AU2013203747B2

AU2013203747B2 - Pharmaceutical dosage forms comprising poly(e-caprolactone)

Info

Publication number: AU2013203747B2
Application number: AU2013203747A
Authority: AU
Inventors: Meridith Lee Machonis
Original assignee: Purdue Pharma LP
Current assignee: Purdue Pharma LP
Priority date: 2008-09-18
Filing date: 2013-04-11
Publication date: 2016-01-07
Anticipated expiration: 2029-09-17
Also published as: AU2013203747A1

Abstract

The present invention relates to pharmaceutical dosage forms, for example pharmaceutical dosage forms comprising poly(s-caprolactone), and processes of manufacture, uses, and methods of treatment thereof.

Description

1 PHARMACEUTICAL DOSAGE FORMS COMPRISING POLY (c-CAPROLACTONE) TECHNICAL FIELD OF THE INVENTION 5 [001] The present invention relates generally to pharmaceutical dosage forms, for example pharmaceutical dosage forms comprising poly(s-caprolactone), and processes of manufacture, uses, and methods of treatment thereof. 10 BACKGROUND OF THE INVENTION [002] Extended release oral dosage forms allow a specific release of active agent over an extended period of time. Larger dosing intervals, e.g. twice- or once-a day dosing, may provide fewer side effects and overall better patient compliance. 15 [003] Pharmaceutical products and in particular extended release dosage forms which usually comprise a larger amount of active agent in a single dose are increasingly the subject of abuse. For example, a particular dose of opioid agonist may be more potent when administered parenterally as compared to the same dose 20 administered orally. Some formulations can be tampered with to provide the opioid agonist contained therein for illicit use. Controlled release opioid agonist formulations are sometimes milled or ground, and/or subject to extraction with solvents (e.g., ethanol) by drug abusers to provide the opioid contained therein for immediate release upon oral or parenteral administration. 25 [004] Extended release opioid agonist dosage forms which can liberate a portion of the opioid upon exposure to ethanol, can also result in a patient receiving the dose more rapidly than intended if a patient concomitantly uses alcohol with the dosage form. 30 -2 [005] There continues to exist a need in the art for extended release pharmaceutical oral dosage forms. In particular there continues to exist a need for such dosage forms that resist illicit use and are safe when concomitantly used with alcohol. 5 OBJECTS AND SUMMARY OF THE INVENTION [006] It is an object of certain embodiments of the present invention to provide an extended release dosage form comprising poly(s-caprolactone) and/or to provide a 10 solid tamper resistant oral extended release dosage form which is resistant to milling and/or to provide a solid extended release dosage form which is resistant to milling, resistant to grinding and resistant to alcohol extraction and/or to provide the above dosage forms comprising an opioid analgesic and/or to at least provide the public with a useful choice. 15 [007] In one aspect, the present invention relates to a solid oral extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, 20 comprising at least one poly(s-caprolactone), and at least one active agent, wherein the melt is formed by an extrusion method; or wherein the melt is formed by a casting method; or 25 wherein the melt is formed by an injection molding method.

-3 [008] In another aspect the invention relates to a solid oral extended release pharmaceutical dosage form of the invention which is resistant to milling and grinding. [009] In another aspect the invention relates to a method of treatment wherein a 5 solid oral extended release pharmaceutical dosage form according to the invention is administered for treatment of pain to a patient in need thereof, wherein the dosage form comprises an opioid analgesic. [009a] In another aspect the invention relates to the use of a solid extended release pharmaceutical dosage form according to the invention for the manufacture 10 of a medicament comprising a solid oral extended release pharmaceutical dosage form for the treatment of pain, wherein the dosage form comprises an opioid analgesic. [009b] In another aspect the invention relates to the use of poly(s-caprolactone) as matrix forming material in the manufacture of a solid oral extended release 15 pharmaceutical dosage form comprising an active agent selected from opioids for imparting to the solid oral extended release dosage form resistance to milling. [009c] In another aspect the invention relates to a process of preparing a solid oral extended release pharmaceutical dosage form comprising the steps of: - Melting and blending the poly(s-caprolactone) (PCL) and possible further 20 ingredients except the active agent on a Thermodyne Hot Plate (temperature range 900 - 160 0 C) to obtain a mixture; - Adding the active agent to the mixture on the Thermodyne Hot Plate (temperature range about 900 - about 160 0 C) until the mixture appeared homogeneous to obtain a blend; 25 - Placing the molten blend on a stainless steel plate and pressing with a second stainless steel plate and cooling to room temperature to obtain a sheet with a given thickness; and - Pelletizing the sheet by cutting into pellets.

-4 [009d] In another aspect the invention relates to a process of preparing a solid oral extended release pharmaceutical dosage form comprising the steps of: - Screening active agent, poly(s-caprolactone) and optionally other ingredients through a # 20 US mesh screen; 5 - Blending the screened materials at ambient temperature; - Extruding the screened and blended materials in a twin screw extruder fitted with a die and set on counter-rotation with zone (barrel) temperatures ranged from about 1 8'C to about 110 C to obtain strands; - Cooling the strands to ambient temperature; 10 - Pelletizing the cooled strands into pellets. [009e] In another aspect the invention relates to a solid oral extended release pharmaceutical dosage form obtained by a process of the invention. [009f] Certain statements that appear below are broader than what appears in the statements of the invention above. These statements are provided in the interests of 15 providing the reader with a better understanding of the invention and its practice. The reader is directed to the accompanying claim set which defines the scope of the invention. [0010] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate 20 extended release matrix formulation, comprising at least one poly(s-caprolactone), and at least one active agent. [0011] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, comprising at least one poly(s-caprolactone), 25 and at least one active agent, wherein at least one poly(s-caprolactone) has an approximate number average molecular weight of at least 10,000. [0012] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate -5 extended release matrix formulation, comprising at least one poly(s-caprolactone), and at least one active agent, wherein poly(s-caprolactone) is present at an amount of at least about 50 weight-% of the extended release matrix formulation. 5 [0013] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, comprising at least one poly(s-caprolactone), and at least one active agent, wherein the multi particulates have a diameter in the range of about 0.1 to about 3 mm. 10 [0014] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, comprising at least one poly(s-caprolactone), and at least one active agent, and additionally comprising at least one high molecular 15 weight polyethylene oxide. [0015] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form as described in the above paragraphs, wherein the active agent is an opioid analgesic, in particular selected from the group of 20 codeine, morphine, oxycodone, hydrocodone, hydromorphone, or oxymorphone or pharmaceutically acceptable salts, hydrates and solvates thereof, and mixtures of any of the foregoing. [0016] According to certain embodiments described herein is a solid extended 25 release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, comprising at least one poly(s-caprolactone), and at least one active agent, wherein the dosage form provides release rates of the active agent in-vitro when measured by the USP Basket Method at 100 rpm at 900 ml simulated gastric fluid at 37 'C, between 12.5 % and 55 % (by wt) active agent -6 released after 1 hour, between 25 % and 65 % (by wt) active agent released after 2 hours, between 45 % and 85 % (by wt) active agent released after 4 hours and between 55 % and 95 % (by wt) active agent released after 6 hours. These dosage forms comprise in particular oxycodone hydrochloride, hydromorphone 5 hydrochloride, morphine sulfate or oxymorphone hydrochloride in the active agent. [0017] According to certain other embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, comprising at least one poly(r 10 caprolactone), and at least one active agent, wherein the dosage form provides release rates of the active agent in-vitro when measured by the USP Basket Method at 100 rpm at 900 ml simulated gastric fluid at 37 'C between 10 % and 30% (by wt) active agent released after 2 hour, 40 % and 75 % (by wt) active agent released after 8 hours and no less than 80%(by wt) active agent released after 22 hours. 15 [0018] Also described herein is a method of treatment wherein a dosage form comprising an opioid analgesic as described herein is administered for treatment of pain to a patient in need thereof. 20 [0019] Also described herein is the use of a dosage form comprising an opioid analgesic as described herein for the manufacture of a medicament for the treatment of pain. [0020] Also described herein is the use of poly(s-caprolactone) as matrix forming 25 material in the manufacture of a solid extended release dosage form comprising an active agent selected from opioids for imparting to the solid extended release dosage form resistance to milling.

-7 [0021] Also described herein is a process of preparing a solid extended release pharmaceutical dosage form. [0022] Also described herein is a solid extended release pharmaceutical dosage 5 form obtainable by a process as described herein. [0023] As described herein the solid extended release pharmaceutical dosage form is preferably an oral dosage form. According to certain embodiments the solid extended release pharmaceutical dosage form is for use as a suppository. 10 [0024] The term "extended release" is defined for purposes of the present invention as to refer to products which are formulated to make the drug available over an extended period after ingestion thereby allowing a reduction in dosing frequency compared to a drug presented as a conventional dosage form (e.g. as a 15 solution or an immediate release dosage form). [0025] The term "immediate release" is defined for the purposes of the present invention as to refer to products which are formulated to allow the drug to dissolve in the gastrointestinal contents without substantial delay or prolongation of the 20 dissolution or absorption of the drug. [0026] The term "solid oral extended release pharmaceutical dosage form" for the purpose of the present invention refers to the administration form comprising a unit dose of active agent in extended release form such as an "extended release 25 matrix formulation" and optionally other adjuvants and additives conventional in the art, such as a protective coating or a capsule and the like, and optionally any other additional features or components that are used in the dosage form. Unless specifically indicated the term "solid oral extended release pharmaceutical dosage form" refers to said dosage form in intact form i.e. prior to any tampering. The -8 extended release pharmaceutical dosage form can e.g. be a tablet comprising the extended release matrix formulation or a capsule comprising the extended release matrix formulation in the form of multi particulates. The "extended release pharmaceutical dosage form" may comprise a portion of active agent in extended 5 release form and another portion of active agent in immediate release form, e.g. as an immediate release layer of active agent surrounding the dosage form or an immediate release component included within the dosage form. [0027] The term "extended release matrix formulation" is defined for purposes of 10 the present invention as shaped solid form of a composition comprising at least one active agent and at least one extended release feature such as an extended release matrix material such as e.g. poly(s-caprolactone). The composition can optionally comprise more than these two compounds namely further active agents and additional retardants and/or other materials, including but not limited to high 15 molecular weight polyethylene oxides and other adjuvants and additives conventional in the art. [0028] The term "poly(s-caprolactone) "may for the purpose of the invention be abbreviated by PCL. The molecular weight of "poly(s-caprolactone)" for the purpose 20 of the present invention relates to a number average molecular weight. Poly(F caprolactone) is considered to have an approximate number average molecular weight of 10,000 when the viscosity is 400-1000 MPA at 25 degrees Celsius. Poly(F caprolactone) is considered to have an approximate number average molecular weight of 37,000 when the melt flow index is 40g/10 minutes at 160 degrees Celsius 25 and 2.16kg. Poly(s-caprolactone) is considered to have an approximate number average molecular weight of 42,500 when the melt flow index is 1.8 G/10 minutes at 80'C and 44 psi. Poly(s-caprolactone) is considered to have an approximate number average molecular weight of 80,000 when the melt flow index is 1.0 G/10 minutes at 80 degrees Celsius and 44 psi. .

