The present invention relates to compositions comprising polyplex formulations for delivery of RNA to a target organ or a target cell after parenteral administration, in particular after intramuscular administration. More precisely, the present invention relates to formulations for administration of RNA such as self-replicating RNA, in particular by intramuscular injection. In more detail, the formulations comprise polyplex particles from single stranded RNA and a polyalkyleneimine. The RNA may encode a protein of interest, such as a pharmaceutically active protein. Furthermore, the present invention relates to pharmaceutical products, comprising said RNA polyplex formulations for parenteral application to humans or to animals. The present invention relates as well to manufacturing of such pharmaceutical products, comprising, optionally, steps of sterile filtration, freezing and dehydration.Linvention porte sur une formule polyplexes dadministration dARN à un organe ou à une cellule cible par voie parentérale, notamment intramusculaire. La formule dadministration dun ARN, tel quun ARN auto-réplicatif, par injection intramusculaire comprend des particules polyplexes provenant dun ARN simple brin et dune polyalkylèneimine. La présente invention porte également sur des produits pharmaceutiques, comprenant la formule de polyplexes dARN, les étapes de filtration, de congélation et de déshydratation stériles, pour une application parentérale à des êtres humains ou à des animaux.
