The safety and efficacy of clindamycin phosphate foam 1% versus clindamycin phosphate topical gel 1% for the treatment of acne vulgaris

Journal of Drugs in Dermatology, Jan-Feb, 2005 by Alan R. Shalita, Judith A. Myers, Lincoln Krochmal, Alex Yaroshinsky

Because the foam formulation is highly spreadable, dries quickly, and is easy to apply, it is suitable for application to both hair-bearing and non-hair-bearing sites. Moreover, the foam vehicle is thermolabile and breaks down with body heat to deposit the active ingredient on the skin without residue. Thus, the foam vehicle is desirable for the treatment of acne located on all affected areas such as the face, neck, back, and chest.

Once-daily treatment with clindamycin foam was safe and generally well tolerated. The most commonly occurring adverse experiences were mild to moderate in severity. Application site burning was the only treatment-related adverse experience reported by 6% of clindamycin foam patients in the study, a finding consistent with the adverse experiences previously reported for topical clindamycin gel and solution formulations. (14) Application site burning was reported more frequently in the clindamycin foam group than in the clindamycin gel group, possibly due to the alcohols in the foam formulation. However, no application site adverse experiences were considered severe except for the dryness, irritation, and pain at the application site that occurred in 1 patient in the clindamycin gel group. No severe treatment-related adverse experiences were reported by clindamycin foam recipients.

It is noteworthy that, in a separate cumulative skin irritation trial, clindamycin foam application resulted in transient cutaneous irritation that was similar in severity to that observed following application of clindamycin gel (data on file, Connetics Corporation). This finding suggests that clindamycin foam has a tolerability profile comparable to that of clindamycin gel.

An in vitro study of the pharmacokinetics of clindamycin when delivered in the foam vehicle showed that the clindamycin penetration into the stratum corneum was faster and greater with the foam vehicle than with the gel vehicle. (15) These data suggest that foam delivery facilitates rapid and increased skin penetration of the antibiotic but does not appear to be associated with a less favorable systemic safety profile. Indeed, treatment-related systemic adverse experiences were not reported with clindamycin foam in this study. Consistent with these findings, a bioavailability study in which patients received either clindamycin foam or clindamycin gel showed that once-daily application of 4 g of clindamycin phosphate in foam or gel formulation for 5 days resulted in peak plasma clindamycin concentrations that were less than 3.1 ng/mL and 5.3 ng/mL, respectively (data on file, Connetics Corporation). Thus, the systemic exposure to clindamycin following topical application of the foam is negligible, and comparable to, or less than, that observed following topical application of the gel formulation.

A simple, once-daily, versatile, easy-to-use, safe, and effective therapeutic regimen can help encourage patient compliance with the treatment of acne vulgaris. The somewhat stronger efficacy of clindamycin foam relative to that of clindamycin gel, together with its excellent safety profile support clindamycin foam as an attractive therapeutic option for the treatment of acne vulgaris for all affected areas. Moreover, the foam formulation offers cosmetic elegance that has been lacking in some of the more traditional topical drug vehicles. Thus, along with the clinical benefits conferred by the antibiotic, the improved cosmetic aspects associated with the foam delivery could enhance patient compliance with clindamycin treatment.