Abstract
Background: Poly(lactic-co-glycolic acid) (PLGA), an FDA-approved copolymer, is widely recognized for its biocompatibility, biodegradability, and versatility in drug delivery systems. Despite its advantages, challenges, such as poor drug loading and burst release, motivate the exploration of innovative modifications. The current research aimed to modify the linear PLGA to lipoyl ester terminated star PLGA polymer to minimize initial burst release by increasing the molecular weight and fabricate risperidone-loaded microspheres.
Methods: In this study, we have presented a novel approach involving the synthesis of star PLGA through the direct melt polycondensation of PLGA with pentaerythritol, followed by conjugation with lipoic acid to form lipoyl ester terminated star PLGA. Structural confirmation was done by Fourier Transform Infrared spectroscopy (FT-IR), proton Nuclear Magnetic Resonance (1H-NMR), and Gel Permeation Chromatography (GPC). Microspheres were fabricated from lipoyl ester terminated star PLGA and characterized for their particle size and surface morphology by Scanning Electron Microscopy (SEM) and in vitro drug release by dialysis bag method.
Results: The results of the study have indicated successful conjugation of lipoic acid to star PLGA forming lipoyl ester terminated star PLGA, as confirmed by FT-IR, 1H-NMR, and GPC analyses. Microspheres developed from the synthesized polymer exhibited particle sizes ranging from 4.64 μm to 11.7 μm and demonstrated sustained drug delivery, with 99.8% release over 45 d, in contrast to the plain drug that achieved complete dissolution within 3 h.
Conclusion: The resulting material has demonstrated unique bioresponsive and multifunctional properties, with evidence of successful synthesis provided through comprehensive characterization techniques, and suitability for the fabrication of microspheres for sustained drug delivery systems.
Graphical Abstract
