Quantification of Pluronic F127 used on PLGA nanoparticle preparation and comparing purification techniques by centrifugation, tangential flow filtration, and ultrafiltration

Emerging research in polymeric nanoparticles (PNP) in the field of drug delivery systems focuses on the preferable use of biocompatible materials like poly(lactic-co-glycolic) acid (PLGA). However, the substantial use of surfactant in achieving colloidal stability requires its subsequent elimination to avoid side effects. This study aimed to establish suitable conditions for detecting and quantifying Pluronic® F127 (F127), a non-ionic surfactant widely used for this specific purpose, through a precise Size Exclusion Chromatography (SEC) method. Then, comparing the F127 removal efficacy via three purification techniques: Centrifugation (Cf), Ultrafiltration (UF), and tangential flow filtration (TFF), determining the minor influence of surfactant removal on the colloidal and morphological properties of surfactant-free PLGA suspensions. Thus, to determine the most suitable strategy for purifying PNP. The initial results of the SEC method revealed two distinct molar mass distributions of F127, associated with a blend of triblock alongside a minor fraction of homopolymer or diblock. The method exhibited a high linear correlation (R² 0.99991) for surfactant concentrations ranging from 0.3 to 14.7 mg/mL. While assessing the three purification techniques, UF demonstrated proficiency in concentrating nanoparticle suspensions, albeit tending to retain a significant portion of the surfactant. In contrast, Cf displayed a remarkable capability in removing more than 90 % of the incorporated F127. However, Cf recovered only 60 % of the initial nanoparticles, predominantly eliminating smaller diameter particles. Conversely, TFF demonstrated high efficacy in surfactant removal, requiring an extended washing process and leading to minimal nanoparticle loss while leaving the colloidal variables unaffected.