HK1092381A - Pharmaceutical combinations of adenosine a-2a and beta-2-adrenergic receptor agonists - Google Patents

Description

Adenosine A-2aPharmaceutical combination with beta-2 adrenoceptor agonists

no marking

The invention relates to adenosine A_2aInhaled combinations of a receptor agonist with an adrenergic beta 2 receptor agonist, pharmaceutical compositions thereof, including devices for administration, and uses of such combinations.

Adenosine A_2aThe combination of a receptor agonist and an adrenergic beta 2 receptor agonist can be used to treat airway obstruction and other inflammatory diseases, particularly the airway obstruction disease asthma, Chronic Obstructive Pulmonary Disease (COPD) and other obstructive airway diseases that are exacerbated by enhanced bronchial reflexes, inflammation, bronchial hyperreactivity and bronchospasm.

Examples of specific diseases that may be treated using the present invention include the respiratory diseases asthma, acute respiratory distress syndrome, chronic pulmonary inflammatory disease, bronchitis, chronic obstructive pulmonary (airway) disease and silicosis as well as immune system diseases such as allergic rhinitis and chronic sinusitis.

Adenosine has a wide range of physiological activities, including immune and inflammatory responses, is receptor-mediated and involved in at least four interactions with adenosineType of plasma membrane receptor interaction. These receptors are generally referred to as A₁，A_2a，A_2bAnd A₃. Adenosine and its analogues have been found to have broad spectrum anti-inflammatory activity involving a large number of different types of immune and inflammatory cells, including neutrophils and eosinophils. On neutrophils A_2aActivation of the receptor inhibits these cells from producing reactive oxidants and other inflammatory mediators such as elastase, and reduces the expression of β 2-integrin.

Known as A_2aReceptors are present on lymphocytes, neutrophils, eosinophils, basophils, monocytes/macrophages, epithelial cells, and vascular endothelial tissue with which they interact. Adenosine and A_2aReceptor binding can reduce inflammation by affecting the activity of several of these cell types. For example, A_2aReceptor agonists significantly inhibit oxidative species produced by physiological stimuli such as neutrophilic chemoattractants, cytokines and lipid products.

Adenosine A_2aOccupancy of the receptor activates neutrophil adenylate cyclase, which results in an increase in intracellular cyclic AMP. In turn, increased neutrophilic cyclic AMP results in a decrease in activated neutrophilic oxidative activity. Through a related effect on various other types of inflammatory cells, A_2aThe anti-inflammatory activity of an agonist is more than indicative of inhibition of neutrophil activity. Adenosine also reduced endotoxin-stimulated monocyte/macrophage TNF α release, and endogenous adenosine and adenosine analogs were observed by conjugation with adenosine A_2aReceptor binding reduces the production of human monocyte TNF-alpha.

Having a_2aAdenosine analogs of the various activities of the adenosine receptor can reduce endotoxin-stimulated release of interleukin-6 (IL-6) and interleukin-8 (IL-8). Interleukin-10 (IL-10) also has anti-inflammatory activity due to its ability to reduce endotoxin-stimulated release of TNF- α from monocytes, to inhibit oxidative activity, and to reduce expression of leukocyte adhesion molecules. Adenosine promotes the production of IL-10 by activated human monocytes; thus, in A_2aReceptor binding of adenosine agonistsAnd further to eliminate any ongoing inflammatory response that may be involved.

Activating the migration of eosinophils into tissues, causing cellular damage, and inflammation in diseases such as allergic and non-allergic asthma, allergic rhinitis, and atopic dermatitis. By interaction with A on eosinophils_2aReceptor binding, adenosine and adenosine A_2aReceptor agonist analogs inhibit the stimulated release of reactive oxide species, a species that interacts with A on neutrophils_2aInhibition of responses at the receptor parallels the effect.

Further, inhaled A_2aAgonists inhibit eosinophil aggregation in the lungs of sensitized guineA pigs viA action in the lungs (see WO-A-99/67263). This is at A_2aAgonists are important in relaxing blood vessels and lowering blood pressure in animals, whereby A_2aThe agonists are ideally anti-inflammatory by inhalation type formulations which have a high therapeutic index in the lungs compared to the peripheral compartments.

Adrenergic beta receptors are present in the sympathetic nervous system. It has at least two types. The adrenergic beta 1 receptor is found in the heart and plays an important role in regulating heart rate through the action of agonists adrenaline and noradrenaline. The adrenergic β 2 receptor is present in various types of cells within the lung (e.g., airway smooth muscle cells, epithelial cells and various inflammatory cells), and adrenergic β 2 receptor agonists are potent bronchodilators, causing relaxation of airway smooth muscle. Sympathetically similar amines have a long history of use in the treatment of chronic airway diseases characterized by partially reversible airway narrowing such as COPD (chronic obstructive pulmonary disease) and asthma, and were first used as bronchodilators in the form of intravenous epinephrine. Subsequently, inhaled beta adrenergic agents such as isoproterenol, which are relatively non-selective for the beta 2 receptor as compared to the beta 1 receptor, are used to cause tachycardia at effective bronchodilator doses. More recently inhaled beta-adrenergic agents such as norepinephrine are more selective for the beta 2 receptor but are less potent. The inhaled beta adrenergic agents formoterol (formoterol) and salmeterol (salmeterol) are both selective and long acting.

It has now surprisingly been found that certain adenosine A' s_2aReceptor agonists in combination with adrenergic beta 2 receptor agonists have significant advantages in the treatment of obstructive airways and other inflammatory diseases over either agent alone and over other known combinations. The advantage of this combination is that it provides optimal control of the trachea while effectively inhibiting adverse inflammation by the mechanism most appropriate for the pathology of the disease, i.e. adrenergic beta 2 receptor agonism. In this way, the symptoms of the disease are controlled by correcting the abnormal airway neuroreflex that causes coughing, production of mucus and dyspnea. Simultaneous administration of an adrenergic beta 2 receptor agonist and A by inhalation_2aAgonists, give various significant effects without producing adverse peripheral effects. Further, the particular combinations of the present invention produce unexpected synergy, resulting in greater efficacy than either drug alone at the maximum tolerated dose.

