Enhancing Topical Pharmacotherapy for Acne and Rosacea: Vehicle Choices and Outcomes.

The choice of vehicle is an important consideration in the treatment of acne and rosacea. Agents used to treat these common conditions may be limited by multiple factors, including poor stability during storage, limited residence time in the skin and follicular unit, and high potential for skin irritation. Novel drug delivery systems have been developed to address these problems, including microencapsulation, liposomal encapsulation, and the use of a variety of nanocarriers. New vehicle technologies for acne and rosacea treatments have appeared over the past 20 years and have somewhat improved stability, tolerability, and possibly efficacy. One of the latest vehicle technologies in acne and rosacea to enhance efficacy, stability, and tolerability is microencapsulation of benzoyl peroxide and tretinoin, which resulted in significant efficacy and good tolerability in patients with each of these two diseases. Other new vehicle technologies include a polymeric form of tretinoin and a microsphere product that combines tretinoin plus clindamycin. It is likely that there will be more reports of clinical success as experience with the rapidly evolving delivery technologies increases. This review summarizes drug delivery systems that have been developed with the aim of improving outcomes for patients being treated for either acne or rosacea. It also focuses, where possible, on formulations that have been evaluated in clinical studies.