Advanced Membrane Technology
Precision-engineered membranes for exact polymer manufacturing
Exactmer is a provider of disruptive technology for exact polymer synthesis in liquid phase. The foundation of our innovation is our proprietary range of Organic Solvent Nanofiltration (OSN) membranes — applied upstream in Nanostar Sieving®, and downstream in Tangential Flow Filtration, post-conjugation purification, and in-process solvent recycling.
Inside our Advanced Membrane Manufacturing Suite — Dagenham, UK
The Core Platform
One membrane technology. Many ways to apply it.
Our advanced membrane capabilities enable the production of membranes with unparalleled stability in organic solvents, and high permeance, selectivity and durability. From our Advanced Membrane Manufacturing Suite in Dagenham, we produce a range of membranes tailored to the needs of specific applications — today spanning synthesis, purification and solvent recovery, with new applications in active development.
Exact-10â„¢
The membrane behind Nanostar Sieving® — for exact polymer synthesis, purifying the growing chain at every iteration.
View specificationsExact-20â„¢
Optimised for Tangential Flow Filtration — concentration, solvent exchange and by-product removal, with limited fouling and high yield.
View specificationsExact-01â„¢
In-process solvent recovery and reuse, reducing virgin solvent consumption without energy-intensive distillation — paired with our Nanostar Hub for short oligo fragments (5–10mer).
View specifications The Mechanism
How OSN separation works
Applied pressure drives the process across the membrane, separating molecules purely by size. Because separation is size-based, this same mechanism underpins every membrane above — from synthesis to purification to solvent recovery.
Large molecules (the growing oligo) are retained by the membrane.
Small molecules (monomers and reaction debris) permeate through.
Flagship Application 
Nanostar Sieving® — the next generation of polymer synthesis in liquid phase
Where liquid phase polymer synthesis and our advanced membranes meet, to enable superior manufacturing of advanced therapeutics.
The Nanostar Sieving® platform is built on Organic Solvent Nanofiltration separation, using our proprietary Exact-10™ membranes.
Our technology allows the synthesis of exact polymer pharmaceuticals fully in liquid phase, using a single solvent mixture, without the need for precipitation or extraction steps.
- 1A first monomer is attached to a central hub molecule, creating a "nanostar" with enhanced molecular size.
- 2Further monomers are added iteratively, with the growing polymer purified at every step — reaction debris and by-products removed via purpose-designed nanomembrane filtration.
- 3Because separation happens purely by molecular size, the platform is chemistry-agnostic and slots into our semi-automated Nanostar Synthesiser with minimal manual handling.
Why Nanostar Sieving®
The platform behind commercial-scale therapeutics manufacturing.
Discover what's possible
Oligonucleotides
Learn more
Antibody Drug Conjugate Linkers
Learn moreUnimolecular Polyethylene Glycols
Learn more Let's Build Together
The journey starts here
We are committed to supporting the delivery of first-class advanced pharmaceuticals. Let's explore how we can work together.
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