The present invention therefore provides (a) adenosine A of the formula_2aReceptor agonists

Or a pharmaceutically acceptable salt or solvate thereof, and (b) an adrenergic beta 2 receptor agonist,

wherein in formula I:

R¹is H, C₁-C₆Alkyl or fluorenyl, said C₁-C₆Alkyl is optionally substituted with 1 or 2 substituents independently selected from phenyl and naphthyl, said phenyl and naphthyl optionally substituted with C₁-C₆Alkyl radical, C₁-C₆Alkoxy, halogen or cyano;

(A)R²is H orC₁-C₆Alkyl radical, R¹⁵Is H or C₁-C₆Alkyl, X is (i) optionally substituted by C₁-C₆Alkyl or C₃-C₈Cycloalkyl-substituted unbranched C₂-C₃Alkylene, or (ii) a group having the general structure:

-(CH₂)_n-W-(CH₂)_p-

wherein W is C₅-C₇Cycloalkylene radical, optionally substituted by C₁-C₆Alkyl substituted, n is 0 or 1, and p is 0 or 1, or

(B)R¹⁵Is H or C₁-C₆Alkyl radical, R²And X, together with the nitrogen atom to which they are attached, each optionally substituted by C₁-C₆Alkyl-substituted azetidin-3-yl, pyrrolidin-3-yl, piperidin-4-yl, homopiperidin-3-yl or homopiperidin-4-yl, or

(C)R²Is H or C₁-C₆Alkyl radical, R¹⁵And X, together with the nitrogen atom to which they are attached, represent each optionally substituted by C₁-C₆Alkyl-substituted azetidin-3-yl, pyrrolidin-3-yl, piperidin-4-yl, homopiperidin-3-yl or homopiperidin-4-yl;

or, R³And R⁴And together with the nitrogen atom to which they are attached represent azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, homopiperidinyl or homopiperazinyl, each optionally substituted on the ring nitrogen or carbon by C₁-C₆Alkyl or C₃-C₈Cycloalkyl substituted, optionally by NR on a ring carbon atom not adjacent to the ring nitrogen atom⁶R⁷The substitution is carried out by the following steps,

or, R³Is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or benzyl, and R⁴Is composed of

(a) Azetidin-3-yl, pyrrolidin-3-yl, piperidin-4-yl, homopiperidin-3-yl or homopiperidinePiperidin-4-yl, each optionally substituted by C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, benzyl or het substituted, or

(b)-(C₂-C₆Alkylene) -R⁸，

(c)-(C₁-C₆Alkylene) -R¹³Or is or

(d)C₁-C₆Alkyl or C₃-C₈A cycloalkyl group;

R⁵is CH₂OH or CONR¹⁴R¹⁴；

R⁶And R⁷Each independently is H or C₁-C₆Alkyl or, together with the nitrogen atom to which they are attached, represents azetidinyl, pyrrolidinyl or piperidinyl, wherein said azetidinyl, pyrrolidinyl and piperidinyl groups are optionally substituted by C₁-C₆Alkyl substitution;

R⁸is (i) azetidin-1-yl, pyrrolidin-1-yl, piperidin-1-yl, morpholin-4-yl, piperazin-1-yl, homopiperidin-1-yl, homopiperazin-1-yl, or tetrahydroisoquinolin-1-yl, each of which is optionally substituted on a ring carbon atom with a substituent as follows: c₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, C₁-C₆Alkoxy radical- (C₁-C₆) -alkyl, R⁹R⁹N-(C₁-C₆) -alkyl, fluoro- (C)₁-C₆) -alkyl, -CONR⁹R⁹、-COOR⁹Or C₂-C₅Alkanoyl optionally substituted on a ring carbon atom not adjacent to a ring nitrogen atom with the following substituent: fluoro- (C)₁-C₆) -alkoxy, halogen, -OR⁹Cyano, -S (O)_mR¹⁰、-NR⁹R⁹、-SO₂NR⁹R⁹、-NR⁹COR¹⁰or-NR⁹SO₂R¹⁰And said piperazin-1-yl and homopiperazin-1-yl are not substituted with C₂-C₆To ring nitrogen atoms linked by C₁-C₆Alkyl, phenyl, C₁-C₆Alkoxy radical- (C₂-C₆) -alkyl, R⁹R⁹N-(C₂-C₆) -alkyl, fluoro- (C)₁-C₆) Alkyl radical, C₂-C₅Alkanoyl, -COOR¹⁰、C₃-C₈Cycloalkyl, -SO₂R¹⁰、-SO₂NR⁹R⁹or-CONR⁹R⁹Is substituted, or

(ii)NR¹¹R¹²；

R⁹Is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or phenyl;

R¹⁰is C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or phenyl;

R¹¹is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or benzyl;

R¹²is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, benzyl, fluoro- (C)₁-C₆) -alkyl, -CONR⁹R⁹、-COOR¹⁰、C₂-C₅Alkanoyl or-SO₂NR⁹R⁹；

R¹³Is (a) phenyl, pyridin-2-yl, pyridin-3-yl or pyridin-4-yl, each optionally substituted with C₁-C₆Alkyl radical, C₁-C₆Alkoxy, - (C)₁-C₃Alkylene group) - (C₁-C₆Alkoxy), halogen, cyano, - (C)₁-C₃Alkylene) -CN, -CO₂H、-(C₁-C₃Alkylene) -CO₂H、-CO₂(C₁-C₆Alkyl), - (C)₁-C₃Alkylene) -CO₂(C₁-C₆Alkyl), - (C)₁-C₃Alkylene) -NR¹⁴R¹⁴、-CONR¹⁴R¹⁴Or- (C)₁-C₃Alkylene) -CONR¹⁴R¹⁴Or (b) azetidin-2-yl, azetidin-3-yl, pyrrolidin-2-yl, pyrrolidin-3-yl, piperidin-2-yl, piperidin-3-yl, piperidin-4-yl, homopiperidin-2-yl, homopiperidin-3-yl or homopiperidin-4-yl, each optionally substituted with C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, benzyl, or het;

R¹⁴is H or C optionally substituted by cyclopropyl₁-C₆An alkyl group;

m is 0, 1 or 2;

y is CO, CS, SO₂Or C ═ n (cn); and

at R⁴And R¹³"het" as used in the definition is a C-linked, 4-to 6-membered heterocyclic ring having 1 to 4 ring nitrogen heteroatoms, or having 1 or 2 nitrogen ring heteroatoms, and 1 oxygen or 1 sulfur ring heteroatom, optionally substituted by C₁-C₆Alkyl radical, C₃-C₈-cycloalkyl, C₁-C₆Alkoxy radical, C₃-C₈Cycloalkoxy, hydroxy, oxo, or halo.