-9 [0029] The term "polyethylene oxide" may for the purpose of the invention be abbreviated by PEO. Preferably it has a molecular weight of at least 25,000, measured as is conventional in the art, and more preferably having a molecular 5 weight of at least 100,000. Compositions with lower molecular weight are usually referred to as polyethylene glycols. W02008/023261, which is hereby incorporated by reference, describes pharmaceutical dosage forms prepared with PEO. [0030] The term "high molecular weight polyethylene oxide" is defined for 10 proposes of the present invention as having an approximate molecular weight of at least 1,000,000. For the purpose of this invention the approximate molecular weight is based on rheological measurements. Polyethylene oxide is considered to have an approximate molecular weight of 1,000,000 when a 2% (by wt) aqueous solution of said polyethylene oxide using a Brookfield viscometer Model RVF, spindle No. 1, at 15 10 rpm, at 25'C shows a viscosity range of 400 to 800 mPa s (cP). Polyethylene oxide is considered to have an approximate molecular weight of 2,000,000 when a 2% (by wt) aqueous solution of said polyethylene oxide using a Brookfield viscometer Model RVF, spindle No. 3, at 10 rpm, at 25'C shows a viscosity range of 2000 to 4000 mPa s (cP). Polyethylene oxide is considered to have an approximate 20 molecular weight of 4,000,000 when a 1% (by wt) aqueous solution of said polyethylene oxide using a Brookfield viscometer Model RVF, spindle No. 2, at 2 rpm, at 25'C shows a viscosity range of 1650 to 5500 mPa s (cP). Polyethylene oxide is considered to have an approximate molecular weight of 5,000,000 when a 1% (by wt) aqueous solution of said polyethylene oxide using a Brookfield 25 viscometer Model RVF, spindle No. 2, at 2 rpm, at 25'C shows a viscosity range of 5500 to 7500 mPa s (cP). Polyethylene oxide is considered to have an approximate molecular weight of 7,000,000 when a 1% (by wt) aqueous solution of said polyethylene oxide using a Brookfield viscometer Model RVF, spindle No. 2, at 2 rpm, at 25'C shows a viscosity range of 7500 to 10,000 mPa s (cP). Polyethylene - 10 oxide is considered to have an approximate molecular weight of 8,000,000 when a 1% (by wt) aqueous solution of said polyethylene oxide using a Brookfield viscometer Model RVF, spindle No. 2, at 2 rpm, at 25'C shows a viscosity range of 10,000 to 15,000 mPa s (cP). Regarding the lower molecular weight polyethylene 5 oxides; Polyethylene oxide is considered to have an approximate molecular weight of 100,000 when a 5% (by wt) aqueous solution of said polyethylene oxide using a Brookfield viscometer Model RVT, spindle No. 1, at 50 rpm, at 25'C shows a viscosity range of 30 to 50 mPa s (cP) and polyethylene oxide is considered to have an approximate molecular weight of 900,000 when a 5% (by wt) aqueous solution of 10 said polyethylene oxide using a Brookfield viscometer Model RVF, spindle No. 2, at 2 rpm, at 25'C shows a viscosity range of 8800 to 17,600 mPa s (cP). [0031] The term "low molecular weight polyethylene oxide" is defined for purposes of the present invention as having, based on the rheological measurements 15 outlined above, an approximate molecular weight of less than 1,000,000. [0032] The term "melt formed" is defined for the purpose of the invention to relate to a process wherein an at least partially molten mass is formed and shaped. It includes without being limited to formed by extrusion, formed by casting and formed 20 by injection molding. [0033] The term "extrusion" is defined for purposes of the present invention as referring to a process by which material is mixed and at least partially melted then forced through a die under controlled conditions. 25 [0034] The term "casting" is defined for purposes of the present invention as referring to a process by which molten material is poured into a mold of a desired shape or onto a surface.

- 11 [0035] The term "injection molding" is defined for purposed of the present invention as referring to a process by which molten material is injected under pressure into a mold. 5 [0036] The term "direct compression" is defined for purposes of the present invention as referring to a tableting process wherein the tablet or any other compressed dosage form is made by a process comprising the steps of dry blending the compounds and compressing the dry blend to form the dosage form, e.g. by using a diffusion blend and/or convection mixing process (e.g. Guidance for Industry, 10 SUPAC-IR/MR: Immediate Release and Modified Release Solid Oral Dosage Forms, Manufacturing Equipment Addendum). [0037] For the purpose of certain embodiments described herein dosage forms are regarded as "resistant to milling" when the respective dosage form provides after 15 milling an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C, characterized by the percent amount of active released at 1 hour of dissolution that deviates no more than about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without 20 milling. [0038] For the purpose of certain embodiments dosage forms are regarded as "resistant to grinding" when the respective dosage form provides after grinding an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 25 900 ml simulated gastric fluid at 370 C, characterized by the percent amount of active released at 1 hour of dissolution that deviates no more than about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without grinding.

- 12 [0039] For the purpose of certain embodiments dosage forms are regarded as "resistant to alcohol extraction" when the respective dosage form provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid comprising 40% ethanol at 370 C, characterized by the percent 5 amount of active released at 1 hour of dissolution that deviates no more than about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without ethanol. 10 [0040] For the purpose of certain embodiments dosage forms are regarded as "resistant to milling and alcohol extraction" when the respective dosage form after milling provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid comprising 40% ethanol at 370 C, characterized by the percent amount of active released at 1 hour of dissolution that 15 deviates no more than about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without ethanol and without milling. [0041] For the purpose of certain embodiments dosage forms are regarded as 20 "resistant to grinding and alcohol extraction" when the respective dosage form after grinding provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid comprising 40% ethanol at 370 C, characterized by the percent amount of active released at 1 hour of dissolution that deviates no more than about 20 % points from the corresponding in-vitro dissolution 25 rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without ethanol and without grinding. [0042] The term "milling" refers to the following procedure Number of doses: 2 - 13 Duration of Milling: 15 seconds Milling machine: IKA Al 1 Basic Impact Mill Milling Chamber: Stainless steel Chamber Volume: 80 ml 5 Blade: Stainless steel Beater: Stainless steell.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute 10 Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W For demonstration purposes only and irrelevant for the definition of milling 15 resistance, milling can also be performed in a coffee mill. For demonstration sake Figure 14-3 shows the multi particulates described herein and a comparison tablet after milling in a coffee mill. [0043] The term "grinding" refers to the following procedure: 20 Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 Duration of grinding: 20 rotations [0044] The term "Simulated Gastric Fluid" (SGF) relates to Simulated Gastric 25 Fluid without enzymes and either without sodium lauryl sulfate (SLS), with 0.5% sodium lauryl sulfate or 0.1% sodium lauryl sulfate. The term "Simulated Gastric Fluid with 40% Ethanol" relates to SGF with 40% Ethanol and without enzymes and without sodium lauryl sulfate.

- 14 [0045] For the purpose of the present invention the term "active agent" is defined as a pharmaceutically active substance which includes without limitation opioid analgesics. 5 [0046] For purposes of the present invention, the term "opioid analgesic" includes single compounds and combinations of compounds selected from the group of opioids and which provide an analgesic effect such as one single opioid agonist or a combination of opioid agonists, one single mixed opioid agonist-antagonist or a combination of mixed opioid agonist-antagonists, or one single partial opioid agonist 10 or a combination of partial opioid agonists and combinations of an opioid agonists, mixed opioid agonist-antagonists and partial opioid agonists with one ore more opioid antagonists, stereoisomers, ether or ester, salts, hydrates and solvates thereof, compositions of any of the foregoing, and the like. 15 [0047] The present invention disclosed herein is specifically meant to encompass the use of the opioid analgesic in form of any pharmaceutically acceptable salt thereof. [0048] Pharmaceutically acceptable salts include, but are not limited to, 20 inorganic acid salts such as hydrochloride, hydrobromide, sulfate, phosphate and the like; organic acid salts such as formate, acetate, trifluoroacetate, maleate, tartrate and the like; sulfonates such as methanesulfonate, benzenesulfonate, p-toluenesulfonate, and the like; amino acid salts such as arginate, asparginate, glutamate and the like, and metal salts such as sodium salt, potassium salt, cesium salt and the like; alkaline 25 earth metals such as calcium salt, magnesium salt and the like; organic amine salts such as triethylamine salt, pyridine salt, picoline salt, ethanolamine salt, triethanolamine salt, dicyclohexylamine salt, N,N'-dibenzylethylenediamine salt and the like.

- 15 [0049] The opioids used according to the present invention may contain one or more asymmetric centers and may give rise to enantiomers, diastereomers, or other stereoisomeric forms. The present invention is also meant to encompass the use of all such possible forms as well as their racemic and resolved forms and compositions 5 thereof. When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, it is intended to include both E and Z geometric isomers. All tautomers are intended to be encompassed by the present invention as well. 10 [0050] As used herein, the term "stereoisomers" is a general term for all isomers of individual molecules that differ only in the orientation of their atoms is space. It includes enantiomers and isomers of compounds with more than one chiral center that are not mirror images of one another (diastereomers). 15 [0051] The term "chiral center" refers to a carbon atom to which four different groups are attached. [0052] The term "enantiomer" or "enantiomeric" refers to a molecule that is nonsuperimposeable on its mirror image and hence optically active wherein the 20 enantiomer rotates the plane of polarized light in one direction and its mirror image rotates the plane of polarized light in the opposite direction. [0053] The term "racemic" refers to a mixture of equal parts of enantiomers and which is optically inactive. 25 [0054] The term "resolution" refers to the separation or concentration or depletion of one of the two enantiomeric forms of a molecule.

