Albumin-purification method comprising a nanofiltration step, solution, and composition for therapeutic use containing the same
The invention relates to an albumin-purification method comprising a step consisting in subjecting an aqueous albumin solution, with a concentration of between 15 g/l and 80 g/l and a pH of not lass than 7, to nanofiltration in a temperature range of between 15 DEG C and 55 DEG C. The invention also relates to: a virally-safe aqueous albumin solution which can be obtained using the inventive method and in which the sites for the transport and binding of the active therapeutic ingredients of the albumin are available; and an albumin composition for therapeutic use, which is obtained by adapting the albumin solution that is intended for clinical use.
1. A method for purifying an albumin solution containing virus particles to produce a virally safe albumin solution comprising a step of submitting an aqueous albumin solution, with a concentration of 15 g/L to 80 g/L, an ionic strength in the range of 0.01 to 0.3M, and a pH not lower than 7, to a nanofiltration carried out on qualified filters having porosities of 15±2 nm to 20 nm±2 nm in a temperature range of 15° C. to 55° C.
2. The method according to claim 1 wherein the pH of the aqueous albumin solution is in the range of 7.8 to 11.5.
3. The method according to claim 1 , wherein the ionic strength is provided by the addition of a pharmaceutically acceptable salt of an alkali metal.
4. The method according to claim 3 , wherein the salt of an alkali metal is sodium chloride present in an amount imparting to the albumin solution an ionic strength of 0.15 M.
5. The method according to claim 1 , wherein the concentration of the aqueous albumin solution is in the range of 40 g/L to 60 g/L.
6. The method according to claim 1 , wherein the temperature of the aqueous albumin solution is between 30° C. and 55° C.
7. The method according to claim 1 , wherein the nanofiltration of the aqueous albumin solution is carried out in two successive steps on two filters with decreasing porosities, respectively.
8. The method according to claim 7 , wherein the two successive nanofiltration steps are carried out on filters with porosities of 23 to 50 nm and 15 or 20 nm, respectively.
9. The method according to claim 1 , wherein it is implemented with regenerated cellulose filters of 15 nm having a surface area of 0.01 m 2 , at a pressure not exceeding 1 bar.
10. The method according to claim 9 , wherein the pressure is in the range of 0.2 to 0.8 bar.
11. The method according to claim 1 , wherein the albumin is obtained by ethanol extraction and by purification by ion-exchange or affinity chromatography.
12. The method according to claim 1 , further comprising a subsequent step of processing the aqueous albumin solution to make it suitable to a therapeutic use.
13. The method according to claim 1 , wherein the pH of the aqueous albumin solution is in the range of 9 to 10.5.