Biodegradable Amphiphilic Tri-Block Copolymeric Nanoparticles for Controlled MTB Drug Delivery
. A series of biodegradable amphiphilic tri-block copolymers (PLGA–PEG–PLGA) have been derived from the diblock copolymer poly (lactic–co–glycolic acid (PLGA)) and polyethylene glycol (PEG). The mycobacterium tuberculosis (MTB) drug pyrazinamide (PZA) loaded polymer nanoparticles (NPs) have been prepared by probe-sonication followed by w/o/w double emulsification technique. The copolymers have been characterized by FTIR and 1HNMR spectroscopic techniques, TG-DTA analysis, GPC analysis and powder XRD pattern. The MTB drug loaded polymeric NPs have been characterized by FESEM, powder XRD, HRTEM and XPS analysis. The drug loading efficiency, drug content and in vitro drug release studies have been carried out by spectrophotometry. The drug loading efficiency and drug content of triblock copolymeric NPs were higher than these of diblock copolymeric microparticles (MPs). The in vitro drug release studies indicate that the NPs exhibit initial burst release followed by controlled release of PZA for longer durations. The drug release kinetics mechanism has been evaluated by zero order, first order, Korsemeyer-Peppas (KP) and Higuchi models.