Characterization of Copaxone® by TDAmax

Revital Krispin, Discovery Research and development, Teva pharmaceutical Ind., Netanya, Israel
Arthur Komlosh, Discovery Research and development, Teva pharmaceutical Ind., Netanya, Israel

Copaxone® is an aqueous solution containing 20mg/mL of the active ingredient Glatiramer Acetate (GA) and 40mg Mannitol. Glatiramer Acetate is a complex mixture of synthetic amino acid copolymer composed of a huge number of indiscriminate sequences of L-alanine, L-Lysine, L-Glutamate and L-Tyrosine. This complex mixture of linear polypeptides results in a varying chain sizes, therefore the molecular weight distribution of the GA components span over wide range of about 2,500 – 20,000Daltons.

Viscotek TDAmax is a dedicated multi-detector SEC system for polymers and macromolecules analysis. The Triple Detector Array (TDA) is comprised of three detectors that act simultaneously; refractive index (RI), viscometer and light scattering detector (LSD) providing complimentary characteristic data on the sample being analyzed including molecular weight and molecular size.

In this study Viscotek TDAmax was used for characterization of Copaxone® by certain molecular weight characteristics (such as Mn, Mw, and Mz), Polydispersity, hydrodynamic radius and intrinsic viscosity properties. These values are physical characteristics of the polypeptide chains and are derived from their chemical structure. Using this technique Copaxone® displayed a good batch to batch consistency, whereas purported generic copies showed differences within their characteristic parameters. The Viscotek TDAmax method demonstrated to be specific and discriminatory, and thus suitable for the analysis of Copaxone®.