Search

In this study we aimed to develop a semi-solid formulation of polymeric nanoparticles loaded with adapalene to enhance the efficacy and improve the skin tolerability in acne therapy. An amphiphilic and biocompatible copolymer that self-assembles to nanospheres (known as TyroSpheres) was used to encapsulate adapalene and increase its solubility. A water-soluble viscous agent was applied to prepare a gel formulation of adapalene-loaded TyroSpheres (aapalene-TyroSphere). Particle size, morphology, homogeneity, and rheological characteristics of the adapalene-TyroSphere gel formulations were studied. The formulation with the preferred physical and structural properties was further investigated for in vitro skin irritation and in vivo comedolytic activity in a rhino mouse model. Based on the in vitro skin irritation study encapsulation of adapalene in TyroSphere significantly decreased secretion of pro-inflammatory cytokines (IL-1α and IL-8), confirming that the TyroSphere formulation of adapalene is less irritant than the commercial gel (Differin). TyroSphere gel formulation of adapalene improved the comedolytic properties of the formulation by significantly reducing the size of open utricles in rhino mice compared to Differin treatment. Using TyroSpheres, we were able to develop an alternative topical formulation of adapalene, which is potentially less irritant and more potent than the commercial product.

The purpose of this study is to develop a new formulation of adapalene for the topical treatment of acne. We investigated applicability of polymeric nanocarriers based on tyrosine-derived nanospheres (TyroSpheres) for adapalene delivery. TyroSpheres effectively encapsulated adapalene and substantially enhanced its aqueous solubility, while decreasing the crystallinity of the drug in the formulation. Skin distribution of adapalene via TyroSphere formulation was evaluated ex vivo using human cadaver and porcine ear skin, and this was compared with the commercial adapalene formulation, Differin®. Sustained drug release across stratum corneum in 51 h was observed from TyroSpheres. Additionally, in vitro skin irritation studies demonstrated that encapsulation of adapalene in TyroSpheres significantly reduced the irritancy of the drug to monolayer HaCaTs and reconstituted human epidermis (EpiDerm™, MatTek Corp.). The results suggest that TyroSpheres provide a promising carrier system to deliver hydrophobic drugs to hair follicles and upper epidermis while minimizing skin irritation of the encapsulated drug., (Copyright © 2016 Elsevier Inc. All rights reserved.)