Further, the present invention provides an inhalation combination comprising (a) an adenosine A having the general formula (I) as defined above, for use as a medicament_2aA receptor agonist and (b) an adrenergic beta 2 receptor agonist.

Further, the present invention provides a combination comprising (a) an adenosine receptor agonist of formula (I) as defined above and (b) an adrenergic β 2 receptor agonist, for simultaneous, sequential or separate administration by inhalation in the treatment of an obstructive airways or other inflammatory disease.

Further, the present invention provides a pharmaceutical composition comprising adenosine A having the general formula (I) as defined above_2aReceptor agonists, adrenergic beta 2 receptor agonists and pharmaceutically acceptable excipients, diluents or carriers thereforIn the treatment of airway obstruction or other inflammatory diseases by inhalation.

Further, the present invention provides adenosine A having the general formula (I) as defined above_2aUse of a receptor agonist, or an adrenergic β 2 receptor agonist, in the manufacture of a medicament for the treatment of an obstructive airways or other inflammatory disease, for simultaneous, sequential or separate administration by inhalation.

Further, the present invention provides a method for the treatment of airway obstruction or other inflammatory diseases comprising administering to a mammal in need of such treatment, by inhalation, simultaneously, sequentially or separately, an effective amount of adenosine A having the general formula (I) as defined above_2aReceptor agonists and adrenergic beta 2 receptor agonists.

Further, the present invention provides an inhalation device for the simultaneous, sequential or separate administration of adenosine A of formula (I) as defined above in the treatment of airway obstruction or other inflammatory diseases_2aReceptor agonists and adrenergic beta 2 receptor agonists.

The preparation of compounds of formulA (I) is described in International patent application No. PCT/IB01/00973, publication No. WO-A-01/94368.

Preferred adenosine a for use in the present invention_2aThe receptor agonist comprises 6- [ (2, 2-diphenylethyl) amino]-9- { (2R, 3R, 4S, 5S) -5- [ (ethylamino) carbonyl]-3, 4-dihydroxytetrahydro-2-furanyl } -N- {2- [ ({ [1- (2-pyridinyl) -4-piperidinyl)]Amino } carbonyl) amino]Ethyl } -9H-purine-2-carboxamide (examples 8 and 35 of WO-A-01/94368) and pharmaceutically acceptable salts and solvate compounds thereof.

Preferably, the adrenergic β 2 receptor agonist used in the combination of the invention is a selective adrenergic β 2 receptor agonist, i.e. it has a greater affinity for the adrenergic β 2 receptor than for all other known adrenergic β receptors. Preferably, such selective adrenergic beta 2 receptor agonists have an affinity for the adrenergic beta 2 receptor which is at least 100-fold greater than its affinity for other adrenergic beta receptors.

Preferred adrenergic beta 2 receptor agonists for use in the present invention include salmeterol (salmeterol), formoterol (formoterol) and pharmaceutically acceptable salts and solvates thereof.

Particularly preferred adenosine A for use in the present invention_2aThe combination of a receptor agonist and an adrenergic beta 2 receptor agonist includes: :

6- [ (2, 2-diphenylethyl) amino ] -9- { (2R, 3R, 4S, 5S) -5- [ (ethylamino) carbonyl ] -3, 4-dihydroxytetrahydro-2-furanyl } -N- {2- [ ({ [1- (2-pyridinyl) -4-piperidinyl ] amino } carbonyl) amino ] ethyl } -9H-purin-2-amide, or a pharmaceutically acceptable salt or solvate thereof, and salmeterol (salmeterol), or a pharmaceutically acceptable salt or solvate thereof; and

6- [ (2, 2-diphenylethyl) amino ] -9- { (2R, 3R, 4S, 5S) -5- [ (ethylamino) carbonyl ] -3, 4-dihydroxytetrahydro-2-furanyl } -N- {2- [ ({ (1- (2-pyridyl) -4-piperidyl ] amino } carbonyl) amino ] ethyl } -9H-purine-2-carboxamide, or a pharmaceutically acceptable salt or solvate thereof, and formoterol, or a pharmaceutically acceptable salt or solvate thereof.

Adenosine A for use in the present invention_2aThe receptor agonist or adrenergic beta 2 receptor agonist may optionally be used in the form of a pharmaceutically acceptable salt or solvate thereof. The salts may be acid addition salts or base salts.

Suitable acid addition salts are formed from acids which form non-toxic salts and are exemplified by hydrochloride, hydrobromide, hydroiodide, sulphate, bisulphate, nitrate, phosphate, hydrogenphosphate, acetate, maleate, fumarate, lactate, tartrate, citrate, gluconate, succinate, gluconate, benzoate, methanesulphonate, ethanesulphonate, benzenesulphonate, p-toluenesulphonate and pamoate.

Suitable base salts are formed from bases which form non-toxic salts, examples being the sodium, potassium, aluminium, calcium, magnesium, zinc and diethanolamine salts.

For a review of suitable salts see Berge et al j.pharm.sci., 66, 1-19, 1977.

Adenosine A for use in the present invention_2aA pharmaceutically acceptable solvate of a receptor agonist with an adrenergic β 2 receptor agonist, or a salt thereof, including hydrates thereof.

Adenosine A of the invention_2aThe receptor agonist and the adrenergic β 2 receptor agonist may exist in one or more polymorphic forms.

