Split-Face Clinical and Bio-Instrumental Comparison of 0.1% Adapalene and 0.05% Tretinoin in Facial Acne

Abstract

Background: Adapalene and tretinoin are topical compounds active for treating acne. Objective: To compare the efficacity and safety of adapalene 0.1% gel and tretinoin 0.05% gel in moderately severe facial acne using clinical and objective biometrological assessments. Such information is currently lacking in the literature. Methods: The split-face method was used in 25 acne volunteers for a 6-week treatment. In addition to clinical counts of lesions, the amount of comedones was assessed using computer-assisted morphometry of cyanoacrylate follicular biopsies. The erythema index and squamometry values were used to quantitate skin irritation. Results: The tretinoin formulation brought better comedolysis and clinical improvement than the adapalene formulation. Erythema was transiently more pronounced on the tretinoin-treated side. Squamometry yielded no significant difference between both products. Conclusion: Tretinoin 0.05% gel exhibits a greater anti-acne efficacy than adapalene 0.1% gel, although with temperate tolerability.

A multi‐sample design for assessing the comedolytic activity of topical products

“…Retin-A Ò produced a significant comedolytic effect agreeing with data from previous authors obtained for different body sites [10,11]. In addition, the study detected differences between products.…”

Topical tretinoin or adapalene in acne vulgaris: an overview

“…In contrast, in a Adapalene 0.1% gel vs tretinoin 0.025% gel split-face clinical and bio-instrumental comparison of 0.1% adapalene and 0.05% tretinoin gel in facial acne, the erythema index 39 and squamometry values were used to quantitate skin irritation. 27 The evaluation of skin colour outside the acne lesion using narrowband refractive sphectrophotometry showed the development of minimal erythema on both the treated sides. The between-product comparison indicated that erythema was transiently more pronounced on the tretinoin 0.05% gel treated side at weeks 2 and 4, with no further difference at week 6.…”

“…In contrast to previous studies, the present trial revealed the greater efficacy of tretinoin 0.05% gel over adapalene 0.1% gel. This may be ascribed to the higher concentration of tretinoin, 27 and its higher affinity for gamma receptors. 33 The adverse reactions to adapalene are of the same type, but of significantly lower frequency and lesser severity than for tretinoin (Table IV).…”

“…Scaliness was explored using the squamometry method and no significant difference was yielded between the two test sides. 27 Several explanations have been proposed for the greater tolerability of adapalene. These too, as will be evident in the following paragraphs, are debatable.…”

The Conundrum of Skin Pores in Dermocosmetology

“…The material is stained with toluidine blue and basic fuchsin dyes for 3 min. This method combined with computerized image analysis [24, 25, 26, 27]allows to quantify the density and size of follicular casts and comedones (fig. 5).…”