Solid pharmaceutical compositions comprising biopterin derivatives and uses of such compositions
The present invention relates to a method of preparing 4-Amino-(6R,S)-5,6,7,8-tetrahydro-L-biopterin dihydrochloride dihydrate.
1. A method of preparing 4-Amino-(6R,S)-5,6,7,8-tetrahydro-L-biopterin dihydrochloride dihydrate, the method comprising hydrogenating 4-Amino-L-biopterin of Formula (A)
using PtO 2 in diluted HCl as catalyst.
2. The method of claim 1 , wherein hydrogenation is carried out in 0.5 M HCl.
3. The method of claim 1 , wherein pre-hydrogenated PtO2 is used as catalyst.
4. The method of claim 2 , wherein the evaporation of water from the hydrogenated product of Formula (A) is performed in the presence of a co-solvent.
5. The method of claim 4 , wherein the co-solvent is 2-propanol to yield a solid having the formula (B)
6. The method of claim 5 , further comprising removing residual solvent from the solid of formula (B) to yield 4-Amino-(6R,S)-5,6,7,8-tetrahydro-L-biopterin dihydrochloride dihydrate.
7. The method of claim 6 , wherein removing of residual solvent is carried out by lyophilisation.