CN116744903A

CN116744903A - Pharmaceutical composition comprising diphenylpyrazine derivatives

Info

Publication number: CN116744903A
Application number: CN202280012076.9A
Authority: CN
Inventors: 卡蒂·阿姆索姆斯; 埃迪·德普罗斯特; 董文宇; 保罗·哈特曼科克; 雷内·霍尔姆; 克里斯托夫·金姆佩; 格里特·莫伊尔斯; 马克西姆·维尔施特雷滕
Original assignee: Actelion Pharmaceuticals Ltd
Current assignee: Actelion Pharmaceuticals Ltd
Priority date: 2021-01-29
Filing date: 2022-01-28
Publication date: 2023-09-12

Abstract

The present invention relates to a pharmaceutical composition comprising {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate, in particular to a long-acting injectable formulation comprising the pharmaceutical composition, the use of the pharmaceutical composition for treating or preventing a specific disease, and a method of preparing the same.

Description

Pharmaceutical composition comprising diphenylpyrazine derivatives

Technical Field

The present invention relates to a composition comprising: {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I):

the compound of formula (I) is the calcium salt of the metabolite of Sailexipa (Selexipag) (the calcium salt of ACT-333679), and has the formula Ca (C) ₂₅ H ₂₈ N ₃ O ₃ ) ₂ C, i.e ₅₀ H ₅₆ N ₆ O ₆ Ca (MW: 877.109). In the present invention, the term "{4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino group]Butoxy calcium acetate "; "2- [4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ]]Butoxy group]Calcium acetate "; "2- [4- [ (5, 6-diphenylpyrazin-2-yl) -isopropyl-amino ]]Butoxy group]Calcium acetate "; "2- [4- [ (5, 6-diphenylpyrazin-2-yl) - (propan-2-yl) amino ]]Butoxy calcium acetate "," {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino group ]Calcium salt of butoxy } acetic acid "; "{4- [ (5, 6-diphenylpyrazin-2-yl) (isopropyl) amino group]Calcium salt of butoxy } acetic acid "; "calcium salt of 2- (4- ((5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino) butoxy) acetic acid"; "calcium salt of 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid"; "bis [ [2- [4- [ (5, 6-diphenylpyrazin-2-yl) -isopropyl ]Amino-amino group]Butoxy group]Acetyl group]Oxy group]Calcium) "and the calcium salt of the celecoxib metabolite (calcium salt of ACT-333679) are used synonymously.

Sailexipa (INN) is 2- {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ]]Butoxy } -N- (methylsulfonyl) acetamide (ACT-293987, NS-304, CAS:475086-01-2;2- {4- [ N- (5, 6-diphenylpyrazin-2-yl) -N-isopropylamino)]Butoxy } -N- (methylsulfonyl) acetamide), also known as Uptavi ^TM . The metabolite of celecoxib is 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid (MRE-269, ACT-333679,2- {4- [ (5, 6-diphenylpyrazin-2-yl) -propan-2-ylamino)]Butoxy } acetic acid; {4- [ (5, 6-diphenylpyrazin-2-yl) (isopropyl) amino group]Butoxy } acetic acid; {4- [ (5, 6-diphenylpyrazin-2-yl) - (propan-2-yl) amino ]]Butoxy } acetic acid; CAS:475085-57-5 (MW 419.52)). Salts of the celecoxib metabolite are described in JP 2019-149945.

The pharmaceutical compositions of the present invention in the form of an aqueous suspension are suitable for intramuscular or subcutaneous injection. It can also be filled into vials as a solid product or lyophilized and reconstituted to give the corresponding aqueous suspension. Furthermore, the present invention relates to the use of the pharmaceutical composition for the treatment or prevention of specific diseases, such as pulmonary arterial hypertension, and in particular Pulmonary Arterial Hypertension (PAH) and chronic embolic pulmonary arterial hypertension (CTEPH), and to a method of preparing the same.

Background

The preparation and medical use of celecoxib and the active metabolite 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid is described in WO2002/088084; WO2009/157396; WO2009/107736; WO2009/154246; WO2009/157397; WO2009/157398; WO2010/150865; WO2011/024874; nakamura et al, biorg Med Chem (2007), 15,7720-7725; kuwano et al J Pharmacol Exp Ther (2007), 322 (3), 1181-1188; kuwano et al J Pharmacol Exp Ther (2008), 326 (3), 691-699; sitbon et al, N Engl J Med (2015), 373,2522-33; asaki et al, bioorg Med Chem (2007), 15,6692-6704; asaki et al, j.med.chem (2015), 58,7128-7137. Intravenous formulations of celecoxib are disclosed in WO 2018/162527. Salts of the celecoxib metabolite are described in JP 2019-149945. US20190022004 describes liposome compositions comprising weak acid drugs and uses thereof. EP3718537 describes stealth liposomes having prostaglandin I2 receptor agonists encapsulated therein.

Celecoxib has been shown to be beneficial in the treatment of pulmonary hypertension. In phase III clinical trials, the risk of the primary complex endpoint of mortality or complications associated with pulmonary hypertension in patients receiving celecoxib was significantly lower than in patients receiving placebo. Celecoxib is approved for example in the united states and is indicated for the treatment of pulmonary arterial hypertension (PAH, WHO group I) to delay disease progression and reduce risk of hospitalization for PAH.

To date, standard film coated tablet formulations of celecoxib intended for twice daily oral administration have been used, wherein the excipients include D-mannitol, corn starch, low substituted hydroxypropylcellulose, hydroxypropylcellulose and magnesium stearate; the tablets were film coated with a coating material containing a mixture of hypromellose, propylene glycol, titanium dioxide, carnauba wax, and iron oxide.

Furthermore, safety studies (NCT 03187678) have been conducted on the transition from oral celecoxib to intravenous injection of celecoxib in patients with PAH, whereby celecoxib is administered twice daily for approximately 87 minutes per infusion. For each patient, the dose was personalized to correspond to his/her current oral dose of celecoxib.

Celecoxib is believed to act as a prodrug (while retaining some agonistic activity of itself on the IP receptor) that exerts long-acting selective IP receptor agonist activity of the active metabolite 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid in mammals, particularly humans. In vivo metabolism of celecoxib can effectively act as a class of 'sustained release mechanisms' that potentially prolong activity and reduce the typical side effects associated with high concentrations of PGI2 agonists (Kuwano et al, JPharmacol Exp Ther (2007), 322 (3), 1181-1188).

In some cases, the use of oral formulations of celecoxib may be inappropriate or impossible, for example, in emergency care, or in cases where the patient is not able to swallow a tablet for some reason.

Furthermore, in general, it is desirable to reduce the drug burden, particularly for treatment regimens that may last for months or longer.

The number and/or volume of dosage forms containing the drug to be administered is often referred to as the "drug burden". High drug loading is undesirable for a number of reasons, such as frequency of administration, which is often combined with the inconvenience of having to swallow large dosage forms and the need to store and transport large or bulky pharmaceutical formulations. The high drug burden increases the risk that the patient does not take his full dose and is unable to follow the prescribed dosage regimen.

Thus, there is a need to develop a pharmaceutical composition or formulation whose efficacy is maintained for, for example, one week or more, or one month or more, whereby it only needs to be administered at long intervals, such as one week or more, or even one month or more (long acting formulation), i.e. three months.

Long Acting Injectable (LAI) pharmaceutical formulations that allow for less frequent dosing (about a week or more, even a month or more) are options to address patient compliance challenges and are more convenient for the patient. In addition, more stable drug levels in the blood improve efficacy and safety. However, the suboptimal physicochemical properties of a drug often limit its formulation to conventional drug suspensions, resulting in problems such as stability of the suspension and inadequate maintenance of therapeutically effective plasma concentrations.

Both long acting formulations of celecoxib or a metabolite thereof and long acting formulations for the treatment of PAH or CTEPH are unknown.

Disclosure of Invention

It is an object of the present invention to provide a long acting formulation of the celecoxib metabolite 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid.

The task of the inventors of the test drug product described herein is to create a test drug product that is safe for testing in humans to ultimately evaluate whether the test drug product is safe and effective for treating diseases modulated by IP receptors, in particular pulmonary arterial hypertension, and in particular PAH or CTEPH.

For example, in view of the long-term treatment of PAH or CTEPH, the inventors have not only focused on determining a specific and stable formulation of a test drug product comprising 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid, but also focused on ensuring that the formulation will release 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid to a patient in need of PAH or CTEPH for a period of at least 14 days, and not exhibit significant burst release at the first hour/day after administration, and at the same time provide the patient with a therapeutically effective dose of 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid throughout the release period.

Thus, they have now found that it is advantageous to formulate a celecoxib metabolite into a long-acting formulation by using a calcium salt of the celecoxib metabolite in micronized form or in suspension or in solid form, or a hydrate or solvate thereof, i.e. calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate.

Accordingly, the present invention relates to a pharmaceutical composition suitable for administration by intramuscular or subcutaneous injection, comprising {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate, or a hydrate or solvate thereof, in the form of an aqueous suspension. In particular, such suspensions are aqueous suspensions comprising particles of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate and hydrates and solvates thereof.

The long-acting nature of the formulation allows avoiding peak plasma levels and achieving minimum toxic concentrations and longer treatment durations.

Drawings

FIG. 1 shows the plasma concentrations over time of various study formulations containing celecoxib, the celecoxib metabolite (2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) -butoxy) acetic acid; ACT 333679) and the calcium salt of the celecoxib metabolite ({ 4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate; the calcium salt of ACT 333679).

Figures 2 and 3 show pK rat curves for different particles of calcium salt of the celecoxib metabolite (2 μm (microns), 5 μm (microns), 8 μm (microns)) and different surfactants/wetting agents (polysorbate 20 and poloxamer 338).

Figure 4 shows the resulting particle size distribution of differently formulated drugs (calcium salts of celecoxib metabolites) with different particle sizes.

Figure 5 shows the resulting particle size distribution of differently formulated drugs (calcium salts of celecoxib metabolites) with different surfactants/wetting agents.

FIG. 6 shows the resulting particle size distribution of calcium salt of the celecoxib metabolite at a concentration of 200 mg/mL.

Figure 7 shows the resulting particle size distribution of differently formulated drugs (calcium salts of celecoxib metabolites) with different amounts of re-suspending agent.

Fig. 8 shows the results of zeta potential as a function of pH of the suspension.

Detailed Description

The present invention relates to a pharmaceutical composition in the form of an aqueous suspension comprising {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof:

in some embodiments, the present invention relates to a pharmaceutical composition in the form of an aqueous suspension comprising

(a) A method of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof:

the Particle Size Distribution (PSD) Dv50 is 1 μm (micrometers) to 50 μm (micrometers);

(b) A surfactant and/or a wetting agent;

(c) Optionally, a re-suspending agent; and

(d) A pharmaceutically acceptable aqueous carrier having a pH in the range of 6 to 9, and specifically in the range of 6 to 8.5.

The pharmaceutical composition of the present invention is a suspension, by which is meant that the active ingredient calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate is suspended in a pharmaceutically acceptable aqueous carrier.

Thus, the pharmaceutical composition in the form of an aqueous suspension is suitable for intramuscular and/or subcutaneous injection, in particular for use in human patients in need thereof.

