Crystalline D-isoglutamyl-D-tryptophan and the mono ammonium salt of D-isoglutamyl-D-tryptophan
AssigneeApotex Technologies Inc.
InventorsTim Fat Tam, Blaise N'Zemba, Regis Leung-Toung, Yingsheng Wang, Yanqing Zhao, Lily Yu
Life of this patent
Estimating the term…
Abstract
A process for making pure crystalline D-isoglutamyl-D-tryptophan is provided which includes the step of deprotecting essentially pure N-tert-butoxycarbonyl-D-isoglutamyl-D-tryptophan or its diester to yield essentially pure D-isoglutamyl-D-tryptophan. A process is also provided for the preparation of pure mono ammonium salt of D-isoglutamyl-D-tryptophan from essentially pure N-tert-butoxycarbonyl-D-isoglutamyl-D-tryptophan. D-isoglutamyl-D-tryptophan, ammonium salt (1:1) is a stable pharmaceutical solid.
Claims16
An aqueous phase process for the preparation of D-isoglutamyl-D-tryptophan, free of inorganic salts, which process comprises the following steps:
- (a) preparing a solution of H-D-iGlu-D-Trp-OH acid addition salt in an aqueous medium essentially free of organic solvent;
- or preparing a solution of H-D-iGlu-D-Trp-OH base addition salt in an aqueous medium essentially free of organic solvent;
- (b) adjusting the pH to from about 2.0 to about 3.2 with an alkali metal hydroxide solution or a mineral acid solution, to cause the precipitation of H-D-iGlu-D-Trp-OH;
- (c) recovering the precipitated H-D-iGlu-D-Trp-OH thereof;
- and
- (d) vacuum drying the product resulting from step (c) to give H-D-iGlu-D-Trp-OH.
Dependencies are inferred from the claim text.