Mode of action
- SPS® are individual compositions of 5-8 excipients
- All compounds are available in pharmaceutical grade and are regulatory established excipients
LEUKOCARE’s SPS® excipients and formulations stabilize and protect the three dimensional structure and functionality of proteins

SPS® are individual compositions of 5-8 excipients applied as aqueous solutions and demonstrate the following characteristics:
- Excipients listed in pharmacopoeias (USP, EP, JP)
- Excipients in general listed as inactive ingredients by FDA
- All excipients available in pharmaceutical grade
- Formulations usually sugar and protein free, but fully compatible with bulking agents etc.
- Formulations easily adaptable to specific biomolecules and needs
SPS® are successfully applied to molecules ranging from small peptides, large proteins and antibodies to viral antigens and live viruses.
The individual SPS® compositions can be adapted with regard to the specific excipients and their concentrations, pH, osmolality, other compounds (salt, bulking agents), etc.
Stabilization and protection by SPS® can be explained by the principles of water replacement and preferential exclusion. These result in protection against damage during manufacturing and terminal sterilization as well as extended shelf life.

- In dry formulation appropriately selected SPS® excipients replace water and build hydrogen bonds and other non-covalent interactions with the target protein.
- Replacement of water by SPS® excipients prevents oxygen radical formation during increased temperature or irradiation.
- SPS® excipients provide anti-oxidative effects.
- SPS® formulations build a glassy state and an amorphous shell to protect the three dimensional structure e.g. to avoid unfolding or aggregation.
- SPS® formulated biologics can be easily reconstituted.

- In liquid formulation appropriately selected SPS® excipients are purposely excluded.
- Water-protein interactions are stronger than SPS®excipient-protein interactions resulting in a stabilizing hydration of the protein.
- The hydration shell prevents interaction with co-solvents (preferential exclusion) resulting in a lower free energy and thus increased stability of the target protein.