TL;DR
- Lyophilisation removes water by freezing a product, then sublimating the ice away under vacuum.
- Peptides in solution degrade through hydrolysis, oxidation and aggregation. Removing the water slows all three.
- The cycle has three stages: freezing, primary drying and secondary drying.
- A good cake is uniform and intact, low in residual moisture, and reconstitutes quickly and clearly.
- Ask any supplier for cycle validation data and batch moisture results, not just a purity figure.
Lyophilisation is not just a presentation format. It is a stability decision, and it is usually the difference between a peptide that holds its specification for years and one that drifts out of it in weeks.
Lyophilisation, or freeze-drying, removes water from a product by first freezing it, then lowering the surrounding pressure so the frozen water sublimates directly from solid to vapour. For peptides it is the preferred presentation because it extends shelf life and reduces the risk of degradation during storage and transport.[1]
Why do peptides degrade in solution?
Peptides in aqueous solution are subject to hydrolysis, oxidation and aggregation. These degradation pathways are temperature-dependent and accelerate significantly above 4°C, which is why liquid presentations are typically shipped and held cold.[2]
Water is the medium most of these reactions need. Removing it does not stop degradation altogether, but it slows the dominant pathways by orders of magnitude, which is what makes ambient or refrigerated storage practical.
What are the stages of lyophilisation?
There are three, and each one is a separate control point.
- Freezing. The product is cooled below its critical temperature so it forms a solid matrix. Freezing rate influences ice crystal size, which in turn affects how quickly the product dries and how the cake looks.
- Primary drying. The bulk of the water is removed by sublimation under reduced pressure. This is the longest stage, and running it too warm risks collapse of the cake structure.
- Secondary drying. Residual bound water is removed by desorption, usually at a slightly elevated shelf temperature, to bring moisture down to the target specification.[1]
UK Peptide Manufacturing & Supply
Thanet Labs is a UK-based peptide manufacturing and supply facility working towards MHRA manufacturing authorisation. We are establishing supply relationships with research institutions, universities, and pharmaceutical development partners. Enquiries are welcome at this stage.
Liquid or lyophilised: how do they compare?
The practical difference is how long the peptide stays within specification, and how much handling discipline it demands along the way.
| Liquid formulation | Lyophilised | |
|---|---|---|
| Water present | Yes | Trace only (residual moisture) |
| Main degradation risk | Hydrolysis, oxidation, aggregation | Low while sealed and dry |
| Storage | Usually refrigerated or frozen | Often more tolerant of temperature |
| Transport | Cold chain, closely controlled | More robust in transit |
| Before use | Ready to use | Requires reconstitution |
What should you look for in a lyophilised product?
Start with the cake. A well-lyophilised peptide cake should be white or off-white, uniform in appearance, and free from collapse or melt-back. Shrinkage, browning or a glassy layer at the base all point to a cycle that ran too warm.
- Residual moisture. Typically specified low, often below 3% by Karl Fischer titration, with the result reported on the batch Certificate of Analysis.
- Reconstitution. The product should dissolve readily in the specified solvent, without particulates, cloudiness or persistent foaming.
- Cycle validation. A credible supplier holds documented cycle development and validation data, rather than a single recipe applied to every product.
- Stability data. Storage claims should be supported by stability testing under defined conditions, not inferred from the format alone.[3]
Purity is not the whole picture. A high HPLC purity figure says nothing about moisture content, cake integrity or how the product will behave after six months on a shelf. Those come from the lyophilisation cycle and the data behind it.
References
- Rey L, May JC (eds). Freeze-Drying/Lyophilization of Pharmaceutical and Biological Products. 3rd ed. Informa Healthcare; 2010.
- Carpenter JF, Pikal MJ, Chang BS, Randolph TW. Rational design of stable lyophilized protein formulations: some practical advice. Pharm Res. 1997;14(8):969–75.
- ICH Q1A(R2). Stability Testing of New Drug Substances and Products. 2003.
Thanet Labs is a UK-based sterile development and manufacturing company building capabilities in aseptic fill-finish, lyophilisation, and contract manufacturing for peptides, small molecules, biologics, and inactivated pathogens. Its platform is designed to support the development and manufacture of stable sterile products for pharmaceutical, biotechnology, diagnostic, and research applications. MHRA licensing in progress.