Excipients (Additives) in Parenteral Biologics

Excipients are an integral part of biological products, used in multiple ways, and have well defined functional roles. These roles include (a) enhancing solubility of the active, (b) enhancing process and shelf life stability of the active, (c) controlling pH and tonicity, (d) maintaining preferred stable conformation for proteins (e) preventing aggregation or degradation of the active, (f) several other functions like bulking agents, antioxidants, or preservatives. Selection and use of the appropriate excipients is crucial in formulating satisfactory therapeutic protein products.

Biologics are inherently unstable and prone to degradation by several physical and chemical degradation mechanisms. Therefore, a variety of excipients are required to stabilize the biologics during processing and storage. These excipients include solubility enhancer, anti-adsorption agent, anti-aggregation agent, buffer components, preservative, anti-oxidant and osmotic agent In this section the effect of arginine on solubility of three TPA formulations is illustrated. In addition, human albumin is demonstrated to reduce aggregation and polymerization of insulin products