A randomized, parallel, vehicle-controlled comparison of two erythromycin/benzoyl peroxide preparations for acne vulgaris.

BACKGROUND: Topical erythromycin/benzoyl peroxide (EBP), marketed for acne treatment, must be compounded by a pharmacist and requires subsequent refrigeration, warranting the development of alternate formulations.

OBJECTIVE: This trial compared the efficacy and tolerability of a single-use EBP combination package (EBP Pak) with those of its matching vehicle control (VC Pak) and the original, reconstituted formulation packaged in a jar (EBP Jar). The matching VC for the original formulation (VC Jar) was used to achieve study blinding.

METHODS: In this double-blind, parallel-group, multicenter study, patients were randomly assigned to the 4 treatment arms. The primary efficacy evaluations were lesion reductions from baseline and treatment success (as defined by a Physician's Global Acne Severity score of 0 [clear] or 0.5 [sparse comedones with few or no inflammatory lesions]). Secondary evaluations were Physician's Global Acne Severity scores, facial-oiliness scores, and end-point patient evaluations of global improvement and treatment acceptability. Tolerability was based on the incidence and severity of adverse events.

RESULTS: Three hundred twenty-seven patients (age range, 12-46 years) were randomly assigned to the 4 treatment groups (EBP Pak, 124; VC Pak, 42; EBP Jar. 121; VC Jar, 40). Mean percent reductions in total acne lesions, inflammatory acne lesions, and come-dones from baseline were significantly greater with EBP Pak than with VC Pak (P < or = 0.001 for the intent-to-treat patient population after 8 weeks). Statistical significance for all lesion parameters was demonstrated at week 2 (P < 0.05) and maintained throughout the study. At 8 weeks, a significantly greater proportion of patients demonstrated treatment success with the EBP Pak compared with VC Pak (28% vs 2%, respectively; P < 0.001). The EBP Pak was comparable to the EBP Jar in terms of reduction in acne lesions, Physician's Global Acne Severity scores, and end-of-treatment patient evaluations of global improvement. No serious drug-related adverse events were reported.

CONCLUSIONS: Results of this 8-week trial demonstrate that the single-use combination package of EBP is well tolerated, effective, and comparable to the original formulation for the treatment of acne vulgaris in this selected patient population.