Pharmaceutical dosage forms

1. A solid oral extended release pharmaceutical dosage form comprising an extended release matrix formulation, the extended release matrix formulation comprising:

(1) at least one active agent salt comprising a cationic active agent molecule and an anionic counterion, wherein the at least one active agent salt comprises oxycodone hydrochloride;

(2) about 15% by weight to about 25% by weight (based on the weight of the extended release matrix formulation) of at least one anionic surfactant comprising sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, ethanolammonium lauryl sulfate, diethanolammonium lauryl sulfate, and triethanolammonium lauryl sulfate or mixtures thereof, wherein the molar ratio of the at least one anionic surfactant to the at least one active agent salt is from about 1:2 to about 10:1; and

(3) at least about 40% by weight (based on the weight of the extended release matrix formulation) of at least one polyethylene oxide;

wherein the dosage form, when subjected to an in-vitro dissolution test in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without enzymes (SGF) at 37.0±0.5° C., provides a dissolution rate with an amount of the at least one active agent released at x hours, wherein x is an integer selected from a number between 2 and 12; and

an amount of the at least one active agent released at y hours, wherein y is an integer selected from a number between 6 and 24, and y≥x+4;

which complies at least for one combination of x and y with equations (I) and (II):

the amount released at y hours≤(y/x×amount released at x hours)×1.25 (I),

the amount released at y hours≥(y/x×amount released at x hours)×0.75 (II),

wherein the dosage form is free of core-shell particulates.

2. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the molar ratio of the at least one anionic surfactant to the at least one active agent is from about 2:1 to about 8:1.

3. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the molar ratio of the at least one anionic surfactant to the at least one active agent salt is from about 2:1 to about 5:1.

4. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the molar ratio of the at least one anionic surfactant to the at least one active agent salt is from about 3:1 to about 4:1.

5. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the at least one polyethylene oxide has, based on rheological measurements, an approximate molecular weight of from 900,000 to 8,000,000.

6. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the at least one polyethylene oxide has, based on rheological measurements, an approximate molecular weight of from 4,000,000 to 8,000,000.

7. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the extended release matrix formulation comprises from about 50% by weight to about 90% by weight (based on the weight of the extended release matrix formulation) of said at least one polyethylene oxide.

8. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the at least one anionic surfactant is sodium lauryl sulfate.

9. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the extended release matrix formulation comprises from about 5% by weight to about 25% by weight (based on the weight of the extended release matrix formulation) of said at least one anionic surfactant.

10. The solid oral extended release pharmaceutical dosage form of claim 1 , wherein the extended release matrix formulation comprises from about 0.5% by weight to about 5% by weight (based on the weight of the extended release matrix formulation) of a lubricant.

11. A process of preparing a solid oral extended release pharmaceutical dosage form, comprising the steps of

(a) combining at least

(1) at least one active agent salt comprising a cationic active agent molecule and an anionic counterion, wherein the at least one active agent salt comprises oxycodone hydrochloride;

(2) about 15% by weight to about 25% by weight (based on the weight of the extended release matrix formulation) of at least one anionic surfactant comprising sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, ethanolammonium lauryl sulfate, diethanolammonium lauryl sulfate, and triethanolammonium lauryl sulfate or mixtures thereof, wherein the molar ratio of the at least one anionic surfactant to the at least one active agent salt is from about 1:2 to about 10:1; and

(3) at least about 40% by weight (based on the weight of the extended release matrix formulation) of at least one polyethylene oxide;

to form a composition;

(b) shaping the composition to form an extended release matrix formulation; and

(c) optionally curing said extended release matrix formulation comprising at least a curing step of subjecting the extended release matrix formulation to a temperature which is at least the softening temperature of said polyethylene oxide for a time period of at least about 1 minute;

wherein the dosage form, when subjected to an in-vitro dissolution test in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without enzymes (SGF) at 37.0±0.5° C., provides a dissolution rate with

an amount of the at least one active agent released at x hours, wherein x is an integer selected from a number between 2 and 12; and

an amount of the at least one active agent released at y hours, wherein y is an integer selected from a number between 6 and 24, and y≥x+4;

which complies at least for one combination of x and y with equations (I) and (II):

the amount released at y hours≤(y/x×amount released at x hours)×1.25 (I),

the amount released at y hours≥(y/x×amount released at x hours)×0.75 (II).

12. A method of treating or preventing pain comprising administering to a patient identified in need thereof a solid oral extended release pharmaceutical dosage form of claim 1 , wherein the at least one active agent comprises an opioid agonist, and said opioid agent is present in an analgesically effective amount.