Preparation of biodegradable cyclosporine nanoparticles by high-pressure emulsification-solvent evaporation process

The cyclic endecapeptide cyclosporine (CsA), a potent immunosuppressive drug, was incorporated into biodegradable poly (dl-lactide-co-gylcolide) (dl-PLG) 50/50, 65/35 and PEG 5000-70/30 dl-PLG to improve the oral bioavailability and pharmacokinetics. Nanoparticles were prepared by a high-pressure emulsification-solvent evaporation (HPESE) process. The CsA-loaded nanoparticles were evaluated for particle size, zeta potential, surface morphology by scanning electron microscopy (SEM), thermal characterizations by differential scanning calorimetry (DSC), encapsulation efficiency (E.E.%) and in vitro release. The amount of CsA loaded into the nanoparticles was determined using high-performance liquid chromatography (HPLC) at a detection wavelength of 210 nm. The mobile phase was acetonitrile–water (70:30% v/v) and flow rate was set at 1.5 ml min−1. The photon correlation spectroscopy showed that the particles size were