Innovation Showcase Polypropylene Glycol (PPG) for Advanced Applications

Poly(ethylene glycol) PEG has become a gold standard in delivery science. The importance of PEG purity is being highlighted by an increasing number of researchers. At Polypure, we are providing monodisperse PEG derivatives in a multi-kilo scale. Our products have been successfully applied in various pharmaceutical formulations that are currently on the market.

Based on our expertise in PEG chemistry, we have recently expanded the product portfolio to another polyether - poly(propylene glycol) (PPG). PPG exhibits a unique set of properties, including thermoresponsiveness and amphiphilic character. Both of these properties can be deemed interesting for controlled release.

So far, only polydisperse PPG has been commercially available. This means it is characterized by a wide molecular weight distribution and presence of unsaturated impurities stemming from the polymerization process. We addressed this issue by combining our proprietary chromatographic purification with a synthetic approach. This strategy has allowed us to obtain oligomers up to n = 15 of 99% purity and easily scalable processes.

Such high purity enabled employing precise chemical derivatization to render activated PPG oligomers, e.g., acrylates, thiols, and amines. These derivatives can be readily coupled to monodisperse PEG to form precise ABA copolymers. They can also linked to biomolecules, such as peptides or proteins. Similar to PEG, PPG can be used for surface functionalization to prevent aggregation. We trust that just as PEG, monodisperse PPG can emerge as a new benchmark for formulation development. This combination will ensure precision and reproducibility when using it in advanced pharmaceutical applications.