- 16 [0055] Opioid agonists useful in the present invention include, but are not limited to, alfentanil, allylprodine, alphaprodine, anileridine, benzylmorphine, bezitramide, buprenorphine, butorphanol, clonitazene, codeine, desomorphine, dextromoramide, dezocine, diampromide, diamorphone, dihydrocodeine, dihydromorphine, 5 dimenoxadol, dimepheptanol, dimethylthiambutene, dioxaphetyl butyrate, dipipanone, eptazocine, ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitazene, etorphine, dihydroetorphine, fentanyl and derivatives, hydrocodone, hydromorphone, hydroxypethidine, isomethadone, ketobemidone, levorphanol, levophenacylmorphan, lofentanil, meperidine, meptazinol, metazocine, methadone, 10 metopon, morphine, myrophine, narceine, nicomorphine, norlevorphanol, normethadone, nalorphine, nalbuphene, normorphine, norpipanone, opium, oxycodone, oxymorphone, papaveretum, pentazocine, phenadoxone, phenomorphan, phenazocine, phenoperidine, piminodine, piritramide, propheptazine, promedol, properidine, propoxyphene, sufentanil, tilidine, tramadol, pharmaceutically 15 acceptable salts, hydrates and solvates thereof, mixtures of any of the foregoing, and the like. [0056] Opioid antagonists useful in combination with opioid agonists as described above are e.g. naloxone, naltrexone and nalmephene or pharmaceutically 20 acceptable salts, hydrates and solvates thereof, mixtures of any of the foregoing, and the like. [0057] In certain embodiments e.g. a combination of oxycodone HCl and naloxone HCl in a ratio of about 2:1 is used. Examples for ratios of 25 oxycodone HCl : naloxone HCl are 5: 2.5, 10:5, 20:10, 30:15, 40:20, 60:30, 80:40, 100:50 and 120:60. [0058] In certain embodiments, the opioid analgesic is selected from codeine, morphine, oxycodone, hydrocodone, hydromorphone, or oxymorphone or - 17 pharmaceutically acceptable salts, hydrates and solvates thereof, mixtures of any of the foregoing, and the like. [0059] In certain embodiments, the opioid analgesic is oxycodone, 5 hydromorphone or oxymorphone or a salt thereof such as e.g. the hydrochloride. The dosage form comprises from about 5 mg to about 500 mg oxycodone hydrochloride, from about 1 mg to about 100 mg hydromorphone hydrochloride or from about 5 mg to about 500 mg oxymorphone hydrochloride. If other salts, derivatives or forms are used, equimolar amounts of any other pharmaceutically acceptable salt or derivative 10 or form including but not limited to hydrates and solvates or the free base may be used. The dosage form may comprise e.g. 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 45 mg, 50 mg, 60 mg, or 80 mg, 90 mg, 100 mg, 120 mg or 160 mg oxycodone hydrochloride or equimolar amounts of any other pharmaceutically acceptable salt, derivative or form including but not limited to hydrates and solvates 15 or of the free base. The dosage form may comprise e.g. 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30, mg, 40 mg, 45 mg, 50 mg, 60 mg, or 80 mg, 90 mg, 100 mg, 120 mg or 160 mg oxymorphone hydrochloride or equimolar amounts of any other pharmaceutically acceptable salt, derivative or form including but not limited to hydrates and solvates or of the free base. The dosage form may comprise e.g. 2 mg, 20 4 mg, 5 mg, 8 mg, 12 mg, 15 mg, 16 mg, 24 mg, 25 mg, 32 mg, 48 mg, 50 mg, 64 mg or 75 mg hydromorphone hydrochloride or equimolar amounts of any other pharmaceutically acceptable salt, derivative or form including but not limited to hydrates and solvates or of the free base. 25 [00601 WO 2005/097801 Al, US 7,129,248 B2 and US 2006/0173029 Al, all of which are hereby incorporated by reference, describe a process for preparing oxycodone hydrochloride having a 14-hydroxycodeinone level of less than about 25 ppm, preferably of less than about 15 ppm, less than about 10 ppm, or less than about - 18 5 ppm, more preferably of less than about 2 ppm, less than about 1 ppm, less than about 0.5 ppm or less than about 0.25 ppm. [0061] The term "ppm" as used herein means "parts per million". Regarding 14 5 hydroxycodeinone, "ppm" means parts per million of 14-hydroxycodeinone in a particular sample product. The 14-hydroxycodeinone level can be determined by any method known in the art, preferably by HPLC analysis using UV detection. [0062] In certain embodiments, wherein the active agent is oxycodone 10 hydrochloride, oxycodone hydrochloride is used having a 14-hydroxycodeinone level of less than about 25 ppm, preferably of less than about 15 ppm, less than about 10 ppm, or less than about 5 ppm, more preferably of less than about 2 ppm, less than about 1 ppm, less than about 0.5 ppm or less than about 0.25 ppm. 15 [0063] In certain other embodiments other therapeutically active agents may be used as described herein, either in combination with opioids or instead of opioids. Examples of such therapeutically active agents include antihistamines (e.g., dimenhydrinate, diphenhydramine, chlorpheniramine and dexchlorpheniramine maleate), non -steroidal anti-inflammatory agents (e.g., naproxen, diclofenac, 20 indomethacin, ibuprofen, sulindac, Cox-2 inhibitors) and acetaminophen, anti emetics (e.g., metoclopramide, methylnaltrexone), anti-epileptics (e.g., phenytoin, meprobmate and nitrazepam), vasodilators (e.g., nifedipine, papaverine, diltiazem and nicardipine), anti-tussive agents and expectorants (e.g. codeine phosphate), anti asthmatics (e.g. theophylline), antacids, anti-spasmodics (e.g. atropine, scopolamine), 25 antidiabetics (e.g., insulin), diuretics (e.g., ethacrynic acid, bendrofluthiazide), anti hypotensives (e.g., propranolol, clonidine), antihypertensives (e.g., clonidine, methyldopa), bronchodilatiors (e.g., albuterol), steroids (e.g., hydrocortisone, triamcinolone, prednisone), antibiotics (e.g., tetracycline), antihemorrhoidals, hypnotics, psychotropics, antidiarrheals, mucolytics, sedatives, decongestants (e.g.

- 19 pseudoephedrine ), laxatives, vitamins, stimulants (including appetite suppressants such as phenylpropanolamine) and cannabinoids, as well as pharmaceutically acceptable salts, hydrates, and solvates of the same. 5 [0064] In certain embodiments, described herein is the use of Cox-2 inhibitors as active agents, in combination with opioid analgesics or instead of opioid analgesics, for example the use of Cox-2 inhibitors such as meloxicam (4-hydroxy-2-methyl-N (5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide), as disclosed in U.S. Serial No. 10/056,347 and 11/825,938, which are hereby 10 incorporated by reference, nabumetone (4-(6-methoxy-2-naphthyl)-2-butanone), as disclosed in U.S. Serial No. 10/056,348, which is hereby incorporated by reference, celecoxib (4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1 yl]benzenesulfonamide), as disclosed in U.S. Serial No. 11/698,394, which is hereby incorporated by reference, nimesulide (N-(4-Nitro-2 15 phenoxyphenyl)methanesulfonamide), as disclosed in U.S. Serial No. 10/057,630, which is hereby incorporated by reference, and N-[3-(formylamino)-4-oxo-6 phenoxy-4H-1-benzopyran-7-yl] methanesulfonamide (T-614), as disclosed in U.S. Serial No. 10/057,632, which is hereby incorporated by reference. 20 [0065] Also described herein are dosage forms utilizing active agents such as for example, benzodiazepines, barbiturates or stimulants such as amphetamines. These may be combined with the respective antagonists. [0066] The term "benzodiazepines" refers to benzodiazepines and drugs that are 25 derivatives of benzodiazepine that are able to depress the central nervous system. Benzodiazepines include, but are not limited to, alprazolam, bromazepam, chlordiazepoxide, clorazepate, diazepam, estazolam, flurazepam, halazepam, ketazolam, lorazepam, nitrazepam, oxazepam, prazepam, quazepam, temazepam, triazolam, methylphenidate as well as pharmaceutically acceptable salts, hydrates, - 20 and solvates and mixtures thereof. Benzodiazepine antagonists that can be used in the present invention include, but are not limited to, flumazenil as well as pharmaceutically acceptable salts, hydrates, and solvates. 5 [0067] Barbiturates refer to sedative-hypnotic drugs derived from barbituric acid (2, 4, 6-trioxohexahydropyrimidine). Barbiturates include, but are not limited to, amobarbital, aprobarbotal, butabarbital, butalbital, methohexital, mephobarbital, metharbital, pentobarbital, phenobarbital, secobarbital and as well as pharmaceutically acceptable salts, hydrates, and solvates mixtures thereof. 10 Barbiturate antagonists that can be used in the present invention include, but are not limited to, amphetamines as well as pharmaceutically acceptable salts, hydrates, and solvates. [0068] Stimulants refer to drugs that stimulate the central nervous system. 15 Stimulants include, but are not limited to, stimulants such as amphetamines, such as amphetamine, dextroamphetamine resin complex, dextroamphetamine, methamphetamine, methylphenidate as well as pharmaceutically acceptable salts, hydrates, and solvates and mixtures thereof. Stimulant antagonists that can be used in the present invention include, but are not limited to, benzodiazepines, as well as 20 pharmaceutically acceptable salts, hydrates, and solvates as described herein. BRIEF DESCRIPTION OF THE DRAWINGS [0069] Fig. 1 to 14-1 depict the dissolution profiles of the respective Examples 1 25 to 14 as described below. [0070] Fig .14-2 depicts the intact (a), milled (b) and grinded(c) multiparticulates of Example 14 - 21 [0071] Fig. 14-3 depicts the multiparticulates of Example 14 after milling in a coffee mill (a) and a comparison tablet after milling in a coffee mill (b). DETAILED DESCRIPTION 5 [0072] According to certain embodiments described herein is a solid extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, comprising at least one poly(s-caprolactone), and at least one active agent. 10 [0073] The inventors have found that poly(s-caprolactone) is a suitable polymeric material for forming an extended release matrix formulation which can provide a wide variety of release profiles when used in the form of melt formed multi particulates. The melt forming according to the invention can be accomplished by 15 several methods, including extrusion, casting and injection molding. The multi particulates have preferably a diameter in the range of about 0.1 to about 3 mm. [0074] Without wanting to be bound to any theory, it has also been found that poly(s-caprolactone), due to its specific polymer characteristics, imparts a milling 20 and/or grinding resistance to the extended release formulation in that the multi particles comprising poly(s-caprolactone) do not form during milling and/or grinding smaller individual particles but in case of milling tend to fuse/melt together forming a lumpy mass and in case of grinding might deform. This is shown by Figures 14-2 and 14-3. It is believed that the release of the active agent does therefore not 25 substantially change upon milling or grinding. In some cases the release is even slowed down. Thereby the extended release dosage form comprising said multi particulates is rendered less attractive for abuse.

- 22 [0075] According to certain embodiments at least one poly(s-caprolactone) with an approximate number average molecular weight of at least about 6,000 is used. According to certain embodiments the at least one poly(s-caprolactone) has an approximate number average molecular weight of at least about 10,000. According to 5 certain embodiments the at least one poly(s-caprolactone) has an approximate number average molecular weight of at least about 20,000. According to certain embodiments the at least one poly(s-caprolactone) has an approximate number average molecular weight of at least about 25,000. According to certain embodiments the at least one poly(s-caprolactone) has an approximate number 10 average molecular weight of at least about 37,000. According to certain embodiments the at least one poly(s-caprolactone) has an approximate number average molecular weight of about 42,500. According to certain embodiments the at least one poly(s-caprolactone) has an approximate number average molecular weight of at least about 80,000. According to further certain embodiments, the at least one 15 poly(s-caprolactone) has an approximate number average molecular weight of between about 6,000 to about 80,000, or between about 10,000 and about 80,000, or between about 20,000 and about 80,000, or between about 25,000 and about 80,000or between about 37,000 and about 80,000, or between about 42,500 and about 80,000. 20 [0076] According to certain embodiments the extended release matrix formulation comprises at least two poly(s-caprolactone) with an approximate number average molecular weight of between about 6,000 and about 25,000 and between about 37,000 and about 80,000, or between about 10,000 and about 25,000 and 25 between about 37,000 and about 80,000, or between about 10,000 and about 25,000 and between about 42,500 and about 80,000. [0077] According to certain embodiments in the extended release matrix formulation the overall content of poly(s-caprolactone) is at least about 50 weight-%, - 23 or at least about 60 weight-%, or at least about 70 weight-%, or at least about 80 weight-%, or at least about 90 weight-%, or between about 50 and about 90 weight %, or between about 60 and about 90 weight-%, or between about 70 and about 90 weight-%, or between about 80 and about 90 weight-% of the extended release 5 matrix formulation. [0078] According to certain embodiments the extended release matrix formulation comprises least one poly(s-caprolactone) with an approximate number average molecular weight of between about 37,000 and about 80,000 which is 10 present at an amount of between about 50 and about 90 weight-% of the extended release matrix formulation. [0079] According to certain embodiments the extended release matrix formulation comprises further at least one polyethylene glycol, which may be present 15 at an amount of between about 1 and about 20 or about 1 and about 15 weight-%. [0080] According to certain embodiments the extended release matrix formulation comprises further at least one high molecular weight polyethylene oxide with an approximate molecular weight of between about 1,000,000 and about 20 10,000,000, based on rheological measurements. It is the finding of the inventors that the combination of poly(s-caprolactone) and high molecular polyethylene oxide provide a resistance to milling and/or grinding in combination with a resistance to alcohol extraction thereby rendering the dosage form less attractive for illicit use and rendering the dosage form safer when used in combination with alcohol. The high 25 molecular weight polyethylene oxide may be present at an amount of between about 5 and about 35 weight-%. [0081] According to certain such embodiments the high molecular weight polyethylene oxide used has been screened through a screen with a size of 15/100 of - 24 the average diameter of the resulting melt formed multi particulate extended release formulation. According to certain embodiments the high molecular weight polyethylene oxide used has been screened with a 100 US mesh screen. 5 [0082] According to certain embodiments the extended release matrix formulation further comprises at least one poloxamer. The extended release matrix formulations may comprise further any other ingredients/excipients as conventional in the art. 10 [0083] According to certain embodiments the active agent is an opioid analgesic, in particular selected from the group of alfentanil, allylprodine, alphaprodine, anileridine, benzylmorphine, bezitramide, buprenorphine, butorphanol, clonitazene, codeine, desomorphine, dextromoramide, dezocine, diampromide, diamorphone, dihydrocodeine, dihydromorphine, dimenoxadol, dimepheptanol, 15 dimethylthiambutene, dioxaphetyl butyrate, dipipanone, eptazocine, ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitazene, etorphine, dihydroetorphine, fentanyl and derivatives, hydrocodone, hydromorphone, hydroxypethidine, isomethadone, ketobemidone, levorphanol, levophenacylmorphan, lofentanil, meperidine, meptazinol, metazocine, methadone, metopon, morphine, myrophine, 20 narceine, nicomorphine, norlevorphanol, normethadone, nalorphine, nalbuphene, normorphine, norpipanone, opium, oxycodone, oxymorphone, papaveretum, pentazocine, phenadoxone, phenomorphan, phenazocine, phenoperidine, piminodine, piritramide, propheptazine, promedol, properidine, propoxyphene, sufentanil, tilidine, tramadol, pharmaceutically acceptable salts, hydrates and solvates thereof, 25 mixtures of any of the foregoing. According to certain preferred embodiments the opioid analgesic is selected from the group of codeine, morphine, oxycodone, hydrocodone, hydromorphone, or oxymorphone or pharmaceutically acceptable salts, hydrates and solvates thereof, mixtures of any of the foregoing.

