(671g) Glass Transition Temperature in PLGA Nanoparticles
AIChE Annual Meeting
Thursday, November 17, 2022 - 5:00pm to 5:15pm
Studies showed that, even after purification, a small amount of residual polyvinyl alcohol (PVA), a common surfactant during particle synthesis, remains in the PLGA nanoparticle matrix. This residual PVA can be attached to the particle surface or remain inside the particle itself, and its weight percentage can be as high as 13 wt%. The surface attached surfactant is going to change the hydrophilicity of the particle thus leading to different cellular uptake. Therefore, measuring the residual surfactant is important in drug delivery of PLGA particles. Herein, we proposed a novel method to evaluate the remaining PVA by TMDSC (temperature modulated differential scanning calorimetry). According to our findings, nanoprecipitation PLGA nanoparticles had a residual PVA content of 8% ~ 12%, while particles prepared by nanoemulsion had between 6% to 10%. Results from 1H nuclear magnetic resonance spectroscopy (NMR) and UV/Vis spectroscopy will also be presented.
Furthermore, we selected the non-polymeric surfactant didodecyl dimethyl ammonium bromide (DMAB) as alternative stabilizer in PLGA nanoparticle preparation in order to minimize the Tg increase from a second component in the particle matrix. Our results showed that Tg of DMAB-PLGA NPs is higher than that of bulk, which is in contrast to previous investigations of PS nanoparticles in confinement, suggesting the role of surfactant and interfaces in the Tg of PLGA particles may differ from that of PS.