A Double-Blind, Randomized, Bilateral Comparison of Skin Irritancy Following Application of the Combination Acne Products Clindamycin/Tretinoin and Benzoyl Peroxide/Adapalene

December 2012 | Volume 11 | Issue 12 | Original Article | 1422 | Copyright © December 2012

Renato Goreshi MD, Aman Samrao MD, and Benjamin D. Ehst MD PhD


Background: The use of topical medications for acne vulgaris is often limited by their irritant properties. Newer combination preparations are available and offer convenience, but irritant potential may still be a hindrance, perhaps more so with the combination of 2 agents. Few studies have compared these formulations directly for tolerability.
Objective: We sought to compare the tolerability of 2 combination topical acne products, clindamycin 1.2%-tretinoin 0.025% (CLIN/RA) gel and benzoyl peroxide 2.5%-adapalene 0.1% (BPO/ADA) gel.
Methods: CLIN/RA and BPO/ADA were applied daily to opposite sides of a subject's face for 21 days in a double-blinded fashion. Investigators' Global Assessments and study subject self-assessments of burning/stinging, itching, erythema, and dryness/scaling were collected. Transepidermal water loss (TEWL) was also measured as an objective measure of skin irritation. A mixed model analysis and repeated-measures analysis of variance were used to compare outcomes for both acne formulations.
Results: CLIN/RA produced significantly less burning/stinging than BPO/ADA (P<.001) as well as significantly less pruritus than BPO/ADA (P<.001). BPO/ADA caused significantly more TEWL than CLIN/RA (P=.005). There was no significant difference in the amount of erythema or the amount of dryness/scaling caused by either formulation.
Conclusion: CLIN/RA produced significantly less skin irritancy and TEWL than BPO/ADA.

J Drugs Dermatol. 2012;11(12):1422-1426.


Acne vulgaris affects about 45 million people in the United States, and 85% of those aged 12 to 24 years.1-3 Acne vulgaris causes significant physical and psychological morbidity.1-3 Topical antibiotics, keratolytics, and retinoids are the main first-line treatment options for comedonal and mild inflammatory acne.4 Combination therapy is often used in many clinical settings in order to target different pathogenic factors.5,6 Retinoids in particular have shown superior clinical efficacy when combined with another agent, eg, an antibiotic, as this offers a multimodality approach to treating acne.7
Two major barriers to successful treatment with these agents is the difficulty in adhering to continued daily or twice-daily use and their irritant properties. Compliance decreases because of both issues. Newer compound formulations of 2 medications have been developed to address the former issue and indeed to improve compliance.8,9 The tolerability of topical medications has been addressed by improved vehicle preparations and micronization of agents, but the potential for irritancy still remains.
The first 2 topical acne preparations combining medications approved by the US Food and Drug Administration were released in 2006 and 2008. The first, a formulation of clindamycin 1.2% and tretinoin 0.025% (CLIN/RA), has been shown to be significantly better tolerated than tretinoin 0.1% gel microspheres in terms of redness, scaling, itching, burning, and stinging.10 In addition, there was a trend toward better tolerability of CLIN/RA when compared with adapalene 0.1% gel (ADA) monotherapy.10 The second approved combination product of benzoyl peroxide 2.5% and ADA (BPO/ADA) was also found to have better tolerability than BPO monotherapy in terms of cutaneous tolerability.6 No studies to date have compared these 2 products to each other. The aim of the current study was to compare the tolerability of CLIN/RA and BPO/ADA fixed-dose combination therapies using objective and subjective measures of skin irritancy.


Study Population

Twenty-four Caucasian subjects were enrolled in the study (27 subjects were screened, and 3 were excluded because they failed to meet inclusion and exclusion criteria). Inclusion criteria were: 1) diagnosis of mild to moderate facial acne vulgaris at baseline (20-150 total acne lesions, including 10-100 noninflammatory lesions and/or 10-50 inflammatory lesions, and no more than 2 cysts/