The {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I) having the structure of formula (I) above may be in anhydrous form, or in the form of a hydrate or a pharmaceutically acceptable solvate. The term "pharmaceutically acceptable solvent" refers to a solvent that retains the desired biological activity of the compound and exhibits minimal undesirable toxicological effects. Preferably in anhydrous form or in the form of a hydrate.

The calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate of formula (I) may be in the form of a hydrate. The hydrate form may be about 0.1 to about 1 water molecule/{ 4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate molecule. In some embodiments, the molar ratio of water to calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate ranges from about 0.1 to about 1, such as from about 0.1 to about 0.15, from about 0.15 to about 0.2, from about 0.2 to about 0.25, from about 0.25 to about 0.3, from about 0.3 to about 0.35, from about 0.35 to about 0.4, from about 0.4 to about 0.45, from about 0.45 to about 0.5, from about 0.5 to about 0.55, from about 0.55 to about 0.6, from about 0.6 to about 0.65, from about 0.65 to about 0.7, from about 0.7 to about 0.75, from about 0.75 to about 0.8, from about 0.8 to about 0.85, from about 0.85 to about 0.9, from about 0.9 to about 0.95, from about 0.95, and from about 0.95 to about 1. The molar ratio of water in the hydrate form may vary based on the storage conditions of the compound, the method of formation of the compound, and the crystal structure of the compound.

In some embodiments, calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate or a hydrate or solvate thereof is provided in micronized form, i.e., in particulate form having the following Particle Size Distribution (PSD) Dv 50: 1 μm (micrometer) to 50 μm (micrometer), or 1 μm (micrometer) to 40 μm (micrometer), or 1 μm (micrometer) to 30 μm (micrometer), or 1 μm (micrometer) to 20 μm (micrometer), or 1 μm (micrometer) to 18 μm (micrometer), or 1 μm (micrometer) to 15 μm (micrometer), or 2 μm (micrometer) to 50 μm (micrometer), or 2 μm (micrometer) to 40 μm (micrometer), or 2 μm (micrometer) to 30 μm (micrometer), or 2 μm (micrometer) to 20 μm (micrometer), or 2 μm (micrometer) to 18 μm (micrometer), or 2 μm (micrometer) to 15 μm (micrometer), or 3 μm (micrometer) to 50 μm (micrometer), or 3 μm (micrometer) to 40 μm (micrometer), or 3 μm (micrometer) to 30 μm (micrometer), or 3 μm (micrometer) to 20 μm (micrometer), or 3 μm (micrometer) to 18 μm (micrometer), or 3 μm (micrometer) to 4 μm (micrometer) to 50 μm (micrometer), or 4 μm (micrometer) to 50 μm (micrometer) to 15 μm (micrometer) Or 4 μm (micrometers) to 20 μm (micrometers), or 4 μm (micrometers) to 18 μm (micrometers), or 2 μm (micrometers) to 15 μm (micrometers), or 5 μm (micrometers) to 50 μm (micrometers), or 5 μm (micrometers) to 40 μm (micrometers), or 5 μm (micrometers) to 30 μm (micrometers), or 5 μm (micrometers) to 20 μm (micrometers), or 5 μm (micrometers) to 18 μm (micrometers), or 5 μm (micrometers) to 15 μm (micrometers). In some embodiments, the Particle Size Distribution (PSD) Dv50 is 5 μm (microns) ± 10%, or 5 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 6 μm (microns) ± 10%, or 6 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 7 μm (microns) ± 10%, or 7 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 8 μm (microns) ± 10%, or 8 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 9 μm (microns) ± 10%, or 9 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 10 μm (microns) ± 10%, or 10 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 11 μm (microns) ± 10%, or 11 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 12 μm (microns) ± 10%, or 12 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 13 μm (microns) ± 10%, or 13 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 14 μm (microns) ± 10%, or 14 μm (microns) ± 5%; in some embodiments, the Particle Size Distribution (PSD) Dv50 is 15 μm (microns) + -10%, or 15 μm (microns) + -5%.

The particles used herein are microparticles, and the aqueous suspension is referred to as a microsuspension, i.e., an aqueous microsuspension.

The particle size distribution is defined herein as Dv50, also referred to as median diameter. Median is defined as the value where half of the population is above the point and half is below the point. For particle size distribution, the median is referred to as D50 (or x50 when certain ISO guidelines are followed). D50 is the dimension in microns (microns, μm) that divides the distribution into above half the diameter and below half the diameter. Dv50 (or Dv 0.5) is the median of the volume distribution. The volume distribution is the main result from laser diffraction. Herein, PSD is given in the form of a volume distribution.

Particle Size Distribution (PSD) can be measured by methods well known in the art, such as laser diffraction, sedimentation field flow separation, photon correlation spectroscopy, or disk centrifugation.

Thus, laser diffraction measures particle size distribution by measuring the angular change in intensity of scattered light as a laser beam passes through a dispersed particle sample.

The large particles scatter light at small angles relative to the laser beam, while the small particles scatter light at large angles. Larger particles scatter more light than smaller particles and will appear more concentrated in the output of the LD analysis, volumetric size distribution. The angular scattering intensity data is then analyzed to calculate the size of the particles responsible for creating the scattering pattern.

In this patent application, PSD was measured using laser diffraction measurement methods and Mie theory with Malvern Mastersizer 3000 equipment from Malvern Panalytical. The results of the laser diffraction analysis are reported as cumulative insufficient size values Dv50 based on particle size volume distribution. Measurement methods are disclosed in the experimental section.

Preferably; the {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate having the structure of formula (I) as described above is used in a crystalline form.

In some embodiments, the pharmaceutical composition comprises a surfactant and/or a wetting agent, or a mixture of surfactants and/or wetting agents. As used herein, "surfactant and/or wetting agent" (surfactant/wetting agent) is pharmaceutically acceptable and is capable of stabilizing an aqueous suspension so as to avoid particle size growth during shelf life. The surfactant and/or wetting agent may be nonionic or ionic. Surfactants and/or wetting agents are well known in the art.

Representative examples of surfactants and/or wetting agents include gelatin, casein, lecithin, salts of negatively charged phospholipids or acid forms thereof (such as phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, phosphoric acid and salts thereof, such as alkali metal salts, e.g., their sodium salts, e.g., egg yolk phosphatidylglycerol sodium, such as under the trade name Lipoid ^TM EPG derived products), gum arabic, stearic acid, benzalkonium chloride, polyoxyethylene alkyl ethers (e.g., polyethylene glycol ethers such as cetomagine 1000), polyoxyethylene castor oil derivatives (such as polyoxyethylene 35 castor oil (Cremophor) ^TM EL) or polyoxyethylene 40 hydrogenated castor oil (Cremophor ^TM RH 40); polyoxyethylene stearate, colloidal silicon dioxide, sodium lauryl sulfate, sodium carboxymethyl cellulose, bile salts (such as sodium taurocholate, sodium deoxytaurocholate, sodium deoxycholate); methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethyl cellulose, magnesium aluminum silicate, polyvinyl alcohol (PVA), poloxamers (which are block copolymers of ethylene oxide and propylene oxide), such as poloxamer 188, poloxamer 338 and poloxamer 407 (commercially available as Pluronic ^TM F68, F108 and F127); tyloxapol; vitamin E-TGPS (alpha-tocopheryl polyethylene glycol succinate, specifically alpha-tocopheryl polyethylene glycol 1000 succinate); poloxamines, e.g. Tetronic ^TM 908 (T908), which is a tetrafunctional block copolymer, derived from the sequential addition of ethylene oxide and propylene oxide to ethylenediamine; dextran; lecithin; dioctyl esters of sodium sulfosuccinate, e.g. under the trade name Aerosol OT ^TM (AOT) sales products; laurylsulfideSodium acid (Duponol) ^TM P) is as follows; under the trade name Triton ^TM An alkylaryl polyether sulfonate obtained from X-200; polyoxyethylene sorbitan fatty acid esters or polysorbates (such as polysorbates 20, 40, 60, and 80, known as Tweens) ^TM 20. 40, 60 and 80); sorbitan esters of fatty acids (Span ^TM 20. 40, 60 and 80 or Arlacel ^TM 20. 40, 60 and 80); sucrose stearate and sucrose distearate mixtures, such as those sold under the trade name Crodesta ^TM F110 or Crodesta ^TM A SL-40 obtained product; hexyl decyl trimethyl ammonium chloride (CTAC); polyvinylpyrrolidone (PVP), sodium Dodecyl Sulfate (SDS), sodium docusate, sodium deoxycholate, polyethylene glycol 15 hydroxystearate (Solutol HS 15), octoxynol (octoxynol-9, octoxynol-10) or dimethicone. Two or more surfactants and/or wetting agents may be used in combination, if desired.

In one embodiment, the surfactant/wetting agent may be selected from one or more of polysorbate, poloxamer, alpha-tocopheryl polyethylene glycol succinate, salts of negatively charged phospholipids (e.g., egg yolk phosphatidylglycerol), lecithin, polyvinylpyrrolidone (PVP), docusate sodium, deoxycholate sodium, sodium Dodecyl Sulfate (SDS), polyoxyethylene castor oil derivatives, polyethylene glycol 15 hydroxystearate, or mixtures thereof.

Preferred surfactants/wetting agents are polysorbates, poloxamers and alpha-tocopheryl polyethylene glycol succinates, such as polysorbate 20, polysorbate 80, poloxamer 188, poloxamer 338, poloxamer 407, vitamin E TPGS, egg yolk phosphatidylglycerol (eggpg), and mixtures thereof.

Particularly preferred surfactants/wetting agents are polysorbate 20, poloxamer 338 and vitamin E TPGS, such as polysorbate 20 and/or poloxamer 338.

Polysorbate is a polyoxyethylene sorbitan fatty acid ester. Polyoxyethylene sorbitan fatty acid esters/polysorbates are non-proprietary names and several grades are available, such as polysorbate 20, polysorbate 40, polysorbateSorbitol ester 60 or polysorbate 80. Polysorbates are derived from ethoxylated sorbitan (derivatives of sorbitol) esterified with fatty acids. Examples of polysorbates are polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate), polysorbate 40 (polyoxyethylene (20) sorbitan monopalmitate), polysorbate 60 (polyoxyethylene (20) sorbitan monostearate) and polysorbate 80 (polyoxyethylene (20) sorbitan monooleate). Different types of polysorbates differ in fatty acids, average number of polyoxyethylene units in the molecule, and degree of esterification. The two-digit numbers of each polysorbate name follow a specific scheme: the first digit represents the predominantly esterified fatty acid: 2=lauric acid, 4=palmitic acid, 6=stearic acid, 8=oleic acid, 12=isostearic acid. The second number indicates the type of esterification: 0 is a monoester having 20 polyoxyethylene units, 1 is a monoester having 4 or 5 polyoxyethylene units, and numeral 5 represents a triester having 20 polyoxyethylene units. Preferred Polysorbate 20 (catalog number 9005-64-5, E432) is for example under the trade name Tween ^TM 20 are sold.