Adenosine A of the invention_2aReceptor agonists and adrenergic β 2 receptor agonists may contain one or more asymmetric carbon atoms and thus exist in two or more stereoisomeric forms (e.g., R' formoterol (formoterol) is a preferred embodiment). Where the agonist contains an alkenyl or alkene group, the cis/trans (or Z/E) isomer may also occur. The compounds of the present invention include the individual stereoisomers of these compounds, as well as, where appropriate, the individual tautomers thereof and mixtures thereof.

The diastereoisomers or cis and trans isomers may be separated by conventional methods, for example by fractional crystallisation, chromatography or h.p.l.c. separation of a mixture of stereoisomers of a compound of the invention or a suitable salt or derivative thereof. The individual enantiomers of the compounds of the invention can also be prepared, as desired, by the corresponding optically pure intermediates or by resolution, for example by separation of the corresponding racemic compound by h.p.l.c. using a suitable chiral carrier, or by fractional crystallization of the diastereoisomers formed by reaction of the corresponding racemic compound with a suitable optically active acid or base.

The invention also includes all isotopic forms of the compound or pharmaceutically acceptable salt. The isotopic form is defined as one in which at least one atom is replaced by an atom having the same atomic number but an atomic mass different from the atomic mass usually found in nature. Can be included in the inventionExamples of isotopes of the compounds and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine and chlorine, for example²H，³H，¹³C，¹⁴C，¹⁵N，¹⁷O，¹⁸O，³¹P，³²P，³⁵S，¹⁸F and³⁶and (4) Cl. Certain isotopic forms of the compounds of the present invention, as well as pharmaceutically acceptable salts thereof, for example, those in which a radioactive isotope such as³H or¹⁴C, can be used for drug and/or culture medium tissue distribution research. Tritiated, i.e.,³h, and carbon 14, i.e.¹⁴C, an isotope is particularly preferred. Further, substitution of isotopes such as deuterium, i.e.²H, being more metabolically stable, e.g., increasing in vivo half-life or reducing the necessary dose, may provide certain therapeutic advantages and is therefore preferred in some instances.

The classes of diseases that can be treated using the compounds of the present invention include, but are not limited to: asthma, chronic or acute bronchoconstriction, chronic bronchitis, small airway obstruction, emphysema, Chronic Obstructive Pulmonary Disease (COPD), COPD with chronic bronchitis, emphysema or dyspnea associated therewith, and COPD characterized by irreversible, progressive chronic obstructive pulmonary disease.

Asthma (asthma)

One of the most important respiratory diseases that can be treated using the pharmaceutical combination of the present invention is asthma. Asthma is a chronic, increasingly common worldwide disease characterized by intermittent reversible airway obstruction, airway hyperreactivity, and inflammation. The cause of asthma remains to be determined, but the most common pathological manifestation of asthma is airway inflammation, which may be evident in the airways of even mildly asthmatics. This inflammation causes airway reflexes, resulting in plasma protein leakage, dyspnea, and bronchoconstriction. From bronchial biopsy and lavage studies, it has been clearly shown that asthma involves infiltration of mast cells, eosinophils and T-lymphocytes into the airways of patients. Bronchoalveolar lavage (BAL) shows the activation of Interleukins (IL) -3, (IL) -4, (IL) -5, and granulocyte/macrophage colony stimulating factor (GM-CSF) in atopic asthma, indicating the presence of a T-helper 2(Th-2) like T cell population.

The pharmaceutical combination of the invention is useful for the treatment of both specific and non-specific asthma. The term "specificity" refers to a genetic predisposition toward the evolution of a type I (immediate) hypersensitivity reaction to a common environmental antigen. The most common clinical manifestations are allergic rhinitis, whereas bronchial asthma, atopic dermatitis and food allergies occur with a slightly lower frequency. Thus, the expression "specific asthma" as used herein is synonymous with "allergic asthma", i.e. bronchial asthma with allergic manifestations in allergic humans. The term "non-specific asthma" as used herein refers to all other asthmatics, particularly basic or "real" asthma, which are induced by various factors including vigorous exercise, irritant particles, psychological stress, etc.

Chronic Obstructive Pulmonary Disease (COPD)

The pharmaceutical combinations of the invention may also be used to treat COPD or COAD, including chronic bronchitis, emphysema or dyspnea associated therewith. COPD is characterized by a weakly reversible, progressive airway obstruction. Chronic bronchitis is associated with hypertrophy and hyperplasia of mucous secretory glands in the submucosa of the large cartilaginous airways. Goblet cell proliferation, mucosal and submucosal inflammatory cell infiltration, edema, fibrosis, mucus plugs, and smooth muscle increase are found in both the terminal and respiratory bronchioles. Small airways are known to be the primary site of airway obstruction. Emphysema is characterized by damage to the alveolar walls and loss of lung elasticity. Many risk factors have been identified in connection with the development of COPD. A link between smoking and COPD has been established. Other risk factors include exposure to coal fines and various genetic factors. See Sandford et al, "Genetic risk factors for respiratory architectural efforts disease", Eur.Respir.J.101380-1391, 1997. The incidence of COPD is rising and is an important economic burden for the population of industrialized countries. COPD has clinically diverse forms ranging from simple chronic bronchitis, which is not without loss of function, to patients in a severe, loss-of-function chronic respiratory failure state.

Chronic obstructive pulmonary disease is characterized by airway inflammation, as is asthma, but the inflammatory cells that have been found in the lavage fluid of bronchoalveolar ducts and sputum of patients are neutrophils and macrophages rather than eosinophils. Increased levels of inflammatory mediators, including IL-8, LTB, have also been found in COPD patients₄And TNF- α, and it has been found that the bronchial surface epithelium and the subepithelial layer of the patient are infiltrated by T lymphocytes and macrophages. Symptoms in COPD patients can be alleviated by the use of beta-agonists as well as anticholinergic bronchodilators, but the progression of the disease cannot be altered. Theophylline has been used to treat COPD, but has not been much successful, in part because it can produce side effects. Steroids also cannot be satisfactorily used as agents for treating COPD because they are relatively ineffective as anti-inflammatory drugs.

