CA2662748A1 - Liquid pharmaceutical formulations for oral administration of a cgrp antagonist - Google Patents

Abstract

Liquid formulations comprising the compound 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide have surprisingly improved bioavailability and stability in comprising polyethylene glycol, Tween (polysorbate 80), Cremophor® EL (polyoxyl 35 castor oil), propylene glycol, and optionally water, and may be filled into soft or hard gelatin capsules useful for treating conditions including migraine headache and cluster headache.

Description

TITLE OF THE INVENTION
LIQUID PHARMACEUTICAL FORMULATIONS FOR ORAL ADMINISTRATION OF A
CGRP ANTAGONIST

BACKGROUND OF THE INVENTION
The pharmaceutical industry is faced with the challenge of developing formulations for an increasing number of active molecules that possess low aqueous solubility and/or intestinal epithelial permeability. In some cases, as in the case of the CGRP receptor antagonist 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide (Compound I), acceptable bioavailability can not be readily achieved by means of traditional tablet or capsule formulations. Therefore, there remains a need to develop stable oral formulations of Compound I that would maximize exposure and provide for a faster onset of exposure. A
formulation that permits the presentation of large doses per capsule would also be a desirable result. This invention provides pharmaceutical compositions that are liquid solutions of Compound I, said solutions being orally administrable. The active solutions may be administered, for example, as fill in encapsulated dosage forms such as liquid filled and sealed hard gelatin capsules or soft gelatin capsules. Other technologies commonly used for delivering poorly water soluble compounds as oral agents, such as particle size reduction, amorphous formulations (hot melt extrusion or spray drying) are typically explored, as was the case with Compound I. However, due to physicochemichemical limitations these alternative formulation approaches were found not to be feasible.

SUMMARY OF THE INVENTION .
The compound 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino} carbonyl)piperidin-4-yl]-2-oxo-l,2-dihydroimidazo[4,5-b]pyridin-3-ide (Compound I) N O
O

N
H O
F F N NH

d is a CGRP receptor antagonist. I
Compound I, its free base form and various salt and solvate forms are described in Intemational Patent Application No. PCT/LJS07/008703, filed Apri16, 2007, and published International Patent Application W004/092166, published October 28, 2004.
This invention relates to liquid formulations of Compound I (and salts thereof, and solvate forms and free base forms of Compound I) for use in mammals, especially humans, especially in connection with encapsulated formulations including hard and soft gelatin capsules.
One salt form of compound I is the potassium ethanolate salt.
These liquid formulations provide increased solubility of Compound I, and salts thereof, for absorption and hence higher bioavailability. Compositions of the present invention comprising Formulations of compound I, and salts thereof, are useful in the treatment of diseases mediated by the antagonism of the CGRP receptor, including migraine headache and cluster headache.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a graph of the mean plasma concentration of Compound I over time generated in the experiment described in Example 6, wherein healthy men ages 18 to 45 were orally administered a 400 mg dosage of Compound I in a liquid filled gelatin capsule and in several different carrier formulations.

DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to pharmaceutical compositions for the oral administration of 1-[ 1-( { [(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino} carbonyl)piperidin-4-yl]-2-oxo-l,2-dihydroimidazo[4,5-b]pyridin-3-ide (Compound I), or salts thereof, a compound with low aqueous solubility (<0.05 mg/mL). The invention is a formulation which increases the oral bioavailability, as determined by elevated drug plasma levels, while maintaining chemical integrity of Compound I in the formulation upon long term storage.
When dosed as a pin milled crystalline solid, in a dry blend with excipients the compound was found to be poorly bioavailable in dogs It has been found that bioavailability is increased dramatically by using a liquid dosage formulation (see Table, below) in which the compound is in solution in certain combinations of liquid excipients:

