Preparation and comprehensive physicochemical characterization of trastuzumab-loaded PEGylated liposomal nanoparticles for systemic delivery

ObjectiveThe primary objective of this experimental formulation-development study was to prepare and physicochemically characterize a trastuzumab-loaded liposomal formulation containing post-inserted DSPE-PEG2000 for systemic-delivery research. The secondary objective was to determine whether the preparation and recovery process preserved trastuzumab monomeric integrity and HER2-binding activity.MethodsLiposomes were prepared by thin-film hydration, pulsed probe sonication, sequential membrane extrusion, post-insertion of DSPE-PEG2000, and dialysis purification. The 65:30:5 phosphatidylcholine:cholesterol:DSPE-PEG2000 molar composition was selected using literature-guided operational criteria; no formal Design of Experiments model was used. Particle size, PDI, zeta potential, dialysis-based apparent encapsulation efficiency, morphology, physicochemical properties, antibody integrity, HER2-binding activity, and 28-day storage stability were evaluated using DLS, microscopy, FTIR, DSC, TGA, XRD, SEC-HPLC, and HER2-binding ELISA.ResultsThe selected formulation had a mean particle size of 149.3 ± 5.8 nm, PDI of 0.22 ± 0.02, apparent zeta potential of +39.1 ± 2.1 mV under low-conductivity measurement conditions, and dialysis-based apparent encapsulation efficiency of 73.6 ± 3.7%. Recovered trastuzumab remained predominantly monomeric (94.9 ± 1.4%) and largely retained HER2-binding activity (92 ± 6%). Refrigerated samples showed the smallest 28-day changes, whereas 37 °C storage increased particle size and PDI and reduced apparent encapsulation efficiency.ConclusionsThe selected formulation met the predefined physicochemical and protein-quality endpoints and largely preserved trastuzumab integrity and HER2-binding activity. Refrigeration provided the greatest short-term stability. The findings establish an integrated characterization benchmark under the tested conditions but do not demonstrate quantified surface PEG density, physiological zeta-potential behavior, hemocompatibility, prolonged circulation, biodistribution, or therapeutic efficacy.

Abstract from PubMed (PMID 42969552). This entry was added automatically by our daily literature monitor because it matches the topics we follow; read the full paper at the original source.