Poloxamers are nonionic triblock copolymers consisting of two hydrophilic chains of polyoxypropylene (poly (propylene oxide)) flanked by central hydrophobic chains of polyoxyethylene (poly (ethylene oxide)), i.e., they are polyoxypropylene-polyoxyethylene copolymers. Preferred poloxamers are poloxamer 188, poloxamer 338 and poloxamer 407, in particular poloxamer 338.

As used herein, alpha-tocopheryl polyethylene glycol succinate refers to vitamin E TPGS, d-alpha-tocopheryl polyethylene glycol 1000 succinate, also known as tocassam (INCI), catalog No. 9002-96-4.

Lecithin is phosphatidylcholine. In this context lecithin refers to any one of a group of phospholipids present in animal and plant tissues and egg yolk, consisting of choline, phosphoric acid, fatty acids and glycerol elements.

Salts of negatively charged phospholipids or their acid forms are for example phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, phosphoric acid, and salts thereof, such as alkali metal salts, for example sodium thereofSalts, e.g. sodium yolk phosphatidyl glycerol, such as that available under the trade name Lipoid ^TM EPG obtained product).

Polyvinylpyrrolidone (PVP) has the formula (C ₆ H ₉ NO) _n . United States Pharmacopeia (USP) 32 describes povidone as a synthetic polymer consisting essentially of linear 1-vinyl-2-pyrrolidone groups, the different degrees of polymerization of which result in polymers of various molecular weights. Characterized in that its viscosity in aqueous solution is expressed as a K value in the range of 10-120, relative to the viscosity of water. The K value is calculated using the Fikentscher equation. Several K values are available, such as PVP K12, PVP K15, PVP K17, PVP K25, PVP K30, PVP K60, PVP K90 or PVP K120. PVPK17 is preferred.

Relative to surfactant/wetting agent; the optimum relative amount of calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate depends on the surfactant/wetting agent selected, the specific surface area of the drug suspension as determined by the average effective particle size and drug concentration, the critical micelle concentration of the surfactant/wetting agent (if it forms micelles), and the like. The relative amounts (weight/weight) of drug and surfactant/wetting agent are preferably in the range of 20:1 to 2:1, in particular in the range of 18:1 to 4:1.

The pharmaceutical composition optionally comprises a resuspension agent. As used herein, a resuspension agent is pharmaceutically acceptable and is capable of stabilizing an aqueous suspension so as to avoid caking during shelf life, or to unnecessarily clog, or to facilitate resuspension of the formulation after storage.

The re-suspending agent is selected from various polymer grade polyethylene glycols (PEG), sodium carboxymethylcellulose and poloxamers, or mixtures thereof; preferably, various polymer grades of polyethylene glycol (PEG) and sodium carboxymethyl cellulose, or mixtures thereof.

Preferred resuspension agents are selected from PEG 4000, PEG 3350, PEG 6000, PEG 8000, PEG 20000 and sodium carboxymethyl cellulose or mixtures thereof; in particular PEG 4000.

It may be noted that poloxamers may act as surfactants/wetting agents, as well as re-suspending agents, as they contribute to some viscosity in the suspension. In one embodiment, the resuspension agent is selected from PEG 4000, PEG 3350, PEG 6000, PEG 8000, PEG 20000, sodium carboxymethylcellulose, poloxamer 338 and poloxamer 407, or mixtures thereof. Preferred resuspension agents are selected from PEG 4000, PEG 3350, PEG 6000, PEG 8000, PEG 20000 and sodium carboxymethyl cellulose, or mixtures thereof, in particular polyethylene glycol 4000.

Polyethylene glycol (PEG) exists in a variety of polymeric grades. The structure of PEG is generally denoted as H- (O-CH) ₂ -CH ₂ ) _n -OH. Polyethylene glycol (PEG) is available in various grades, expressed by numbers, such as PEG 2000, PEG 3000, PEG 3350, PEG 4000, PEG 4600, PEG 6000, PEG 8000 or PEG 20000. The number represents the average molecular weight of the polymer.

Preferred sodium carboxymethylcellulose (sodium carboxymethylcellulose) has a viscosity of 27mpa.s to 50mpa.s (viscosity 2%), a degree of substitution of 0.65 to 0.90 and a sodium content of 7.0% -8.8% (calculated relative to DS). The product accords with the special theory about sodium carboxymethyl cellulose in the current European pharmacopoeia.

The optional relative amount (weight/weight) of the drug, i.e. calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate, relative to the suspending agent, depends on the selected resuspension agent and is preferably in the range of 2:1 to 1:3, in particular in the range of 2:1 to 1:1.

It should be noted that each of the above indicated surfactants/wetting agents may be combined with each of the resuspension agents mentioned herein. Particularly preferred combinations are polysorbate 20 and PEG 4000, poloxamer 338 and PEG 4000, vitamin E TPGS and PEG 4000, poloxamer 338 and sodium carboxymethyl cellulose, polysorbate 80 and carboxymethyl cellulose, and poloxamer 338 and vitamin E TPGS.

The pharmaceutical composition comprises a pharmaceutically acceptable aqueous carrier. The aqueous carrier comprises sterile water, i.e. water suitable for injection, optionally in admixture with other pharmaceutically acceptable ingredients. These ingredients may be selected from one or more of buffers, pH adjusters, preservatives or isotonic agents.

The aqueous carrier has a pH in the range of 6 to 8.5. The additional pH ranges from 7 to 8.5, or pH 8, i.e. pH 8.+ -. 1/2 or pH 7.5, i.e. 7.5.+ -. 1/2.

In one embodiment, the composition comprises one or more buffers and/or pH adjusters such that the pH of the aqueous carrier is between 6 and 8.5;7 to 8.5, or pH 8, i.e., pH 8.+ -. 1/2, or pH 7.5, i.e., 7.5.+ -. 1/2.

In some embodiments, the buffer and/or pH adjuster is selected from disodium hydrogen phosphate, citric acid, TRIS (hydroxymethyl) aminomethane (TRIS), histidine, HCl, and NaOH, or mixtures thereof. Thus, the buffers are disodium hydrogen phosphate, citric acid, TRIS (hydroxymethyl) aminomethane (TRIS) and histidine; and the pH adjuster is HCl or NaOH, preferably in the form of an aqueous solution. In particular, the buffering agent and/or pH adjuster is selected from disodium hydrogen phosphate, citric acid, TRIS (hydroxymethyl) aminomethane (TRIS), HCl and NaOH, or mixtures thereof. Thus, the buffering agents are disodium hydrogen phosphate, citric acid and TRIS (hydroxymethyl) aminomethane (TRIS); and the pH adjuster is HCl or NaOH, preferably in the form of an aqueous solution.

Preferably, the pharmaceutically acceptable aqueous carrier comprises citric acid. Citric acid thus acts as a buffer, but also as a chelating agent and an antioxidant.

The preferred pH of the aqueous suspension is pH 8.+ -. 1/2. Microsuspension may be formulated with TRIS buffer, however, mcIlvaine buffer (citric acid and disodium hydrogen phosphate) is preferred. The McIlvaine buffer, pH 8+ -1/2, consists of anhydrous disodium hydrogen phosphate and citric acid, with a buffer strength ranging from 5mM to 100mM. Preferably 10mM to 50mM. However, more citric acid may also be added and the pH adjusted to pH 8.+ -. 1/2 with NaOH.

The buffer or buffer is capable of providing stability to the formulation, i.e. preventing decomposition into the free form of the celecoxib metabolite, i.e. the free acetic acid derivative. The buffer strength ranges from 5 millimoles (mM) to 100 millimoles (mM), or from 10mM to 50mM.

Optional preservatives suitable for use in the pharmaceutical composition include antimicrobial agents and antioxidants which may be selected from the group consisting of: benzoic acid, benzyl alcohol, butylated Hydroxyanisole (BHA), butylatedHydroxytoluene (BHT), chlorobutanol, gallate, hydroxybenzoate, EDTA, phenol, chlorocresol, m-cresol, benzethonium chloride, myristyl-y-pyridine chloridePhenylmercuric acetate and thimerosal. Radical scavengers include BHA, BHT, vitamin E and ascorbyl palmitate, and mixtures thereof. Oxygen scavengers include sodium ascorbate, sodium sulfite, L-cysteine, acetylcysteine, methionine, thioglycerol, sodium acetosulfite, isoascorbic acid, hydroxypropyl cyclodextrin. Chelating agents include sodium citrate, sodium EDTA and malic acid. In one embodiment, the composition does not comprise a preservative.

An isotonic agent or isotonic agent may be present to ensure isotonicity of the pharmaceutical composition, and include sugars such as mannitol, dextrose, sucrose, fructose, trehalose, lactose; polyhydroxy sugar alcohols, preferably trihydric or higher sugar alcohols, such as glycerol, erythritol, arabitol, xylitol, sorbitol, and mannitol. Alternatively, sodium chloride, sodium sulfate, or other suitable inorganic salts may be used to render the solution isotonic. These isotonic substances may be used alone or in combination. The aqueous suspension conveniently comprises from 0% to 10% (w/v), in particular from 0% to 6%, of isotonic agent. Non-ionic isotonic substances, such as glucose, are of interest because electrolytes can affect colloidal stability. In one embodiment, the composition contains an isotonic agent or isotonicity, and in another embodiment, is a nonionic isotonicity, such as a suitable sugar, e.g., mannitol.

The desired characteristics of the pharmaceutical composition relate to ease of administration. The viscosity of the pharmaceutical composition should be low enough to allow administration by injection and high enough to maintain slow precipitation and good re-suspension. In particular, it should be designed such that it can be easily absorbed in a syringe (e.g. from a vial) for injection through a thin needle (e.g. 19G to 25G needle) in a not too long time span. In one embodiment, the viscosity of the composition is in the range of 200s ^-1 Lower 1mPa.s to 75 Pa.s, or at 200s ^-1 5mpa.s to 40mpa.s below.

Desirably, the aqueous suspension will contain as much of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate or a pharmaceutically acceptable hydrate or solvate thereof as possible that is tolerated in order to keep the injection volume at a minimum, specifically 2% to 50% (w/v), or 2% to 45% (w/v), or 2% to 40% (w/v), or 2% to 35% (w/v), or 2% to 30% (w/v), or 2% to 25% (w/v), or 2% to 20% (w/v), or 2% to 15% (w/v), specifically 2.5% to 10% (w/v).

Desirably, the amount of surfactant/wetting agent is selected to be as low as possible but effective and robust, specifically 0.5% to 20% (w/v), or 0.5% to 15% (w/v), or 0.5% to 12% (w/v), or 0.5% to 10% (w/v), or 0.5% to 8% (w/v), or 0.5% to 7% (w/v), or 0.5% to 6% (w/v), or 0.5% to 5% (w/v), or 0.5% to 4% (w/v), or 0.5% to 3% (w/v), or 0.5% to 2% (w/v) surfactant/wetting agent, or surfactant/wetting agent mixture.

Desirably, the amount of re-suspending agent is selected to be as low as possible but effective, specifically 0% to 30% (w/v), or 1% to 25%, or 1% to 20% (w/v), or 1% to 15% (w/v), or 3% to 10% (w/v) of re-suspending agent or mixture of re-suspending agents.

Desirably, the amount of buffer is selected to be as low as possible but effective, specifically 0mM to 100mM, or 5mM to 50mM, or 10mM to 50mM, or a mixture of buffers.