Mean pharmacokinetic parameters after oral administration of 40 mg Compound I in dry filled capsules or Imwitor/Tween 80 solution filled capsules to male Beagle dogs (mean SD).
Dry Filled Capsule Imwitor/Tween 80 Solution AUCa-24 M-hr 0.229 0.293 2.073 1.427 Cmax m 0.0495 0.560 0.637 0.377 Tmax (hr) 2.2 1.8 2.0 0.0 However, the low solubility and/or chemical instability of Compound I in the overwhelming majority of vehicles typically used in the formulation of low aqueous solubility compounds necessitated extensive research and ingenuity to arrive at the surprising invention disclosed herein.
The formulations of the present invention possess the advantages of increased bioavailability, excellent stability, increased potency per unit dose, good safety and tolerability, and ease of processing.
Thus, in one embodiment of the present invention, there is provided a liquid formulation comprising Compound I or any pharmaceutically acceptable salt or solvate thereof, a surfactant component, a solvent component and other optionally present components such as the solvent water. In this embodiment the surfactant cornponerit may comprise one or more surfactants. Similarly, the solvent component may comprise one or more solvents.
Suitable surfactants for use in the present invention include polyethoxylated castor oil (such as Cremophor EL (polyoxyl 35 castor oil), Cremophor RH60, Cremophor RH40);
polysorbates (such as Tween-80, Tween-20); Polyethylene glycol ester glycerides (such as Labrasol , Labrifil 1944); sorbitan monooleate (such as Span -80, Span -20);
Vitamin E-TPGS (vitamin E d-alpha-tocopherol polyethylene glycol succinate); saturated polyglycolized glycerides (such as Gelucire(D 44/14 and and Gelucire 50/13);
polypropoxylated stearyl alcohols (such as Acconon MC-8, Acconon CC-6). Preferred surfactants for use in the present invention include Cremophor EL, Tween-80, Tween-20, and Labrasol .
Most preferred surfactants for use in the present invention include Tween 80 (polysorbate 80) and Cremophor EL (polyoxyl 35 castor oil). The surfactants may be used alone or in combination.
Most preferably, Tween 80 and Cremophor EL are used in combination with one another.
Suitable solvents for use in the present invention include ethanol, propylene glycol, glycerin, polyethylene glycols (such as PEG 200, PEG 400, PEG 600, PEG
900 and PEG
1000), DMSO, ethoxydiglycol (Transcutol ), diethyleneglycol, polyoxypropylene block copolymers (such as Polaxamer), and water. Preferred solvents for use in the present invention include ethanol and propylene glycols (PEG 400 and PEG 600). Most preferred solvents for use in the present invention include polyethylene glycol 400 (PEG-400) and propylene glycol (PG).
The solvents may be used alone or in combination. Most preferably, PEG-400 and PG are used in combination with one another.
Within the first embodiment of the invention, there is a genus wherein the liquid forrnulation comprises Compound I, PEG-400, polysorbate 80, Cremophor EL, PG
and optionally water, in the following amounts:
Component % (by wei ht Compound I 5 to 40 PEG-400 0 to 95 Polysorbate 80 0 to 95 Cremo hor EL 0 to 95 Propylene GI col 0 to 95 Water 0 to 20 Within this genus there is a sub-genus wherein the liquid formulation comprises Compound I, PEG-400, polysorbate 80, Cremophorv EL, PG and optionally water, in the following amounts:
Component % (by wei ht Compound I 20 to 35 PEG-400 0 to 50 Polysorbate 80 0 to 50 Cremo hor EL 0 to 50 Propylene Glycol 0 to 50 Water 0 to 10 Within this sub-genus there is a further sub-genus wherein the liquid formulation comprises Compound I, PEG-400, polysorbate 80, Cremophor EL, PG and water, in the following amounts:

Component % (by wei ht Compound I 28.5 PEG-400 23.3 Polysorbate 80 18.1 Cremo hor EL 18.1 Propylene Glycol 7 Water 5 The invention further relates to an oral pharmaceutical composition comprising the liquid formulations described above.
In a second embodiment of the invention, there is provided a capsule comprising the liquid formulation of the first embodiment, wherein the capsule is filled with 50 to 1200 mg, and preferably 333 to 1050 mg of the liquid formulation of the first inventive embodiment. The fill amount corresponds to the presence of 100 to 300 mg of the active agent Compound I or a pharmaceutically acceptable salt or solvate thereof, 81.6 to 245 mg PEG-400, 47.5 to 190 mg polysorbate 80, 47.5 to 190 mg Cremophor EL, 25 to 75 mg propylene glycol and up to 50 mg water; and preferably 300 mg the active agent Compound I, 245 mg PEG-400, 190 mg polysorbate 80, 190 mg Cremophor EL, 75 mg propylene glycol and 50 mg water;
or 150 mg the active agent Compound I, 122.5 mg PEG-400, 95 mg polysorbate 80, 95 mg Cremophor EL, 37.5 mg propylene glycol and 25 mg water.
Within the second embodiment, there is a genus wherein the capsule is selected from a soft gelatin capsule and a hard gelatin capsule.
Within the second embodiment of the invention, there is a genus which is an oral pharmaceutical composition comprising a liquid filled capsule comprising Compound I.
In a third embodiment of the invention, there is provided a method of making the liquid formulation of the first embodiment, and a method of making the liquid filled capsule of the second embodiment of the invention, wherein the method of making the liquid formulation comprises the steps of combining a pharmaceutically effective amount of Compound I with one or more solvents and one or more surfactants, and the method of making the liquid filled capsule further comprises filling a capsule with the liquid formulation and sealing the capsule. In a preferred aspect of this embodiment, Compound I is combined with one or more solvents selected from ethanol, propylene glycol, glycerin, PEG 200, PEG 400, PEG 600, PEG 900, PEG
1000, DMSO, Transcutol , diethyleneglycol, Polaxamer, water, and one or more surfactants selected from Cremophor EL, Tween-80, Tween-20, Labrasol , Labrifil 1944, Cremophor RH60, Cremophor RH40, Span -80, Vitamin E-TPGS, Geluicire 44/14, Acconon MC-8, Span&-20, Acconon CC-6, Gelucire 50/13, and the resulting liquid formulation is filled into a softgel and sealed. In a more preferred aspect, Compound I is combined with the surfactants Cremophor EL and polysorbate 80 and the solvents PEG 400 and propylene glycol, and optionally water, and the resulting liquid formulation is filled into a softgel and sealed.
In a fourth embodiment of the invention, there is provided a method of treating one or more conditions selected from: migraine headache and cluster headache with the capsule of the second embodiment of the invention with the filled capsules of the present invention (containing Compound I). The method includes administering one or more capsules to a patient in need thereof, either to treat or prevent migraine headache or cluster headache, or both.
Reference herein is made to a soft gelatin capsule, "softgel" being an abbreviation for soft gelatin capsules. It is understood that when reference is made to the term "softgel" alone, it shall be understood that the invention applies equally to all types of gelatin and non-gelatin capsules, regardless of hardness, softness, and so forth. In one embodiment of the present invention, the soft gelatin capsule contains plasticizers, such as glycerin and sorbitol. Colorant may be added to the gel mixture prior to encapsulation to produce soft gelatin capsules of a desired hue.
Referring to certain surfactants discussed herein, the terms Cremophor EL and polyoxyl 35 castor oil are used interchangeably. Likewise, the terms Tween-80 and polysorbate 80 are interchangeable as used in this document. -Referring to certain solvents discussed herein, the terms polyethylene glycol, polyethylene glycol 400 and PEG 400 are used interchangeably. Similarly, propylene glycol is sometimes referred to as PG.
Reference to a specific weight or percentage of "active ingredient", or Compound I, is on the basis of the free base weight, absent the weight of any counterion or solvate present, unless otherwise indicated. For example, the phrase "1 mg 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}
carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide," or "1 mg Compound I" means that the amount of the compound selected is based on 1 mg of the free base form of Compound I
absent the weight of the solvent present in the solvate.

