Key tools for understanding drug efficacy and stability

Which tools do you need to understand drug efficacy and stability? Notes from our webinar with Xenocs 

Over the last decade, the range of tools pharmaceutical companies can choose from for their drug substance analysis has multiplied. This is largely a result of biophysical analytics becoming more and more demanding in terms of speed, accuracy, precision, and the information needed to better understand what is happening to molecules in solution. 

Malvern Panalytical offers a powerful suite of analytical tools to help, using established particle characterization techniques, such as Dynamic light scattering (DLS) or electrophoretic light scattering (ELS) being critical tools to reports on sample size, polydispersity and zeta potential. Differential scanning calorimetry (DSC) provides a “fingerprint” of the particle structure we can use to identify sample changes due to environmental stress or process changes.  However, not many people know how these tools can be complemented by small-angle X-ray scattering (SAXS) technique.  

That’s why we’re hosting a new webinar series in partnership with SAXS specialists Xenocs. We’re bringing together Malvern Panalytical and Xenocs experts to deep-dive into the ways that SAXS can round out your characterization processes – without requiring a huge step up in complexity. 

Here are the highlights from our first event with Malvern Panalytical’s Pharma and Food Marketing Director Hanna Jankevics-Jones and the Managing Director of Xenocs Nordic, Søren Skou. 

Key takeaways  

Small-angle X-ray scattering (SAXS) is an analytical technique that identifies the nanoscale structural features of a sample. It does this by passing X-rays through the sample and measuring the scattered beams at small angles between 0.1° and 5°. 

Understanding the nanoscale structural features of your drug products can help you optimize the conditions that promote better drug behavior, for instance more efficient release of RNA from LNPs. 

Combining Malvern Panalytical’s instruments with Xenocs’ SAXS technology enables more comprehensive biophysical characterization with a high throughput and without the need for a synchrotron particle accelerator. 

Key quote   

"Current drug development is exceptionally hard, with a head-spinning 90% failure rate of drugs reaching clinical development. There is [therefore] a strong motivation to understand complex molecules better and fail earlier in the drug development process, rather than at one of the most expensive parts." – Søren Skou, Managing Director of Xenocs Nordic 

Understanding the chemical structure of your pharmaceuticals 

As Hanna discusses at the start of the webinar, Malvern Panalytical’s solutions for biophysical characterization can be split into roughly three areas:  

• Interaction analysis, looking at the biological function of the sample and trying to understand its behavior 
• Stability profiling, illuminating critical degradation pathways and helping scientists develop suitable formulations and robust processing  
• Bioparticle characterization, for instance, identifying contaminants and monitoring higher order structure (HOS)  

These types of analysis can help you better understand your drug substances, propviding multiple parameters to characterize, quantify, compare and predict behavior of your drug products.  

But what if you want insight into the nanostructural details of your sample, too? That’s where small-angle X-ray scattering comes in. 

Introducing small-angle X-ray scattering (SAXS) 

Small-angle X-ray scattering (SAXS) gives you insight into particle size, shape, and internal structure, typically up to around 250 nm. It does this by shining a focused X-ray beam through a sample and measuring the intensity of the scattered light as a function of the scattering angle.  

This scattering pattern can then be analyzed to deliver nanostructural insights such as nanoparticle size and size distribution and morphology, both of which are important factors in determining and its biocompatibility.  

So, what information can be extracted from a SAXS measurement?   

Firstly, you can extract the size and size distribution of the nanoparticles. Through Pair-distance distribution analysis it is possible to find out the shape of the particles as well as the longest interparticle distance. Using this data one can then do the overall shape reconstruction, which provides a very valuable insight into the conformation and aggregation behavior of the protein samples. It is also possible to obtain information about the folding state of the biomolecules and interactions between those. Furthermore, for protein samples you can calculate radius of gyration and knowing the concentration of the sample, you can also extract its molecular weight. 

These insights can in turn help you fine-tune your drug delivery system early on in the drug development process.  

For example, lipid nanoparticles (LNPs) are often inefficient in their release of RNA into the cytosol after cell uptake, successfully delivering only 2-5% of the total RNA. The precision and high throughput of SAXS technology enables you to systematically optimize your conditions and promote better behavior. 

Key quote   

"Systematic optimization of conditions that promote better behavior is really hindered by the lack of internal structural information, if you’re only relying on the more traditional techniques or other structural characterization methods that do not have the same high throughput capabilities as SAXS." – Søren Skou 

A powerful lab-based characterization solution  

Søren explains that, although 10 years ago you might not have been able to run high-quality bioSAXS measurements in a lab, this technology applied to biomolecules has matured significantly since then. Now, lab SAXS instruments like Xenocs’ Xeuss Pro offer high measurements speed as well as a high throughput, with 96 well trays for your samples, all in a lab setting – no need to go to synchrotron radiation facilities.  

Importantly, data reduction and data analysis steps have also improved and with the whole process has been simplified significantly. Now, you don’t need a PhD in physics to complete a SAXS experiment or to read the results, thanks to Xenocs’ user-friendly software and hardware offerings. 

These features combine well with Malvern Panalytical’s suite of user-friendly analytics to help you gain a more holistic view of the characteristics of your biopharmaceuticals.   

This has many benefits for your drug development process. For instance, you could use DLS and DSC to  understand what kind of nanoparticles has been made and test its’ stability over time or upon changing environment (T or pH), then use SAXS to probe nanoscale structural details inside the particles and verify that the nanoparticles in the sample are equipped for efficient drug delivery.  

Watch the webinar now to hear expert tips for incorporating SAXS into a holistic biophysical characterization process.