In one embodiment, the pharmaceutical composition comprises, by weight, based on the total volume of the composition:

(a) 2% to 50% (w/v), or 2% to 30% (w/v), or 2% to 15% (w/v), or 2.5% to 10% (w/v) of calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate (or a pharmaceutically acceptable hydrate or solvate thereof; but wherein the w/v is calculated based on its anhydrous form);

(b) 0.5% to 20% (w/v), or 0.5% to 15% (w/v), or 0.5% to 12% (w/v), or 0.5% to 10%, or 0.5% to 8% (w/v), or 0.5% to 7% (w/v), or 0.5% to 6% (w/v), or 0.5% to 5% (w/v), or 0.5% to 4% (w/v), or 0.5% to 3% (w/v) of a surfactant/wetting agent, or a mixture of surfactants/wetting agents;

(c) 0% to 30% (w/v), or 1% to 20% (w/v), or 1% to 15% (w/v), or 3% to 10% (w/v) of a resuspension agent or a mixture of resuspension agents; and

(d) 0mM to 100mM, or 5mM to 50mM, or 10mM to 50mM buffer, or mixtures thereof;

(e) Proper amount of water for injection is added to 100%.

(a) 2% to 15% (w/v) or 2.5% to 10% (w/v) of calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate (or a pharmaceutically acceptable hydrate or solvate thereof; but wherein the w/v is calculated based on its anhydrous form);

(b) 0.5% to 12% (w/v), or 0.5% to 10%, or 0.5% to 8% (w/v), or 0.5% to 7% (w/v), or 0.5% to 6% (w/v), or 0.5% to 5% (w/v), or 0.5% to 4% (w/v), or 0.5% to 3% (w/v) of a surfactant/wetting agent or a mixture of surfactants/wetting agents;

(c) 0% to 15% (w/v), or 1% to 15% (w/v), or 3% to 10% (w/v) of a resuspension agent or a mixture of resuspension agents; and

(d) 5mM to 50mM, or 10mM to 50mM buffer, or mixtures thereof;

(e) Proper amount of water for injection is added to 100%.

Thus, the surfactant/wetting agent, optional re-suspending agent and buffer, and mixtures thereof are as described above.

Calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate of formula (I) can be prepared as described in the examples section.

The pharmaceutical composition as described herein may be in a container, in particular in a vial or a syringe; particularly in syringes.

In some embodiments, a pharmaceutical composition as described herein can be prepared by a process comprising the steps of:

(a) Adding {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate or a pharmaceutically acceptable hydrate or solvate thereof to a liquid medium comprising a surfactant and/or wetting agent, optionally a re-suspending agent, having a pH in the range of 6 to 8.5 to form a premix/pre-dispersion; a pharmaceutically acceptable aqueous carrier; and

(b) The pre-mix is subjected to a mechanical process in the presence of a grinding medium to reduce the average effective particle size.

The particle size of the microparticles may be prepared by mechanical methods known in the art. In one embodiment, a method is used that includes the steps of: calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate or a pharmaceutically acceptable hydrate or solvate (drug) thereof is dispersed in a liquid dispersion medium, and a mechanical method is applied in the presence of a grinding medium to reduce the particle size of the drug to an average effective particle size of 50 μm (microns) or less, specifically to the desired particle size distribution Dv50 as described above.

The grinding medium used for the particle size reduction step may be selected from rigid media, preferably spherical or particulate form, having an average size of less than 3mm, and more preferably less than 2mm, such as 1mm ± 10% or 1mm ± 5%. An example of a grinding medium is ZrO ₂ Such as 95% ZrO stabilized with magnesium oxide or with yttrium ₂ Zirconium silicate, glass grinding media, polymer beads, stainless steel, titanium dioxide, aluminum oxide, and the like. Preferred grinding media have a particle size of greater than 2.5g/cm ³ And comprises 95% ZrO stabilized with magnesium oxide ₂ And polymer beads.

The size of the particles should be reduced at a temperature that does not significantly degrade the drug. Processing temperatures below 30 ℃ to 40 ℃ are generally preferred. The processing equipment may be cooled with conventional cooling equipment, if desired. The process is conveniently carried out at ambient temperature and processing pressure conditions that are safe and effective for the milling process.

The liquid medium for grinding comprises a surfactant/wetting agent, optionally a re-suspending agent; and a pharmaceutically acceptable aqueous carrier having a pH in the range of 6 to 8.5 to form a premix/pre-dispersion. Surfactants/wetting agents, optional re-suspending agents and pharmaceutically acceptable aqueous carriers (including buffers and pH adjusting agents) are preferably those described above. Preferably, the pre-mix/pre-dispersion is over-concentrated and then directly to the final volume before filling.

The final formulation is separated from the milling media by suitable separation methods known in the art.

The {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate obtainable by the present process can be sterilized using gamma irradiation and used for the aseptic manufacture of the final pharmaceutical product. The final pharmaceutical product may be sterilized using gamma irradiation or heat sterilization, for example autoclaving (steam sterilization) at elevated temperatures.

Suitable conditions for autoclaving (steam sterilization) are at 121 ℃ -124 ℃ (+ -2 ℃) for 15 minutes. Pressure is established to allow the desired temperature to be obtained. Conditions related to validation as specified in the pharmacopoeias (e.g. "united states pharmacopeia" or "international pharmacopeia, ninth edition, 2019", etc.) should be considered.

Conditions suitable for gamma irradiation are determined by exposure to a source of a suitable radioisotope such as ⁶⁰ Gamma irradiation of Co (cobalt 60) or in the form of electrons excited by a suitable electron accelerator. Suitable conditions are irradiation levels of 5kGy to 40kGy, for example 5kGy, 25kGy or 40 kGy. Conditions related to validation as specified in the pharmacopoeias (e.g. "united states pharmacopeia" or "international pharmacopeia, ninth edition, 2019", etc.) should be considered.

The present invention therefore also relates to a process for preparing a sterile pharmaceutical composition as described above, wherein the pharmaceutical composition is sterilized by autoclaving (steam sterilization) or by gamma irradiation; or wherein {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate is sterilized with gamma-radiation and then used to prepare a pharmaceutical composition.

Sterile pharmaceutical compositions can be obtained by the process.

Biological indicator strains proposed for validating autoclaving (steam sterilization) processes are: spores of Bacillus stearothermophilus (e.g., ATCC 7953 or CIP 52.81) with D values (i.e., 90% reduction in microbial population) of 1.5 minutes to 2 minutes at 121℃with about 106 spores per indicator.

The biological indicator strains proposed for validating gamma irradiation sterilization processes are typically: spores of Bacillus pumilus (e.g., ATCC 27142 or CIP 77.25) with a D value of about 3kGy (0.3 Mrad) using 107-108 spores/indicator; for higher doses, spores of Bacillus cereus (e.g., SSI C1/1) or Bacillus sphaericus (e.g., SSl C1A) are used.

The pharmaceutical composition as described herein may be further lyophilized, i.e. freeze-dried, and a lyophilized injectable composition will be obtained.

Prior to lyophilization, the pharmaceutical composition should preferably be filled into containers (unit dose or multi-dose containers, such as vials) suitable for storing the lyophilized cake and for later reconstitution of the pharmaceutical composition. Such containers may be filled under an inert gas atmosphere, such as in particular a nitrogen atmosphere. Such inert gas atmospheres can reduce oxidative degradation of the active ingredient. Thus, another embodiment relates to a container, such as for example a vial, ampoule, syringe, coupled chamber device, pen device or automatic injection device, in particular a vial, such container being filled with a pharmaceutical composition as described above.

The lyophilization/freeze-drying step of the pharmaceutical composition in the form of an aqueous suspension as described herein comprises the step of freezing the pharmaceutical composition in a container and drying it by applying a vacuum.

The freezing temperature is between-55 ℃ and-35 ℃, preferably between-50 ℃ and-35 ℃, preferably between-45 ℃ and-35 ℃; for example in the range of-40 ℃ + -3 ℃.

The drying temperature is in the range of-55 ℃ to +30 ℃, preferably-50 ℃ to 28 ℃, preferably-45 ℃ to 28 ℃.

The freezing temperature and the drying temperature may be applied in the form of a fixed temperature or in the form of a temperature ramp. Preferably, the final temperature of each program step is reached via a temperature ramp.

During lyophilization, vacuum is applied to the pharmaceutical composition. Preferably, a vacuum of 0.05 mbar to 1.5 mbar, for example 0.1 mbar, is applied. Vacuum is applied after the freezing step and during drying.

The drying procedure may be divided into several steps, such as a primary drying step and a secondary drying step, whereby each step may be followed by a holding step, i.e. maintaining the pharmaceutical composition at the temperature and pressure reached at the end of the previous drying step.

In addition, the container may be plugged after the freeze-drying procedure. The step of capping the container may also comprise the step of capping the container.

The method of freeze-drying preferably comprises the steps of:

a) Preparing an aqueous pharmaceutical composition as described above; and

b) Lyophilizing the aqueous pharmaceutical composition to form a cake using a method comprising the steps of:

(i) Freezing the aqueous pharmaceutical composition at a first temperature for a period of time sufficient to convert the liquid formulation to a solid state, wherein the first temperature is between-55 ℃ and-35 ℃, preferably between-50 ℃ and-35 ℃, preferably between-45 ℃ and-35 ℃; for example, in the range of-40 ℃ + -3 ℃;

(ii) Optionally maintaining the frozen composition at the temperature of step (i);

(iii) By subjecting the frozen composition to vacuum (preferably a vacuum of 0.05 mbar to 1.5 mbar) at the temperature of step (i) or (ii) and applying at-55 ℃ to-25 ℃; preferably-50 ℃ to-25 ℃, preferably-45 ℃ to-25 ℃, such as a temperature ramp in the range of-40 ℃ ± 3 ℃ to-20 ℃ ± 3 ℃;

(iv) Optionally maintaining the frozen composition at the end temperature of step (iii) under vacuum (preferably a vacuum of 0.05 mbar to 1.5 mbar);

(v) Applying a secondary drying step by subjecting the composition of step (iii) or (iv) to a vacuum (preferably a vacuum of 0.05 mbar to 1.5 mbar) and applying a temperature ramp, starting from the end temperature of step (iii) or (iv) and proceeding to a temperature in the range 15 ℃ to 30 ℃, preferably 20 ℃ to 28 ℃, for example 25 ℃ ± 3 ℃;

(vi) Optionally maintaining the end temperature and vacuum of step (v);

(vii) The vacuum is released.

The method may be adapted to contain an aqueous composition as described above in a container, whereby the container is plugged and optionally capped after releasing the vacuum.

The term "cake" refers to a dry solid material obtained when a liquid formulation is lyophilized or freeze-dried.

The pharmaceutical composition as described herein may be in the form of a lyophilized pharmaceutical composition. In particular, it may be a lyophilized pharmaceutical composition obtainable by the above-described lyophilization process, for example by freezing the pharmaceutical composition in a container and drying it by applying vacuum.

Furthermore, a lyophilized pharmaceutical composition as described herein may be reconstituted by adding at least one diluent to the lyophilized pharmaceutical composition to provide a reconstituted pharmaceutical composition.

