INTRODUCTION
Benzoyl peroxide (BPO) is a cornerstone of acne therapy
that is often used in combination with a topical antibiotic
and/or a retinoid. The use of varying concentrations of BPO
with an antibiotic such as clindamycin (as clindamycin phosphate
1.2%) minimizes the emergence of antibacterial resistance1 while
enhancing efficacy compared with the individual agents.2,3 Furthermore,
topical fixed-dose combinations of BPO and clindamycin
phosphate 1.2% possess very low irritation potential4,5 and are
often better tolerated than either agent alone.3 Improved tolerability
of a fixed-combination of BPO–clindamycin phosphate 1.2%
has also been demonstrated in combination with a retinoid.6
The tolerability and efficacy of topical fixed-dose combinations
of low-strength BPO (2.5%) with either clindamycin phosphate
1.2% (Acanya® Gel)7–9 or adapalene 0.1% (Epiduo® Gel) have
been widely demonstrated.10–14 The antibacterial dapsone 5%
gel (Aczone® Gel) used alone15,16 or in combination with BPO
(4%)17 is also an effective and well tolerated acne treatment.18
Acanya Gel results in less irritation than a higher concentration
of BPO (5%) in combination with clindamycin phosphate 1.2%
(Duac® Gel).19 No studies have compared the safety and tolerability
of Duac Gel with Epiduo Gel or Aczone Gel.
The primary objectives of the three studies described here were
to evaluate the tolerability and irritation potential of Duac Gel
compared with Acanya Gel, Aczone Gel, or Epiduo Gel. Secondary
objectives included assessment of potential changes in the
integrity of the stratum corneum barrier and skin surface hydration
after each treatment, and estimation of subject tolerability
through skin assessment questionnaire and Product Acceptability
and Preference Questionnaire.
METHODS
Eligible Subjects
Three independent single-blind, single-center, parallel group,
randomized, 2-week studies were conducted between May
and September 2009 in healthy subjects to evaluate the
tolerability and irritation potential of topical Duac Gel (BPO 5%–
clindamycin phosphate 1.2%) compared with Acanya Gel (BPO
2.5%–clindamycin phosphate 1.2%), Aczone Gel (dapsone 5%),
or Epiduo Gel (BPO 2.5%–adapalene 0.1%).
Eligible volunteers (screened 3 days prior to randomization)
were males and females aged 18 to 45 years who did not have
facial acne, and had a Fitzpatrick Skin Type of I, II, or III. All
study procedures and protocols were reviewed and approved
by the institutional review board in accordance with the International
Conference on Harmonization Good Clinical Practice
Guidelines, Good Laboratory Practice Guidelines, and COLIPA
(European Cosmetics Trade Association) Efficacy Testing
Guidelines (Study numbers NCT01015638, NCT00964366, and
NCT00926367; www.clinicaltrials.gov).