title: In vitro drug release behavior, mechanism and antimicrobial activity of rifampicin loaded low molecular weight PLGA-PEG-PLGA triblock copolymeric nanospheres.
abstract: Poly (lactic-co-glycolic acid) (PLGA (92:8)) and a series of PLGA-PEG-PLGA tri block copolymers were synthesized by direct melt polycondensation. The copolymers were characterized by FTIR, and 1HNMR spectroscopic techniques, viscosity, gel permeation chromatography (GPC) and powder x-ray diffraction (XRD). The rifampicin (RIF) loaded polymeric nanospheres (NPs) were prepared by ultrasonication-W/O emulsification technique. The NPs have been characterized by field emission scanning electron microscopy (FESEM), TEM, powder X-ray diffraction (XRD), UVvisible spectroscopy and DLS measurements. The drug loaded triblock copolymeric NPs have five folds higher drug content and drug loading efficiency than that of PLGA microspheres (MPs). The in vitro drug release study shows that the drug loaded NPs showed an initial burst release after that sustained release up to 72 h. All the triblock copolymeric NPs follow anomalous drug diffusion mechanism while the PLGA MPs follow non-Fickian super case-II mechanism up to 12 h. The overall in-vitro release follows second order polynomial kinetics up to 72 h. The antimicrobial activity of the RIF loaded polymer NPs was compared with that of pure RIF and tetracycline (TA). The RIF loaded triblock copolymeric NPs inhibited the bacterial growth more effectively than the pure RIF and TA.
authors.affiliation: Department of Inorganic Chemistry, Guindy Campus, University of Madras, Chennai, India-600 025. bala2010@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Gajendiran
authors.forename: S
authors.initials: S
authors.lastname: Divakar
authors.forename: N
authors.initials: N
authors.lastname: Raaman
authors.forename: S
authors.initials: S
authors.lastname: Balasubramanian
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002850:Chromatography, Gel; D003692:Delayed-Action Preparations; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008863:Microspheres; D008970:Molecular Weight; D054118:Nanospheres; D011092:Polyethylene Glycols / Q000737:chemistry; D011098:Polyglactin 910 / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D012293:Rifampin / Q000008:administration & dosage / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013752:Tetracycline / Q000494:pharmacology; D014783:Viscosity; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011108:Polymers; C528571:poly(lactic-co-glycolic acid)-polyethylene glycol-poly(lactic-co-glycolic acid); D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011098:Polyglactin 910; D011092:Polyethylene Glycols; D013752:Tetracycline; D012293:Rifampin