Suitable diluents for reconstitution of the pharmaceutical compositions include any diluent that acts as a safe, stable and pharmaceutically acceptable carrier. Preferred is water for injection (WFI), such as in particular sterile water for injection (SWFI) or bacteriostatic water for injection (BWFI), optionally containing tonicity adjusting agents or a mixture of several tonicity adjusting agents, such as aqueous (preferably physiological) saline.

One embodiment relates to a pharmaceutical composition as described herein for use in the prevention and/or treatment of a disease and/or disorder selected from the group consisting of: ulcers, finger ulcers, diabetic gangrene, diabetic foot ulcers, pressure ulcers (bedsores), hypertension, pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, fang Tan disease and pulmonary arterial hypertension associated with Fang Tan disease, sarcoidosis and pulmonary arterial hypertension associated with sarcoidosis, peripheral circulatory disorders (e.g., chronic arterial occlusion, intermittent claudication, peripheral embolism, shock syndrome, raynaud's disease), connective tissue disorders (e.g., systemic lupus erythematosus, scleroderma, mixed connective tissue disease, vasculitis syndrome), post Percutaneous Transluminal Coronary Angioplasty (PTCA) restenosis/restenosis, arteriosclerosis, thrombosis (e.g., acute phase cerebral thrombosis, pulmonary embolism), transient Ischemic Attacks (TIAs), diabetic neuropathy, ischemic conditions (e.g., cerebral infarction, myocardial infarction), angina (e.g., stable angina, unstable angina), chronic kidney disease including glomerulonephritis and diabetic nephropathy at any stage, allergies, bronchial asthma, coronary interventions such as atherectomy and restenosis after stent implantation, thrombocytopenia due to dialysis, diseases involving organ or tissue fibrosis (e.g., kidney diseases such as tubular interstitial nephritis), respiratory diseases (e.g., interstitial pneumonia, (idiopathic) pulmonary fibrosis, chronic obstructive pulmonary disease), digestive system diseases (e.g., liver cirrhosis, viral hepatitis, chronic pancreatitis and hard gastric cancer), cardiovascular diseases (e.g., myocardial fibrosis), bone and joint diseases (e.g., myelofibrosis and rheumatoid arthritis), skin diseases (e.g., postoperative scars, scald scars, keloids, and hypertrophic scars), obstetric diseases (e.g., uterine fibroids), urinary system diseases (e.g., prostatic hyperplasia), other diseases (e.g., alzheimer's disease, sclerosing peritonitis, type I diabetes, and postoperative organ adhesions), erectile dysfunction (e.g., diabetic erectile dysfunction, cardiac erectile dysfunction, psychotic erectile dysfunction, erectile dysfunction associated with chronic kidney failure, post-pelvic surgical erectile dysfunction for removal of the prostate, and vascular erectile dysfunction associated with aging and arteriosclerosis), inflammatory bowel diseases (e.g., ulcerative colitis, crohn's disease, intestinal tuberculosis, ischemic colitis, and intestinal ulcers associated with white plug disease), gastritis, gastric ulcers, ischemic ocular diseases (e.g., retinal artery occlusion, retinal vein occlusion, ischemic optic neuropathy), sudden ear necrosis, non-vascular osteonecrosis, and inflammatory lesions associated with the administration of non-vascular osteogenic agents, and symptoms associated with the stenosis.

Preferred diseases and/or disorders are selected from: ulcers, finger ulcers, diabetic gangrene, diabetic foot ulcers, pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, fang Tan disease and pulmonary arterial hypertension associated with Fang Tan disease, sarcoidosis and pulmonary arterial hypertension associated with sarcoidosis, peripheral circulatory disorders, connective tissue disease, chronic kidney disease including glomerulonephritis and diabetic nephropathy at any stage, diseases involving fibrosis of organs or tissues, or respiratory diseases.

In certain embodiments, the pharmaceutical compositions described herein are used to treat and/or prevent pulmonary arterial hypertension, in particular Pulmonary Arterial Hypertension (PAH), chronic embolic pulmonary arterial hypertension, pulmonary arterial hypertension associated with Fang Tan disease, or pulmonary arterial hypertension associated with sarcoidosis. Particularly preferred are Pulmonary Arterial Hypertension (PAH) or chronic embolic pulmonary arterial hypertension (CTEPH).

The pharmaceutical compositions described herein, in particular for the treatment of the above mentioned diseases and/or disorders, are preferably in the form of intramuscular or subcutaneous injections. Thus, the injection is a long-acting injection (LAI). The term "long-acting injection" is used herein for administration intervals of one week to three months, or 1 week to two months, or 1 week to one month, or 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, or 12 weeks.

The pharmaceutical compositions described herein provide for the release of the active ingredient over an extended period of time and thus may also be referred to as sustained release or delayed release compositions. After administration, the composition stays in the body and stably releases 2- (4- ((5, 6-diphenylpyrazin-2-yl) (isopropyl) amino) butoxy) acetic acid or its calcium salt, maintaining such levels of this active ingredient in the patient's system for an extended period of time, providing suitable treatment or prevention of the above given diseases and/or disorders, particularly PAH and CTEPH, during said period of time. Due to the fact that the pharmaceutical composition described herein facilitates the residence of the active ingredient in the body and the stable release of the active ingredient, it may be referred to as a pharmaceutical composition suitable as a long-acting (or depot) formulation.

The pharmaceutical compositions described herein may be administered in the long-term treatment or long-term prevention of the diseases and/or disorders disclosed herein, in particular PAH and CTEPH.

The pharmaceutical compositions as described herein comprise a therapeutically effective amount of the active ingredient, namely calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate (or a pharmaceutically acceptable hydrate or solvate thereof).

The term "therapeutically effective amount" refers to the amount or concentration of a composition (or the amount/concentration of active ingredient within such composition) that results in effective plasma levels for the treatment of the disease (specifically PAH and CTEPH). For example, a therapeutically effective amount may be from 1mg to 200mg, such as from 2mg to 150mg or from 5mg to 100mg, and especially from 25mg to 100mg of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate per month. By "effective plasma levels" is meant those plasma levels of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetic acid that provide effective treatment or effective prevention of the indicated diseases and/or disorders, particularly PAH and CTEPH.

The dose (or amount) of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate (or a pharmaceutically acceptable hydrate or solvate thereof) administered also depends on the frequency of administration (i.e., the time interval between each administration). Generally, the dosage will be higher when the frequency of administration is lower.

In particular, the term "subject" relates to a human.

The present invention also relates to a method of treating a subject suffering from the above-mentioned diseases and/or disorders, in particular PAH and CTEPH, comprising administering to a human subject in need thereof a therapeutically effective amount of a pharmaceutical composition as described herein. The pharmaceutical composition of the present invention will be administered via intramuscular or subcutaneous injection.

In particular, the present invention relates to a method for preventing and/or treating ulcers, finger ulcers, diabetic gangrene, diabetic foot ulcers, pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, fang Tan disease and pulmonary arterial hypertension associated with Fang Tan disease, sarcoidosis and pulmonary arterial hypertension associated with sarcoidosis, peripheral circulatory disorders, connective tissue disease, chronic kidney disease including glomerulonephritis and diabetic nephropathy at any stage, diseases involving fibrosis of organs or tissues, and respiratory diseases, the method comprising administering to a human subject in need thereof a pharmaceutical composition as described herein.

The invention also relates to the use of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for the manufacture of a medicament for the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, comprising a therapeutically effective amount of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, in the form of an aqueous suspension.

The invention also relates to {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for use in the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, wherein the {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, is in an aqueous suspension.

The invention also relates to the use of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for the manufacture of a medicament for the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, comprising a therapeutically effective amount of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, in the form of a lyophilized cake.

The invention also relates to {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for use in the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, wherein the {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, is in the form of a lyophilized cake.

The invention also relates to the use of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for the manufacture of a medicament for the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, comprising a therapeutically effective amount of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, having a particle size distribution Dv50 of 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer); a surfactant and/or a wetting agent; and a pharmaceutically acceptable aqueous carrier having a pH in the range of 6 to 8.5, the medicament being in the form of an aqueous suspension.

The invention also relates to {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for use in the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, wherein the particle size distribution Dv50 is 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer) of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof; a surfactant and/or a wetting agent; and a pharmaceutically acceptable aqueous carrier having a pH in the range of 6 to 8.5 in an aqueous suspension.

The invention also relates to the use of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for the manufacture of a medicament for the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, comprising a therapeutically effective amount of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, in the form of an intramuscular or subcutaneous injection.

The invention also relates to {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for use in the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, wherein the {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, is in the form of an intramuscular or subcutaneous injection.

The invention also relates to the use of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for the manufacture of a medicament for the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, comprising a therapeutically effective amount of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, wherein the medicament is administered at a time interval of one to three months, preferably one or three months.

The invention also relates to {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, for use in the treatment of the above diseases and/or disorders, in particular PAH and CTEPH, wherein the {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof, is administered at intervals of one to three months, preferably one or three months.

The invention also relates to a pharmaceutical composition for use as a long-acting injection in the treatment and/or prevention of pulmonary arterial hypertension, wherein the pharmaceutical composition is in the form of an aqueous suspension comprising: a method of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof:

in particular, the pharmaceutical composition for use as a long-acting injection will be used for the treatment and/or prevention of pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, pulmonary arterial hypertension associated with Fang Tan disease or pulmonary arterial hypertension associated with sarcoidosis. The pharmaceutical composition for use as a long-acting injection is particularly useful for the treatment and/or prevention of Pulmonary Arterial Hypertension (PAH). The pharmaceutical composition used as the long-acting injection can also be used for treating and/or preventing chronic embolic pulmonary arterial hypertension (CTEPH). The pharmaceutical composition for the aforementioned use may be in the form of intramuscular injection or subcutaneous injection. In particular, the intramuscular or subcutaneous injection may be administered at intervals of one week to three months, in particular at intervals of two weeks to one month. The suspended particles of the intramuscular or subcutaneous injection may have a particle size distribution Dv50 of 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer).

The invention also relates to {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof,

the particle size distribution Dv50 is 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer).

the particle size distribution Dv50 is 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer), wherein the particles are suspended in an aqueous medium. In addition to water, the aqueous medium may also contain (i) a surfactant and/or a wetting agent; and optionally (ii) a resuspension agent. Furthermore, the pH of the aqueous medium may be in the range of 6 to 9, and in particular in the range of 6 to 8.5.