- 25 [0084] According to certain embodiments the opioid analgesic is oxycodone hydrochloride and the dosage form comprises from about 5 mg to about 500 mg of oxycodone hydrochloride or in particular comprises 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30, mg, 40 mg, 45 mg, 50 mg, 60 mg, or 80 mg, 90 mg, 100 mg, 120 mg or 160 5 mg of oxycodone hydrochloride. According to certain such embodiments the oxycodone hydrochloride has a 14-hydroxycodeinone level of less than about 25 ppm, preferably of less than about 15 ppm, less than about 10 ppm, or less than about 5 ppm, or even less than 1 ppm. 10 [0085] According to certain embodiments the opioid analgesic is oxymorphone hydrochloride and the dosage form comprises from about 1 mg to about 500 mg of oxymorphone hydrochloride, in particular 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 45 mg, 50mg, 60 mg, or 80 mg, 90 mg, 100 mg, 120 mg or 160 mg of oxymorphone hydrochloride. 15 [0086] According to certain embodiments the opioid analgesic is hydromorphone hydrochloride and the dosage form comprises from about 1 mg to about 100 mg of hydromorphone hydrochloride, in particular 2 mg, 4 mg, 5 mg, 8 mg, 12 mg, 15 mg, 16 mg, 24 mg, 25 mg, 32 mg, 48 mg 50 mg, 64 mg or 75 mg of hydromorphone 20 hydrochloride. [0087] According to certain embodiments the dosage form contains active in immediate release form, wherein the same or different active agents are in extended release and in immediate release form. 25 [0088] According to certain embodiments the dosage form provides release rates of the active agent in-vitro when measured by the USP Basket Method at 100 rpm at 900 ml simulated gastric fluid at 37 'C, between about 12.5 % and about 55 % (by wt) active agent released after 1 hour, between about 25 % and about 65 % (by wt) - 26 active agent released after 2 hours, between about 45 % and about 85 % (by wt) active agent released after 4 hours and between about 55 % and about 95 % (by wt) active agent released after 6 hours. 5 [0089] According to certain embodiments the dosage form provides release rates of the active agent in-vitro when measured by the USP Basket Method at 100 rpm at 900 ml simulated gastric fluid at 37 'C between about 10 % and about 30% (by wt) active agent released after 2 hour, about 40 % and about 75 % (by wt) active agent released after 8 hours and no less than about 80%(by wt) active agent released after 10 22 hours. [0090] According to certain embodiments the dosage form provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid comprising 40% ethanol at 370 C, characterized by the percent 15 amount of active agent released at 1 hour of dissolution that deviates no more than about 20 % points or no more than about 10 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without ethanol. 20 [0091] According to certain embodiments the dosage form provides after milling an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that increases no more than about 20 % points or no more than 10 % points or even decreases when compared to the 25 corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without milling. [0092] According to certain embodiments the dosage form provides after grinding an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) - 27 at 100 rpm in 900 ml simulated gastric fluid at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that increases no more than about 20 % points or more than about 10 % points or even decreases when compared to the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 5 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without grinding. [0093] According to certain embodiments the dosage form after milling provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid comprising 40% ethanol at 370 C, characterized 10 by the percent amount of active agent released at 1 hour of dissolution that deviates no more than about 20 % points or no more than 10 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without ethanol at 370 C without milling. 15 [0094] According to certain embodiments the dosage form after grinding provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid, comprising 40% ethanol, at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that deviates no more than about 20 % points or no more than 10 % points from the 20 corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without ethanol at 370 C without grinding. [0095] According to certain such embodiments as described in the paragraphs [0086] to [0092] above the active agent is oxycodone hydrochloride, hydromorphone 25 hydrochloride or oxymorphone hydrochloride. [0096] According to a certain embodiment the dosage forms as described herein are used in a method of treating pain in a patient in need thereof, wherein the dosage - 28 form comprises an opioid analgesic and the use of such a dosage form for the manufacture of a medicament for the treatment of pain. [0097] According to a certain embodiment poly(s-caprolactone) is used as matrix 5 forming material in the manufacture of a solid extended release oral dosage form comprising an active agent selected from opioids for imparting to the solid extended release oral dosage form resistance to milling and/or grinding. [0098] According to a certain embodiment a process of preparing a solid oral 10 extended release pharmaceutical dosage form is provided comprising the steps of: - Melting and blending the poly(s-caprolactone)and possible further ingredients except the active agent on a Thermodyne Hot Plate (temperature range about 900 - about 160 0 C) for optionally approximately 3 minutes to obtain a mixture; 15 - Adding the active agent to the mixture on the Thermodyne Hot Plate (temperature range about 900 - about 160 0 C) until the mixture appeared homogeneous to obtain a blend; - Casting the molten blend by pressing between two stainless steel plates to a thickness of optionally approximately 2 millimeters and cooling to room 20 temperature to obtain a sheet; and - Pelletizing the sheet by cutting into pellets of optionally approximately 2 mm in length and width. According to a certain embodiment a process of preparing a solid oral extended 25 release pharmaceutical dosage form is provided comprising the steps of: - Screening active agent, poly(s-caprolactone) and optionally other ingredients through a # 20 US mesh screen; - Blending the screened materials for optionally 10 minutes at ambient temperature; - 29 - Extruding the screened and blended materials in a twin screw extruder fitted with a die and set on counter-rotation with zone (barrel) temperatures ranged from about 1 8'C to about 110 C to obtain strands with a Leistritz - ZSE 27 Twin Screw Extruder (Counter-Rotation) 5 Neslab Model CFT-150 Chiller Accurate Powder Feeder Dorner 8-foot Conveyor Grablab Electronic Timer - Cooling the strands to ambient temperature; 10 - Pelletizing the cooled strands into pellets. In such a process the polyethylene oxide may be screened through a # 100 US mesh screen [0099] According to a further embodiment the solid oral extended release 15 pharmaceutical dosage form is obtainable by a process as described above. EXAMPLES [00100] The present invention will now be more fully described with reference 20 to the accompanying examples. It should be understood, however, that the following description is illustrative only and should not be taken in any way as a restriction of the invention. EXAMPLE 1 25 The composition of the poly(s-caprolactone) multiparticulates is summarized in Table 1 below.

- 30 Table 1 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Naltrexone HCl 12.0 2.4 Poly(s-caprolactone) , Mn ~ 42500 61.0 12.2 Butylated Hydroxytoluene 1.0 0.2 Total 74.0 14.8 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates 5 are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature 10 range 900 - 160 0 C) for approximately 3 minutes. 3. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 3 minutes. 4. Casting: The molten drug/polymer blend was pressed between two stainless 15 steel plates to a thickness of approximately 2 millimeters. 5. Cooling: The drug/polymer blend was cooled at room temperature. 6. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. 20 Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C.

-31 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid with 0.1% Sodium Lauryl Sulfate or 900 ml Simulated Gastric Fluid with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with 5 flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5ml/min). 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell 10 Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 15 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized 20 in Figure 1 and Table la. Table la Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media I h 2 h 3 h 4 h 5 h 6 h 8 h 10h 12 h 18 h 24 h SGF /w 3 4 5 6 7 8 10 11 13 17 21 0.1% SLS SGF with 7 11 15 18 20 23 27 30 34 41 47 40% EtOH - 32 Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 5 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 10 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W 15 Motor rating output: 100 W Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 20 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were difficult to grind and fused/melted during milling. 25 EXAMPLE 2 The composition of the poly(s-caprolactone) multiparticulates is summarized in Table 2 below. 30 - 33 Table 2 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Naltrexone HCl 12.0 1.2 Poly(s-caprolactone) , Mn ~ 42500 48.4 4.84 Polyethylene Glycol 3350 (Carbowax 10.1 1.01 PEG 3350) Butylated Hydroxytoluene 1.8 0.18 Total 72.3 7.23 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates 5 are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature 10 range 900 - 160 0 C) for approximately 3 minutes. 3. Melting and Blending: The polyethylene glycol (PEG 3350) was melted and mixed with the PCL/BHT mixture on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 3 minutes. 4. Weighing: The resulting polymer blend was weighed to determine the 15 amount of PEG incorporated with Mettler, Sartorious balances. 5. Melting and Blending: The polymer blend was melted (temperature range 900 - 160 0 C). The Naltrexone HCl was slowly added to the molten polymer blend and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 3 minutes.

- 34 6. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters. 7. Cooling: The drug/polymer blend was cooled at room temperature. 8. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm 5 in length and width. Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 10 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid with 0.1% Sodium Lauryl Sulfate or 900 ml Simulated Gastric Fluid with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 15 ml/min). 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump 20 Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator 25 Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 2 and Table 2a.

- 35 Table 2a Dissolution Result Dissolutio Naltrexone HCl % Released (n=1) n Media I h 2 h 3 h 4 h 5 h 6 h 8 h 10h 12 h 18 h 24 h SGF /w 17 26 34 41 47 53 63 72 80 94 97 0.1% SLS SGF with 28 43 54 63 69 75 82 87 89 92 94 40% EtOH 5 Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds Milling Chamber: Stainless steel 10 Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute 15 Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W 20 Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 - 36 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were difficult to grind but did not fuse/melt during milling. 5 EXAMPLE 3 The composition of the poly(s-caprolactone) multi particulates is summarized in Table 3 below. 10 Table 3 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Naltrexone HCl 12.0 1.2 Poly(s-caprolactone) , Mn ~ 42500 51.0 5.1 Polyethylene oxide (Polyox WSR 301) 10.0 1.0 Butylated Hydroxytoluene 1.0 0.1 Total 74.0 7.4 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates 15 are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature 20 range 900 - 160 0 C) for approximately 3 minutes.

