Nanoemulsion based gel for transdermal delivery of meloxicam: Physico-chemical, mechanistic investigation

Aims: The aim of the present investigation was to develop a nanoemulsion (NE) gel formulation for the transdermal delivery of meloxicam (MLX) in order to ensure maximum controlled and sustained drug release capacity. Main methods: The MLX containing NE gel was prepared and characterized for particle size, zeta potential, pH, rheology, in vitro drug release, in vitro skin permeation, and in vitro hemolysis. Differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FTIR) of MLX-NE gel treated rat skin was performed to investigate the skin permeation mechanism of meloxicam from NE gel. Skin permeation potential of the developed gel formulation was assessed using confocal laser scanning microscopy (CLSM). The in vivo toxicity of MLX-NE gel was assessed by histopathological examination in rat. The rat paw edema test was performed to evaluate the anti-inflammatory activity of MLX-NE gel. Key findings: Percutaneous absorption studies demonstrated a higher permeation of meloxicam from NE gel, than the drug solution. FTIR and DSC studies supported stratum corneum lipid extraction as a possible penetration enhancer mechanism for MLX-NE gel. CLSM studies confirmed the permeation of the NE gel formulation to the deeper layers of the skin (up to 130 mu m). MLX-NE gel turned out to be non-irritant, biocompatible, and provided maximum inhibition of paw edema in rats over 24 h in contrast to MLX solution. Significance: The nanoemulsion gel formulation may hold promise as an effective alternative for the transdermal delivery of meloxicam. (c) 2013 Elsevier Inc. All rights reserved.