Furthermore, the present invention relates to calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof,

The particle size distribution Dv50 is 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer), wherein the particles are suspended in an aqueous medium for the treatment of a disease and/or disorder selected from the group consisting of: ulcers, finger ulcers, diabetic gangrene, diabetic foot ulcers, pressure ulcers (bedsores), hypertension, pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, fang Tan disease and pulmonary arterial hypertension associated with Fang Tan disease, sarcoidosis and pulmonary arterial hypertension associated with sarcoidosis, peripheral circulatory disorders (e.g., chronic arterial occlusion, intermittent claudication, peripheral embolism, shock syndrome, raynaud's disease), connective tissue disorders (e.g., systemic lupus erythematosus, scleroderma, mixed connective tissue disease, vasculitis syndrome), post Percutaneous Transluminal Coronary Angioplasty (PTCA) restenosis/restenosis, arteriosclerosis, thrombosis (e.g., acute phase cerebral thrombosis, pulmonary embolism), transient Ischemic Attacks (TIAs), diabetic neuropathy, ischemic conditions (e.g., cerebral infarction, myocardial infarction), angina (e.g., stable angina, unstable angina), chronic kidney disease including glomerulonephritis and diabetic nephropathy at any stage, allergies, bronchial asthma, coronary interventions such as atherectomy and restenosis after stent implantation, thrombocytopenia due to dialysis, diseases involving organ or tissue fibrosis (e.g., kidney diseases such as tubular interstitial nephritis), respiratory diseases (e.g., interstitial pneumonia, (idiopathic) pulmonary fibrosis, chronic obstructive pulmonary disease), digestive system diseases (e.g., liver cirrhosis, viral hepatitis, chronic pancreatitis and hard gastric cancer), cardiovascular diseases (e.g., myocardial fibrosis), bone and joint diseases (e.g., myelofibrosis and rheumatoid arthritis), skin diseases (e.g., postoperative scars, scald scars, keloids, and hypertrophic scars), obstetric diseases (e.g., uterine fibroids), urinary system diseases (e.g., prostatic hyperplasia), other diseases (e.g., alzheimer's disease, sclerosing peritonitis, type I diabetes, and postoperative organ adhesions), erectile dysfunction (e.g., diabetic erectile dysfunction, cardiac erectile dysfunction, psychotic erectile dysfunction, erectile dysfunction associated with chronic kidney failure, post-pelvic surgical erectile dysfunction for removal of the prostate, and vascular erectile dysfunction associated with aging and arteriosclerosis), inflammatory bowel diseases (e.g., ulcerative colitis, crohn's disease, intestinal tuberculosis, ischemic colitis, and intestinal ulcers associated with white plug disease), gastritis, gastric ulcers, ischemic ocular diseases (e.g., retinal artery occlusion, retinal vein occlusion, ischemic optic neuropathy), sudden ear necrosis, non-vascular osteonecrosis, and inflammatory lesions associated with the administration of non-vascular osteogenic agents; in particular pulmonary arterial hypertension, and in particular diseases and/or disorders selected from PAH and CTEPH. In addition to water, the aqueous medium may also contain (i) a surfactant and/or a wetting agent; and optionally (ii) a resuspension agent. Furthermore, the pH of the aqueous medium may be in the range of 6 to 9, and in particular in the range of 6 to 8.5.

In particular, the invention relates to: (4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy) calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof,

the particle size distribution of which is from 1 μm (micrometer) to 50 μm (micrometer), preferably from 2 μm (micrometer) to 30 μm (micrometer) or from 2 μm (micrometer) to 20 μm (micrometer) or from 5 μm (micrometer) to 15 μm (micrometer), wherein the particles are suspended in an aqueous medium for the treatment of pulmonary arterial hypertension, in particular PAH or CTEPH, wherein the particles suspended in the aqueous medium are for administration by intramuscular injection or subcutaneous injection. In addition to water, the aqueous medium may also contain (i) a surfactant and/or a wetting agent; and optionally (ii) a resuspension agent. Furthermore, the pH of the aqueous medium may be in the range of 6 to 9, and in particular in the range of 6 to 8.5. In particular, the intramuscular or subcutaneous injection is for administration at intervals of one week to three months, in particular at intervals of two weeks to one month.

The present invention also relates to a test drug ("ID") in the form of an aqueous suspension comprising a method of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof:

By "test new drug" or "test drug" is meant herein a new drug or biological drug for clinical trials. Preferably, the test drug will be used in a clinical trial with respect to the treatment of pulmonary arterial hypertension, in particular PAH or CTEPH.

According to one embodiment, the ID will be safe and effective for treating and/or preventing pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, pulmonary arterial hypertension associated with Fang Tan disease, or pulmonary arterial hypertension associated with sarcoidosis, in particular for treating pulmonary arterial hypertension, and in particular for treating PAH or CTEPH. The ID for the aforementioned use may be in the form of intramuscular injection or subcutaneous injection. In particular, the intramuscular or subcutaneous injection may be administered at intervals of one week to three months, in particular at intervals of two weeks to one month. The suspended particles of the intramuscular or subcutaneous injection may have a particle size distribution Dv50 of 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer).

The invention also relates to an ID in the form of an aqueous suspension comprising {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof

In particular, the present invention relates to an ID in the form of an aqueous suspension comprising {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof

All documents cited herein are incorporated by reference in their entirety.

The following examples are intended to illustrate the invention and should not be construed as limiting the invention thereto.

Examples

Abbreviations (as used herein and in the description above):

ADME absorption, distribution, metabolism, and excretion

API active pharmaceutical ingredient

aq. Water-containing

BHA butylated hydroxyanisole

BHT butylated hydroxytoluene

CTAC hexyl decyl trimethyl ammonium chloride

EDTA ethylenediamine tetraacetic acid

HPLC high performance liquid chromatography

IM intramuscular injection

International naming of INCI cosmetic ingredients

INN International nonproprietary name

IP receptor prostacyclin receptor

ISO International organization for standardization

LAI long-acting injection

LD laser diffraction

min

mM millimoles

NMP N-methylpyrrolidone

PEG polyethylene glycol

PSD particle size distribution

PAH pulmonary hypertension

CTEPH chronic embolic pulmonary hypertension

PBS phosphate buffered saline

pK pharmacokinetics

PVP polyvinylpyrrolidone

Proper amount (enough)

The proper amount is added in proper amount (enough) to form

RT room temperature

SC subcutaneous

SDS dodecyl sodium sulfate

TRIS (hydroxymethyl) aminomethane

UPLC ultra-high performance liquid chromatography

WFI (Water-Fidelity) injection water

WHO world health organization

w/v weight/volume

w/w weight/weight

XRPD X-ray powder diffraction

PSD measurement

PSD was measured using laser diffraction measurement methods and Mie theory using Malvern Mastersizer 3000 equipment from Malvern Panalytical. The results of the laser diffraction analysis are reported as cumulative insufficient size value dv50 based on particle size volume distribution. The following settings were used:

/>

the software used: mastersizer software v3.81; malvern Instruments Ltd

Examples:

example 1: preparation of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino }]Butoxy acetic acid calcium salt：

12g (28.604 mmol) of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino group]Butoxy } acetic acid was added to a two-piece 400ml reactor and 145.34g acetone/water (95/5 wt/wt%). Gradual stirring was applied to a speed of 400rpm and the reactor was heated to 50℃at 1K/min and held at that temperature for 30 minutes. Then, 15% by volume (4.2 ml) of Ca (OAc) was added over 30 minutes ₂ ×1/2H ₂ O-dissolved solution in Water (2.51 g (15.012 mmol) Ca (OAc) in 26.66g water) ₂ ×1/2H ₂ O stock solution)). The mixture was kept for 8 hours. Then, the remaining Ca (OAc) was added over 2 hours ₂ A stock solution dissolved in water. The mixture was stirred for 7.75 hours and the resulting solid was filtered off and washed with 24g (2 g/g) acetone/water 80/20 wt/wt% at 50 ℃. Vacuum and N at 50deg.C ₂ After drying under purging, 12.46g of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino are obtained]-calcium butoxy } acetate (99.3%) as a crystalline solid.

Example 2: feasibility pK rat study

Initial pK rat studies were performed to demonstrate the LAI potential of aqueous microsuspensions of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate. For this study, an aqueous microsuspension of calcium celecoxib, {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetic acid, {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate was prepared. An overview of the study design can be found in table 1.

TABLE 1 pK rat study design (ADME) showing LAI feasibility

The release profile and average AUC for the different formulations are depicted in figure 1.

As shown in fig. 1, the study group taking the calcium salt of ACT-333679 exhibited significantly lower plasma concentrations than the other two groups, which exhibited a long-acting release profile of up to 336 hours (i.e., 14 days), and AUC increased up to 720 hours. Sailexipa and its metabolites (group F and group H) do not exhibit long-acting release profile due to their high solubility and high dissolution rate.

Example 3: pK rat study comparing particle size and surfactant/wetting agent

A pK rat study was set up to evaluate the effect of the calcium salt physical properties (i.e. PSD) of ACT-333679, surfactant/wetting agent and route of administration on the in vivo drug release rate. The particle size of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate at Dv50 varied between 2 μm, 5 μm and 8 μm. The API concentration of the aqueous suspensions of the different studies remained constant at 100mg/mL equivalent. Intramuscular and subcutaneous routes were investigated in this rat study. An overview of the groups studied is shown in table 2.

Table 2. Overview of the design of pk rat study example 3

* N=4 male rats per group

An overview of pK curves for the different study groups is shown in figures 2 and 3. It can be concluded that long-acting prolonged in vivo release profiles are observed over the whole Dv50 range from 2 μm to 8 μm. The larger the particle size, the lower the initial release observed and the longer the duration. In order to achieve drug release for 1 month (or longer), the particle size at Dv50 should be equal to or greater than 8 μm.

Example 4: preparation of formulation examples-particle size

4 individual vials (volume=50 mL) were prepared with different target particle sizes (Dv 50 of 2 μm (micrometers), 5 μm (micrometers), 8 μm (micrometers) and 12 μm (micrometers)). In each vial, 1.568g (100 mg/mL equivalent) of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] -butoxy } calcium acetate was weighed. Immediately following the active ingredient, 45g of 1mm zirconium beads were added to each vial. In the next step, 12mL of a 125% over-concentrated stock solution of polysorbate 20, PEG 4000 and buffer was added to each vial. The composition of the stock solution depends on the experiment. The composition of each stock solution is shown in table 3 below.

Table 3: the test was performed with 125% over-concentrated polysorbate 20/PEG 4000/buffer (pH 8) Group of stock solutions Finished products

In the final step, 3mL of purified water was added to each vial. All 4 vials were placed on a roller mill at 300 rpm. In order to achieve different particle sizes (Dv 50 of 2 μm, 5 μm, 8 μm and 12 μm) different milling times are required. Different milling times and resulting particle sizes (using3000) are shown in table 4.

Table 4: summary of different milling times and resulting particle sizes。

Each milled suspension was collected in an 8mL vial and used3000 the final particle size was determined. The overlap of the resulting particle size distributions is shown in figure 4.

Example 5: preparation of formulation examples-surfactant/wetting agent

3 separate vials (volume=50 mL) with different surfactants/wetting agents (polysorbate 20, poloxamer 338 and vitamin E TPGS) were prepared. In each vial, 1.568g (100 mg/mL equivalent) of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] -butoxy } calcium acetate was weighed. Immediately following the active ingredient, 45g of 1mm zirconium beads were added to each vial. In the next step, 12mL of a 125% over-concentrated stock solution of surfactant/wetting agent, PEG4000 and McIlvaine buffer was added to each vial. The composition of the stock solution depends on the experiment. The composition of each stock solution is shown in table 24 below.

Table 5: 125% over-concentrated surfactant (and/or wetting agent)/PEG 4000/McIlvaine buffer tested Composition of stock solution of liquid (pH 8)

In the final step, 3mL of purified water was added to each vial. All 3 vials were placed on a roller mill with a rotational speed of 300 rpm. Different surfactants/wetting agents require different milling times in order to achieve a target particle size Dv50 of 8 μm. Different milling times and resulting particle sizes (using3000) are shown in table 6.

