I skimmed the literature on this and the ritonavir story seems legit.
There really is a peer-reviewed paper saying that there are five crystalline forms of the stuff. ("Elucidation of crystal form diversity of the HIV protease inhibitor ritonavir by high-throughput crystallization", Applied Physical Sciences, Feb 2003).
It really does seem that in 1998 the more stable Form II suddenly started coming out of the factory, with lower solubility and such bad oral bioavailability that the oral capsules were withdrawn from the market until Abbott figured out a new way to make the drug. (I think they were already moving from a capsule to a gelcap and the gelcap didn't have the same issue? Just reading … this is not such a good source perhaps but lovely bare HTML: https://www.natap.org/1998/norvirupdate.html )
There really is a peer-reviewed paper saying that there are five crystalline forms of the stuff. ("Elucidation of crystal form diversity of the HIV protease inhibitor ritonavir by high-throughput crystallization", Applied Physical Sciences, Feb 2003).
It really does seem that in 1998 the more stable Form II suddenly started coming out of the factory, with lower solubility and such bad oral bioavailability that the oral capsules were withdrawn from the market until Abbott figured out a new way to make the drug. (I think they were already moving from a capsule to a gelcap and the gelcap didn't have the same issue? Just reading … this is not such a good source perhaps but lovely bare HTML: https://www.natap.org/1998/norvirupdate.html )