DIOGO BALTAZAR¹, JOANA MARTO², THORDIS BERGER³, PEDRO PINTO^2,4, HELENA M. RIBEIRO²*
*Corresponding author
1. Cosmetic Science Research Group, London College of Fashion, University of the Arts London, London, United Kingdom
2. Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, Portugal
3. Skinspiration HealthCare, Ltd., Funchal, Portugal
4. R&D, PhD Trials, Lisbon, Portugal

Abstract

Donkey milk, allegedly used by Cleopatra, is a complex, traditional cosmetic ingredient composed of hydrating substances. In this work, donkey milk was mixed with pomegranate extract and an optimised blend of UV filters in a cosmetic O/W emulsion. The antiageing efficacy of this synergistic blend was assessed by imaging, biomechanical and electrometric methods on 32 volunteers, after 28 days of application. The wrinkle count decreased by 32.9% and the wrinkle length was reduced by 9.6%. Skin hydration increased by 11.4%, while skin firmness and elasticity increased by 9.6% and 16.1%, respectively. Furthermore, skin colour homogeneity was enhanced. Thus, this product was proven to have antiageing effects, both by preventing photoageing and by diminishing existing signs of ageing.

INTRODUCTION
Skin ageing is influenced by both intrinsic and extrinsic factors that promote the accumulation of physicochemical alterations in the cutaneous structure and function (1, 2). These alterations reveal themselves as clinical changes, including e.g. wrinkling, dyschromias and elastosis (3). Ultraviolet (UV) radiation exposure, particularly UVA and UVB, is the major extrinsic ageing factor responsible for premature skin ageing (4, 5).

Donkey milk is highly hydrating due to its protein-rich content, namely casein, α-lactoalbumin and β-lactoglobulin (6, 7) and it contains traces of lactic acid, lactate and calcium, claimed to have positive effects on aged skin (8, 9).

An O/W emulsion for topical application was developed to address signs of skin ageing (skin firmness, elasticity and wrinkle reduction, among others) by a combination of different cosmetic ingredients: donkey milk, pomegranate extract and UV filters (SPF 20). The UV filters were selected in order to provide a broad-spectrum (UVA and UVB) protection when blended in the final product. The synergistic efficacy of these raw materials was assessed in vivo.

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