For over 20 years I worked for American Home Products. We made Dristan, Anacin, Prep H, Advil, Semicid, Today Sponge, and Robitussin to name a few. I worked various jobs over that time, and one of them was being a compounder for Anacin aspirin.
A compounder is essentially a mixer. You have a bulk sheet (same as a recipe that a cook uses) that has numbered steps. Each step must be signed for by the person who performs the step and verified by their co-worker. It doesn't matter if you perform the step or verify the step. If something goes wrong, you are both in equal and VERY job threatening trouble.
All raw materials coming in are accompanied by a manufacturers spec sheet, showing the tests that it passed and the values in those tests. Upon acceptance of the lot of material, every drum or container is tested by our lab and our results are compared to those of the supplier/manufacturer.
Anacin (any aspirin) is comprised of 3 components, in descending order of amount. Aspirin, caffeine, corn starch. That's it. Well, you need pressure, in the range of 3/4 to 2 tons to form the tablet. We mixed the aspirin on the second floor in 12 ton batches, ten tons of aspirin, 1.5 tons of caffeine and .5 ton of corn starch. The corn starch acts as both a lubricant and a binder to hold the tablet together. It was fed to tablet press machines in the rooms below that ran 24 hours per day, 5 days per week
The company bought aspirin from China. It came in wooden drums with steel bands binding them closed. We soon discovered that Chinese aspirin would pass all our tests, but would make aspirin that would not pass our friability test. That is a test of how long it takes a tablet to dissolve in pure water at 72 degrees F. IIRC, the spec was from 65 to 100 seconds. No matter what the press operator did, the tablets made from Chinese aspirin would not dissolve in under 150 seconds. Chinese aspirin was cheaper than aspirin from other manufacturers.
To make a long story short, a new bulk sheet had to be printed which allowed 15% Chinese aspirin by weight and 85% non-Chinese aspirin by weight to make a tablet which passed friability tests.
This cost our company over 1.5 million dollars in lost production, destroyed product and research time and cost to come up with a formula that would reliably make tablets. But the Chinese aspirin was cheaper than aspirin from other manufacturers.......by 20%.
