Work Item
ASTM WK67980

New Test Method for Quantifying Poly(ethylene glycol) Coating on the Surface of Gold Nanostructured Materials Using High Performance Liquid Chromatography with Evaporative Light Scattering Detection (HPLC/ELSD)

1. Scope

Poly(ethylene glycol) (PEG) with thiol functionality is routinely used to provide a non-immunogenic, passivating, bio-compatible coating on gold nanoparticles to provide long-term colloidal stability in biological environment. Variability in these coatings/stability can influence biocompatibility and altered biodistribution. Different molecular weights of PEG are used in different products and are often difficult to quantify as unmodified PEG are non-chromophoric, requiring a lot of sample. Accurate quantitation of these coatings with sensitive methods is critical for quality control for medical products. This test method describes a protocol for quantitative assessment of PEG coating on gold nanoparticles or gold nanorods, with commonly available HPLC instrumentation in analytical laboratories with ELSD detection.




Poly(ethylene glycol) (PEG) and their derivatives are utilized in many drug products, devices, cosmetics, and consumer products. PEG derivatives and bifunctional PEGs with various molecular weights have been utilized for surface functionalization and bioconjugations with nanomaterials to provide aqueous solubility, long-term colloidal stability, and biocompatibility. The differences in the quantity of nanomaterial surface-bound PEG in drug products containing nanomaterials may lead to an altered biocompatibility, immune system recognition, biodistribution, safety and efficacy. Hence, the quantitative measurement of PEG (i.e., either bound or unbound to the nanomaterial surface) is a critical quality attribute for drug products containing PEGylated nanomaterials and requires standardized methods and methodologies. This test method describes a standardized assay for the quantitative assessment of PEG coating on a gold nanoparticle (AuNP) using a high-performance liquid chromatography (HPLC) system with a mass-flow sensitive evaporative light-scattering detector. This test method is critical to the drug development, quality control, and assurance of nanoparticle containing products for pharmaceutical industry and the review of such products by regulatory agencies.

The title and scope are in draft form and are under development within this ASTM Committee.


Developed by Subcommittee: E56.08

Committee: E56

Staff Manager: Frank McConnell

Work Item Status

Date Initiated: 04-26-2019

Technical Contact: Goutam Palui

Item: 000