- 37 3. Melting and Blending: The polyethylene oxide (PE0301) was slowly added to the beaker containing the melted PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous. 5 4. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/PEO/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 5. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters. 10 6. Cooling: The drug/polymer blend was cooled at room temperature. 7. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. Dissolution Method 15 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid with 0.l1% Sodium Lauryl Sulfate or 900 ml Simulated Gastric Fluid with 40% ethanol. 20 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow 5. through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 6. Equipment 25 Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel - 38 Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator 5 The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 3 and Table 3a. Table 3a 10 Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media I h 2 h 3 h 4 h 5 h 6 h 8 h 10h 12 h 18h 24 h SGF /w 14 22 31 38 45 51 63 73 81 98 106 0.1% SLS SGF with 20 37 51 63 72 79 89 95 98 101 103 40% EtOH Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 15 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 20 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s - 39 Motor rating input: 160 W Motor rating output: 100 W Grinding Procedure 5 Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were difficult to grind and fused/melted during 10 milling. EXAMPLE 4 The composition of the poly(s-caprolactone) multiparticulates is summarized in 15 Table 4 below.

- 40 Table 4 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Naltrexone HCl 12.0 1.2 Poly(s-caprolactone) , Mn ~ 42500 72.0 7.2 Polyethylene oxide (Polyox WSR 301) 35.0 3.5 Butylated Hydroxytoluene 1.0 0.1 Total 120.0 12.0 5 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were 10 melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 5 minutes. 3. Melting and Blending: The polyethylene oxide (PEO301) was slowly added to the beaker containing the melted PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture 15 appeared homogeneous. 4. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/PEO/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 5. Casting: The molten drug/polymer blend was pressed between two stainless 20 steel plates to a thickness of approximately 2 millimeters. 6. Cooling: The drug/polymer blend was cooled at room temperature.

- 41 7. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. Dissolution Method 5 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 720 minutes. 3. Media - 900 ml Simulated Gastric Fluid, Simulated Gastric Fluid with 0. 1% Sodium Lauryl Sulfate or 900 ml Simulated Gastric Fluid with 40% ethanol. 10 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow 5. through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 6. Equipment 15 Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel 20 Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator 25 The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 4 and Table 4a. Table 4a - 42 Dissolution Results Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h SGF 25 45 61 73 82 87 93 96 97 99 99 SGF /w 28 51 69 83 94 102 109 112 112 113 113 0.1% SLS SGF with 33 58 77 89 97 102 105 105 104 102 99 40% EtOH SGF with 40% EtOH 32 55 64 82 89 92 95 95 94 92 90 Repeated Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 5 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 10 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W 15 Motor rating output: 100 W - 43 Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 5 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were difficult to grind but did not fuse/melt during milling. 10 EXAMPLE 5 The composition of this poly(s-caprolactone) multiparticulate formulation is summarized in Table 5. 15 Table 5 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 10.00 1.2 Poly(s-caprolactone), Mn ~ 97.0 80.83 9.7 42500 Poloxamer (Lutrol 68) 10.0 8.33 1.0 Butylated Hydroxytoluene 1.0 0.83 0.1 Total 120.0 100.0 12.0 - 44 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 5 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 5 minutes. 3. Melting and Blending: The poloxamer (Lutrol 68) was slowly added to the beaker containing the melted PCL/BHT and mixed on a Thermodyne 10 Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous. 4. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/Poloxamer/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 15 5. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters. 6. Cooling: The drug/polymer blend was cooled at room temperature. 7. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. 20 Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 25 3. Media - 900 ml Simulated Gastric Fluid or 900 ml Simulated Gastric Fluid with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min).

-45 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump 5 Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator 10 Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 5 and Table 5a. 15 Table 5a Dissolution Result Dissoluti Mean Naltrexone HCl % Released (n=2) onMedia Ilh 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h SGF 15 22 27 31 35 38 43 48 52 62 69 SGF 26 39 47 54 59 64 71 76 80 87 92 with 40% EtOH - 46 Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds 5 Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute 10 Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W 15 Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 Duration of grinding: 20 rotations 20 The dissolution results for the milled poly(s-caprolactone) multiparticules are summarized in Figure 5a and Table 5b. The poly(s-caprolactone) pellets were tough. The pellets did not fuse/melt during 25 milling.

- 47 Table 5b Dissolution Result Milled Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 40 52 60 65 69 73 78 82 85 90 94 SGF with 63 77 84 89 91 93 95 96 97 96 95 40% EtOH EXAMPLE 6 5 The composition of this poly(s-caprolactone) multiparticulate formulation is summarized in Table 6. Table 6 10 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 10.00 1.2 Poly(s-caprolactone), Mn ~ 61.0 50.83 6.1 42,500 Poly(s-caprolactone) , Mn ~ 36.0 30.00 3.6 10,000 Polyethylene oxide (Polyox 10.0 8.33 1.0 WSR 301) Butylated Hydroxytoluene 1.0 0.83 0.1 Total 120.0 100.0 12.0 - 48 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 5 2. Melting and Blending: The low moleculare weight poly(s-caprolactone) (PCL), high moleculare weight polycaprolactne (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 5 minutes. 3. Melting and Blending: The polyethylene oxide (PE0301) was slowly added 10 to the beaker containing the melted PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous. 4. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/PEO/BHT and mixed on a Thermodyne Thermodyne Hot Plate 15 (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 5. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters. 6. Cooling: The drug/polymer blend was cooled at room temperature. 7. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm 20 in length and width. Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 25 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid, Simulated Gastric Fluid with 0. 1% Sodium Lauryl Sulfate or 900 ml Simulated Gastric Fluid with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with - 49 Flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell 5 Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 10 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized 15 in Figure 6 and Table 6a. Table 6a Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5h 6h 8lh 10h 12h 18h 24h SGF 10 16 21 25 29 33 39 44 49 60 69 SGF/w 10 17 22 27 32 36 45 52 59 73 84 0.1% SLS SGF with 19 34 45 54 61 67 76 82 88 97 101 40% EtOH 20 Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 - 50 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 5 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s 10 Motor rating input: 160 W Motor rating output: 100 W Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle 15 Number of doses: 2 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were tough and difficult to grind. During milling the discrete matrix particles formed a single fused mass. 20 EXAMPLE 7 The composition of this poly(s-caprolactone) multiparticulate formulation is summarized in Table 7. 25 -51 Table 7 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 9.9 1.2 Poly(s-caprolactone) , Mn ~ 108.0 89.3 10.8 42500 Butylated Hydroxytoluene 1.0 0.8 0.1 Total 121.0 100.0 12.1 The following processing steps were used to manufacturing the poly(s-caprolactone) 5 multiparticulates. 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) and milled BHT were 10 melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 3 minutes. 3. Melting and Blending: The Naltrexone HCl was slowly added to the polymer mixture and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the blend appeared homogeneous. 15 4. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 3. 5. Cooling: The drug/polymer blend was cooled at room temperature. 6. Pelletizing: The drug/polymer sheet was cut into pellets approximately 3 mm in length and width. 20 Dissolution Method - 52 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid (SGF), or Simulated Gastric Fluid with 40% ethanol (EtOH). 5 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell 10 Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 15 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized 20 in Figure 7 and Table 7a.

- 53 Table 7a Dissolution Result Dissolution Mean Naltrexone HCl % Released Media I h 2 h 3 h 4 h 5 h 6 h 8 h 10h 12 h 18h 24h SGF (n=6) 2 2 3 4 4 5 6 7 8 10 12 SGF with 6 8 10 12 13 14 16 17 19 22 24 40% EtOH (n=2) Milling Procedure 5 Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml 10 Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s 15 Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W The poly(s-caprolactone) pellets were tough and fused/melted during milling. 20 - 54 EXAMPLE 8 The composition of this poly(s-caprolactone) multiparticulate formulation is summarized in Table 8. 5 Table 8 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 12.77 2.4 Poly(s-caprolactone) , Mn ~ 81.0 86.17 16.2 42500 Butylated Hydroxytoluene 1.0 1.06 0.2 Total 94.0 100.00 18.8 The following processing steps were used to manufacturing the poly(s-caprolactone) 10 multiparticulates. 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were 15 melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 3 minutes. 3. Melting and Blending: The Naltrexone HCl was slowly added to the polymer mixture and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the blend appeared homogeneous. 20 4. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters. 5. Cooling: The drug/polymer blend was cooled at room temperature.

- 55 6. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. Dissolution Method 5 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid (SGF) with 0.5% Sodium Lauryl Sulfate (SLS), Simulated Gastric Fluid (SGF) with 0.1% Sodium Lauryl 10 Sulfate (SLS) or Simulated Gastric Fluid with 40% ethanol (EtOH). 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 5. Equipment 15 Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel 20 Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator 25 The dissolution results for the poly(s-caprolactone) multiparticulates are summarized in Figure 8 and Table 8a.

- 56 Table 8a Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media I h 2 h 3 h 4 h 5 h 6 h 8 h 10h 12 h 18h 24 h SGF /w 4 6 7 8 10 11 13 15 17 23 27 0.1% SLS SGF/w 5 7 9 11 13 14 17 20 22 29 34 0.5% SLS SGF with 9 14 18 21 24 26 31 35 38 45 50 40% EtOH 5 Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds Milling Chamber: Stainless steel 10 Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute 15 Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W 20 Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle - 57 Number of doses: 2 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were difficult to grind and fused/melted during 5 milling. EXAMPLE 9 The composition of this poly(s-caprolactone) multiparticulate formulation is 10 summarized in Table 9. Table 9 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 10.00 1.2 Poly(s-caprolactone) , Mn ~ 82.0 68.33 8.2 42500 Polyethylene oxide (Polyox 25.0 20.83 2.5 WSR 301) Butylated Hydroxytoluene 1.0 0.83 0.1 Total 120.0 100.0 12.0 15 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle.

- 58 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) for approximately 5 minutes. 3. Melting and Blending: The polyethylene oxide (PE0301) was slowly added 5 to the beaker containing the melted PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous. 4. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/PEO/BHT and mixed on a Thermodyne Thermodyne Hot Plate 10 (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 5. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters. 6. Cooling: The drug/polymer blend was cooled at room temperature. 7. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm 15 in length and width. Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 20 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid or 900 ml Simulated Gastric Fluid with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow 25 5. through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 6. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) - 59 Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 5 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized 10 in Figure 9 and Table 9a. Table 9a Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 14 26 39 49 57 64 76 84 90 96 97 SGF with 23 42 57 69 78 85 91 93 93 92 90 40% EtOH 15 Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds Milling Chamber: Stainless steel 20 Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute - 60 Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W 5 Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 Duration of grinding: 20 rotations 10 The poly(s-caprolactone) pellets were difficult to grind and fused/melted during milling. EXAMPLE 10 15 The composition of this poly(s-caprolactone) multiparticulate formulation is summarized in Table 10.

