The development and optimization of a fixed combination of clindamycin and benzoyl peroxide aqueous gel

Fixed combination products of clindamycin 1% (as 1.2% clindamycin phosphate) and benzoyl peroxide (BPO) 5% are commonly used in the treatment of acne vulgaris. Although any given topical acne product may be therapeutically effective, signs and symptoms of cutaneous tolerability may lead to missed applications by the patient, thus limiting adherence to therapy. BPO and other formulation components such as surfactants, preservatives and high levels of organic solvents can cause cutaneous irritation and dryness. BPO irritation is dose-dependent. An approach to optimizing the BPO concentration was undertaken to develop a surfactant- and preservative-free, clindamycin and low concentration (<5%) BPO formulation. A 33% reduction in skin irritation was seen when the BPO concentration was halved from 5% to 2.5% (clindamycin-BPO 2.5% gel), maintaining a comparable amount of total BPO delivered to the skin. As a result, clindamycin-BPO 2.5% gel appears to provide efficacy comparable to that of higher concentration (5%) fixed clindamycin-BPO combination products and should optimize patient compliance as a result of the reduction in cutaneous tolerability reactions, including signs of skin irritation or dryness. Clinical studies have shown clindamycin-BPO 2.5% gel to be highly effective with the potential for a more favorable tolerability profile compared to products containing higher concentrations of BPO.