The present invention relates to a method of producing low viscous and highly concentrated biopharmaceutical drug products comprising a biomolecule of interest, the method comprising: (a) a first phase of preparing a drug substance of the biomolecule of interest, said first phase comprising at least one processing step selected from (a1) harvesting, (a2) purification, (a3) re-buffering, and (a4) enrichment, wherein said at least one processing step in this first phase is carried out in the presence of a composition comprising at least three amino acids, wherein the combination of said at least three amino acids provides at least one positively charged functional group, at least one anti-oxidative functional group, at least one osmolytic function, and at least one buffering function, and (b) a second phase of further processing the drug substance prepared in (a) to obtain a low viscous and highly concentrated biopharmaceutical drug product, said second phase comprising at least one processing step selected from (b1) re-buffering, (b2) freezing, (b3) thawing, and (b4) filling； wherein said at least one processing step in this second phase is carried out in the presence of a composition comprising (i) at least three amino acids, wherein the combination of said at least three amino acids provides at least one positively charged functional group, at least one anti-oxidative functional group, at least one osmolytic function, and at least one buffering function； and (ii) one or more sugar(s)； in an amino acid:sugar ratio between 10:1 to 1:100 (w/w). The present invention further relates to a low viscous and highly concentrated biopharmaceutical drug product obtained or obtainable by the method of the invention.La présente invention concerne un procédé de production de produits médicamenteux biopharmaceutiques à faible viscosité et hautement concentrés comprenant une biomolécule d'intérêt, le procédé comprenant : (a) une première phase de préparation d'une substance médicam
