A Review of Anti-Irritants, Part I: Barrier Cream Efficacy on Contact Dermatitis*

By: Howard I. Maibach, MD, University of California School of Medicine; and Hongbo Zhai, MD, University of California

Posted: March 2, 2011, from the March 2011 issue of Cosmetics & Toiletries.

page 7 of 8

Milk, cream and ointment protection: Ortonne and Queille-Roussel performed a single-center, blinded, randomized, controlled study in 20 healthy Caucasian women. During the irritation period, SLS at 5% was used to induce skin irritation on both forearms of each subject daily for five days. A milk (w/o emulsion), cream (w/o emulsion) and ointment (water-free emulsion)e were applied twice daily to three of the four test sites on days 1–5. The fourth site served as a control.

The cream was comprised of: water (aqua), caprylic/capric triglyceride, polyglyceryl-3 diisostearate, glycerin, dicaprylyl ether, cetearyl ethylhexanoate, petrolatum, Cera alba, sodium lactate, polyglyceryl-2 dipolyhydroxystearate, magnesium sulphate, lactic acid and ethylhexylglycerin. The milk contained: water (aqua), caprylic/capric triglyceride, cetearyl ethylhexanoate, urea, polyglyceryl-2 dipolyhydroxystearate, sodium lactate, glycerin, dicaprylyl ether, polyglyceryl-3 diisostearate, lactic acid, magnesium sulphate and ethylhexyl-glycerin. Finally, the ointment included: petrolatum, Paraffinum liquidum, microcrystalline wax, oleyl erucate, urea and Zea mays (corn) starch.

Visual readings, subjective symptom assessments, TEWL and colorimetric measurements, corneometry and skin microrelief macrophotographs were recorded on days 1–6. On day 6, TEWL with the cream or the ointment was found to be significantly lower than control. Skin capacitance was 94%, 100% and 85% of baseline value for the cream, milk and ointment, respectively, versus 72% for the control. All test products were well-tolerated and the researchers concluded that the products showed both protective properties against epidermal dysfunction and significant hydrating effects.

Pimecrolimus cream against irritation: Engel et al. tested the anti-inflammatory effect of pimecrolimus cream on SLS-induced skin damage in a randomized, placebo-controlled, observer-blinded study. SLS at 3% was applied under occlusion on the backs of 36 healthy volunteers for 24 hr. Subsequently, the test areas were treated for 24 hr on three consecutive days with pimecrolimus cream, 1% hydrocortisone in a hydrophilic ointment, and the vehicle alone. A control area remained untreated. The erythema index and the TEWL were measured. Pimecrolimus cream and 1% hydrocortisone cream significantly reduced the SLS-induced erythema but did not have a significant effect on TEWL.

Conclusion

The studies described in this literature review evaluate the efficacy of anti-irritant agents for reducing ICD in human skin. For instance, tannic acid significantly reduced damage, and beeswax and white petrolatum were significant in their efficacy to protect barrier function. As noted, this investigation of anti-irritants will continue in the April 2011 edition with the efficacy of moisturizers and anti-irritant substances, as well as provide an overall interpretation.