- 61 Table 10 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 10.00 1.2 Poly(s-caprolactone) , Mn ~ 42500 72.0 60.00 7.2 Polyethylene oxide (Polyox WSR 25.0 20.83 2.5 303) Polyethylene Glycol 3350 10.0 8.33 1.0 (Carbowax Sentry PEG 3350) Butylated Hydroxytoluene 1.0 0.83 0.1 Total 120.0 100.0 12.0 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates 5 are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature 10 range 900 - 160 0 C) for approximately 5 minutes. 3. Melting and Blending: The polyethylene Glycol (PEG 3350) was slowly added to the beaker containing the melted PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous. 15 4. Melting and Blending: The polyethylene oxide (PEO301) was slowly added to the beaker containing the melted PCL/PEG/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous.

- 62 5. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/PEO/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 6. Casting: The molten drug/polymer blend was pressed between two stainless 5 steel plates to a thickness of approximately 2 millimeters. 7. Cooling: The drug/polymer blend was cooled at room temperature. 8. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. 10 Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid, Simulated Gastric Fluid with 0. 1% 15 Sodium Lauryl Sulfate or 900 ml Simulated Gastric Fluid with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow 5. through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 20 6. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells 25 Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator - 63 Branson 8510 Sonicator The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 10 and Table 10a. 5 Table 10a Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 34 55 71 82 89 93 97 98 98 98 98 SGF with 38 60 77 87 94 98 101 102 102 102 100 40% EtOH Milling Procedure 10 Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml 15 Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s 20 Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W Grinding Procedure - 64 Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 Duration of grinding: 20 rotations 5 The poly(s-caprolactone) pellets were difficult to grind and fused/melted during milling. The dissolution results for milled samples are summarized in Figure 1 Oa and Table 1Ob. Table 10b 10 Dissolution Result Milled Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 32 53 67 77 84 89 95 98 99 99 99 SGF with 35 52 64 72 79 84 92 97 100 106 108 40% EtOH EXAMPLE 11 The composition of this poly(s-caprolactone) multiparticulate formulation is 15 summarized in Table 11.

- 65 Table 11 Amt/unit Amt/unit Amt/Batch Ingredient (Trade Name) (mg) (%) (g) Naltrexone HCl 12.0 10.00 1.2 Poly(s-caprolactone) , Mn ~ 82.0 68.33 8.2 10,000 Polyethylene oxide (Polyox WSR 25.0 20.83 2.5 301) Butylated Hydroxytoluene 1.0 0.83 0.1 Total 120.0 100.0 12.0 The processing steps for manufacturing the poly(s-caprolactone) multiparticulates 5 are as follows: 1. Milling: The butylated hydroxytoluene (BHT) was milled with a mortar and pestle. 2. Melting and Blending: The poly(s-caprolactone) (PCL) and milled BHT were melted and mixed on a Thermodyne Thermodyne Hot Plate (temperature 10 range 900 - 160 0 C) for approximately 5 minutes. 3. Melting and Blending: The polyethylene oxide (PEO301) was slowly added to the beaker containing the melted PCL/BHT and mixed on a Thermodyne Thermodyne Hot Plate (temperature range 900 - 160 0 C) until mixture appeared homogeneous. 15 4. Melting and Blending: The Naltrexone HCl was slowly added to the PCL/PEO/BHT and mixed on a Thermodyne Hot Plate (temperature range 900 - 160 0 C) until the mixture appeared homogeneous. 5. Casting: The molten drug/polymer blend was pressed between two stainless steel plates to a thickness of approximately 2 millimeters.

- 66 6. Cooling: The drug/polymer blend was cooled at room temperature. 7. Pelletizing: The drug/polymer sheet was cut into pellets approximately 2 mm in length and width. 5 Dissolution Method 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid or 900 ml Simulated Gastric Fluid 10 with 40% ethanol. 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow 5. through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 15 6. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells 20 Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator 25 The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 11 and Table 11 a.

- 67 Table 11a Dissolution Result Dissoluti Mean Naltrexone HCl % Released (n=2) onMedia Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 52 82 95 99 100 101 102 102 103 104 105 SGF 48 75 92 99 102 105 106 107 108 109 109 with 40% EtOH Milling Procedure 5 Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml 10 Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s 15 Circumferential Speed, under load: 53 m/s Motor rating input: 160 W Motor rating output: 100 W The poly(s-caprolactone) pellets were waxy and brittle. They did not fuse/melt 20 during milling.

- 68 EXAMPLE 12 The composition of the poly(s-caprolactone) melt extruded multiparticulates is summarized in Table 12 below. 5 Table 12 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Naltrexone HCl 12.0 200.00* Poly(s-caprolactone) Mw ~ 42500 97.0 1,616.67 Polyethylene oxide (Polyox WRS 10.0 166.67 301) Butylated hydroxytoluene (BHT), 1.0 16.67 Milled Total 120.0 2000.0 * Weigh is not corrected for water or impurities The processing conditions at the time of sampling are summarized below. 10 Extruder: Leistritz ZSE 27 Screw Configuration: Counter-rotation -69 Heating Zone 1 2 3 4 5 6 7 8 9 10 11 12 Temperature 18 36 66 78 78 78 77 76 77 80 88 76 (OC) Torque (%): 97 Melt Pressure (psi): 1930 5 Feed rate (g/min.): 20 Screw speed (rpm): 66 Die Plate Hole diameter (mm): 1.0 (8-hole die plate) Equipment 10 Leistritz - ZSE 27 Twin Screw Extruder (Counter-Rotation) Neslab Model CFT-150 Chiller Accurate Powder Feeder Dorner 8-foot Conveyor Grablab Electronic Timer 15 The processing steps for manufacturing Poly(s-caprolactone) melt extruded multiparticulates are as follows: 1. Screening: Naltrexone HCl, Poly(s-caprolactone), Polyethylene oxide and BHT were screened through a # 20 US mesh screen. 20 2. Blending: The materials screened in Step 1 were loaded into an 8 qt. V blender (% Poly(s-caprolactone), Naltrexone HCl, Polyethylene oxide, BHT and % Poly(s-caprolactone)) and blended for 10 minutes at ambient temperature. 3. Extrusion: Materials blended in Step 2 were metered into a twin screw 25 extruder fitted with a die and processed into approximately 1 mm strands.

- 70 The extruder was set on counter-rotation with zone (barrel) temperatures ranged from 18'C to 88'C. 4. Cooling: The strands were cooled on a conveyor at ambient temperature. 5. Pelletizing: The cooled strands were cut into pellets approximately 1 mm in 5 length. Dissolution Method The following method was used to test the dissolution of the poly(s-caprolactone) 10 multiparticulates. 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid (SGF) or Simulated Gastric Fluid 15 with 40% ethanol (EtOH). 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 ml/min). 5. Equipment 20 Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel 25 Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator Branson 8510 Sonicator - 71 The dissolution results for the poly(s-caprolactone) multiparticules are summarized in Figure 12 and Table 12a. Table 12a 5 Dissolution Result Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 19 32 44 54 63 69 80 87 92 98 99 SGF with 42 67 83 92 98 101 104 104 104 103 102 40% EtOH Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 10 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 15 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W 20 Motor rating output: 100 W Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle Number of doses: 2 - 72 Duration of grinding: 20 rotations The poly(s-caprolactone) pellets were difficult to crush with a mortar and pestle. They fused/melted during milling but incomplete after 15 seconds. 5 The dissolution results for the ground (Figure 12a and Table 12b) and milled (Figure 12b and Table 12c) poly(s-caprolactone) pellets are summarized below. Table 12b 10 Dissolution Result Ground Dissolution Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18 h 24h SGF 12 18 23 28 32 35 41 47 51 62 70 SGF with 34 51 63 71 78 83 90 94 97 100 101 40% EtOH Table 12c Dissolution Result Milled Dissolution Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18 h 24h SGF 38 58 72 81 87 91 96 98 98 99 99 SGF with 69 90 97 99 100 100 100 99 99 97 95 40% EtOH 15 EXAMPLE 13 The composition of the Poly(s-caprolactone) melt extruded multiparticulates is summarized in Table 13 below.

- 73 Table 13 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Naltrexone HCl 12.0 150.0* Poly(s-caprolactone) Mw ~ 42500 97.0 1,212.5 Polyethylene oxide (Polyox WRS 303) 7.0 87.5 Polyethylene Glycol (PEG 3350) 3.0 37.5 Butylated hydroxytoluene (BHT), 1.0 12.5 Milled Total 120.0 1500.0 * Weigh is not corrected for water or impurities The processing conditions at the time of sampling are summarized below. 5 Extruder: Leistritz ZSE 27 Screw Configuration: Counter-rotation Sample 1 mm Strands Heating Zone 1 2 3 4 5 6 7 8 9 10 11 12 Temperature 46 54 75 90 90 90 94 96 92 89 90 88 (OC) 10 Torque (%): 53 Melt Pressure (psi): 890 Feed rate (g/min.): 11 Screw speed (rpm): 20 15 Melt Temp. ('C): 94 Die Plate Hole diameter (mm): 1.0 (8-hole die plate) - 74 Sample 1.5 mm Strands Heating Zone 1 2 3 4 5 6 7 8 9 10 11 12 Temperature 45 53 74 90 89 91 93 89 90 90 89 89 (OC) 5 Torque (%): 55 Melt Pressure (psi): 870 Feed rate (g/min.): 11 Screw speed (rpm): 20 Melt Temp. ('C): 93 10 Die Plate Hole diameter (mm): 1.0 (8-hole die plate) Sample 2 mm Strands HeatingZone 1 2 3 4 5 6 7 8 9 10 11 12 Temperature 48 60 87 95 97 10 11 10 93 95 80 81 (OC) 3 0 3 15 Torque (%): 62 Melt Pressure (psi): 370 Feed rate (g/min.): 22 Screw speed (rpm): 50 Melt Temp. ('C): 89 20 Die Plate Hole diameter (mm): 3.0 (10-hole die plate) Equipmet Leistritz - ZSE 27 Twin Screw Extruder (Counter-Rotation) - 75 Neslab Model CFT-150 Chiller Accurate Powder Feeder Dorner 8-foot Conveyor Grablab Electronic Timer 5 The processing steps for manufacturing Poly(s-caprolactone) melt extruded multiparticulates are as follows: 1. Screening: Naltrexone HCl, Poly(s-caprolactone), Polyethylene Glycol and 10 BHT were screened through a # 20 US mesh screen. Polyethylene oxide screened through a #100 US mesh screen. 2. Blending: The materials screened in Step 1 were loaded into an 8 qt. V-blender (% Poly(s-caprolactone), Naltrexone HCl, Polyethylene oxide, polyethylene glycol, BHT and % Poly(s-caprolactone)) and blended for 10 minutes at 15 ambient temperature. 3. Extrusion: Materials blended in Step 2 were metered into a twin screw extruder fitted with a die and processed into strands. The extruder was set on counter-rotation with zone (barrel) temperatures ranged from 1 8'C to 110 C. 4. Cooling: The strands were cooled on a conveyor at ambient temperature. 20 5. Pelletizing: The cooled strands were cut into pellets approximately 1.0 mm, 1.5 mm and 2.0 mm in length for Sample #3, Sample #4 and Sample #1, respectively. Dissolution Method 25 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling time - every minute up to 1440 minutes.

