Doxepin manufacturer?

Doxepin isn’t made by a single company. It’s a generic drug produced by many manufacturers around the world. The original branded version in the U.S. was Sinequan (and Adapin in earlier times), developed by Pfizer (Upjohn lineage).

If you tell me your country and the dosage form (capsule, tablet, or topical), I can name some current manufacturers you’re likely to see there.