[cyberax]

Perfect crystals. Also, the proof-of-concept drug was ritonavir, and it's nearly impossible to consistently grow large crystals of it on Earth. All of the labs that work with ritonavir are contaminated by a more stable form ("polymorph") that rapidly converts any ritonavir crystals into a less-useful form.

[throwup238]

> All of the labs that work with ritonavir are contaminated by a more stable form ("polymorph") that rapidly converts any ritonavir crystals into a less-useful form.

The incredible case of the disappearing polymorphs: https://en.wikipedia.org/wiki/Disappearing_polymorphs

It's an actual virulent molecule!

[boffinAudio]

Is it virulence, or surface tension?

[dekhn]

You just need a crystallographer with a beard in the lab (https://improbable.com/2011/02/09/legend-of-chrystallographe... https://www.science.org/content/article/pure-stupid-luck https://www.chemistryworld.com/opinion/czochralskis-pulley/3...).

More seriously: this was pretty much solved already through improved techniques. I'm generally of the opinion that if you have to send a molecule to space to crystallize it better, you should probably spend your money on other, more terrestrial approaches. I do credit Varda for doing this automatically, rather than on ISS, because launch costs for autonomous vehicles are much more affordable than human space flight.

[cyberax]

It's actually still not solved, you can't grow large ritonavir crystals on Earth.

Ritonavir used as a drug works around the issue. It's produced as dispersed molten droplets inside a matrix of inactive material. Its heated above the melting temperature of ritonavir, so it prevents contamination.