Delayed-release formulation of duloxetine

A pharmaceutical composition comprising a plurality of beads, wherein each bead in the plurality of beads comprises:

• a sugar sphere;
• a nitrosamine scavenger layer coated over the sugar sphere, the scavenger layer comprising L-cysteine or a pharmaceutically acceptable salt thereof, and hydroxypropyl methylcellulose;
• a drug-containing layer coated over the nitrosamine scavenger layer, the drug-containing layer comprising duloxetine hydrochloride, and hydroxypropyl methylcellulose;
• a seal coating layer coated over the drug-containing layer, the seal coating layer comprising L-cysteine or a pharmaceutically acceptable salt thereof, and hydroxypropyl methylcellulose, sucrose, and talc;
• and
• an enteric coating layer coated over the seal coating layer, the enteric coating layer comprising hydroxypropyl methylcellulose phthalate;
• wherein the L-cysteine or the pharmaceutically acceptable salt thereof is present in a total amount from about 1% to about 10% by weight of the pharmaceutical composition;
• wherein the seal coating layer comprises about 20% to about 35% by weight of the total amount of the L-cysteine or the pharmaceutically acceptable salt thereof, with the remaining L-cysteine or pharmaceutically acceptable salt thereof being present in the nitrosamine scavenger layer;
• and
• wherein the L-cysteine inhibits the formation of nitrosoduloxetine.