Custom Synthesis

If additional product optimization is required, we can provide developmental input and custom synthesis. A large percentage of our polymer business at Evonik is devoted to the development of polymers with customized characteristics.

For example, we have worked closely with clients to:

  • Increase polymer solubility. For example, solubility is a key attribute for microsphere products. To meet customer needs in this area, we have used our synthetic expertise to manufacture 50:50 poly(DL-lactide-co-glycolide) with increased solubility in common solvents.
  • Optimize release kinetics, hydrophilicity, and degradation by tailoring end group chemistries, such as hydroxyl, ester, free carboxylic acids and PEG.
  • Tightly control polymer molecular weight.
  • Vary monomer ratios to give desired drug release profiles and excipient degradation times.

Subtle changes in molecular architecture can have a profound effect on degradation and drug release rates. For example, altering the polymer end groups can affect water uptake and degradation rate. Typical examples are shown below. Our scientists can help you determine the characteristics necessary for your application through developmental input and custom synthesis. Please contact Technical Support to discuss your needs.


Initiator-Polymer End Group Effects


InitiatorEnd GroupsEffects
Monofunctional alchoholEster and HydroxylSlightly hydrophilic
DiolHydroxyl and HydroxylMore hydrophilic
Water or α-hydroxyl acidCarboxylic acid and HydroxylMore hydrophilic; increase water uptake and degradation rate
Polyethylene glycol (PEG)PEG and HydroxylMost hydrophilic

Order Polymers

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We offer a variety of polymers and sample kits in stock for prompt delivery.

Technical Data

Technical Data Image

Data describing characteristics of lactide, glycolide and ε-caprolactone polymers to assist you in selecting the optimal polymer for your program.