Xeragenx Cobalamin Ribbon

Cobalok™ is a value-added biopharmaceutical ingredient complex consisting of vitamin B12 as hydroxocobalamin (OHCbl) pre-bound to its natural binding protein, intrinsic factor.

The intrinsic factor used in Cobalok™ is a recombinant form of human intrinsic factor (rhIF) that was transgenically expressed in the plant Arabidopsis thaliana.  The rhIF contains an exact 100% match in its genomic sequence to human IF and has demonstrated equivalent B12 binding and superior cubilin receptor binding when compared with native human IF.[5]

Intrinsic factor protein attaches to the vitamin B12 molecule in a 1:1 molecular ratio (see ribbon diagram of intrinsic factor bound to cobalamin with the Cbl molecule shown in ball and stick).[28]  Thus, the amount of intrinsic factor pre-bound to OHCbl in Cobalok™ is determined by the ratio between the two molecular masses, which calculates to a coefficient of proportionality of approximately 37.  For every 1 mcg of OHCbl in Cobalok™, approximately 37 mcg of rhIF will be pre-bound.

Cobalok™ will be offered as an active pharmaceutical ingredient (API) granulate for use in products formulated to deliver vitamin B12 in oral dosage forms.