Thus, the use of the pharmaceutical combination of the present invention for the treatment of COPD and related diseases, as well as diseases involving airway obstruction, is a significant advance in the art. The present invention is not limited to any particular mode of action or any hypothesis as to the method of use in which the desired therapeutic objectives have been achieved by the use of the pharmaceutical combination of the present invention.

Bronchitis and bronchiectasis

As mentioned above, the pharmaceutical combinations of the invention have the specific and different inhibitory activities indicated above, and therefore they are useful in the treatment of bronchitis of any kind, aetiology or pathogenesis, including, for example, acute bronchitis with a transient and severe course, caused by exposure to cold, to substances irritating by inhalation, or by acute infections; catarrhal bronchitis (catarrhal bronchiasis), a form of acute bronchitis, is manifested by the release of large amounts of purulent mucus; chronic bronchitis, a long-lasting form of bronchitis, more or less with a tendency to recur after an intermittent phase, is attributed to the recurrent episodes of general illness, either acute or chronic, characterized by episodes of cough, lack or excess of expectoration, and secondary changes in the pulmonary tissue; dry bronchitis, characterized by a lack of mucus secretion; infectious asthmatic bronchitis, a syndrome characterized by the further development of symptoms of bronchospasm following respiratory tract infection in asthmatic patients; proliferative bronchitis, a bronchitis associated with productive cough.

The use of the pharmaceutical combination of the present invention in the treatment of atopic or non-atopic asthma, COPD, or other chronic inflammatory airway diseases can be demonstrated and demonstrated by using several different models of inhibition of airway reflexes known in the art, including the plasma exudation and bronchospasm models described below.

Bronchodilator activity-cAMP is not only involved in smooth muscle relaxation, but also has a global inhibitory effect on airway smooth muscle proliferation, both of which may be due to activation of A by the component of the invention_2aReceptor induced. Airway smooth muscle hypertrophy and hyperplasia can be regulated by cAMP, which is a common morphological feature of chronic asthma.

The use of the pharmaceutical combination of the invention in the treatment of atopic or non-atopic asthma, COPD or other chronic inflammatory airways diseases may be demonstrated and demonstrated by the use of several different models known in the art as described below.

In vitro bronchospasm activity-the following test procedure shows the ability of the drug combination of the present invention to induce relaxation of tracheal smooth muscle in guinea pigs. Guinea pigs (350-500 g) were sacrificed using thiopentasodium (100mg/kgi. p.). Dissect the outlet tube and cut into 2-3cm pieces. On alternate cartilage plates, the trachea was transected from a cross-section to obtain a tissue ring with a thickness of 3-5 mm. The proximal and distal rings were discarded. The rings were mounted vertically on stainless steel supports, one of which was fixed to the base of the organ bath and the other was connected to an isometric sensor. The rings were soaked in Krebs solution (composition. mu.M: NaHCO) at 37 ℃₃25；NaCl113；KCl4.7；MgSO₄·7H₂O1.2；KH₂PO₄1.2；CaCl₂2.5；Glucose 11.7) and passing in O₂/CO₂(95: 5, v/v) gas. The loop prepared in this manner is contracted by a domain stimulation. To determine spasmolytic activity, the drug combination of the present invention used in the test was dissolved in physiological saline and added to the organ bath in increments at 5 minute intervals to provide a cumulative concentration response curve.

In the above test model, the pharmaceutical combination of the present invention inhibits the domain-stimulated contraction of the guinea pig tracheal ring-making product generally in a concentration range of 0.001 to 1.0. mu.M.

Relaxation of human bronchi-samples of human lungs were excised during tumor surgery and obtained within 3 days after removal. Small bronchi (internal diameter ≈ 2 to 5 mm) were excised, fragmented and placed in 2ml of a liquid nitrogen storage ampoule filled with Fetal Calf Serum (FCS) containing 1.8M Dimethylsulfoxide (DMSO) and 0.1M sucrose as an anti-freezing agent. The ampoule was placed in a polystyrene box (11X 22cm) and slowly frozen in a freezer kept at-70 ℃ with an average cooling rate of about 0.6 ℃/m. After 3-15 hours, the ampoule is transferred to liquid nitrogen (-196 ℃) and stored therein until use. The tissue was placed at-70 ℃ for 30-60 minutes prior to use and then thawed by placing it in a 37 ℃ water bath for 2.5 minutes. The bronchial fragments were then rinsed in a plate containing Krebs-Henseleit solution (μ M: NaCl118, KCl4.7, MgSO 2) at 37 deg.C₄1.2，CaCl₂1.2，KH₂PO₄1.2，NaHCO₃25, glucose 11, EDTA0.03), cut into rings and suspended in a 10ml organ bath (organbath) so as to record isometric tensions under a preload of about 1 g. Further increases in tone are provided by the application of domain stimulation, which is known to cause neural activation in airway samples, as well as the generation of tone through the release of acetylcholine and other neuro-genic mediators. Concentration response curves were prepared by cumulative addition, increasing the concentration when the previous concentration had produced the greatest effect. Papaverine (300 μ M) was added at the end of the concentration response curve to cause complete relaxation of the bronchial cartilage ring. The effect is recorded as 100% relaxation.

In the above test model, the concentration range in which the pharmaceutical combination of the present invention produces concentration-dependent relaxation in the finished human bronchial annuluses is generally from 0.001 to 1.0. mu.M, with a preferred embodiment in the concentration range from 5.0nM to 500 nM.

Inhibition of capsaicin-induced bronchoconstriction-use of sodium phenobarbital (100mg/kg, i.p. [ intra-abdominal)]) Male Dunkin-Hartley guinea pigs (400-800g) which had free access to food and water prior to the experiment were anesthetized. The animals were ventilated with an air-oxygen mixture (45: 55 v/v) via a tracheal cannula (approximately 8mL/kg 1Hz), maintained at 37 ℃ with a heating pad and controlled using an anal thermometer. Ventilation was monitored on the trachea by a respiratory rate meter connected to a differential pressure sensor in line with a respiratory pump. Pressure changes inside the thorax are monitored directly via a chest cannula using a differential pressure sensor to measure and display the pressure differential between the thorax and the trachea. From these pairs of airflow and pressure measurements between the lungs and the lung lumen (transpulmonary), the airway resistance (R) per respiratory cycle was calculated using a digital electronic breath analyzer₁cmH₂O/l/s) and consistency (Cd)_dyn). Blood pressure and heart rate were recorded from the carotid artery using a pressure transducer.

