Extended release pharmaceutical formulation

1. A method of treating a patient for treatment-resistant depression, 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, norketamine, pharmaceutically acceptable salts thereof, and combinations thereof, wherein the active agent is present at a concentration of at least about 12% 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 norketamine Cmax of about 74 ng/mL after administration of a single dose of 60 mg to a patient; a mean norketamine Cmax of about 161 ng/mL after administration of a single dose of 120 mg to a patient; a mean norketamine Cmax of about 315 ng/mL after administration of a single dose of 240 mg to a patient;

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 norketamine AUC 0-∞ of about 872 ng.h/mL after administration of a single dose of 60 mg to a patient; a mean norketamine AUC 0-∞ of about 2133 ng.h/mL after administration of a single dose of 120 mg to a patient; and a mean norketamine AUC 0-∞ of about 4079 ng.h/mL after administration of a single dose of 240 mg to a patient,

wherein the tablet treats the symptoms of said treatment-resistant depression.

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 symptoms of said treatment-resistant depression are alleviated within 2 hours of oral administration of said ketamine.

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

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

9. 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 depression for 3-7 days.

10. The method of claim 1 wherein tablet has no or minimal dissociative side effects in the patient.

11. The method of claim 1 wherein maximal mean improvements in ratings of depressed mood were noted after approximately 6 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 antidepressant 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 mood stabilizer selected from the group consisting of lithium carbonate, lithium orotate, lithium salt, valproic acid, divalproex sodium, sodium valproate, lamotrigine, carbamazepine, gabapentin, oxcarbazepine, topiramate, pharmaceutically acceptable salts, isomers, and combinations thereof;

at least one herbal antidepressants selected from the group consisting of St John's Wort; kava kava; echinacea ; saw palmetto; holy basil; valerian; milk thistle; Siberian ginseng ; Korean ginseng ; ashwagandha root; nettle; Ginkgo biloba ; gotu kola; ginkgo /gotu kola supreme; astragalus ; goldenseal; dong quai; ginseng ; St. John's wort supreme; echinacea ; bilberry, green tea; hawthorne; ginger, gingko, turmeric; Boswellia serata ; black cohosh; cats claw; catnip; chamomile; dandelion; chaste tree berry; black elderberry; feverfew; garlic; horse chestnut; licorice; red clover blossom and leaf rhodiola rusa; Coleus forskohlii ; Passion Flower; eyebright; yohimbe; blueberry plant; black pepper plant; Hydrocotyle asiatica ; astragalus; valerian poppy root and grape seed; vervain; echinacea ang root; Skull Cap; 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.