As used herein, the term "treatment" or "treating" means any administration of a compound of the invention and includes (1) inhibiting the disease in an animal that is experiencing or displaying the pathology or symptomatology of the diseased (i.e., arresting further development of the pathology and/or symptomatology), or (2) ameliorating the disease in an animal that is experiencing or displaying the pathology or symptomatology of the diseased (i.e., reversing the pathology and/or symptomatology). The term "controlling"
includes preventing treating, eradicating, ameliorating or otherwise reducing the severity of the condition being controlled.
The liquid formulations of the invention are solutions of Compound I, one or more solvents, and optionally one or more surfactants. A "solution" refers to a clear liquid state where the drug is dispersed at the molecular level, dissolved with no apparent solid particles, in a liquid environment provided by the solvent.
The invention is not limited to a particular mechanism of action. However, it is believed that upon release into the gastrointestinal fluids that the surfactants of the formulation will form micelle assemblies and micro-emulsions which are able to solubilize Compound 1 above the solubility limit without surfacants present. The solubilized drug is available for absorption through the intestinal membrane, and hence systemic exposure in vivo. In the absence of surfactants the drug precipitates from the gastric juices, and the poorly soluble drug is not bioavailable.
The composition can be formulated as a fill encapsulated in a gelatin capsule of appropriate gelatin composition, a hard gelatin capsule with an appropriate seal, a non-gelatin capsule such as a hydroxypropyl methylcellulose capsule, or an oral liquid or emulsion by methods commonly employed in the art. In one embodiment of the present invention, the fill is encapsulated in a sealed hard gelatin capsule or a soft gelatin capsule containing plasticizers, such as glycerin and sorbitol. In one class of this embodiment, the hard gelatin capsule is sealed by band sealing using a gelatin ribbon, or LEMS (i.e., spraying with a hydroalcoholic solution to locally melt and seal the gelatin capsule pieces). The fill is prepared by mixing the excipients and Compound I with heating if required.
In addition to the main softgel capsule ingredients previously noted, other stabilizing additives, as conventionally known in the art of softgel formulation, can be introduced to the fill as needed, usually in relatively small quantities, such as antioxidants (BHA (butylated hydroxyanisole), BHT (t- butylhydroxytoluene), tocopherol, propyl gallate, etc.) and other preservatives such as benzyl alcohol or parabens. Preferably, the antioxidant or preservative is present in a weight percent range of 0.01 % to 0.1 %. The composition can be formulated as a fill encapsulated in a soft gelatin capsule, a hard gelatin capsule with an appropriate seal, a non-gelatin capsule such as a hydroxypropyl methylcellulose capsule or an oral liquid or emulsion by methods commonly employed in the art.
Oral delivery of Compound I is particularly difficult because its aqueous solubility is extremely low, typically being less than 5 ug/mL. Achieving therapeutic drug levels in the blood by oral dosing of practical quantities of a drug generally requires a large enhancement in drug concentrations in the gastrointestinal fluid and a resulting large enhancement in bioavailability. The formulations of this invention will be administered in such an amount that an effective dose of Compound I is administered to the patient. The amount of Compound I will generally be known or determined by the attending physician. Thus, the amount or volume of administered dose will be determined by the amount of Compound I prescribed and/or otherwise desired as a dose and the solubility of the Compound I in the formulation. In general, an effective dose for Compound I is from 100 mg to about 1000 mg per day, in single or divided doses; preferably from about 200 mg to about 800 mg per day, more preferably from about 100 mg to about 600 mg per day, even more preferably about 150 or 300 mg per day, in single or divided doses. For oral administration, the compositions are preferably provided in the form of one or more liquid-filled capsules containing (in total, if more than one liquid-filled capsule is administered) from 100 to 1000 mg, preferably 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000, most preferably 200, 300, 400, 500 and 600 milligrams of the active ingredient, for the symptomatic adjustment of the dosage to the patient to be treated.
The liquid formulations of the present invention are pre-concentrates which are generally administered orally, in soft or hard gelatin capsules, gelatin encapsulation technology being well known to the pharrnaceutical arts.
The liquid formulations of the present invention have utility in treating, preventing, ameliorating, controlling or reducing the risk of one or more of the following conditions or diseases: headache; migraine; cluster headache; chronic tension type headache;
pain; chronic pain; neurogenic inflammation and inflammatory pain; neuropathic pain; eye pain;
tooth pain; diabetes; non-insulin dependent diabetes mellitus; vascular disorders; inflammation;
arthritis; bronchial hyperreactivity, asthma; shock; sepsis; opiate withdrawal syndrome; morphine tolerance; hot flashes in men and women; allergic dermatitis; encephalitis;
brain trauma;
epilepsy; neurodegenerative diseases; skin diseases; neurogenic cutaneous redness, skin rosaceousness and erythema; tinnitus; inflammatory bowel disease, irritable bowel syndrome, cystitis; and other conditions that may be treated or prevented by antagonism of CGRP receptors.
Of particular importance is the acute or prophylactic treatment of headache, including migraine and cluster headache.