When basal resistance and consistency stabilized, acute bronchoconstriction was induced by intravenous bolus capsaicin. Capsaicin was dissolved in 100% ethanol and diluted with phosphate buffered saline. The response was measured after 2-3 administrations over a 10 minute interval and the pharmaceutical combination of the invention was administered for testing when the response to capsaicin was stable. Reversal of bronchoconstriction was measured 1-8 hours after intratracheal (i.t.) or duodenal instillation or intravenous bolus injection. Bronchospasm activity was expressed as% inhibition of initial, maximal Resistance (RD) after capsaicin injection. ED (electronic device)₅₀Values represent doses that reduced the resistance increase induced by capsaicin by 50%. Duration of action is defined as the time in minutes over which bronchoconstriction is reduced by 50% or more. ED (electronic device)₂₀The values characterize the effect on Blood Pressure (BP) and Heart Rate (HR), i.e. the 20% reduction in BP or HR dose is measured 5 minutes after administration.

In the above test model, the pharmaceutical combination of the present invention generally shows bronchodilatory activity in the range of 0.001-0.1mg/kgi.t. [ intratracheal ]. Furthermore, the combination delivered intratracheally (i.t.) showed at least an additional inhibitory effect on bronchospasm, with each individual component being able to inhibit more than 50% of the observed control response.

LPS-induced neutrophilia in the lung-neutrophil accumulation and activation in the lung is considered an important pathological feature of COPD and severe asthma. Inhibition of all or any of the endpoints in animals thus provides supportive evidence of the utility of the invention.

Male Wistar-Albino rats (150-. 1-24 hours after administration of the compound, animals were stimulated with an inhaled aerosol of bacterial Lipopolysaccharide (LPS) sufficient to induce significant pulmonary neutrophilia over the next 1-24 hours. Neutrophilia is detected by cell counting in bronchial washes or by measuring neutrophil production in lung washes or tissues. In this test system, the drug of the present invention generally showed anti-inflammatory activity in the i.t. dose range of 0.0001 to 0.1 mg/kg. Unexpectedly, delivery of the combination into the trachea (i.t.) has at least an additive effect on inflammation, although the components alone do not exert a significant anti-inflammatory effect. In addition, it can be observed that the anti-inflammatory effect with the lower dose, as used in the combination of the present invention, is the same as the anti-inflammatory effect with one of the individual components at the high dose, and thus systemic side effects are minimized.

Guinea pig allergy test-test for the evaluation of the therapeutic efficacy of the pharmaceutical combination of the invention on dyspnea and bronchospasm symptoms, i.e. dyspnea or difficulty and increased lung resistance, and on inflammatory symptoms, i.e. pulmonary neutrophilia and eosinophilia, using Dunkin-Hartley guinea pigs (400 + 600g body weight).

Ovalbumin (EA), grade V, crystallized and lyophilized, aluminum hydroxide and mepyramine maleate (mepyramine maleate) for this assay are commercially available. Stimulation and subsequent breath readings were performed in a clear plastic box with internal dimensions of 10 x 6 x 4 inches. The tank head and torso portions are separable. In use the two are held firmly together by a clamp and an air-tight seal is maintained between the two chambers by a soft rubber gasket. The sprayer is inserted through the center of the head end of the tank, through an airtight gasket, and has outlets at each end of the tank. The pneumotach is inserted into one end of the tank and coupled to a volumetric pressure sensor, which is then connected to a dynagraph by means of a suitable connector. Nebulize the antigen, open the outlet and isolate the pneumotachometer from the chamber. The outlet is then closed and the respiration rate meter is connected to the tank during the recording of the respiration pattern. 2ml of 3% saline solution of the antigen was placed in each nebulizer and aerosol was generated with 10psi of air in a small diaphragm pump at 8l/m flow rate for stimulation.

Guinea pigs were sensitized by subcutaneous and intraperitoneal injection of 1ml of a suspension containing 1mg of EA and 200mg of an aqueous solution of aluminium hydroxide. The guinea pigs were used 12 to 24 days after sensitization. To remove the histamine component of the reaction, guinea pigs were pretreated intraperitoneally with 2mg/kg mepyramine (mepyramine) 30 minutes before aerosol stimulation. Guinea pigs were then exposed to an aerosol of 3% EA saline solution for a precise period of 1 minute, and then a breathing profile was recorded for the next 30 minutes. Pulmonary inflammation was then measured 1-48 hours post-mortem. The duration of continuous dyspnea is calculated from the breath recordings.

The pharmaceutical combination of the invention, which is tested 0.5-4 hours prior to stimulation, is generally administered intratracheally (i.t.) or by aerosol administration. The compound combination is dissolved in saline or in a biocompatible solvent. The activity of the compounds was determined on the basis of their magnitude and duration of reduction of dyspnea and bronchospasm symptoms and/or the magnitude of lung inflammation, by comparison with vehicle-treated controls. Through aSerial dose evaluation testing of the pharmaceutical combination of the invention to obtain ED₅₀，ED₅₀Dose defined as 50% inhibition of symptom duration (mg/kg).

Anti-inflammatory activity-the anti-inflammatory activity of the pharmaceutical combination of the invention is indicated by inhibition of eosinophil or neutrophil activation. In this experiment, test blood samples (50ml) were collected from non-specifically reactive volunteers with eosinophil values ranging between 0.06 and 0.47X 10⁹L^-1In the meantime. Venous blood was collected into centrifuge tubes containing 5ml sodium citrate (3.8%, pH 7.4).

