Study Results of Benzoyl Peroxide 5%/Clindamycin 1% Topical Gel, Adapalene 0.1% Gel and Use in Combination for Acne Vulgaris

June 2007 | Volume 6 | Issue 6 | Original Article | 616 | Copyright © June 2007

James Q. Del Rosso DO FAOCD

Clinical Associate Professor, Department of Dermatology, University of Nevada School of Medicine, Touro University College of Osteopathic
Medicine, Dermatology Residency Director, Valley Hospital Medical Center, and Las Vegas Skin & Cancer Clinics, Las Vegas, NV

Combination therapy is the standard of care in the management of acne vulgaris. It is essential to treat as many aspects of acne pathogenesis as possible. Due to increasing insensitivity of Propionibacterium acnes to antibiotics, the concomitant use of other topical agents that exhibit other modes of antibacterial and anti-inflammatory activity is integral to the successful treatment of acne. The combination of topical benzoyl peroxide and clindamycin gel has been shown to be more effective than either agent alone. The addition of a topical retinoid may further enhance therapeutic results. This 12-week study evaluated the safety and efficacy of initial topical benzoyl peroxide 5%/clindamycin 1% gel as monotherapy and in combination with adapalene gel versus adapalene gel monotherapy in the management of acne.


The Consensus Guidelines for acne management suggest that enhanced therapeutic benefits may be obtained by combining therapeutic agents with different but complementary mechanisms of action.1 The topical combination of a an antibiotic/ antimicrobial plus a retinoid targets ductal hypercornification, bacterial proliferation, and inflammation. The addition of benzoyl peroxide (BP) may help minimize the development of Propionibacterium acnes’ (P. acnes) resistance to the antibiotics that are typically used to treat it.1-3 It also confers significant activity against inflammatory acne lesions and exhibits a moderate ability to reduce comedonal lesions.4,5
Numerous studies have demonstrated increased efficacy with the combination of BP and a topical antibiotic over either agent alone.1-3,6 For example, Cunliffe et al showed that topical therapy with BP 5%/clindamycin 1% (BP/C) in a waterbased vehicle reduced P. acnes counts significantly compared to clindamycin 1% monotherapy. Unlike topical clindamycin monotherapy, which was associated with a progressive increase in P. acnes resistant strains after 8 weeks of use, the combination of BP/C obviated the emergence of clindamycin resistance.3
In addition to the therapeutic effects of the active ingredients, the efficacy and safety of topical formulations can be influenced by excipients. The BP/C gel used in this study is formulated in a water-based, fragrance-free vehicle and does not contain alcohol. The vehicle contains glycerin, a humectant, and dimethicone, an emollient with occlusive properties. These ingredients are known to reduce irritation and dryness and may obviate the need for an additional noncomedogenic moisturizer. These excipients may affect local tolerability and efficacy, particularly when the antibiotic gel is used in combination with topical retinoids.7,8 In a study comparing 2 gel formulations of BP/C, the formulation containing glycerin and dimethicone was shown to be both better tolerated and preferred by patients.7
Adapalene (AP) is a third-generation synthetic retinoid that has been shown to be less irritating than tretinoin. In addition to having efficacy equivalent to that of tretinoin, adapalene has been shown to have potent anti-inflammatory activity of its own.5,9 Because of its reduced irritation potential, AP is well suited for use in combination regimens particularly in topical regimens such as BP, which is also potentially irritating.10 Besides the fact that topical retinoids add comedolytic activity to the BP/C regimen, they have also been shown to increase the penetration of topical antibiotics.11
A recent single-blind, parallel-group, multicenter study in the UK compared the use of BP/C gel and AP 0.1% gel in the management of mild to moderate acne. The BP/C combination was found to produce significantly superior reductions in inflammatory lesion counts beginning at week 1 and continuing through the 12 weeks of the study (P=.001). In addition, the BP/C combination had a more rapid onset of action compared to AP, and was associated with markedly fewer local tolerability reactions. The authors of the study concluded that greater efficacy, more rapid onset of clinical effect, and better tolerability of the BP/C topical gel formulation is likely to result in better patient compliance with therapy and thus better treatment outcomes.12
In a study of BP/C gel and tazarotene cream13 versus tazarotene alone, the combination regimen was shown to enhance efficacy and demonstrated a trend toward improved tolerability. The combination therapy was at least as well tolerated as tazarotene cream monotherapy. The authors noted that the addition of BP/C gel to the topical retinoid also conferred increased comedolytic activity. While this study found no significant intergroup differences in pruritus, burning, dryness, or erythema, there were significant intergroup differences in peeling at week 4. At this time point, a higher number of subjects in the BP/C plus tazarotene group (67% vs. 57%) had no peeling or only a trace of peeling. This suggested that BP/C gel containing the excipients glycerin and dimethicone may