Hyaluronic acid is one of the most important ingredients in dermal fillers, where it is often cross-linked to gain more favorable rheological properties and to improve the implant duration. Poly(ethylene glycol) diglycidyl ether (PEGDE) has been recently introduced as a crosslinker because of its very similar chemical reactivity with the most-used crosslinker BDDE, while giving special rheological properties. Monitoring the amount of the crosslinker residues in the final device is always necessary, but in the case of PEGDE, no methods are available in literature. Here, we present an HPLC-QTOF method, validated according to the guidelines of the International Council on Harmonization, which enables the efficient routine examination of the PEGDE content in HA hydrogels.
