Preparation of Gentamicin Sulfate Nanoparticles using Eudragit RS-100 and Evaluation of Their Physicochemical Properties

Improving permeability and absorption of drugs are critical research challenges in pharmaceutical science. Gentamicin sulfate is an aminoglycoside antibiotic, which is very active against gram-negative bacteria; however, it has very poor bioavailability. This study aimed to prepare gentamicin nanoparticles with the intention of increased bioavailability. Accordingly, Eudragit RS-100 nanoparticles loaded with gentamicin sulfate were prepared by the double emulsification and solvent evaporation method, a proper technique for encapsulating hydrophilic molecules. Nanoparticles’ suspensions with polymer to drug ratios of 1:1 ([Formula: see text] and 2:1 ([Formula: see text]) were prepared, lyophilized and evaluated for their production yield, physicochemical properties and morphology. The mean particle size was 195.67[Formula: see text]nm and 228[Formula: see text]nm for [Formula: see text] and [Formula: see text], respectively. The formulations’ loading efficiencies were relatively high (85.73 for [Formula: see text] and 85.20 for [Formula: see text]). The nanoparticles’ surface charge (+40.5[Formula: see text]mV) was sufficient to inhibit their aggregation and facilitate the nanoparticles’ absorption through the gastrointestinal tract. The results of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) revealed that drug and polymer stabilized each other by physical interactions between their functional groups. Both formulations presented an initial burst drug release of nearly 20% after 30[Formula: see text]min in phosphate buffer (pH = 7.4). After 24[Formula: see text]h, [Formula: see text] did not release the drug completely, while [Formula: see text] released the whole drug. Overall, nanoparticles with proper characteristics were obtained. This study puts forward the necessity of conducting further research in order to explore the intestinal absorption of these nanoparticles and the possibility of being utilized for oral administration of gentamicin sulfate.