Identifying the unknown: easily ID particles in drug formulations

Particles in a drug formulation are an unwelcome discovery and can lead to production shutdown or product recalls. Various microscopy instruments and techniques exist to count particles and guess the composition based on morphology. Spectroscopic techniques enable identification based on unique elemental composition or Raman signatures.

The new Hound from Unchained Labs combines automated counting, microscopy, and three identification lasers into one instrument. Hound couples Raman 785 nm, Raman 532 nm, and laser-induced breakdown spectroscopy (LIBS) with automated microscopy to count, analyze, and ID particles. Any operator can determine particle size and morphology distribution of any sample. Hound’s three lasers ensure that essentially any particle can be identified.

In our on-demand SelectScience webinar, Dr. Robin Sweeney demonstrates how new hardware and software advances have made it even simpler to use Hound for identifying particles and tracing contaminants back to the source.

Watch this webinar if you would like to learn about:

• How particle ID has been simplified by combining many detection methods on one instrument
• How to identify protein, organic, inorganic, and metal particles with Raman spectroscopy and LIBS
• How chemical and elemental fingerprinting can be used to ID the root cause of particle

All webinar participants can request a certificate of attendance for continuing education purposes.

Think you could benefit from this webinar, but missed it? You can now watch it on demand at a time that suits you and find highlights from the live Q&A session below.

Q: How do you only count and analyze visible particles if the whole sample is filtered?

RS: If you only care about visible particles or particles of a certain size, you can set up custom-size bins in Hound. For example, you could set up a size bin that is 50 or 80 microns, and only analyze particles larger than that. You could also differentiate between small and large particles using different size bins and get counts for your subvisible and visible particles separately.

Q: If you have multiple samples, do you have to run these one by one?

RS: No, you do not. On Hound, you can have up to four filter rounds, so you can set up a run that will analyze up to four samples automatically.

Q: Can Hound be used to determine the ratio of each ingredient in the sample?

RS: Yes, Hound can determine not only the identity of each particle and provide the ratio of each material type, but Hound can also get size- and identity-dependent ratios. So, if you expect your API to be a certain size, you can ensure this, as well as look at ratios of API versus excipient or one API versus another.

Q: Can you go back and reanalyze spectra against a new reference database if the original reference was not a good fit for the sample?

RS: Yes, you can do that in the Hound analysis software. When you open up your experiment, you can re-analyze your spectra against multiple different databases. So, if you later created a custom-spectra database that you want to analyze it against, you can do that, or if you know that you already have one and you didn't choose that as the optimal one at first, you can go back and re-analyze against that.

Q: How much sample is required?

RS: You could use as little sample as you wanted. Our filter rounds are set up so that you can pipette just a few microliters or even pull out one particle and place it on there. Afterwards, you can filter as much liquid as you want through that filter round.

Q: How long is an analysis using all three lasers?

RS: That really depends on your sample. If your sample has a lot of particles or needs to be done with longer exposure times, it's going to take longer. As a baseline, a LIBS measurement takes one second per particle. For Raman analysis, it can anywhere from one second to four minutes per particle, depending on how long the user needs the laser exposure to be. So, you can get a filter-round scan with all three lasers in anywhere from minutes to hours, and this just depends on what kind and how many particles you have.

Q: What kind of reporting tools does Hound have to summarize finding and maintain data integrity?

RS: Hound has a couple of different reporting tools. With every experiment that you do, there will be an automated PDF report that has all of the data from the entire experiment. If you want to look just at a few different aspects or customize the report, Hound analysis does have custom reporting features. In terms of data integrity, all of these reports, as well as the experiment and method files for Hound client and Hound analysis, have 21 CFR Part 11 compliance tools. So, with that, you can check data integrity and maintain audit trails.

Q: How does Hound know what unique peaks to look for to differentiate similar samples?

RS: When you're setting up a custom database on Hound, the user gets to define those unique peaks. So, when you're entering similar materials into your database, you would look at what peaks are unique and then tell Hound to look at those specific wave numbers or lengths. Hound will first compare the whole spectra, see how similar they are, and then zoom into those specific user-defined ranges to determine how similar these are in order to find your specific material.

Q: Do you need to grind up your sample prior to analysis and would you consider it to be a destructive test?

RS: If you have a tablet sample and want to analyze individual particles, you would have to grind up the tablet. However, these particles are not then consumed during the testing. In addition, Hound is capable of analyzing the outside of a tablet, without the need for destructive grinding.

Q: Can the particles be counted in a solution?

RS: Yes, that is what our wet round is for. If you want to keep your particles suspended in a solution, you can simply pipette your sample into a wet round, load that onto Hound, and not only can you count them in that solution, you can also identify the particles with Raman in that solution.

SelectScience runs 3-4 webinars a month across various scientific topics, discover more of our upcoming webinars>>