pharmaceutics Review Targeted Topical Delivery of Retinoids in the Management of Acne Vulgaris: Current Formulations and Novel Delivery Systems Gemma Latter 1, Jeffrey E. Grice 2, Yousuf Mohammed 2 , Michael S. Roberts 2,3 and Heather A. E. Benson 1,* 1 School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth 6845, Australia;
[email protected] 2 Therapeutics Research Group, The University of Queensland Diamantina Institute, School of Medicine, University of Queensland, Translational Research Institute, Brisbane 4109, Australia; jeff
[email protected] (J.E.G.);
[email protected] (Y.M.);
[email protected] (M.S.R.) 3 School of Pharmacy and Medical Sciences, University of South Australia, Basil Hetzel Institute for Translational Health Research, Adelaide 5011, Australia * Correspondence:
[email protected]; Tel.: +61-8-9266-2338 Received: 19 August 2019; Accepted: 17 September 2019; Published: 24 September 2019 Abstract: Acne vulgaris is a common inflammatory pilosebaceous condition that affects 80–90% of adolescents. Since the introduction of tretinoin over 40 years ago, topical retinoid products have been a mainstay of acne treatment. The retinoids are very effective in addressing multiple aspects of the acne pathology as they are comedolytic and anti-inflammatory, and do not contribute to antibiotic resistance or microbiome disturbance that can be associated with long-term antibiotic therapies that are a common alternative treatment. However, topical retinoids are associated with skin dryness, erythema and pain, and may exacerbate dermatitis or eczema. Thus, there is a clear need to target delivery of the retinoids to the pilosebaceous units to increase efficacy and minimise side effects in surrounding skin tissue.