[Comparative study of the efficacy and tolerability of 0.1 and 0.03 p.100 adapalene gel and 0.025 p.100 tretinoin gel in the treatment of acne].

INTRODUCTION

Adapalene is a new chemical entity with retinoid activity.

PATIENTS AND METHODS

0.1 p. 100 adapalene gel (Différine gel), 0.03 p. 100 adapalene gel and a commercially available 0.025 p. 100 tretinoin gel (Aberel gel) were compared in 89 male and female patients with acne.

RESULTS

Inflammatory, non inflammatory, total lesion counts, and the global facial acne grade regularly decreased as a function of time in the three treatment groups. No statistically or clinicaly significant differences were observed for these parameters between 0.1 p. 100 adapalene gel and 0.025 p. 100 tretinoin gel following a 12-week treatment. Conversely, both of these gels were significantly more effective than 0.03 p. 100 adapalene gel with regards to inflammatory and total lesion counts, and the global facial acne grade. The differences of efficacy seen between both adapalene gels demonstrate a dose-dependent activity of the drug in the topical treatment of acne. The three products induced retinoid-like skin irritation with significant differences in intensity in favour of adapalene for erythema, dryness, scaling and burning after application and in favour of tretinoin for persistent burning. No treatment-related medical events were reported and adapalene plasma levels were lower than 0.15 ng/ml (limit of detection of the analytical method).

CONCLUSIONS

The topical treatment of acne with adapalene gels was found to be safe and effective, with a dose-related response. The efficacy of 0.1 p. 100 adapalene gel and of 0.025 p. 100 tretinoin gel are not different but skin tolerance of 0.1 p. 100 adapalene gel is superior.