- 76 3. Media - 900 ml Simulated Gastric Fluid (SGF) or Simulated Gastric Fluid with 40% ethanol (EtOH). 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 230 nm). Peristaltic pump (flow rate approx 5 5 ml/min). 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump 10 Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator 15 Branson 8510 Sonicator Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: 2 20 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 25 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s Motor rating input: 160 W - 77 Motor rating output: 100 W Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle 5 Number of doses: 2 Duration of grinding: 20 rotations Results 10 The dissolution results for the 1.0 mm (Table 13-la, Figure 13-1), 1.5 mm (Table 13 2a, Figure 13-2) and 2.0 mm (Table 13-3a, Figure 13-3) poly(s-caprolactone) pellets are summarized below. The 1.0 mm, 1.5 mm and 2.0 mm poly(s-caprolactone) pellets were difficult to grind 15 with a mortar and pestle. All pellet samples fused/melted during milling. Dissolution results for the milled and ground pellets are summarized for the 1.0 mm (Figure 13-1 and Table 13-lb and c), 1.5 mm (Figure 13-2 and Table 13-2b and c) and 2.0 mm (Figure 13-3 and Table 13-3b and c) below. 20 Table 13-1a 1.0 mm Pellets Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h SGF 20 33 46 56 65 72 82 89 94 100 102 SGF with 41 65 80 89 94 98 101 101101 100 99 40% EtOH Table 13-1b - 78 1.0 mm Pellets, milled Dissolution Mean Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h SGF 14 25 35 43 51 57 67 74 80 90 95 Table 13-1c 1.0 mm Pellets, ground Dissolution Mean Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5h 6h 8h 10h 12h 18h 24 SGF 14 24 33 41 48 54 64 71 77 87 93 5 Table 13-2a 1.5 mm Pellets Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 13 23 32 40 47 54 65 74 80 92 97 SGF with 30 50 65 76 84 90 97 101 103 104 103 40% EtOH Table 13-2b 1.5 mm Pellets, milled Dissolution Mean Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 7 13 18 23 27 31 38 44 48 59 67 10 Table 13-2c - 79 1.5 mm Pellets, ground Dissolution Mean Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 10 18 25 31 36 41 50 58 64 77 84 Table 13-3a 2.0 mm Pellets Dissolution Mean Naltrexone HCl % Released (n=2) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 11 16 21 26 30 34 41 48 53 68 78 SGF with 22 36 46 55 62 69 78 85 90 97 99 40% EtOH Table 13-3b 2.0 mm Pellets, milled Dissolution Mean Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 5 8 11 13 15 17 21 24 27 34 40 5 Table 13-3c 2.0 mm Pellets, ground Dissolution Mean Naltrexone HCl % Released (n=1) Media Ilh 2h 3h 4h 5 h 6h 8h 10h 12h 18h 24h SGF 13 19 25 29 33 37 44 49 55 67 76 Futher Equipment used in the Examples 10 Mettler, Sartorious balances Starrett Micrometers - 80 Fluka Digital Thermometer Carver Model 4332 Press [00101] The present invention is not to be limited in scope by the specific 5 embodiments disclosed in the examples which are intended as illustrations of a few aspects of the invention and any embodiments that are functionally equivalent are within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art and are intended to fall within the scope of the appended claims. 10 [00102] A number of references have been cited, the entire disclosures of which are incorporated herein by reference in their entireties for all purposes. [00103] In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is 15 generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art. 20 [00104] The term "comprising" as used in this specification and claims means "consisting at least in part of". When interpreting statements in this specification, and claims which include the term "comprising", it is to be understood that other features that are additional to the features prefaced by this term in each statement or claim may also be present. Related terms such as "comprise" and "comprised" are to 25 be interpreted in similar manner.

- 81 EXAMPLE 14 The composition of the Poly(s-caprolactone) melt extruded multiparticulates/pellets is summarized in Table 14 below. 5 - 82 Table 14 Amt/unit Amt/batch Ingredient (Trade Name) (mg) (g) Oxycodone HCl 20.0* 750.00* Poly(s-caprolactone) Mw ~ 42500 101.1 3791.66 Polyethylene oxide (Polyox WRS 303) 7.8 291.66 Polyethylene Glycol (PEG 3350) 3.3 125.00 Butylated hydroxytoluene (BHT), 1.1 41.66 Milled Total 133.3 5000.0 * Weigh is not corrected for water or impurities The processing conditions at the time of sampling are summarized below. 5 Extruder: Leistritz ZSE 27 Screw Configuration: Counter-rotation Heating Zone 1 2 3 4 5 6 7 8 9 10 11 12 Temperature 14- 35- 65- 90 90 90 90 90 90 90 89- 85 (OC) 18 50 75 91 90 Torque (%): 57-67 10 Melt Pressure (psi): 230-270 Feed rate (g/min.): 20-22 Screw speed (rpm): 20 Melt Temp. ('C): 93-96 Die Plate Hole diameter (mm): 3.0 (10-hole die plate) 15 Strand diameter: approximately 1.5 mm - 83 Equipment Leistritz ZSE 27 Twin Screw Extruder (Counter-Rotation) Neslab Model CFT-150 Chiller Accurate Powder Feeder 5 Dorner 8-foot Conveyor Grablab Electronic Timer Lasermike Randcastle Pelletizer 10 The processing steps for manufacturing Poly(s-caprolactone) melt extruded multiparticulates/pellets are as follows: 1. Screening Oxycodone HCl, Poly(s-caprolactone) and BHT were screened through a # 20 US mesh screen. Polyethylene Glycol was screened through a 15 #60 US mesh screen. Polyethylene oxide was screened through a #100 US mesh screen. 2. Blending: The materials screened in Step 1 were loaded into a 16 qt. V-blender (% Poly(s-caprolactone), Oxycodone HCl, Polyethylene oxide, polyethylene glycol, BHT and % Poly(s-caprolactone)) and blended for 10 minutes at 20 ambient temperature. 3. Extrusion: Materials blended in Step 2 were metered into a twin screw extruder fitted with a die and processed into strands. The extruder was set on counter-rotation with zone (barrel) temperatures ranged from 14C to 90'C. 4. Cooling: The strands were cooled on a conveyor at ambient temperature. 25 5. Pelletizing: The cooled strands were cut into pellets approximately 1.5 mm in length.

- 84 Dissolution Method I 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 5 2. Sampling time - every minute up to 1440 minutes. 3. Media - 900 ml Simulated Gastric Fluid or Simulated Gastric Fluid with 40% ethanol (EtOH). 4. Analytical Method - UV Analysis, UV/Vis Spectrophotometer setup with flow through cells (wavelength 240 nm). Peristaltic pump (flow rate approx 5 10 ml/min). 5. Equipment Perkin-Elmer Lambda 20 UV/Vis Spectrophotometer (8 - Position Cell Changer and Dissolution Manifold with tubing/connectors) Gilson Minipuls3 Peristaltic Pump 15 Hellma 10 mm Quarts Flow Cells Perkin-Elmer UV WinLab Software/Microsoft Window 95 and Excel Hewlett-Packard Pavilion Computer Model 8240 Van Kel VK 7010 Dissolution Bath (Fitted with Baskets) Van Kel VK 750D Heater/Circulator 20 Branson 8510 Sonicator Milling Procedure Equipment: IKA Al 1 Basic Impact Mill Number of doses: Approximately 2 25 Duration of Milling: 15 seconds Milling Chamber: Stainless steel Chamber Volume: 80 ml Blade: Stainless steel beater 1.4034 Rotor Shaft: Stainless steel 1.4571 - 85 Motor Speed, idle: 28000 revolutions/minute Motor Speed, under load: 25000 revolutions/minute Circumferential Speed, idle: 76 m/s Circumferential Speed, under load: 53 m/s 5 Motor rating input: 160 W Motor rating output: 100 W Milling Procedure (Coffee Mill) Equipment: Cuisinart Model DCG-12BC (120V, 60Hz, 12W) 10 Number of units: Approximately 2 units for pellets, 1 unit for tablet (comparison) Duration of Milling: 60 seconds Grinding Procedure Equipment: 8 oz Glass Mortar with Pestle 15 Number of doses: 2 Duration of grinding: 20 rotations The dissolution results are summarized below in table 14-la to c. 20 The poly(s-caprolactone) pellets were difficult to grind with a mortar and pestle. All pellet samples fused/melted during milling. Dissolution results for the intact (Table 14-la), milled (Table 14-lb) and ground (Table 14-1c) pellets are summarized below. Figure 14-2 depicts the a) intact, b) milled and c) ground pellets. Figure 14-3 depicts the a) the example pellets milled in a coffee mill and b) a comparison tablet 25 without poly(s-caprolactone) milled in a coffee mill. The composition and preparation of the comparison tablet without poly(s-caprolactone) can be found in WO 2008/023261 Example 14.5.

- 86 Table 14-1a Intact Dissol Mean % Released (n=3) ution 1h 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h Media SGF 16.1 25.0 32.9 40.1 46.7 52.7 62.9 71.1 77.8 91.2 97.8 SGF 32.0 49.0 62.2 71.9 79.0 84.2 91.2 95.2 97.5 99.2 99.0 with 40% EtOH Table 14-1b 5 Milled Dissol Mean % Released (n=3) ution 1h 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h Media SGF 5.1 7.9 10.2 12.3 14.0 15.7 18.7 21.4 23.9 30.1 35.3 SGF 12.1 19.7 25.5 30.3 34.4 37.9 44.0 49.0 53.2 63.0 69.7 with 40% EtOH Table 14-1c Ground Dissol Mean % Released (n=3) ution 1h 2h 3h 4h 5h 6h 8h 10h 12h 18h 24h Media SGF 13.7 21.0 26.5 31.2 35.1 39.2 45.7 51.3 56.1 67.3 75.7 10 Stability Testing The 1.5 mm pellets were placed on stability at 25'C/60% relative humidity (RH) and 40'C/75% RH in induction sealed high density polyethylene bottles (HDPE) with and without desiccant.

- 87 Assay Method The following method was used to assay the multiparticulates described in the example. 5 1. Extraction Solvent: 1:2 mixture acetonitrile and simulated gastric fluid without enzymes (SGF). 2. Analytical Method: Reversed-phase high performance liquid chromatography (HPLC) on a Waters Atlantis dC18 3.0 x 250 mm, 5 ptm column maintained 10 at 60'C using a mobile phase consisting of acetonitrile and potassium phosphate monobasic buffer at pH 3.0 with UV detection at 280 nm. Flow rate 1.0 ml/minute. 3. Equipment Waters Alliance 2695 HPLC system with 2487 UV-Visible absorbance 15 detector Stir Plate Degradation Products Method The following method was used to determine the degradation products of oxycodone 20 HCl in the multiparticulates described in the example. Oxycodone N-oxide is the only known degradation product included in the % total degradation products. Noroxymorphone, oxymorphone, 10-hydroxyoxycodone, 6-a-oxycodol, 7,8-hydro-8, 14-dihydroxycodeinone, and hydrocodone which are known process impurities can be identified with this method but are not included in the calculation of % total 25 degradation products. 1. Extraction Solvent: 1:2 mixture acetonitrile and simulated gastric fluid without enzymes (SGF).

