good manufacturing practice
When you swallow a tablet, you trust that every pill in the bottle contains the same right amount of the right substance, with nothing harmful sneaking in. Good manufacturing practice, almost always shortened to GMP, is the body of regulated rules that makes that trust justified. It governs how medicines are made so that quality is built into the process rather than merely tested for at the end.
GMP covers everything that could affect a product's identity, strength, purity, and consistency: clean and qualified facilities, validated equipment, trained staff, controlled raw materials, written procedures followed exactly, and meticulous documentation so that any batch can be traced and reconstructed. A guiding principle is that you cannot test quality into a product — you must manufacture it in, because sampling a few tablets can never guarantee the millions you did not test.
These standards apply not only to marketed drugs but to the material used in clinical trials, and they are enforced by regulatory inspections of factories. Failing an inspection can halt production or block approval entirely. GMP is unglamorous compared with discovering a molecule, but a brilliant drug that cannot be made reliably and reproducibly is not a usable medicine.
The active ingredient and the finished drug product both fall under GMP; the discipline of designing a robust, scalable manufacturing route is process chemistry.