The High-Tech Valor Glass Vials Used To Deliver The Coronavirus Vaccine

As the world waits for COVID-19 vaccines, some pharmaceutical companies stand armed and ready with an exciting improvement: better vials to hold the doses. Vials haven’t changed much in the last 100 years, but in 2011, Corning decided to do something about that. They started developing an alternative glass that is able to resist damage and prevent cracks. It’s called Valor glass, and it’s amazingly strong stuff. Think Gorilla glass for the medical industry.

Traditionally, pharmaceutical vials have been made from borosilicate glass, which is the same laboratory-safe material as Corning’s Pyrex. Borosilicate glass gets its strength from the addition of boron. Although borosilicate glass is pretty tough, it comes with some issues. Any type of glass is only as strong as its flaws, and borosilicate glasses are prone to some particularly strength-limiting flaws. Pharmaceutical glass must stand up to extreme temperatures, from the high heat of the vial-making process to the bitterly cold freeze-drying process and storing temperature required by the fragile viral RNA of some COVID-19 vaccines. Let’s take a look at how Valor glass vials tackle these challenges.

Eliminating Damage and Delamination

Borosilicate glass flakes float in the vial. Image via Corning Incorporated

The biggest problem with borosilicate vials beyond breakage is that they are prone to delaminating internally, meaning that little pieces of glass flake off inside of the vials and contaminate the medicine. During the converting phase, where long glass tubing is separated and the ends sealed off into vials, boron evaporates from the glass network and leaves sodium borate deposits on the inside of the tube. When the vial is filled with medicine, elements like sodium, silicon, and potassium leach from the glass and into the solution.

Corning spent millions of dollars to do an in-depth study and determined that boron itself was the root cause of delamination. So after combing through the periodic table and mixing various elements with silica, they came up with a boron-free alternative that uses aluminium oxide for strength.

Vials go through several stages of production from raw glass to ready dose, and every stage presents an opportunity for damage. Batches of intravenous drugs are created during a process called lyophilization, which is a three-stage freeze-drying process. Drugs expand at different rates during the lyophilization process, and these expansions generate additional stresses within the vials.

Another problem with borosilicate glass is the dust generated on the production line. All of those vials standing shoulder to shoulder will rub together as they move down the line, generating particulates that can ruin entire batches. Valor glass has a special coating with a low coefficient of friction that reduces dust to almost nothing.

Valor vials can withstand around 1,000 pounds of force. Image provided by Corning

Strong Stuff

The most impressive thing about Valor glass is its strength. In this video, a regular borosilicate vial breaks under a mere 20 kg of force. But this aptly-named super glass can withstand around 1,000 pounds force, which makes it fifty times stronger than borosilicate glass.

After the converting process that cuts and shapes the glass tubes into vials, the vials are submerged in a molten salt bath for toughness. During this process, potassium atoms in the brine swap with sodium atoms in the glass, and this fortification process is what gives Valor its strength. Corning originally developed this process for Gorilla glass — made famous through its use in scratch and shatter-resistant smartphone screens — a material which is similarly Herculean. The vials are then rinsed and coated with a polymer that greatly reduces glass dust when the bottles knock together.

To gauge the strength of the Valor vials, Corning did extensive freeze-thaw testing where they cooled vials from room temperature down to -100 °C in the span of about a minute, then allowed the vials to thaw back to room temperature over the next twelve hours. They processed and filled the vials with mannitol, a drug which expands rather aggressively during the freeze-thaw process. When mannitol crystallizes, it produces high hoop tensile stress within the vials and makes them susceptible to cracking and breakage. Valor vials are “at least 40x less likely to break than borosilicate vials under freeze-thaw conditions” (PDF) because their composition and molten salt bath help them maintain their strength throughout the lyophilization process.

Valor glass has tension layers and compression layers, and cracks that occur in the tension layer don’t propagate to the rest of the vial as they tend to do in borosilicate glasses. Valor glass will still break with enough force, so what the composition and annealing process really do is prevent cracks from growing and turning into breaks.

