LYOPHILIZED COMPOSITION FOR GAS-FILLED MICROVESICLES Russian patent published in 2023 - IPC A61K49/22 A61K9/19 

FIELD: production of contrast agents.

SUBSTANCE: group of inventions concerns a composition for obtaining gas-filled microvesicles for use in ultrasound contrast imaging and a method for its production, as well as a sealed vial containing such a composition and a suspension obtained from such a composition. The lyophilized powder composition for producing gas-filled microvesicles comprises a phospholipid and a polyethylene glycol, said polyethylene glycol being PEG4000 having a number average molecular weight (Mn) of at least 4000 g/mol and having a percentage of folded polymer chains above 35%. A sealed vial is also provided containing the above composition in contact with a physiologically acceptable gas, and a suspension of gas-filled microvesicles obtained by dispersing the above lyophilized composition in the presence of a gas in a physiologically acceptable liquid. A process is also provided for the production of a lyophilized composition containing a phospholipid and polyethylene glycol, comprising: a. dissolving said phospholipid and said polyethylene glycol in a solvent, thereby obtaining a solution; b. freezing solution; and c. removal of the solvent by lyophilization; wherein said polyethylene glycol is PEG4000 having a number-average molecular weight (Mn) of at least 4000 and having a percentage of folded polymer chains above 35%, and a lyophilized composition obtained by said method.

EFFECT: use of PEG4000, which has an increased percentage of folded polymer chains (above 35%), reduces the number of discarded vials.

15 cl, 3 dwg, 8 tbl, 4 ex