Table 6: summary of different milling times and resulting particle sizes。

Each milled suspension was collected in an 8mL vial and prefilled syringe. For final particle size3000 measurement. The overlap of the resulting particle size distributions is shown in figure 5.

All resulting vials and prefilled syringes were stored under different conditions. The vials were stored at 5 ℃, 25 ℃ and 40 ℃ for 12 days. The prefilled syringe was stored only at 5 ℃. After 12 days of storage, all different concepts (both vials and syringes) were evaluated for re-suspension (time to reach visually uniform suspension). The results are shown in Table 7.

Table 7: re-suspension after 12 days of storage under different conditions

Example 6: preparation of formulation examples-drug substance concentration

A separate vial (volume=50 mL) was prepared. In this vial, 3.1350g (200 mg/mL equivalent) of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] -butoxy } calcium acetate was weighed. Immediately following the active ingredient, 45g of 1mm zirconium beads were added to the vial. In the next step, 12mL of a 125% over-concentrated stock solution of polysorbate 20, PEG 4000 and McIlvaine buffer was added to the vial. The composition of the stock solution is shown in table 8 below.

Table 8: the tested 125% over-concentrated polysorbate 20/PEG 4000/McIlvaine buffer (pH 8) Storage device Composition of the preparation solution

Composition of the components	Concentration (mg/mL)
		Experiment ID	n001-00134
Polysorbate 20	12.50
		PEG 4000	93.75
Disodium hydrogen phosphate, anhydrous	10.00
		Citric acid hydrate	0.2125
1N HCl	Proper amount of pH 8
		Purified water	Proper amount of

In the final step, 3mL of purified water was added to the vial. The vials were placed on a roller mill with a rotational speed of 300 rpm. To achieve the target particle size of 10 μm (i.e. dv 50), grinding is required for 6 minutes. The particle size (used)3000) are shown in table 9.

Table 9: summary of different milling times and resulting particle sizes。

The milled suspension was collected in an 8mL vial and used3000 the final particle size was determined. The resulting particle size distribution is shown in figure 6.

Example 7: preparation of formulation examples-resuspension agent

3 separate vials (volume=50 mL) with different concentrations of PEG 4000 (50 mg/mL, 75mg/mL and 100 mg/mL) were prepared. In each vial, 1.568g (100 mg/mL equivalent) of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] -butoxy } calcium acetate was weighed. Immediately following the active ingredient, 45g of 1mm zirconium beads were added to each vial. In the next step, 12mL of a 125% over-concentrated stock solution of polysorbate 20, PEG 4000 and TRIS buffer was added to each vial. The composition of the stock solution depends on the experiment. The composition of each stock solution is shown in table 10 below.

Table 10: the tested 125% over-concentrated polysorbate 20/PEG 4000/TRIS buffer (pH 8) Stock solution Composition of the liquid

In the final step, 3mL of purified water was added to each vial. All 3 vials were placed on a roller mill with a rotational speed of 300 rpm. In order to achieve a target particle size of 8 μm (i.e. dv 50), each concept requires a different milling time. Different milling times and resulting particle sizes (using3000 obtained) overviewShown in table 11.

Table 11: summary of different milling times and resulting particle sizes。

Each milled suspension was collected in a 5mL vial and used 3000 the final particle size was determined. The overlap of the resulting particle size distributions is shown in figure 7.

Example 8: characterization of surface Charge by measurement of zeta potential

A suspension of {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } calcium acetate (100 mg/mL) was prepared to a particle size Dv50 of about 1 micron. The suspension was diluted 10000 times in water. The pH was adjusted from pH 3.0 to pH 9.0 with HCl or NaOH solutions. Zeta potential was measured using a Zetasizer Ultra device from Malvern. Fig. 8 shows the results of zeta potential as a function of pH of the suspension. Zeta potential is an indicator of suspension stability.

Example 9: lyophilization of suspension concepts

To further improve the stability of the suspensions at room temperature (or higher), the lyophilization feasibility of the 4 suspension concepts was performed. The suspension formulation components and lyophilization procedure prior to lyophilization are shown in the table below.

Table 12

Table 13: cold drying procedure

The concept of lyophilization is easily reconstituted in water by gentle shaking in 30 to 60 seconds and the particle size (Dv 50) results are comparable before and after lyophilization. No agglomeration of the particles was observed after lyophilization.

Table 14: particle size distribution before and after Cold drying

Example 10: sterilization of pharmaceutical substances by gamma irradiation

To evaluate whether gamma irradiation can be used to produce a sterile product, the following were tested for different irradiation levels: LAI potential of aqueous microsuspension of calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate. In this study, calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate ("compound") was irradiated with three different grades (i.e., 5kGy, 25kGy and 40 kGy). Each irradiation grade was applied to two different compound vials. For each grade, one of the two vials was flushed with nitrogen for 10 seconds. Included in the assay/purity analysis is a reference vial containing the unirradiated compound. All samples were analyzed immediately after irradiation (table 15) and re-analyzed after storage for 3 months at room temperature.

Table 15: gamma-irradiated {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino group]Butoxy calcium acetate Initial assay/purity results ("Compound")

RRT 1.16 is impurity (1-butanol, 4- [ (5, 6-diphenyl-2-pyrazinyl) (1-methylethyl) amino ] -) with a relative retention time of 1.16 minutes.

RRT 1.35 is an impurity with a relative retention time of 1.31 minutes.

RRT 1.34 is impurity (acetic acid, 2- [4- [ (5, 6-diphenyl-2-pyrazinyl) (1-methylethyl) amino ] butoxy ] -, ethyl ester) with a relative retention time of 1.34 minutes.

A second study was performed on {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } calcium acetate, in which three different irradiation levels (i.e., 5kGy, 25kGy, and 40 kGy) were administered. The results are shown in Table 16.

TABLE 16 gamma-irradiated {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino)]Butoxy calcium acetate Initial assay/purity results ("Compound")

RRT 1.15 is impurity (N-isopropyl-5, 6-diphenyl-pyrazin-2-amine) with a relative retention time of 1.15 minutes

RRT 1.32 is impurity (N-isopropyl-N- (4-methoxybutyl) -5, 6-diphenyl-pyrazin-2-amine) with a relative retention time of 1.32 minutes

Based on the results in tables 15 and 16, it can be concluded that the three impurities/degradation products gradually increased with increasing irradiation grade. However, the chemical stability of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate was considered acceptable, demonstrating the feasibility of sterilizing drug substances using gamma irradiation.

Analytical method used: determination of calcium salts and impurities of the celecoxib metabolites before (reference) and after gamma irradiation were analyzed using reverse phase chromatography. Sample preparation was performed by weighing 50mg of the sample in a 500mL flask. Approximately 100mL of pH7 phosphate buffer was added: ACN (50:50) and then the flask was mechanically shaken for at least 30 minutes until completely dissolved. Phosphate buffer at pH 7: ACN (50:50) was diluted to volume. The resulting solution was diluted 5-fold by pipetting 5mL into a 25mL flask and diluting with the same dilution solvent. According to the same sample preparation A reference solution was prepared but a calcium salt of the celecoxib metabolite ("API") was used.

Analysis was performed using a Waters UPLC H-Class equipped with DAD detector, column manager and autosampler. The separation was carried out on a Acquity UPLC BEH C (2.1 mm. Times.150 mm,1.7 μm) analytical column using a column temperature of 60 ℃. The DAD detector was set at 230nm. 10mM NH ₄ Ac: ACN: meOH (950:38:12) solution was used as mobile phase A. 10mM NH ₄ Ac: ACN: meOH (50:710:240) solution was used as mobile phase B. Mobile phase B initially increased from 5% to 100% in 20 minutes using a 26 minute linear gradient program. Thereafter, the concentration of mobile phase B was returned to 5% within 1 minute, followed by an equilibration time of 5 minutes. The flow rate applied was 0.30mL/min. Analysis was performed using a sample volume of 7 μl. The measured value of the sample was calculated according to the following formula:

% = [ API peak response _{Sample of} Concentration of x _{Reference to} Purity of X _{Reference to} ×100％]Response to the/[ peak ] _{Reference to} Concentration of x _{Sample of} ]

The concentration of impurities was calculated according to the following formula:

percent= [ impurity peak response _{Sample of} Concentration of x _{Reference to} Purity of X _{Reference to} ×100％]Response to the/[ peak ] _{Reference to} Concentration of x _{Sample of} ]

Example 11: sterilization of pharmaceutical products by gamma irradiation

Although demonstrating the feasibility of gamma irradiation of drug substances, terminal sterilization is preferred. For this reason, studies on gamma irradiation and autoclaving (steam sterilization) of the final pharmaceutical product are required. To evaluate the chemical stability of the final drug product during gamma irradiation, 2 different concepts using calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } acetate with a particle size Dv50 of 8 microns were subjected to irradiation scales of 40kGy and 60 kGy. A summary of the study and related assay/purity results is shown in table 17.

Table 17: summary of the concept of pharmaceutical products (i.e., formulations) subjected to gamma-irradiation and corresponding assay/purity results。

RRT 0.60 is an impurity with a relative retention time of 0.60 minutes.

RRT 0.72 is an impurity with a relative retention time of 0.72 minutes.

RRT 1.11 is an impurity with a relative retention time of 1.11 minutes.

When the different concepts are subjected to gamma irradiation, several impurities are formed. In all concepts of gamma irradiation, RRT 1.11 can be found. According to the identification result, the impurity is the esterification product of PEG 4000 and {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate (i.e., PEG adduct).

Impurities RRT 1.15 and 1.16 are less present during gamma irradiation of the formulated drug product than the non-formulated drug substance. The free radicals present in the drug product are assumed to have a higher tendency to react with PEG 4000 and thus less RRT 1.15 is formed. In addition, it is assumed that RRT 1.16 will be converted to RRT 1.32 in the pharmaceutical product.

Based on the results in table 17, it can be concluded that the impurity/degradation products gradually increase as the irradiation level increases. However, the chemical stability of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate in pharmaceutical products is considered acceptable, demonstrating the feasibility of sterilizing pharmaceutical products using gamma irradiation.

Analysis of useMethod: the determination and impurities of gamma-irradiated and non-gamma-irradiated (reference) calcium salts of the celecoxib metabolite suspension (formulation) were analyzed using reverse phase chromatography. Sample preparation was performed by weighing 0.5mL of sample in a 500mL flask. Approximately 200mL of pH7 phosphate buffer was added: ACN (50:50) and then the flask was mechanically shaken for at least 30 minutes until completely dissolved. Phosphate buffer at pH 7: ACN (50:50) was diluted to volume. The resulting solution was diluted 5-fold by pipetting 5mL into a 25mL flask and diluting with the same dilution solvent. The reference solution was prepared following the same sample preparation, but using the calcium salt of the celecoxib metabolite (see example 10).

