10.24.23 -- FDA's Proposed Laboratory-Developed Tests Rule Raises Many Questions But Provides Few Answers

The FDA has issued a new proposed rule on laboratory-developed tests (LDTs), expressly defining LDTs as a type of in vitro diagnostic (IVD) device, and subject to device regulations, including registration and listing, premarket review, and more. The FDA is accepting comments on the proposed rule through December 4.

Most of the instability problems of a drug product come from excipients, in particular, they come from impurities in excipients. Those issues are best cleaned up in the preformulation period to determine excipient compatability.