The subject compounds are fiarther useful in a method for the prevention, treatment, control, amelioration, or reduction of risk of the diseases, disorders and conditions noted herein. The subject compounds are further useful in a method for the prevention, treatment, control, amelioration, or reduction of risk of the aforementioned diseases, disorders and conditions in combination with other agents.
The terms "administration of' and or "administering a" compound should be understood to mean providing the composition of the invention to the individual in need of treatment.
The administration of the composition of the present invention to practice the present methods of therapy is carried out by administering an effective amount of the compound of structural formula I to the patient in need of such treatment or prophylaxis. The need for a prophylactic administration according to the methods of the present invention is determined via the use of well known risk factors. The effective amount of an individual compound is detennined, in the final analysis, by the physician in charge of the case, but depends on factors such as the exact disease to be treated, the severity of the disease and other diseases or conditions from which the patient suffers, the chosen route of administration, other drugs and treatments which the patient may concomitantly require, and other factors in the physician's judgment.
Representative experimental procedures are provided below. These are exemplary only and should not be construed as being limitations on the novel compositions and processes of this invention.

Example 1- Liquid Formulation Component Amount (grams) Compound 297.7 Pol eth lene Gl co1400 245.0 Propylene Glycol 75.0 Cremo hor EL 190 Polysorbate 80 190 Total 997.7 A water bath was preheated 35 C (5 C variance). Liquids PEG 400, propylene glycol, Cremophor EL, and polysorbate 80 were dispensed directly into a stainless steel vessel (diameter is 5'/4 inches) and stirred at 600 RPM stirring using a 2 inch mixer blade. Compound 1(powder) was added into the vortex. After addition of Compound I the contents were mixed for approximately 2 hours at 600 rpm while maintaining the temperature at 35 C
(5 C variance).
As the formulation was mixed it was periodically tested by visual inspection for undissolved particles. After 2 hours of mixing only air bubbles were present (which was attributed to the high level of surfactant), and Compound I was completely dissolved. The solution was deaerated for about 2.5 hours under vacuum, placed at 40 C (5 C variance) overnight, and then again placed under vacuum for an additional 1 hour under to complete deaeration. The formulation was ready for encapsulation.
Example 2 - Liquid Formulation Component Amount kilo rams Compound I 1.70 Pol eth lene Glycol 400 1.39 Propylene Glycol 0.42 Cremo hor EL 1.08 Polysorbate 80 1.08 Water 0.28 Total 5.95 Liquids PEG 400, Propylene Glycol, Cremophor EL, Polysorbate 80 and water were placed into a 5'/4 inch diameter container equipped and mixed with a 2 inch blade at 600 RPM. Compound I

was added to the mixture and mixing continued for an additiona12.5 hours at 25 C :I: 5 C. The mixture was sampled once per hour and examined under microscope to determine visual end point (the lack of solid particles). The solution was mixed for an additional 1 hr. The solution was filtered through a-100 micron filter and de-aerated until a yellowish clear solution free of foam and bubbles was obtained.

Example 3- Soft Gelatin Capsule Fill The fill solution obtained in Example 2 (1050 mg) and the gelatin component was supplied by Banner Pharmacaps and were fed into an encapsulation machine. To encapsulate the fill solution, the gelatin formulation was cast into sheets on two cooled rollers.
These sheets were passed through a series of rolls where a food grade lubricant was applied. The sheets were then fed through the rotary die rolls where the softgel was formed. As the lower edge of the softgel was formed, a reciprocating pump injected 1050 mg of the fill solution into the center of the softgel, after which the upper edge of the die came together to seal the softgel. The newly formed softgels were dislodged from the sheet and pneumatically conveyed to a tumble dryer where they stayed for 45-60 minutes. Upon exiting the dryer, the softgels were spread on trays and placed in a drying tunnel (low humidity chamber) and dried. Upon completion of the drying process, the softgels were visually inspected for defects. Subsequently, the capsules were sized to remove oversized and undersized capsules and polished. The resulting filled softgel capsules each contained 300 mg Compound I.

