Peptides explained: FAQs on peptide synthesis and manufacturing - Sterling Pharma Solutions (2025)

Peptides have emerged as versatile and powerful tools in the development of modern therapeutics, with a variety of unique advantages that result from their high levels of specificity and their ability to mimic complex biological processes. Because of peptides’ utility in treating cancer, bacterial and viral infections, metabolic disorders, and more , peptide chemistry has become an important area of innovation in the pharmaceutical industry.

In this FAQ, we’ll answer commonly asked questions about peptide synthesis, including the advantages of synthetic methods, compliance standards, and the importance of a specialised partner, whether you’re navigating early-stage peptide research or pursuing commercial-scale peptide manufacturing.

Peptide production has grown significantly in the pharmaceutical industry, with more than 200 peptide therapeutics in clinical development and 600 in the preclinical stage today . A variety of factors have contributed to this growth.

One significant reason for peptides’ growth is their ability to target specific receptors in order to increase therapeutic efficacy while mitigating side effects. For this reason, peptides play an important role in personalised medicine, which has an anticipated CAGR of 11.2% by 2031 . The ability to vary chain lengths and sequences also makes it possible to harness peptides for a wide variety of targets. Because of their versatility, peptides can be utilised in the treatment of cancer, viral infections, and other challenging and highly nuanced indications.

Another benefit of peptides is their predictability. Because peptides are naturally occurring and essential in a variety of natural biological processes, they generally have more predictable behaviour compared to small molecules.

Proteins and peptides are both made up of amino acids and follow the same basic structure. However, peptide chains are composed of fewer amino acids than proteins, which leads to differences in synthetic routes.

Peptides, which consist of between two and 50 amino acids, are often developed using solid-phase peptide synthesis (SPPS), where amino acids are added to a peptide chain that is bonded to a solid resin. This can be carried out in a lab setting to produce custom peptides. At Sterling, we offer capabilities to support peptide chain lengths up to 40 amino acids.

Because of their size and complexity, protein synthesis is far more complex, as proteins involve 50+ amino acids. Biologically, proteins are synthesised in living cells, involving the transcription of DNA into mRNA. In a lab setting, this generally occurs via cell-free protein synthesis (CFPS) or in vivo synthesis with recombinant DNA technology, but smaller protein chains can also be synthesised using SPPS.

In solid-phase peptide synthesis, peptides are assembled stepwise by building an amino acid sequence on a solid support. This technique was invented by Bruce Merrifield , who was awarded the 1984 Nobel Prize in Chemistry for his discovery.

Today, solid-phase is the gold-standard method for peptide synthesis for several reasons, including:

• Efficiency: Adding amino acids sequentially simplifies and streamlines the process.
• Precision: The approach used in SPPS ensures that peptide sequences are highly accurate.
• Scalability: SPPS is applicable to small-scale research and larger-scale manufacturing.

Liquid-phase peptide synthesis is an alternative approach where a peptide chain is built in a liquid solution. While this approach can help to minimise the use of excess materials , it is generally better suited to shorter peptide chains. As a result, it is important to choose a synthetic method based on the length of a peptide chain, intended target, and other key factors.

Custom peptide synthesis allows for the creation of precise amino acid sequences to target specific biological pathways. Peptides can be manufactured to mimic or block natural biological processes in order to produce a desired therapeutic effect, such as inhibiting tumour growth or regulating metabolic deficiencies.

Furthermore, while naturally occurring peptides may quickly degrade in the body, custom synthesis enables scientists to improve stability and bioavailability. Synthesised peptides can also be leveraged to identify new targets and screen therapeutic candidates.

Purification is essential in peptide synthesis to remove unwanted byproducts or unreacted reagents. High-performance liquid chromatography (HPLC) is among the most commonly used methods because of its precision, widespread applicability, and effectiveness.

Sterling’s North Carolina, US facility offers standard HPLC equipment to evaluate conditions for peptide purification, while our Cork, Ireland facility houses one of the largest HPLC columns in the world, with a 1.6m diameter, to purify peptides on a large scale.

In addition to HPLC, ion-exchange chromatography, size-exclusion chromatography, and solid-phase extraction may also be used in peptide purification.

At Sterling, we have more than 25 years of expertise in peptide synthesis, manufacturing, and purification. Our Cork, Ireland and North Carolina, US facilities can support peptide projects from the preclinical stage through to commercial-scale manufacturing.

The North Carolina facility supports peptide development with comprehensive analytical services including product characterisation, stability and impurity studies, and more.

The range of specialised peptide equipment at our Cork facility includes two peptide synthesisers up to 170L capacity, a variety of agitated filter dryers, three ion exchange columns, eight lyophilisers up to 1000L capacity, and more, enabling us to support a range of peptide manufacturing project requirements.

In addition, our Cork facility offers a low bioburden manufacturing environment, comprehensive solvent recovery capabilities, and support for cold chain transport.