Colloids and Surfaces B: Biointerfaces 121 (2014) 222–229 Contents lists available at ScienceDirect Colloids and Surfaces B: Biointerfaces jo ur nal ho me p ag e: www.elsevier.com/locate/colsurfb Adapalene loaded solid lipid nanoparticles gel: An effective approach for acne treatment Amit K. Jain a,d , Ashay Jain a,b , Neeraj K. Garg a,b , Abhinav Agarwal a , Atul Jain a,b , Som Akshay Jain a,d , Rajeev K. Tyagi c , Rakesh K. Jain a,d , Himanshu Agrawal e , Govind P. Agrawal a,∗ a Department of Pharmaceutical Sciences, Dr. Hari Singh Gour Vishwavidyalaya, Sagar, MP 470003, India b Drug Delivery Research Group, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Studies, Panjab University, Chandigarh 160014, India c Department of Periodontics, College of Dental Medicine Georgia Regents University, 1120 15th Street, Augusta, GA 30912, USA d Bhagyoday tirth Pharmacy College, Khurai Road, Sagar, MP 470001, India e Pharmaceutics Research Laboratory, M. S. University of Baroda, Vadodara, India a r t i c l e i n f o Article history: Received 12 January 2014 Received in revised form 27 May 2014 Accepted 29 May 2014 Available online 6 June 2014 Keywords: Adapalene Solid lipid nanoparticles (SLNs) Acne Epidermal targeting Rheology Topical delivery a b s t r a c t Salient features such as controlled release, target ability, potential of penetration, improved physical stability, low cost compared to phospholipids, and ease of scaling-up makes solid lipid nanoparticles (SLNs) a viable alternative to liposomes for effective drug delivery. Adapalene (ADA) is a second generation retinoid effective in treating various dermatologic disorders such as Acne vulgaris with a few noticeable dose-mediated side effects. The present study was aimed at developing and characterizing ADA loaded SLNs for effective topical delivery. The formulated SLN system was characterized for particle size, poly dispersity index, entrapment efficiency and drug release properties. The resultant formulation (ADA loaded SLNs incorporated into carbopol hydrogel) was evaluated for in vitro drug release, skin permeation and bio-distribution, rheological behaviour, and texture profile analysis. The SLNs based ADA gel has shown its potential in targeting skin epidermal layer, and reducing systemic penetration. The developed system can avoid systemic uptake of ADA in skin layers, and can localize drug in skin epidermis as confirmed by rat skin model. Our results advocate potential of SLNs as a novel carrier for topical delivery of ADA in topical therapeutic approaches. This study open new avenues for drug delivery which better meets the need of anti-acne research. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Acne vulgaris (AV) is the most common dermatological disorder rarely posing a serious threat, but affecting overall performance millions of individuals [1]. AV is usually associated with inflamma- tion of pilosebaceous units caused by the gram-positive organism, Propionibacterium acnes on mainly face skin, neck, chest and upper back [2,3]. The microenvironment of sebaceous follicles undergoes selective changes that leads plugging of pilosebaceous follicles and development of micro-comedo resulting in to acne lesions, includ- ing non-inflammatory as well as inflammatory nodules [4]. There are effective treatments available such as topical and oral antibi- otics, topical and oral retinoids. The retinitis is one of the regularly prescribed classes of medicine. The topical treatment is the first ∗ Corresponding author. Tel.: +91 9981338997. E-mail address: agrawal.gp.dops@gmail.com (G.P. Agrawal). choice in mild and moderate acne, whereas systemic therapy is applied to treat severe and moderate cases [5]. The topical treat- ment of mild to moderate acne with all trans retinoic acid (RA) has been effective in acne therapeutic [6]. Retinoids, natural or synthetic derivatives of vitamin A, due to their ability to modify abnormal follicular keratinization are highly effective in Acne vulgaris therapeutics [4]. The topical application of RA follows high incidences of skin irritation, photosensitivity, and low patient compliance. The systemic therapy with antibiotics has its own disadvantages such as nausea, vomiting, and contraceptive failure in pregnant women [7]. The administration of a drug via topical route is a better option than systemic route using novel drug delivery systems, and present potential to reduce side effects without having an effect on drug efficacy [8]. Solid lipid nanoparticles (SLNs) as novel nano-particulate car- rier systems have drawn considerable attention due to improved delivery and stability of drugs. SLNs consist of biocompatible lipid core and an amphiphilic surfactant at the outer shell [9]. They have http://dx.doi.org/10.1016/j.colsurfb.2014.05.041 0927-7765/© 2014 Elsevier B.V. All rights reserved.