Example 4- Hard Gelatin Capsule Fill Using a peristaltic pump the solution of Example 1 was pumped into a hopper for encapsulation.
The liquid formulation was dispensed into the size 1, white, opaque hard gelatin capsules (CAPSUGEL, containing gelatin and titanium dioxide) to a target fill weight of 667 mg. The filled capsules were transferred to a LEMS 30 capsule sealer and they were sealed by spraying with a mixture of 1:1 (weight:weight) water:ethanol (dehydrated, 190 proof) solution. After spraying the capsules were dried by gentle heating to approximately 45 C. The sealed capsules were placed onto trays lined with tray paper and were placed into a depression chamber (ZANASI 40E vacuum trap). After the completion of the vacuum cycle the capsules were visually inspected for leaking. The acceptable capsules were passed through a ZANASI capsule sorter to remove empty capsules. The finished capsules were then packaged into appropriate containers. The resulting filled capsules each contain 200 mg Compound I.

Example 5 - Stability Weeks Conditions Mg per Composite Capsule Assay %
Present 0 - 208.0m 104.0%
14 5C/Amb 207.3mg 103.6%
14 25C/60%R 205.1 mg 102.5%
H

39 25C/60%R 201.2 mg 100.6 H

200 mg hard gelatin capsules containing the liquid formulation of Compound I
(capsules and liquid fill prepared according to procedures similar to those described in Examples 1 and 4) were manufactured and stored under the conditions: 5 C at ambient humidity, and at 25 C. at 60%
relative humidity. Composite assay results at 14 and 39 weeks show excellent stability.

Example 6 - Bioavailability Mean (S.D.) Pharmacokinetic Parameter Values Following 400-mg Single Oral Doses of Compound I(n=20) Apparent AUCõ AUCp,qw Cmarz T,naxt t'/2 Formulation (uM-hr) (!iM-hr) (!.-M) (hr) (hr) 17.64 (7.57) 8.08 (3.43) 3.15 (1.29) 1.5 (0.7-4) 6.2 LFC (PEG) 43 !o CV 41 % CV
15.92 (7.77) 7.05 (3.37) 2.97 (1.44) 1.75 (0.7-4) 6.4 LFC (PEG/PG) 49% CV 49% CV
26.35 (9.72) 14.63 (4.39) 6.68 (2.26) 1.5 (0.7-2) 5.7 LFC (PEG/PG/Crem/Tween) 37% CV 34% CV
1.45 (0.56) 0.51 (0.26) 0.21 (0.10) 2.0 (0.7-3) 7.8 DFC (Dynomilled Neutral) 38% CV 50% CV
14.38 (8.03) 6.48 (2.83) 2.65 (1.04) 1.75 (0.7-4) 6.4 DFC (Eudragit) 56% CV 39% CV

