S-[2-[(1-iminoethy)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride crystalline salt
A novel mixed salt of S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine is disclosed. The novel mixed salt, S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride, may be produced to form crystals that may be arranged as generally orderly packed agglomerates, which are particularly useful in making pharmaceutical compositions. Such pharmaceutical compositions are also described, as well as methods to make crystalline S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride, and methods of treating conditions characterized by an overexpression on nitric oxide from the inducible isoform of nitric oxide synthase using the S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride.
1. A method of making generally orderly packed agglomerate crystalline S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride utilizing a crystallization procedure comprising adding an anti-solvent to a solvent solution in which is dissolved S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride, thereby forming a system comprising two phases, and precipitating generally orderly packed agglomerate crystalline S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride, wherein the anti-solvent comprises acetonitrile or acetone and the solvent comprises 1-butanol or N,N-dimethylformamide.
2. The method of claim 1 wherein the anti-solvent is added to the solvent solution in which is dissolved S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride, followed by addition of seed crystals to the system.
3. The method of claim 1 wherein the anti-solvent comprises acetone.
4. The method of claim 1 wherein the solvent solution comprises 1-butanol and S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride.
5. The method of claim 1 wherein the anti-solvent comprises acetonitrile, and the solvent solution comprises N,N-dimethylformamide and S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride.
6. The method of claim 1 wherein the anti-solvent comprises acetone, and the solvent solution comprises 1-butanol and S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride.
7. The method of claim 2 wherein no less than about one percent by weight of the total S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride in the system is introduced as added seed crystals.
8. The method of claim 1 wherein a sufficient amount of anti-solvent is added to a solvent solution comprising S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride in a reaction vessel to form a reaction system, until one of a) turbidity or b) an oily coating on a surface of said reaction vessel is visually apparent, and adding seed crystals to said system.
9. The method of claim 2 wherein the seed crystals are created in-situ by at least one of: reducing the water content of the solvent solution; reducing the amount of maleic acid; or altering the rate of super-saturation generation.
10. The method of claim 1 wherein no seed crystals are added to the system, and the ratio of anti-solvent added to the system exceeds the ratio of solvent solution in which is dissolved S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride by about one hundred and ten percent by weight that of the ratio of anti-solvent to solvent used in a system wherein seed crystals are added, to precipitate generally orderly packed agglomerate crystalline S-[2-[(1-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine maleate hydrochloride.