Improved multidetector asymmetrical-flow field-flow fractionation method for particle sizing and concentration measurements of lipid-based nanocarriers for RNA delivery

•Use of the frit-inlet channel improves MD-AF4 analysis of LNP-RNA.•A robust method for AF4 separation of LNP-RNA has been developed and tested on two different platform.•The method meets all the ISO standard requirements for AF4 analysis.•The method allowed the analysis of particle size, morphology and physical stability.•A macro to display quantitative number based-particle size distributions by AF4-MALS was developed and successfully implemented.