Doryx MPC (doxycycline hyclate) delayed-release tablets for oral use, contain doxycycline hyclate, a tetracycline class drug synthetically derived from oxytetracycline, in a delayed-release formulation consisting of pellets with a modified polymer enteric coat that has increased acid resistance.

Doxycycline is a semi-synthetic antibiotic of a broad spectrum of tetracyclines. Causes bacteriostatic action by suppressing protein synthesis of pathogens as a result of blocking the aminoacyl transport RNA (tRNA) with the "information RNA (rRNA) complex" ribosome.