% = [ API peak response _{Sample of} Concentration of x _{Reference to} Purity of X _{Reference to} ×100％]Response to the/[ peak ] _{Reference to} Concentration of x _{Sample of} X dose requirement]

percent= [ impurity peak response _{Sample of} Concentration of x _{Reference to} Purity of X _{Reference to} ×100％]Response to the/[ peak ] _{Reference to} Concentration of x _{Sample of} X dose requirement]

Example 12: sterilization of pharmaceutical products by autoclaving (steam sterilization)

Autoclaving (steam sterilization) was also evaluated in parallel with gamma irradiation of the final drug product (formulated calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } acetate) with a particle size Dv50 of 8 microns. As shown in table 18, 2 different concepts of autoclaving (122 ℃ for 15 min) were studied in two separate studies.

Table 18: summary of drug product concepts subjected to autoclaving (steam sterilization) and corresponding assay/purity results。

RRT 0.60 is an impurity with a relative retention time of 0.60 minutes.

RRT 0.72 is an impurity with a relative retention time of 0.72 minutes.

RRT 1.11 is an impurity with a relative retention time of 1.11 minutes.

The same analytical method as in example 11 was used.

The results show that no impurities are formed during autoclaving, so that autoclaving (steam sterilization) does not affect the chemical stability of the different drug concepts studied. For the process of autoclaving (steam sterilization), not only the effect on the chemical stability but also the effect on the re-suspension was evaluated. The test samples of experiment 142 were evaluated for re-suspension immediately after autoclaving (T0) and after 14 days of storage at 5 ℃. A summary of the results is shown in table 19. The time required for re-suspension is acceptable at both time points.

Table 19: resuspension results of pharmaceutical product concepts after being subjected to autoclaving (steam sterilization)

Based on the results in tables 18 and 19, it can be concluded that: after sterilization of the pharmaceutical product using autoclaving (steam sterilization), calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (propan-2-yl) amino ] butoxy } acetate is chemically stable in the pharmaceutical product. No agglomeration is formed and the drug product can be easily resuspended after autoclaving.

Example 13: conclusion(s)

To ensure sterility of the final drug product (formulated calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate) with a particle size Dv50 of 8 microns, three potential routes were investigated for feasibility: gamma irradiation of the pharmaceutical product and heat sterilization of the pharmaceutical product. To demonstrate feasibility, both physical stability (i.e., re-suspension and particle size) and chemical stability (i.e., formation of impurities) should be ensured, and the results are shown in table 20.

Table 20: pharmaceutical substances (not formulated) and pharmaceutical products (formulated) sterilized by gamma irradiation and autoclaving Summary of the determination/impurity results of (2)

/>

DP: pharmaceutical product (formulation)

DS: pharmaceutical substance (unformulated)

PX338: poloxamer 338

PS20: polysorbate 20

RRT 0.60 is an impurity with a relative retention time of 0.60 minutes.

RRT 0.72 is an impurity with a relative retention time of 0.72 minutes.

RRT 1.11 is an impurity with a relative retention time of 1.11 minutes.

The same analytical method as in example 11 was used.

Based on Table 20, calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate was chemically stable by autoclaving (steam sterilization) of the final drug product. In the case of gamma irradiated pharmaceutical products, the impurity levels are relatively high, but still within acceptable limits. It can thus be concluded that the final pharmaceutical product can be sterilized with autoclaving (steam sterilization) and gamma irradiation.

Claims

1. A pharmaceutical composition in the form of an aqueous suspension, the pharmaceutical composition comprising:

(a) {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I),

Or a pharmaceutically acceptable hydrate or solvate thereof:

the particle size distribution Dv50 is 1 μm (micrometers) to 50 μm (micrometers);

(b) A surfactant and/or a wetting agent; and

(c) A pharmaceutically acceptable aqueous carrier having a pH in the range of 6 to 8.5.

2. The pharmaceutical composition of claim 1, further comprising a resuspension agent.

3. The pharmaceutical composition according to claim 1 or 2, wherein the particle size distribution Dv50 is 2 μιη (micrometers) to 30 μιη (micrometers).

4. A pharmaceutical composition according to any one of claims 1 to 3, wherein the surfactant and/or wetting agent is selected from polysorbate, poloxamer, alpha-tocopheryl polyethylene glycol succinate, salts of negatively charged phospholipids, lecithin, polyvinylpyrrolidone (PVP), sodium docusate, sodium deoxycholate, sodium Dodecyl Sulphate (SDS), polyoxyethylene castor oil derivatives, polyethylene glycol 15 hydroxystearate, or mixtures thereof.

5. The pharmaceutical composition according to any one of claims 1 to 4, wherein the surfactant and/or wetting agent is selected from poloxamer 338, polysorbate 20 and vitamin E TPGS, or mixtures thereof.

6. The pharmaceutical composition according to any one of claims 2 to 5, wherein the resuspension agent is selected from polyethylene glycol (PEG), sodium carboxymethyl cellulose and poloxamer, or mixtures thereof.

7. The pharmaceutical composition of any one of claims 2 to 6, wherein the resuspension agent is selected from PEG 4000, PEG 3350, PEG 6000, PEG 8000, PEG 20000, sodium carboxymethyl cellulose, or mixtures thereof; in particular polyethylene glycol 4000.

8. The pharmaceutical composition according to any one of claims 1 to 7, wherein the aqueous carrier comprises one or more buffers and/or pH adjusters such that the pH is in the range of 6 to 8.5.

9. The pharmaceutical composition of claim 8, wherein the buffer and/or pH adjuster is selected from disodium hydrogen phosphate, citric acid, tris (hydroxymethyl) aminomethane, HCl and NaOH, or mixtures thereof.

10. The pharmaceutical composition according to any one of claims 8 or 9, wherein the buffer is a buffer with a buffer strength of 5 to 100 millimoles (mM).

11. The pharmaceutical composition according to any one of claims 1 to 10, wherein the pharmaceutically acceptable aqueous carrier comprises citric acid.

12. The pharmaceutical composition according to any one of claims 1 to 11, comprising by weight, based on the total volume of the composition:

(b) 0.5% to 20% (w/v), or 0.5% to 15% (w/v), or 0.5% to 12% (w/v), or 0.5% to 10%, or 0.5% to 8% (w/v), or 0.5% to 7% (w/v), or 0.5% to 6% (w/v), or 0.5% to 5% (w/v), or 0.5% to 4% (w/v), or 0.5% to 3% (w/v) of a surfactant and/or a mixture of surfactants and/or wetting agents;

(d) 0mM to 100mM, or 5mM to 50mM, or 10mM to 50mM buffer, or mixtures thereof;

(e) Proper amount of water for injection is added to 100%.

13. A container containing the pharmaceutical composition according to any one of claims 1 to 12, wherein the container is a syringe or a vial.

14. A process for preparing a pharmaceutical composition according to any one of claims 1 to 12, the process comprising the steps of:

(a) Adding calcium {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } acetate in crystalline form, or a pharmaceutically acceptable hydrate or solvate thereof, to a liquid medium comprising a surfactant and/or wetting agent, optionally a re-suspending agent to form a premix/pre-dispersion; and a pharmaceutically acceptable aqueous carrier having a pH in the range of 6 to 8.5; and

15. A method of preparing a lyophilized pharmaceutical composition, the method comprising the steps of: the pharmaceutical composition according to any one of claims 1 to 12, which is frozen, followed by a drying step comprising applying a vacuum.

16. A lyophilized pharmaceutical composition obtainable by the method according to claim 15.

17. A reconstituted pharmaceutical composition prepared from the lyophilized pharmaceutical composition of claim 16 by adding at least one diluent.

18. A process for preparing a sterile pharmaceutical composition according to any one of claims 1 to 12, wherein the pharmaceutical composition is sterilized with autoclaving (steam sterilization) or with gamma irradiation; or wherein {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate is sterilized with gamma-irradiation and used to prepare the pharmaceutical composition.

19. A sterile pharmaceutical composition obtainable by the method of claim 18.

20. The pharmaceutical composition according to any one of claims 1 to 12 or 16, 17 and 19 for use in the treatment and/or prevention of a disease and/or disorder selected from the group consisting of: ulcers, finger ulcers, diabetic gangrene, diabetic foot ulcers, pulmonary hypertension, fang Tan disease, sarcoidosis, peripheral circulatory disorders, connective tissue diseases, chronic kidney diseases including glomerulonephritis and diabetic nephropathy at any stage, diseases involving fibrosis of organs or tissues, and respiratory diseases.

21. The pharmaceutical composition for use according to claim 20, wherein the disease or disorder is pulmonary arterial hypertension, and the pulmonary arterial hypertension comprises pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, pulmonary arterial hypertension associated with Fang Tan disease, or pulmonary arterial hypertension associated with sarcoidosis.

22. The pharmaceutical composition according to claim 21 for use in the treatment and/or prevention of Pulmonary Arterial Hypertension (PAH).

23. The pharmaceutical composition according to claim 21 for use in the treatment and/or prevention of chronic embolic pulmonary arterial hypertension (CTEPH).

24. The pharmaceutical composition for use according to any one of claims 20 to 23, wherein the pharmaceutical composition is in the form of an intramuscular or subcutaneous injection.

25. The pharmaceutical composition for use according to claim 24, wherein the pharmaceutical composition is administered at intervals of one week to three months.

26. A pharmaceutical composition for use as a long-acting injection in the treatment and/or prevention of pulmonary arterial hypertension, wherein the pharmaceutical composition is in the form of an aqueous suspension comprising: a method of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof:

27. the pharmaceutical composition for use according to claim 26, wherein the pulmonary arterial hypertension comprises pulmonary arterial hypertension, chronic embolic pulmonary arterial hypertension, pulmonary arterial hypertension associated with Fang Tan disease, or pulmonary arterial hypertension associated with sarcoidosis.

28. The pharmaceutical composition according to claim 27 for use in the treatment and/or prevention of Pulmonary Arterial Hypertension (PAH).

29. The pharmaceutical composition according to claim 27 for use in the treatment and/or prevention of chronic embolic pulmonary arterial hypertension (CTEPH).

30. The pharmaceutical composition for use according to any one of claims 26 to 29, wherein the pharmaceutical composition is in the form of an intramuscular or subcutaneous injection.

31. The pharmaceutical composition for use according to claim 30, wherein the pharmaceutical composition is administered at intervals of one week to three months.

32. Particles of {4- [ (5, 6-diphenylpyrazin-2-yl) (prop-2-yl) amino ] butoxy } calcium acetate of formula (I), or a pharmaceutically acceptable hydrate or solvate thereof:

the particles have a particle size distribution Dv50 of 1 μm (micrometer) to 50 μm (micrometer), preferably 2 μm (micrometer) to 30 μm (micrometer) or 2 μm (micrometer) to 20 μm (micrometer) or 5 μm (micrometer) to 15 μm (micrometer).

33. The microparticle of claim 32, wherein the microparticle is suspended in an aqueous medium, which may comprise, in addition to water, (i) a surfactant and/or a wetting agent; and optionally (ii) a resuspension agent.

34. The microparticle of claim 33 for use in treating pulmonary arterial hypertension.

35. The microparticle of claim 34, for administration by intramuscular or subcutaneous injection.

36. The microparticle of claim 35, wherein the intramuscular injection or subcutaneous injection is for administration at intervals of one week to three months, in particular at intervals of two weeks to one month.