Spray-dried indomethacin-loaded polymeric micelles for the improvement of intestinal drug release and permeability

Current study aimed to develop a spray-dried powder containing indomethacin (IND)-loaded polymeric micelles which can be administered perorally as a dissolved powder to enhance the drug release and permeability of the active substance. The resulting low dense spray-dried spherical particles have decreased particle size (7.21 µm) in monodisperse distribution. The polymeric micelles had a nano size range (130 nm) also in monodisperse size distribution. These nanoparticulate properties and the high encapsulation efficiency (80%) lead to the improvement of gastrointestinal drug release in fasted and fed state conditions. Following second order and Higuchi kinetics, a rapid drug release was experienced exceeding the initial IND suspension. In vitro cell line studies on Caco-2 human colorectal adenocarcinoma cells showed that the formulation does not increase the toxicity of initial IND, therefore can be considered safe for oral application. Ex vivo semiquantitative and quantitative studies were performed on porcine small intestine where increased flux and permeability values of IND were achieved. The physical stability of the solid formulation was sufficient through a 6-month intermediate study caused by the hydrogen-bond formation between IND and the micelle-forming co-polymer.