Extended release pharmaceutical formulation

1. 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 C max of about 10 ng/mL after administration of a single dose of 60 mg to a patient; a mean ketamine C max 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 AUC 0-∞ of about 79 ng·h/mL after administration of a single dose of 60 mg; a mean ketamine AUC 0-∞ of about 197 ng·h/mL after administration of a single dose of 120 mg to a patient; a mean ketamine AUC 0-∞ of about 385 ng·h/mL after administration of a single dose of 240 mg, a mean ketamine C max of about 12 ng/mL after administration of 5 doses of 60 mg administered every 12 hours to a patient; a mean ketamine C max of about 21 ng/mL after administration of 5 doses of 120 mg administered every 12 hours to a patient; a mean ketamine C max of about 42 ng/mL after administration of 5 doses of 240 mg administered every 12 hours to a patient; a mean ketamine AUC 0-12 of about 74 ng·h/mL after administration of 5 doses of 60 mg administered every 12 hours to a patient; a mean ketamine AUC 0-12 of about 133 ng·h/mL after administration of 5 doses of 120 mg administered every 12 hours to a patient; a mean ketamine AUC 0-12 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.

2. The method of claim 1 wherein the dosage amount of active agent is selected from the group consisting of about 1 mg, about 2 mg, about 5 mg, about 10 mg, about 30 mg, about 60 mg, about 120 mg, and about 240 mg.

3. The method of claim 1 , wherein the tablet is cured at a temperature of about 70° C. to about 75° C.

4. The method of claim 1 wherein the coating comprises:

i) hydroxypropylmethylcellulose;

ii) titanium dioxide; and

iii) polyethylene glycol.

5. The method of claim 1 wherein the tablet is suitable for once daily administration or twice-daily administration to a patient.

6. The method of claim 1 wherein the tablet has no or minimal dissociative side effects upon administration to a patient.

7. The method of claim 1 wherein the symptoms of said treatment-resistant anxiety are alleviated within 2 hours of oral administration of said ketamine.

8. The method of claim 1 wherein said method comprises oral administration of a single dose of said ketamine.

9. The method of claim 1 wherein said method comprises oral administration of multiple doses of said ketamine.

10. The method of claim 1 wherein a single oral administration of said ketamine in doses between 30-180 mg is sufficient to alleviate the effects of said anxiety for 3-7 days.

11. The method of claim 1 wherein maximal mean improvements in ratings of anxious mood were noted after approximately 2 weeks of maintenance treatment.

12. The method of claim 1 further comprising administering a pharmaceutically effective dose of a second or additional agent, wherein said second or additional agent has anti-anxiety properties.

13. The method of claim 1 wherein said method further comprises an additional therapy selected from:

at least one antidepressant selected from the group consisting of citalopram, escitalopram oxalate, fluoxetine, fluvoxamine, paroxetine, sertraline, dapoxetine; venlafaxine and duloxetine; harmaline, iproniazid, isocarboxazid, nialamide, pargyline, phenelzine, selegiline, toloxatone, tranylcypromine, brofaromine, moclobemide; amitriptyline, amoxapine, butriptyline, clomipramine, desipramine, dibenzepin, dothiepin, doxepin, imipramine, iprindole, lofepramine, melitracen, nortriptyline, opipramol, protriptyline, trimipramine; maprotiline, mianserin, nefazodone, trazodone, pharmaceutically acceptable salts, isomers, and combinations thereof;

at least one serotonin 1a partial agonist selected from the group consisting of buspirone, eltoprazine, or tandospirone, pharmaceutically acceptable salts, isomers, and combinations thereof;

at least one alpha-2-delta ligand selected from the group consisting of gabapentin, pregabalin, 3-methylgabapentin, (1alpha,3 alpha,5alpha)(3-amino-methyl-bicyclo [3.2.0]hept-3-yl)-acetic acid, (3S,5R)-3 aminomethyl-5 methyl-heptanoic acid, (3S,5R)-3 amino-5 methyl-heptanoic acid, (3S,5R)-3 amino-5 methyl-octanoic acid, (2S,4S)-4-(3-chlorophenoxy)proline, (2S,4S)-4-(3-fluorobenzyl)-proline, [(1R,5R,6S)-6-(aminomethyl)bicyclo [3.2.0]hept-6-yl]acetic acid, 3-(1-aminomethyl-cyclohexylmethyl)-4H-[1,2,4]oxadiazol-5-one, C-[1-(1H-tetrazol-5-ylmethyl)-cycloheptyl]-methylamine, (3S,4S)-(1-aminomethyl-3,4-dimethyl-cyclopentyl)-acetic acid, (3S,5R)-3 aminomethyl-5 methyl-octanoic acid, (3S,5R)-3 amino-5 methyl-nonanoic acid, (3S,5R)-3 amino-5 methyl-octanoic acid, (3R,4R,5R)-3-amino-4,5-dimethyl-heptanoic acid and (3R,4R,5R)-3-amino-4,5-dimethyl-octanoic acid, pharmaceutically acceptable salts, isomers, and combinations thereof;

at least one antiadrenergic agents selected from the group consisting of clonidine, prazosin, propranolol, fuanfacine, methyldopa, guanabenz; doxazosin, prazosin, terazosin, silodosin, alfuzosin, tamsulosin, dutasertide/tamsulosin, guanadrel, mecemylamine, guanethidine, pharmaceutically acceptable salts, isomers, and combinations thereof;

at least one benzodiazepine agent selected from the group consisting of alprazolam, bromazepam, chlordiazepoxide, clobazam, clonazepam, clorazepate, diazepam, midazolam, lorazepam, nitrazepam, temazepam, nimetazepam, estazolam, flunitrazepam, oxazepam, triazolam, pharmaceutically acceptable salts, isomers, and combinations thereof;

at least one antipsychotic agent selected from the group consisting of haloperidol, chlorpromazine, fluphenazine, perphenazine, prochlorperazine, thioridazine, trifluoperazine, mesoridazine, promazine, triflupromazine, levomepromazine, promethazine, chlorprothixene, flupenthixol, thiothixene, zuclopenthixol, clozapine, olanzapine, risperidone, quetiapine, ziprasidone, amisulpride, paliperidone, dopamine, bifeprunox, norclozapine, aripiprazole, tetrabenazine, cannabidiol, pharmaceutically acceptable salts, isomers, and combinations thereof;

other therapeutic interventions selected from the group consisting of counseling, psychotherapy, cognitive therapy, electroconvulsive therapy, hydrotherapy, hyperbaric oxygen therapy, electrotherapy and electrical stimulation, transcutaneous electrical nerve stimulation (“TENS”), deep brain stimulation, vagus nerve stimulation, and transcranial magnetic stimulation, and

combinations thereof.