Extended release pharmaceutical formulation

A method of treating a patient for treatment-resistant anxiety, including but not limited to DSM-V Generalized Anxiety Disorder, Social Anxiety Disorder, Panic Disorder, Post-Traumatic Stress Disorder and/or Obsessive-Compulsive Disorder , comprising:

• selecting a patient in need of such treatment;
• and
• orally administering to the patient a tablet comprising:
• (A) a core comprising:
• i) a therapeutically effective amount of an active agent selected from the group consisting of ketamine, pharmaceutically acceptable salts thereof, and combinations thereof, wherein the active agent is present at a concentration of at least 12% ketamine base w/w of the core;
• ii) at least one high molecular weight polyethylene oxide (PEO) that is cured, wherein said high molecular weight PEO has an approximate molecular weight of about 7 million, based upon rheological measurements, and is present in an amount of at least about 75% (by weight) of the core;
• and
• iii) magnesium stearate is present at a concentration of about 1% to about 3% by weight;
• (B) a coating on said core,
• wherein said tablet is crush resistant and has a breaking strength of at least about 200 N;
• and
• wherein said tablet provides a pharmacokinetic parameter selected from the group consisting of:
• a mean ketamine Cmax of about 10 ng/mL after administration of a single dose of 60 mg to a patient;
• a mean ketamine Cmax of about 16 ng/mL after administration of a single dose of 120 mg to a patient;
• a mean ketamine Cmax of about 38 ng/mL after administration of a single dose of 240 mg;
• a mean ketamine AUC0-∞ of about 79 ng·h/mL after administration of a single dose of 60 mg;
• a mean ketamine AUC0-∞ of about 197 ng·h/mL after administration of a single dose of 120 mg to a patient;
• a mean ketamine AUC0-∞ of about 385 ng·h/mL after administration of a single dose of 240 mg, a mean ketamine Cmax of about 12 ng/mL after administration of 5 doses of 60 mg administered every 12 hours to a patient;
• a mean ketamine Cmax of about 21 ng/mL after administration of 5 doses of 120 mg administered every 12 hours to a patient;
• a mean ketamine Cmax of about 42 ng/mL after administration of 5 doses of 240 mg administered every 12 hours to a patient;
• a mean ketamine AUC0-12 of about 74 ng·h/mL after administration of 5 doses of 60 mg administered every 12 hours to a patient;
• a mean ketamine AUC0-12 of about 133 ng·h/mL after administration of 5 doses of 120 mg administered every 12 hours to a patient;
• a mean ketamine AUC0-12 of about 217 ng·h/mL after administration of 5 doses of 240 mg administered every 12 hours to a patient,
• wherein the tablet treats the symptoms of said treatment-resistant anxiety.