Preparation characterization and in vivo evaluation of nifedipine-loaded biodegradable PLGA nanoparticles for improved oral bioavailability / Suhaili Zainal Abidin

In recent years, technological advancements have brought us many innovative drug delivery systems. Among those, polymeric nanoparticles systems from biodegradable and biocompatible polymer are interesting option for drug delivery. Poly lactic-co glycolic acid) PLGA nanoparticles have gained attention for preparation of a wide variety of delivery systems containing several drugs. Nifedipine as a model drug is poorly soluble in water with low bioavailability. Loading nifedipine into PLGA nanoparticles may improve the solubility and bioavailability of the drug. Nifedipine loaded PLGA nanoparticles were prepared by solvent displacement method. For preparation of the PLGA nanoparticles, several parameters were investigated such as PLGA concentration, surfactant concentration, types of surfactants, technique of adding the solvent and ratio of aqueous to organic phases can be characterized by measuring the particle size, size distribution, zeta potential and morphology of PLGA nanoparticles. The results showed that the optimum formulations gave nanoparticles a smaller size and with better distribution and zeta potential. The surface morphology of nanoparticles images showed a spherical shape and smooth surface of blank PLGA nanoparticles and nifedipine loaded PLGA nanoparticles. The drug loaded PLGA nanoparticles were designed in three different formulations with 10, 20 and 30 % w/w of theoretical drug loading. The drug content and the drug entrapment increased with a rise in the theoretical drug loading. It was necessary to examine the interaction between the drug and the polymer during the preparation. The FTIR spectra were used to examine the interaction between the drug and the polymer. Comparing the characteristic absorption bands of nifedipine and PLGA that existed in nifedipine loaded PLGA nanoparticles, no chemical shift was found. In order to assess the in vivo release of nifedipine from PLGA nanoparticles, nifedipine level was measured in the rat plasma.