Isoniazid loaded core shell nanoparticles derived from PLGA-PEG-PLGA tri-block copolymers: in vitro and in vivo drug release.

A series of biodegradable low molecular weight PLGA-PEG-PLGA tri-block copolymers have been synthesized in powder form. The anti-tuberculosis drug Isoniazid (INH) loaded polymeric core-shell nanoparticles (CSNPs) have been prepared by sonication followed by water-in-oil-in-water (w/o/w) double emulsification technique. The nanoparticles (NPs) have been characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and X-ray photo electron spectroscopic (XPS) techniques. The drug loaded CSNPs were found to be 150-400 nm in size with spherical shape. The drug loading efficiency and drug content of the polymer NPs were determined by UV-vis spectrophotometry. The drug loading efficiency and drug content of the NPs were (12.8-18.67%) and (6.4-8.9%) respectively. The in vitro release behavior of the polymer NPs has been investigated by UV-vis spectrophotometry and the release kinetics mechanism has been evaluated by Korsemeyer-Peppas (KP) and Higuchi models. The in vitro release studies show initial burst release followed by controlled and uniform release for longer duration. The pharmacokinetic studies show that the INH bioavailability of INH loaded CSNPs is 28 fold higher than that of free INH and also the CSNPs show sustained drug release for longer duration.