Patent ID: 8329391

Claim:
A method of selecting a batch of a composition comprising glatiramer acetate for use in preparation of a pharmaceutical composition, the method comprising: providing a batch of a composition comprising glatiramer acetate manufactured by a method comprising polymerizing N-carboxy anhydrides of L-alanine, benzyl-protected L-glutamic acid, trifluoroacetic acid (TFA) protected L-lysine and L-tyrosine to generate a protected copolymer; treating the protected copolymer to partially depolymerize the protected copolymer and deprotect benzyl protected groups and deprotect TFA-protected lysines to generate glatiramer acetate; measuring the amount of pyro-glutamate (pyro-Glu) produced during manufacture of glatiramer acetate in a sample of the batch; and selecting the batch when the amount of pyro-Glu in the sample of the batch is less than 7000 ppm, thereby selecting a batch of a composition comprising glatiramer acetate.