Non-invasive cosmetic efficacy testing in human volunteers: some general principles*

Background/aims: The Sixth Amendment to the European Union's Cosmetics Directive 76/768/EEC requires “proof of the effect claimed for the cosmetic product, where justified by the nature of the effect or product”. To avoid unnecessary claim support disputes, it may be helpful for there to be discussion in the literature to clarify what is generally considered to be sufficient proof of efficacy. Certainly most will wish to encourage efficacy study methodologies which simultaneously (a) ensure an adequate level of quality based on accepted principles of good scientific investigation; (b) are broad and flexible so that detailed procedure can be adapted to suit local needs and conditions; (c) are relevant to the needs of producers, regulatory authorities and consumers. Conclusion: To progress these aims, it appears that the same basic set of considerations arises in all contexts. This is outlined under a series of key headings in the present paper, which may serve as a basis for further discussion.     

A double-blind study of tolerance and efficacy of a new urea-containing moisturizer in patients with atopic dermatitis

Background  Atopic dermatitis patients almost all use moisturizers to prevent and treat their skin disease. However, the safety and efficacy of moisturizers are rarely studied in this patient population.
Aims  To evaluate the efficacy and tolerability of urea-containing moisturizers in subjects with atopic dermatitis.
Methods  One hundred subjects with atopic dermatitis were randomized to apply either a new 5% urea moisturizer or a commercially available 10% urea lotion twice a day for 42 days. Scoring Atopic Dermatitis severity index (SCORAD) was performed at Day 0 and Day 42. Cosmetic acceptability questionnaires, adverse events, and a 5-point tolerance evaluation were administered or performed at Day 42.
Results  Both study products were very well tolerated by subjects and only three subjects discontinued their participation in the study due to adverse events. Mean SCORAD significantly decreased between Day 0 and Day 42 by 19.76% and 19.23%, respectively, for subjects treated with the new 5% urea moisturizer or the 10% urea lotion ( P  < 0.001). There was no difference between the two products in SCORAD reduction; however, significantly more subjects preferred using the new 5% urea moisturizer as compared with the 10% urea lotion.
Conclusions  Both the new 5% urea moisturizer and the 10% urea lotion improved atopic dermatitis and were very well tolerated. However, the cosmetic acceptability questionnaire showed that subjects preferred using the new 5% urea moisturizer over the 10% urea lotion.     

A randomized controlled trial of the efficacy and safety of a fixed triple combination (fluocinolone acetonide 0.01%, hydroquinone 4%, tretinoin 0.05%) compared with hydroquinone 4% cream in Asian patients with moderate to severe melasma

Background  Melasma is an acquired, chronic hypermelanosis for which therapy remains a challenge.
Objectives  To compare the efficacy and safety of a triple combination [TC: fluocinolone acetonide 0·01%, hydroquinone (HQ) 4%, tretinoin 0·05%] vs. HQ 4% after 8 weeks of treatment of moderate to severe facial melasma in Asian patients.
Methods  This was a multicentre, randomized, controlled, investigator-blinded, parallel comparison study. East and South-East Asian patients aged 18 years or older, with a clinical diagnosis of moderate to severe melasma, were enrolled in this study. Patients were enrolled at baseline and treated daily for 8 weeks with TC cream (one application at bedtime) or HQ cream (twice daily). There were four study visits: at baseline and weeks 2, 4 and 8. The primary efficacy variable was the melasma global severity score (GSS). Other outcome measures included Melasma Area and Severity Index, global improvement and patient satisfaction. Safety was assessed through the reporting of adverse events.
Results  TC had superior efficacy to HQ for the primary variable: 77/120 patients (64·2%) on TC had GSS 'none' or 'mild' at week 8 vs. 48/122 patients (39·4%) on HQ ( P  < 0·001). The secondary efficacy variables confirmed these results. Patient satisfaction was in favour of TC (90/127, 70·8%, vs. 64/129, 49·6%; P  = 0·005). More patients had related adverse events on TC (63/129, 48·8%) than on HQ (18/131, 13·7%) but most were mild and none was severe.
Conclusions  Efficacy in Asians and patient satisfaction were superior with the fixed TC than with HQ 4%.