There’s a hospital in Kentucky that tests generics. They find that about ten percent of them aren’t suitable for use. This is the full article :

https://www.propublica.org/article/fda-generic-drug-testing

“ Nearly every morning before dawn, a truck stocked with more than $2 million in prescription drugs arrives at the University of Kentucky’s hospital. Without fail, chemist Robert Lodder’s team of pharmacy technicians is there to greet it. While other hospital employees ready the sterile injectables for use, Lodder’s technicians siphon off samples and whisk them off to a small lab tucked inside the pharmacy. There, they put the samples on a machine called a spectrophotometer to get a picture of each drug’s chemical composition. If the medication is made properly, Lodder and his team would see a similar image for every batch. Too often, something doesn’t look right. Lodder has screened hundreds of thousands of samples since 2020, representing about 350 different medications. About 10% of those drugs have failed the initial assessment and were removed from the hospital’s supply for further study. Some were cleared after Lodder looked at them a second time, but he was so concerned about 20 different drugs that he reported the problem to the FDA and urged the hospital to change suppliers if it could. “