The anticoagulated blood was diluted (1: 1, v: v) with phosphate buffered saline (PBS, calcium and magnesium free) and spread in a 50ml centrifuge tube over 15ml isotonic Percoll (density 1.082-1.085g/ml, pH 7.4). After centrifugation (30 min, 1000 Xg, 20 ℃), the mononuclear cells at the plasma/Percoll interface were carefully aspirated and discarded.

Neutrophils/eosinophils/erythrocytes (approximately 5ml in volume) were gently resuspended in 35ml of isotonic ammonium chloride solution (NH)₄Cl，155mM；KHCO₃10 mM; EDTA.0.1mM; 0 to 4 ℃ below zero. After 15 min, cells were rinsed twice (10 min, 400 Xg, 4 ℃) in PBS containing fetal calf serum (2%, FCS).

A magnetic cell separation system was used to separate eosinophils from neutrophils. The system enables the separation of cells in suspension according to surface markers, comprising a permanent magnet in which a column comprising a magnetizable steel matrix is placed. Before use, the column was equilibrated for 1 hour using PBS/FCS and then rinsed with ice-cold PBS/FCS through a 20ml syringe on an inverted basis. A21G hypodermic needle was attached to the base of the column and 1-2ml of ice-cold buffer was allowed to flow through the needle.

After centrifugation of the granulocytes, the supernatant was aspirated and the cells were gently resuspended in 100. mu.l of magnetic particles (anti-CD 16 monoclonal antibody, coupled to superparamagnetic particles). The eosinophil/neutrophil/anti-CD 16 magnetic particle mixture was incubated on ice for 40 minutes and then diluted to 5ml with ice-cooled PBS/FCS. The cell suspension was slowly introduced into the top end of the column and the stopcock was opened to allow the cells to slowly enter the steel matrix. The column was then rinsed with PBS/FCS (35ml), which was carefully added to the top of the column to avoid damaging magnetically labelled neutrophils that had been trapped in the steel matrix. Non-labeled eosinophils were collected into a 50ml centrifuge tube and washed (10 min, 400 Xg, 4 ℃). The resulting particles were resuspended in 5ml Hank's Balanced Salt Solution (HBSS) so that cell number and purity could be checked prior to use. The separation column was removed from the magnet and the neutrophil fraction was eluted. The column was then washed with PBS (50ml) and ethanol (absolute pure) and stored at 4 ℃.

The total cells were counted using a minicell counter. A drop of lysogenic solution was added to the sample and counted again after 30 seconds to determine the contamination of the red blood cells. Cytospin was prepared on a Shandon Cytospin 2 Cytospin instrument (100. mu.l sample, 3 min, 500 rpm). The preparation was stained and different cell counts were performed by light microscopy, examining at least 500 cells. Cell viability was assessed by exclusion of trypan blue.

Eosinophils or neutrophils were diluted in HBSS and pipetted at 1-10X 10³Cells/well were placed in 96-well microtiter plates (MTP). Each well contained 200 μ l of sample, including: 100 μ l of cell suspension; 50 μ l HBSS; 10 μ l lucigenin; 20 μ l of activating stimulus, and 20 μ l of test compound.

The samples were incubated with test compound or vehicle for 10 minutes before adding the activating stimulus fMLP (1-10 μ M) or C5a (1-100nM), which was dissolved in dimethyl sulfoxide and then diluted in buffer to give a maximum solvent concentration of 1% (100 μ M test compound) used. The MTPs were shaken to facilitate mixing of the cells with the medium, and the MTP was placed in a luminometer. The total chemiluminescence versus time profile of each well was measured simultaneously at 20 minutes and the results expressed in arbitrary units, or in the absence of test compoundThe percentage of fMLP-induced chemiluminescence under the conditions of (a). Results were fitted by Hill equation and IC was calculated automatically₅₀The value is obtained.

In the above assay methods, the pharmaceutical combination of the present invention is generally effective at a concentration in the range of 0.0001. mu.M to 0.5. mu.M, and in a preferred embodiment, in the range of 0.1nM to 100 nM.

The anti-inflammatory activity of the pharmaceutical combination of the invention can also be demonstrated by inhibiting plasma exudation to rat airways. In this test, tracheal tissue was removed and the extent of plasma exudation was determined. This test is equally relevant to other chronic inflammatory diseases of the airways including, but not limited to, COPD and so will not be repeated in this section.

Wistar white mice (150-200g) or Dunkin-Hartley guinea pigs (450-600g) were anesthetized with sodium pentobarbital and venous and arterial cannulae were installed. Evans Blue dye was injected intravenously (i.v.) (30mg/kg) to bind plasma proteins. Test drug was administered intratracheally (i.t.) after 10 minutes and capsaicin (3 μ g/kg) was injected intravenously after 10 minutes. After 30 min, tracheal tissue was removed, extracted overnight into formamide, and absorbance read at 620 nm. In some experiments, the order of the doses was reversed, so the compound was administered before evans blue and the inflammatory stimulant.

In general, the pharmaceutical combinations of the present invention exhibit anti-inflammatory activity in the above-described test model at doses ranging from 0.001 to 0.1mg/kg i.t.

From the above, it can be seen that the pharmaceutical combination of the present invention is useful in the treatment of inflammatory or obstructive airways diseases or other diseases involving obstruction of the airways. In particular for the treatment of bronchial asthma.

Due to their anti-inflammatory activity and their effect on airway hyperresponsiveness, the pharmaceutical combinations of the present invention are useful in the treatment, in particular prophylactic treatment, of obstructive or inflammatory airway diseases. Thus, continuous and regular administration of a combination of compounds of the invention over a sustained period of time provides prior protection against the recurrence of bronchoconstriction or other symptoms associated with obstructive or inflammatory airway disease. The combinations of compounds of the present invention are also useful in controlling, ameliorating or reversing the underlying state of these diseases.

Due to its bronchodilator activity, the pharmaceutical combination of the invention can be used as bronchodilator in the treatment of e.g. chronic or acute bronchoconstriction, as well as for symptomatic treatment of obstructive or inflammatory airway diseases.

