Hyoscyamine (Levsin, Levbid, etc) is going off the market
All hyoscyamine products are unapproved. They came on the market before FDA approval was required. The FDA hasn't taken any action against these products...yet. But several companies have voluntarily withdrawn their products.
This has put a squeeze on the few remaining companies, creating a drug shortage.
There are only a handful of hyoscyamine products currently marketed. But these are either not available through some wholesalers and/or the cost of these may be prohibitive for some patients.