Adjusted for assayed potencies of the formulations t Median (range) Harmonic mean Five different capsule formulations (refer to above table) of Compound I were administered orally as a single 400 mg dose in twenty healthy male subjects -between the=
ages of 18 and 45 in an open label, randomized, 5-period brossover study. In each period subjects, after an overnight fast, were administered with a single oral dose of 1 of the 5 formulations with a cup of 240 mL
water and then followed with a minimum washout of 72 hours. Blood was drawn in the presence of sodium heparin as an anticoagulant at predose and at 20, 40 minutes, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, 24, 48 hours after dosing. The plasma was separated by centrifugation and kept frozen at -70 C until analysis by LC-MS/MS.
An online-extraction assay using Cohesive high-turbulence liquid chromatography (HTLC) under quick elution mode coupled with liquid chromatography/tandem mass spectrometry for the determination of Compound I concentration in human plasma was developed and validated. A
stable isotope labeled D5-Compound I was used as the internal standard. Plasma samples were prepared on a Packard Mu1tiPROBE II liquid-handling system, and directly injected on a Cohesive TX1 or TX2 Flux 2300 system (the TX2 system allowed parallel operation of two sets of extraction and analysis to increase sample throughput). The analyte and its internal standard were on-line extracted with a Cohesive C18 column (0.5x50 nun, 60u) using 10:90 acetonitrile:0.1% formic acid, back-eluted with 50:50 acetonitrile:0.1% formic acid, and analyzed on a Thermo-Keystone FluophaseRP column (100x2.1mm, 5u) using ramping gradient from 50:50 to 70:30 acenitonitrile:0.1 % formic acid. Detection was accomplished on a Sciex API4000 mass spectrometer in multiple-reaction monitoring (MRM) mode using positive ionization with a turbo ion-spray interface. Urider these conditions, the diastereomer was well separated from Compound I and no interference was observed for either Compound I or the internal standard from the endogenous components of human plasma. The assay had a lower limit of quantification (LOQ) 5 nM based on 0.05-mL aliquots of human plasma.
The standard curve range was from 5 to 5000 nM. The analysis time was 10.0 minutes per sample on the TX1 system.
Example 7 - Solubility The solubility of the potassium salt ethanolate of Compound I in various liquid components and mixtures commonly used in making capsule formulations is shown below. The units are expressed in free acid equivalents (unionized drug) and the values were ascertained by visual inspection by optical microscopy_ The combinations were studied since the highest solubility was found in these individual excipeints.

Solvent I Surfactant m !
45% PEG 400/55% PEG 400 200-250 Tween 80 250-300 5% PG:95% PEG 400 350-400 5% PG:40% PEG 400:55% 250-300 Tween 80 100% PG >450 10% PG :90% PEG 400 >400 10% PG:35% PEG 400:55% <300 Tween 80 9.2% PG: 35 % PEG 400: >400 27.9%
Tween 80: 27.9% Cremophor@) EL

Example 8 - Phase Stability Because mixtures of PEG 400 and surfactants such as polysorbate 80 are not misicble in all proportions, considerable ingenuity was required to develop a workable surfactant / solvent system. Phase separation is the common term for the point when the two liquid solvents are immiscible and the mixture becomes cloudy. In order to have a completely miscible PEG 400 /
polysorbate 80 mixture the surfactant must be above 40% by weight. However, this level of surfactant is above the allowable limit to dose to human patients. Thus, another surfactant was required in the formulation to allow for a proper balance of PEG and surfactant. On the basis of keeping a single liquid phase a number of potential ingredients were tested as a replacement for about '/z of the polysorbate 80. The preferred ingredients in terms of phase separation include ethanol, polysorbate 20, Labrasol@, Cremophor EL, and Carpryol 90.

Possible Function FDA Phase Stability with Redisperibility Ingredients Allowed PEG/Polysorbate >400 mg 80/PG
PEG 200 Solvent Poor PEG 400 Solvent Poor PEG 600 Solvent Poor PEG 1000 Solvent Poor Propylene Solvent Poor Glycol Ethanol Solvent No Good Gylcerin Solvent Poor Transcutol Solvent Poor Polysorbate Surfactant No Good Polysorbate Surfactant Yes (but not Good 80 >800 mg) Labrasol Surfactant Excellent Cremophor8 Surfactant Yes Excellent Excellent EL
Cremophor Surfactant Poor RH
Labrifil Triglyceride Incompatible Oil lmwitor 742 Triglyceride Poor Oil Capryol 90 Triglyceride Good Oil Gelucire Semisolid Poor 44/14 Oil While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various changes, modifications and substitutions can be made therein without departing from the spirit and scope of the invention. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.

Claims (19)

1. A liquid formulation comprising (1) 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide or a pharmaceutically acceptable salt or solvate thereof, (2) one or more surfactants, (3) one or more solvents, and (4) optionally water, wherein each of said one or more surfactants is selected from the group consisting of polyethoxylated castor oil, polysorbates, polyethylene glycol ester glycerides, sorbitan monooleate, saturated polyglycolized glycerides and polypropoxylated stearyl alcohols, and wherein each of said one or more solvents is selected from the group consisting of ethanol, propylene glycol, glycerin, polyethylene glycol, DMSO, ethoxydiglycol, diethyleneglycol, and polyoxypropylene block copolymers.

