Excipient bulking agents

Certain additives, salts, and bulking agents may be added primarily to improve vaccine stability upon storage (19,20). These excipients such as mannitol, glycine, and trehalose have a direct impact on the stability of the polypeptide or conjugate and are investigated for this purpose. 

Cryo- and Lyoprotectants and Bulking Agents Various mechanisms are proposed to explain why excipients serve as cryo- or lyoprotectants. The most widely accepted mechanism to explain the action of cryoprotection is the preferential exclusion mechanism [177]. Excipients that will stabilize proteins against the effects of freezing do so by not associating with the surface of the protein. Such excipients actually increase the surface tension of water and induce preferential hydration of the protein. Examples of solutes that serve as cryoprotectants by this mechanism include amino acids, polyols, sugars, and polyethylene glycol. 

Hot-melt extruded dosage forms are complex mixtures of active medicaments and functional excipients. The functional excipients may be broadly classified as matrix carriers, release modifying agents, bulking agents, and miscellaneous additives. The selection and use of various excipients can impart specific properties to hot-melt extruded pharmaceuticals in a manner similar to those in traditional dosage forms. 

Freezing forms an amorphous solid of the protein and excipients with associated water in crystalline form. Annealing, an optional step, increases ice-crystal size and allows crystallization of bulking agents (such as glycine or mannitol), removing... 

Most protein pharmaceuticals are multicomponent systems that contain the protein, buffer salts, bulking agents, and stabilizers. Each component has its intended role in the formulation. For example, often a crystallizing excipient... 

---