Over the summer, Corning received a $204M grant from the US government to expand manufacturing of Valor vials under the Operation Warp Speed initiative. And they’re not the only ones seeking new packaging solutions. Another company called SiO2 Materials Science are also producing an alternative to borosilicate that is a hybrid container — plastic lined with a thin glass-like coating that “eliminates the major concerns of glass and plastic when these materials are used alone.” Well, we need all the vials we can get.

70 thoughts on “The High-Tech Valor Glass Vials Used To Deliver The Coronavirus Vaccine

  1. Aluminosilicate glass is interesting stuff – developed in 1936 but it took years to get very good fabrication (eg. screen surfaces) going with it. Used for high temperature lamps/electronics/ignition tubes etc. for some time. Good to see it going down the food chain.

    Broad overview of glass types:

    Deep dive into aluminosilicate:

      1. Pyrex or pyrex is not the same as PYREX. The first two are soda lime glass and are frankly terrible as they are damaged way easier and tend to explode violently. The latter is the original borosilicate glass and is far more durable.

        1. Yes, whoever decided to allow the trademark “Pyrex” needs to be taken to a dark alley. We discovered that sad state of affairs when researching casserole dishes last year. 3 of the 4 smashed were PYREX unfortunately.

        2. It’s less down to allcaps or camelcase, and more down to location of purchase: in the US, the Pyrex/PYREX/pyrex trademark was sold off, and the company that brought it then happily licensed it out to manufacturers of tempered glass cookware (initially marketed as ‘shatter resistant’, which is technically true). Outside the US, the Pyrex trademark was sold to a different company that still manufacturers borosilicate glass cookware.

  2. “20 kg of force. But this aptly-named super glass can withstand around 1,000 pounds force, which makes it fifty times stronger”

    Unit conversion error, obviously the author meant kg-feet of force.

      1. What kind of elephant are you referring to, Asian or African? And would that be a male or female? I assume the color of the elephant isn’t important in this equation, but I would prefer pink. However I’m confused, because perhaps you are referring to the flying type of elephant, a.k.a. Dumbo, however that would be misleading as that kind of elephant is purely fictional and therefore no good reference in this topic.

  3. Aluminium oxide, with trace amounts of impurities is known as ruby (traces of chromium) or sapphire (traces of iron, titanium, chromium, vanadium, or magnesium) both have a hardness of 9.0 on the Mohs scale. And I’m going to guess that the Valor Glass Vials have a similar hardness ?

    So the real question is when will we have Diamond Glass Vials with a hardness of 10.0 on the Mohs scale :)

    1. Also doing me a concern, is the problem of getting labels to stick to them. Bulk handling of medications or patient samples if they use such vials for those, might have the labels transferring between vials.

    1. I’d imagine they’d have some specified longer runs for purposes of cooling or drying more thoroughly, but the rest, IDK, maybe manufacturers who have a process of Machine A, Machine B etc., like arranging their machines AFCBDE instead of ABCDEF

  4. “a regular borosilicate vial breaks under a mere 20 kg of force. But this aptly-named super glass can withstand around 1,000 pounds force”

    I dislike it when people make a comparison using metric units for one and imperial units for the other.

    1. I understand, and while you are eight, I rather like it. It either is noticed and we do a quick mental convertion, or we flounder and end up feeling mad like a kid or glad to be able to laugh at ourselves for our gaf. My 90 Aerostar speedo stopped reporting past 85 mph. Fortunately pushing the metric button there was no 130kph limitation and I, an old uneducated geezer, read basic metric also. Paying attention is harder to teach. It’s also a bit like the debating tactic of mispronouncing a word to distract one’s opponent from the real focus of an issue. How many of you fell for it…? 😏

        1. Was genuinely confused about how he shortened speedometer to ‘speedo’

          As a millennial, I can definitely state that Speedos have maintained their space in popular consciousness than Ford Aerostats

          I don’t know what is better

  5. Mannitol is a drug now? Last time I purchased some it was an artificial sweetener and not even a very good one, it is only called a sweetener because it isn’t licensed as a bulking agent which is what it is often used as.

