screening in vivo, it was important to correlate the findings of the in vitro ranking metric with direct in vivo skin barrier measurements. For this purpose, in vivo soap chamber measurements, including transepidermal water loss, visual skin dryness, and chromameter erythema measurements, were carried out on human volunteers using the aqueous surfactant-humectant solutions described above. The results of these in vivo measurements were found to be consistent with the ranking results obtained using the in vitro ranking metric. To further explore the validity of our model and to verify the skin barrier mitigating effect of glycerol, in vivo soap chamber measurements were carried out for aqueous SDS solutions containing 10 wt% added glycerol. These in vivo measurements support our recent in vitro finding that glycerol reduces the average radius and the pore number density of the skin aqueous pores, such that SDS micelles are hindered from penetrating into the skin and inducing skin barrier perturbation.

Fluorescence excitation spectroscopy for the measurement of epidermal proliferation

Fluorescence excitation spectroscopy was used to assess cellular turnover in human skin by monitoring changes of endogenous fluorescence. Epidermal proliferation was induced with alpha-hydroxy acids. Commercially available glycolic acid creams (8 and 4% wt/wt concentration) and a vehicle cream (placebo) were applied in a randomized double blinded fashion on subjects' forearms, twice daily for 21 days. Excitation spectra were recorded (excitation 250-360 nm, emission 380 nm) at days 0, 1, 3, 7, 10, 11, 14, 17 and 21. The 295 nm excitation band (assigned to tryptophan moieties) was used in this study as a marker for cellular proliferation. To further reduce the day-to-day variability of the skin fluorescence the intensity of the 295 nm band was normalized to the 334 nm band (assigned to collagen crosslinks). The fluorescence emission intensity from placebo-treated skin remained practically unchanged over the period of the measurements while the fluorescence intensity measured from the glycolic acid-treated skin increased monotonically with treatment. The rate of increase of the excitation intensity with treatment was found to be dose dependent. The epidermal 295 nm band may be used as a quantitative marker to monitor the rate of proliferation of epidermal keratinocytes noninvasively.

Comparative anti-dandruff efficacy between a tar and a non-tar shampoo

A randomized double-blind clinical study was conducted on two groups of 30 volunteers using either a non-tar shampoo (2% salicylic acid, 0.75% piroctone olamine and 0.5% elubiol) or a 0.5% coal tar shampoo. Subjects were diagnosed as having moderate to marked dandruff. The study consisted of a 3-week washout, followed by a 4-week treatment and a 4-week posttreatment regression phase. The clinical evaluations and subject self-assessments showed that the non-tar shampoo was as effective as the tar shampoo. Both received high approval ratings (> or =70%). Biometrological methods proved to be more sensitive than clinical evaluations to assess the efficacy of the shampoos. The non-tar shampoo yielded a significantly better reduction of Malassezia spp. counts (p<0.02) during the treatment phase and reduced the spontaneous increase in squamometry values (p< 0.01) during the posttreatment phase. It is concluded that a formulation associating salicylic acid, piroctone olamine and elubiol exhibited increased beneficial effects compared to the coal tar shampoo.

Retinoid therapy: compatible skin care

Topically applied tretinoin (a retinoid) has been used for over 25 years to treat acne and disorders of keratinization. Now, tretinoin emollient cream, 0.05% (Renova(R)), may be prescribed for the treatment of photodamaged and chronologically aged skin, in conjunction with appropriate skin care and sun protection routines. Mild to moderate cutaneous side effects to topical tretinoin, such as xerosis, peeling, erythema and subjective irritation, are experienced by a majority of patients undergoing retinoid therapy. Results of clinical compatibility testing show that concomitant use of effective moisturizers, mild cleansers and daily sunscreens greatly enhance skin tolerance and patient comfort. A frequently prescribed regimen for topical treatment of photodamaged skin includes a combination of tretinoin and glycolic acid. While many clinicians report the use of both these agents for the management of their patients, little information exists in the literature about their compatibility in concomitant use. The results of a double-blind clinical study demonstrate that daytime usage of one of two 8% glycolic acid lotions in addition to nightly applications of Renova was well tolerated as part of a comprehensive skin care and sun protection program.