2. A liquid formulation of claim 1, wherein said one or more surfactants is selected from the group consisting of Cremophor® EL, Tween-80, Tween-20, Labrasol®, Labrifil® 1944, Cremophor® RH60, Creacmophor® RH40, Span®-80, Vitamin E-TPGS, Gelucire® 44/14, Acconon® MC-8, Span®-20, Acconon® CC-6, and Gelucire® 50/13,

3. A liquid formulation of Claim 1, wherein each of said one or more surfactants is selected from Cremophor® EL, Tween-80, Tween-20, and Labrasol®, and wherein each of said one or more solvents is selected from ethanol, propylene glycol, PEG 400 and PEG 600.

4. A liquid formulation according to Claim 1, comprising 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-l,2-dihydroimidazo[4,5-b]pyridin-3-ide or a pharmaceutically acceptable salt or solvate thereof, Cremophor® EL, polysorbate 80, polyethylene glycol 400, propylene glycol and water.

5. A liquid formulation according to Claim 3 comprising:
(a) 5% to 40% 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide;
(b) 0% to 95% polyethylene glycol 400;
(c) 0% to 95% polysorbate 80;

(d) 0% to 95% Cremophor® EL;
(e) 0% to 95% propylene glycol; and optionally (f) 0% to 20% water.

6. A liquid formulation according to Claim 3 comprising:
(a) 20% to 35% 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide;
(b) 0% to 50% polyethylene glycol 400;
(c) 0% to 50% polysorbate 80;
(d) 0% to 50% Cremophor® EL;
(e) 0% to 50% propylene glycol; and optionally (f) 0% to 10% water.

7. A liquid formulation according to Claim 3 comprising, approximately:
(a) 28.5% 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide;
(b) 23.3% polyethylene glycol 400;
(c) 18.1% polysorbate 80;
(d) 18.1% Cremophor® EL;
(e) 7% propylene glycol; and optionally (f) 5% water.

8. A liquid formulation according to Claim 3 comprising:
(a) 28.5% 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide;
(b) 23.3% polyethylene glycol 400;
(c) 18.1% polysorbate 80;
(d) 18.1 % Cremophor® EL;
(e) 7% propylene glycol; and optionally (f) 5% water.

9. A liquid formulation according to Claim 3 comprising:

(a) 28.5% 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5 -b]pyridin-3-ide;
(b) 23.3 % polyethylene glycol 400;
(c) 18.1 % polysorbate 80;
(d) 18.1 % Cremophor®
(e) 7% propylene glycol; and (f) 5% water.

10. A capsule comprising a liquid formulation of Claim 7, wherein the liquid formulation comprises: 100 mg to 300 mg of 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide;.

11. A capsule comprising a liquid formulation according to Claim 7, wherein the amount of 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-1,2-dihydroimidazo[4,5-b]pyridin-3-ide is selected from 100 mg, 150 mg, 200 mg, 250 mg and 300 mg.

12. A capsule comprising a liquid formulation according to Claim 7, wherein the liquid formulation comprises: 150 or 300 mg of active agent potassium 1-[1-({[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]amino}carbonyl)piperidin-4-yl]-2-oxo-l,2-dihydroimidazo[4,5-b]pyridin-3-ide.

13. A method of treating headaches, said method comprising the step of administering the liquid formulation of claim 7 to a patient in need thereof.

14. A method of treating headaches, said method comprising the step of administering the liquid formulation of claim 8 to a patient in need thereof.

15. A method of treating migraine headache, cluster headache, or both, said method comprising the step of administering the liquid formulation of claim 7 to a patient in need thereof.

16. A method of treating migraine headache, cluster headache, or both, said method comprising the step of administering the liquid formulation of claim 8 to a patient in need thereof.

17. A method of treating headaches, said method comprising the step of administering one or more of the liquid-filled capsule of claim 11 to a patient in need thereof.

18. A reconstituted composition comprising micro-emulsion systems and micelle systems, or both, wherein said composition is formed by introducing the liquid formulation of claim 7 into an aqueous system.

19. The composition of claim 18, wherein said aqueous system is the human digestive tract.