  6. > The most impressive thing about Valor glass is its strength. In this video, a regular borosilicate vial breaks under a mere 20 kg of force. But this aptly-named super glass can withstand around 1,000 pounds force, which makes it fifty times stronger than borosilicate glass.

    If we’re going to use metric, use metric.
    If we’re going to use imperial measurement, use imperial measurement.
    Whatever you do, kindly make up your minds and pick ONE, not BOTH.

      1. You’re right with SI but not with metric. kg(force) was always kp (kilopond) before, and kp is still “metric” since the designating property of a a metric unit is the decimal devision and having multiples of 10 or preferrably 1000, and that it combines with meters (like in kpm for torque, or atm = kp/cm² for pressure).
        It never was a SI unit, since the SI system was defined in 1960.
        My first physics lessons were told in kp (German equivalent to middle or high school, early 1970s) but soon changed to N which hat then to be used for force.
        I just checked that the kp was deprecated by law in Germany in 1978.

        1. Nope. All the CGS units were replaced with MKS units, which is what defines what counts as “metric”, plus a few convenience units that are left because we don’t want to measure milk in cubic meters.

          People simply have their own weird interpretations, like saying, “everything should be multiples of 1000”, which is based on absolutely nothing. The actual prefix system goes 1,10,100,1000, 1 000 000…. because that’s the way it has been designed to work, on purpose. Some educators just drop the 10 and 100 out arbitrarily because they think they’re making it “easier” for the kids, or brass about how “simple” the metric system is; well of course it’s simple because you keep ignoring bits of it.

  7. What a shame that it does not reduce the risk of data corruption in the RNA that some of the newer vaccines use, because we all know how problematic that is… At least DNA has a backup copy to help the cell’s repair mechanisms correctly fix the error. How anyone with any computer science knowledge could know about that particular biotech and not be concerned baffles me. Who cares if the occasional vial is dropped and it breaks.

      1. I can’t really comment because as far as I know they never tested the background radiation susceptibility and if they is as great an issue as thermal. You know, expose the stuff to different levels to simulate time periods then put it in human cell cultures to see what nasty spurious proteins are synthesised from the corrupt instructions. They probably should do that, like really soon.

  8. There’s talk of freezing and then heating, but my old glassware shattered from the thermal shock of heating then cooling.
    So, let’s warm these sucker to about 400F (205C) for half an hour, then drop them in ice cold water and see what happens.

    1. PYREX glassware is typically specified for a maximum 220°C thermal shock. The internal stresses depend on the rate of cooling or heating, so dunking a 400F dish in ice water is going to shatter easily because of the high thermal conductivity of water.

      Play stupid games, win stupid prizes.

      1. You said it yourself – a maximum thermal shock of 220°C. The 400°F I specified is, as I said, only 205°C.

        Testing random samples for compliance with thermal shock ratings is not what I’d call stupid.

    1. No, they don’t get sucked into the syringe, because they’re on vials made from the normal borosilicate glass they don’t use. That’s one reason *why* they’re using this glass.
      BS glass is presumably fine for other things which don’t have such extreme storage requirements? Or perhaps they just check them and discard the contaminated ones.

      1. That reminds me of an old industrial tea pot we had, which started giving off little shimmering flakes into the boiling water no matter how well it was cleaned. We just assumed it was water scale breaking off in flakes.

  9. Could you stop referring to “THE coronavirus vaccine”, as:
    – there are several vaccines at various stages of development/trial/approval around the world. It was bad enough last month with an article implying there are only two vaccines.
    – there are multiple known coronaviruses, and the vaccines presently discussed are specific to COVID-19

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