- 88 2. Analytical Method: Reversed-phase high performance liquid chromatography (HPLC) on a YMC-Pack ODS-AQ 4.6 x 250 mm, 3 tm column maintained at 60'C using a mobile phase consisting of acetonitrile and potassium phosphate monobasic buffer at pH 3.0 with UV detection at 206 nm. Flow 5 rate 1.0 ml/min. 3. Equipment Waters Alliance 2695 HPLC system with 2487 UV-Visible absorbance detector Waters Empower Software 10 Stir Plate Dissolution Method II The following method was used to test the dissolution of the multiparticulate stability samples described in the example. 15 1. Apparatus- USP Type I (Baskets), 100 rpm at 37'C. 2. Sampling Time- Generally, 1 hour, 2 hrs., 4 hrs., 8hrs., 12 hrs., 18 hrs. and 24 hrs. 3. Media - 900 ml Simulated Gastric Fluid without enzyme (SGF). 20 4. Analytical Method - Reversed-phase high performance liquid chromatography (HPLC) on a Waters Atlantis dC18 3.0 x 250 mm, 5 Im column maintained at 60'C using a mobile phase consisting of acetonitrile and potassium phosphate monobasic buffer at pH 3.0 with UV detection at 230 nm. Flow rate 1.0 ml/minute. 25 Equipment Waters Alliance 2695 HPLC system with transfer module and 2487 UV-Visible absorbance detector Waters Empower Software - 89 Hanson SR8 Plus Dissolution Bath The assay, impurities and dissolution (Method II) results are summarized in Tables 14-2 and 14-3 after one month at 25'C/60% RH and 40'C/75% RH with and without 5 desiccant. Table 14-2 Assay and Total Impurities Results Method Initial 1-Month, 1-Month, 2-Month, 2-Month, 25 0 C/60% RH 40 0 C/75% RH 25 0 C/60% RH 40 0 C/75% RH Without With Without With With- With With- With Desicca Desicca Desiccant Desicca out Desicca out Desic nt Ut Ut Desicca nt Desic- cant nt cant Avg, % Assay 99.33 98.46 99.34 98.78 99.48 99.02 99.62 99.23 99.32 Oxycodo ne HCl (n=2) % Total Degra- < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ < LOQ Degrada dation tion Products Products (n=1) <LOQ= Less Than Limit of Quantitation 0.1% 10 - 90 Table 14-3 Dissolution Result (Method 11) Mean % Released Dissolution Media 1 hr. 2 hrs. 4 hrs 8 hrs. 12 hrs. 18 hrs. 24 hrs. SGF (Initial, n=6) 17 42 66 81 SGF (1-Month 25'C/60% 16 25 40 63 79 92 99 RH without desiccant, n=3) SGF (1-Month 25'C/60% 17 25 41 64 80 93 99 RH with desiccant, n=3) SGF (1-Month 4 0 'C/75% 16 26 42 65 80 93 99 RH without desiccant, n=3) SGF (1-Month 4 0 'C/75% 16 25 41 63 79 92 98 RH with desiccant, n=3) SGF (2-Month 25'C/60% 17 25 41 64 79 92 99 RH without desiccant, n=6) SGF (2-Month 25'C/60% 17 26 41 65 80 94 100 RH with desiccant, n=6) SGF (2-Month 4 0 'C/75% 16 25 40 63 78 91 98 RH without desiccant, n=6) SGF (2-Month 4 0 'C/75% 17 26 42 65 81 94 100 RH with desiccant, n=6) Small Volume Extraction Testing 5 The extraction of oxycodone HCl from 1.5 mm pellets using absolute anhydrous ethanol was evaluated at room temperature. Small Volume Extraction Method 1. Extraction Solvent: 30 ml Absolute Anhydrous Ethanol 10 2. Number of Units: Approximately 2 3. Shaking Time: 1 hour 4. Diluting Solvent: Absolute Anhydrous Ethanol 5. Analysis: UV/Visible Spectrophotometer (wavelength 240 nm) 6. Equipment - 91 Agilent 8453 UV/Vis Spectrophotometer with ChemStation Software Hewlett-Packard Vectra Computer/Windows XP Hellma 10 mm Quartz Cell Burrell Model 75 Shaker 5 The results are summarized in Table 14-4. An average of 5.6 % oxycodone HCl was extracted.

Claims

1. A solid oral extended release pharmaceutical dosage form, comprising a melt formed multi particulate extended release matrix formulation, 5 comprising at least one poly(s-caprolactone), and at least one active agent, wherein the melt is formed by an extrusion method; or wherein the melt is formed by a casting method; or 10 wherein the melt is formed by an injection molding method.

2. The solid oral extended release pharmaceutical dosage form according to claim 1, wherein the at least one poly(s-caprolactone) has an approximate number average molecular weight of at least about 10,000; or 15 wherein the at least one poly(s-caprolactone) has an approximate number average molecular weight of at least about 37,000; or wherein the at least one poly(s-caprolactone) has an approximate number average molecular weight of between about 10,000 and about 80,000; or wherein the at least one poly(s-caprolactone) has an approximate number average 20 molecular weight of between about 37,000 and about 80,000.

3. The solid oral extended release pharmaceutical dosage form according to claim 1, comprising at least a first poly(s-caprolactone) with an approximate number average molecular weight of between about 10,000 and about 25,000 and a second 25 poly(s-caprolactone) with an approximate number average molecular weight of between about 37,000 and about 80,000. - 93

4. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 3, wherein poly(s-caprolactone) is present at an amount of at least about 50 weight-% of the extended release matrix formulation; or wherein poly(s-caprolactone) is present at an amount of at least about 60 weight 5 % of the extended release matrix formulation; or wherein poly(s-caprolactone) is present at an amount of between about 50 and about 90 weight-% of the extended release matrix formulation.

5. The solid oral extended release pharmaceutical dosage form according to 10 according to claim 1, wherein the at least one poly(s-caprolactone) has an approximate number average molecular weight of between about 37,000 and about 80,000 and is present at an amount of between about 50 and about 90 weight-% of the extended release matrix formulation. 15

6. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 5, wherein the multi particulates have a diameter in the range of about 0.1 to about 3 mm.

7. The solid oral extended release pharmaceutical dosage form according to any 20 one of claims 1 to 6, wherein the extended release matrix formulation further comprises at least one polyethylene glycol.

8. The solid oral extended release pharmaceutical dosage form according to claim 7, wherein the polyethylene glycol is present at an amount of between about 1 25 and about 20 weight-% - 94

9. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 8, wherein the extended release matrix formulation further comprises at least one high molecular weight polyethylene oxide. 5 10. The solid oral extended release pharmaceutical dosage form according to claim 9, wherein high molecular weight polyethylene oxide has a molecular weight of between about 1,000,000 and about 10,000,000, based on rheological measurements; and/or wherein high molecular weight polyethylene oxide is present at an amount of between about 5 and about 35 weight-%.

10

11. The solid oral extended release pharmaceutical dosage form according to claim 9 or 10, wherein a high molecular weight polyethylene oxide is used which has been screened with a screen with a size of 1/10 or less of the average diameter of the resulting melt formed multi particulate extended release formulation; or wherein a 15 high molecular weight polyethylene oxide is used which has been screened with a 100 US mesh screen or a finer screen.

12. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 11, wherein the extended release matrix formulation further 20 comprises at least one poloxamer.

13. The solid oral extended release pharmaceutical dosage form of any one of claims 1 to 12, which contains active in immediate release form. 25

14. The solid oral extended release pharmaceutical dosage form of claim 13, wherein the same or different active agents are in extended release and in immediate release forms. - 95

15. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 14, wherein the dosage form provides release rates of the active agent in-vitro when measured by the USP Basket Method at 100 rpm at 900 ml simulated gastric fluid at 37 'C, between about 12.5 % and about 55 % (by wt) active 5 agent released after 1 hour, between about 25 % and about 65 % (by wt) active agent released after 2 hours, between about 45 % and about 85 % (by wt) active agent released after 4 hours and between about 55 % and about 95 % (by wt) active agent released after 6 hours. 10

16. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 14, wherein the dosage form provides release rates of the active agent in-vitro when measured by the USP Basket Method at 100 rpm at 900 ml simulated gastric fluid at 37 'C between about 10 % and about 3 0% (by wt) active agent released after 2 hour, about 40 % and about 75 % (by wt) active agent released 15 after 8 hours and no less than about 80%(by wt) active agent released after 22 hours.

17. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 16, wherein the dosage form provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated 20 gastric fluid comprising 40% ethanol at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that deviates no more than about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without ethanol. 25

18. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 17, wherein the dosage form provides after milling an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml - 96 simulated gastric fluid at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that increases no more than about 20 % points when compared to the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without 5 milling, or decreases when compared to the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without milling.

19. The solid oral extended release pharmaceutical dosage form according to any 10 one of claims 1 to 18, wherein the dosage form provides after grinding an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that increases no more than about 20 % points when compared to the corresponding in-vitro dissolution rate measured in a USP 15 Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without grinding, or decreases when compared to the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid at 370 C without grinding.

20 20. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 19, wherein the dosage form after milling provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid comprising 40% ethanol at 370 C, characterized by the percent amount of active agent released at 1 hour of dissolution that deviates no more than 25 about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without ethanol at 370 C without milling. - 97

21. The solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 20, wherein the dosage form after grinding provides an in-vitro dissolution rate, when measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid, comprising 40% ethanol, at 370 C, characterized by the 5 percent amount of active agent released at 1 hour of dissolution that deviates no more than about 20 % points from the corresponding in-vitro dissolution rate measured in a USP Apparatus 1 (basket) at 100 rpm in 900 ml simulated gastric fluid without ethanol at 370 C without grinding. 10

22. A solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 21 which is resistant to milling and grinding.

23. The solid oral extended release pharmaceutical dosage form according to claim 22, wherein the dosage form is resistant to alcohol extraction. 15

24. A method of treatment wherein a solid oral extended release pharmaceutical dosage form according to any one of claims 1 to 23 is administered for treatment of pain to a patient in need thereof, wherein the dosage form comprises an opioid analgesic. 20

25. Use of a solid extended release pharmaceutical dosage form according to any one of claims 1 to 23 for the manufacture of a medicament comprising a solid oral extended release pharmaceutical dosage form for the treatment of pain, wherein the dosage form comprises an opioid analgesic. 25

26. Use of poly(s-caprolactone) as matrix forming material in the manufacture of a solid oral extended release pharmaceutical dosage form comprising an active agent - 98 selected from opioids for imparting to the solid oral extended release dosage form resistance to milling.

27. A process of preparing a solid oral extended release pharmaceutical dosage 5 form comprising the steps of: - Melting and blending the poly(s-caprolactone) (PCL) and possible further ingredients except the active agent on a Thermodyne Hot Plate (temperature range 900 - 160 0 C) to obtain a mixture; - Adding the active agent to the mixture on the Thermodyne Hot Plate 10 (temperature range about 900 - about 160 0 C) until the mixture appeared homogeneous to obtain a blend; - Placing the molten blend on a stainless steel plate and pressing with a second stainless steel plate and cooling to room temperature to obtain a sheet with a given thickness; and 15 - Pelletizing the sheet by cutting into pellets.

28. The process of claim 27, wherein the thickness of the sheet is approximately 2 mm and the pellets have approximately 2 mm in length and width. 20

29. A process of preparing a solid oral extended release pharmaceutical dosage form comprising the steps of: - Screening active agent, poly(s-caprolactone) and optionally other ingredients through a # 20 US mesh screen; - Blending the screened materials at ambient temperature; 25 - Extruding the screened and blended materials in a twin screw extruder fitted with a die and set on counter-rotation with zone (barrel) temperatures ranged from about 18'C to about 1 10 C to obtain strands; - Cooling the strands to ambient temperature; - Pelletizing the cooled strands into pellets. - 99

30. The process of claim 29, wherein the solid oral extended release pharmaceutical dosage form comprises polyethylene oxide and the polyethylene oxide is screened through a # 100 US mesh screen or finer. 5

31. A solid oral extended release pharmaceutical dosage form obtained by a process according to any one of claims 27 to 30.