Method for removing residual organic solvent from a crystalline oligosaccharide
The present invention relates to a method of removing residual organic solvent from crystalline oligosaccharides by the use of water vapour as well as the pharmaceutically and nutritionally suitable crystalline oligosaccharides obtained by said method.
1. A method for reducing an amount or concentration of a residue of an organic solvent on a crystalline form of a human milk oligosaccharide hydrate, comprising the steps of:
exposing the crystalline form of a human milk oligosaccharide hydrate to water vapour in a vessel, wherein the interior space of the vessel has, or is maintained at, an elevated humidity relative to that outside the vessel; and
obtaining the same crystalline form of the oligosaccharide hydrate with reduced amount or concentration of a residue of an organic solvent,
wherein the organic solvent is selected from the group consisting of a lower alcohol, a ketone, and acetic acid.
2. The method according to claim 1 , wherein the elevated humidity in the interior space of the vessel is or is maintained within the range of 60-100 RH %.
3. The method according to claim 1 , wherein the amount or concentration of a residue of an organic solvent on the crystalline oligosaccharide hydrate after exposure is less than or equal to 100 ppm.
4. The method according to claim 1 , wherein the method is performed under vacuum.
5. The method according to claim 1 , wherein the crystalline oligosaccharide hydrate is DFL hydrate.
6. The method according to claim 1 , wherein the crystalline human milk oligosaccharide hydrate is LNnT polymorph III.
7. The method according to claim 1 , wherein the crystalline human milk oligosaccharide hydrate is LNT hydrate.
8. The method according to claim 1 , wherein the crystalline oligosaccharide hydrate is pLNnH hydrate.
9. The method according to claim 1 , wherein the lower alcohol is a C 1 -C 4 alkanol.
10. The method according to claim 9 , wherein the C 1 -C 4 alkanol is methanol.
11. A nutritional formulation comprising a crystalline human milk oligosaccharide hydrate obtained according to the method of claim 5 .
12. A nutritional formulation comprising a crystalline human milk oligosaccharide hydrate obtained according to the method of claim 6 .
13. A nutritional formulation comprising a crystalline human milk oligosaccharide hydrate obtained according to the method of claim 7 .
14. A nutritional formulation comprising a crystalline human milk oligosaccharide hydrate obtained according to the method of claim 8 .
15. A pharmaceutical formulation comprising a crystalline human milk oligosaccharide hydrate obtained according to the method of claim 1 .
16. A crystalline human milk oligosaccharide hydrate comprising an organic solvent on the crystalline oligosaccharide hydrate, wherein the amount of the organic solvent on the crystalline oligosaccharide hydrate is less than or equal to 100 ppm, and wherein the crystalline human milk oligosaccharide hydrate is selected from the group consisting of DFL hydrate, LNT hydrate and pLNnH hydrate.
17. A nutritional formulation comprising a crystalline oligosaccharide hydrate according to claim 16 .
18. A pharmaceutical formulation comprising a crystalline oligosaccharide-hydrate according to claim 16 .