Obstructive or inflammatory airway diseases to which the present invention relates include asthma; pneumoconiosis; chronic eosinophilic pneumonia; chronic obstructive airways or lung disease (COAD or COPD); and Adult Respiratory Distress Syndrome (ARDS), and exacerbation of airway hyperresponsiveness caused by other drug therapies, such as aspirin or beta-agonist therapy.

Adenosine A of the invention_2aThe receptor agonist and the adrenergic β 2 receptor agonist may be administered alone or in combination, but are generally administered in admixture with a suitable pharmaceutical excipient, diluent or carrier.

Adenosine A of the invention_2aThe receptor agonist and the adrenergic β 2 receptor agonist are preferably administered by inhalation and are conveniently administered in dry powder form (alone or as a mixture, e.g. a lactose-containing mixture) from a dry powder inhaler or as a spray aerosol from a pressurised container, pump, nebuliser (preferably an electro-hydraulic powered nebuliser which produces a fine mist) or spray device, with or without the use of a suitable propellant, examples of which are: dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, hydrofluoroalkanes such as 1, 1, 1, 2-tetrafluoroethane (HFA 134A [ trade mark ]]) Or 1, 1, 1, 2, 3, 3, 3-heptafluoropropane (HFA 227EA [ trade mark ]]) Carbon dioxide, and perfluoro substituted hydrocarbons such as perfluoroflurron (trademark) or other suitable gases. In the case of a pressurized aerosol, dosing can be achieved by defining a dosage unit through a valve. The pressurised container, pump, spray, atomiser or spray device may contain a solution or suspension of the active compound, for example using ethanol (optionally aqueous ethanol)Alcohol) or a mixture of an agent suitable for dispersion, dissolution and expansion release (extending release) and a propellant, which may further comprise a lubricant, such as sorbitan trioleate (sorbitan trioleate), as a solvent. Capsules for use in an inhaler or insufflator (inhaler) may be prepared, foamers and cartridges (prepared from, for example, gelatin or HPMC) containing a powder mix of a compound of the invention, a suitable powder base such as lactose or starch, and a performance modifier such as 1-leucine, mannitol or magnesium stearate.

Prior to inhalation of the compounds of the invention in a dry powder or suspension formulation, they are micronised to a size suitable for release by inhalation (generally considered to be less than 5 microns). Micronization can be carried out by various methods, such as spiral jet milling, fluidized bed jet milling, or crystallization using supercritical fluids.

In suitable solution formulations for use in electro-hydraulic powered nebulisers for the production of fine droplets, each action comprises from 1 μ g to 10mg of a compound of the invention and the volume may be from 1 to 100 μ l. A typical formulation may comprise a compound of the invention, propylene glycol, sterile water, ethanol and sodium chloride. Instead of propylene glycol, other solvents such as glycerol or polyethylene glycol may be used.

Preferably, an aerosol or dry powder formulation is used which contains from 1 to 4000 μ g of a compound of the invention per metered dose or "puff" administered to the patient. The total dose of the aerosol is in the range of 1 μ g to 20 mg per day, which may be administered in a single dose or, more commonly, in divided doses throughout the day.

Adenosine A used in weight (w/w)_2aReceptor agonists: the preferred ratio of adrenergic beta 2 receptor agonists depends on the particular combination tested. This is due to the difference in potency of the individual compounds. The physician will determine the exact dosage of each compound which will be most suitable for each particular patient and this will vary with the age, weight and response of the particular patient.

It is understood that all references herein to treatment include cure, alleviation and prevention.

Claims (14)

1. A compound (a) adenosine A of the formula_2aReceptor agonists

Or a pharmaceutically acceptable salt or solvate thereof, and (b) an adrenergic beta 2 receptor agonist,

wherein in formula I:

R¹is H, C₁-C₆Alkyl or fluorenyl, said C₁-C₆Alkyl is optionally substituted with 1 or 2 substituents independently selected from phenyl and naphthyl, said phenyl and naphthyl optionally substituted with C₁-C₆Alkyl radical, C₁-C₆Alkoxy, halogen or cyano;

(A)R²is H or C₁-C₆Alkyl radical, R¹⁵Is H or C₁-C₆Alkyl, X is (i) optionally substituted by C₁-C₆Alkyl or C₃-C₈Cycloalkyl-substituted unbranched C₂-C₃Alkylene, or (ii) a group having the general structure:

-(CH₂)_n-W-(CH₂)_p-

wherein W is C₅-C₇Cycloalkylene radical, optionally substituted by C₁-C₆Alkyl substituted, n is 0 or 1, and p is 0 or 1, or

(B)R¹⁵Is H or C₁-C₆Alkyl radical, R²And X, together with the nitrogen atom to which they are attached, each optionally substituted by C₁-C₆Alkyl-substituted azetidin-3-yl, pyrrolidin-3-yl, piperidin-4-yl, homopiperidin-3-yl or homopiperidin-4-yl, or

(C)R²Is H or C₁-C₆Alkyl radical, R¹⁵And X, together with the nitrogen atom to which they are attached, represent each optionally substituted by C₁-C₆Alkyl-substituted azetidin-3-yl, pyrrolidin-3-yl, piperidin-4-yl, homopiperidin-3-yl or homopiperidin-4-yl;

or, R³And R⁴And together with the nitrogen atom to which they are attached represent azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, homopiperidinyl or homopiperazinyl, each optionally substituted on the ring nitrogen or carbon by C₁-C₆Alkyl or C₃-C₈Cycloalkyl substituted, optionally by NR on a ring carbon atom not adjacent to the ring nitrogen atom⁶R⁷The substitution is carried out by the following steps,

or, R³Is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or benzyl, and R⁴Is composed of

(a) Azetidin-3-yl, pyrrolidin-3-yl, piperidin-4-yl, homopiperidin-3-yl or homopiperidin-4-yl, each optionally substituted by C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, benzyl or het substituted, or

(b)-(C₂-C₆Alkylene) -R⁸，

(c)-(C₁-C₆Alkylene) -R¹³Or is or

(d)C₁-C₆Alkyl or C₃-C₈A cycloalkyl group;

R⁵is CH₂OH or CONR¹⁴R¹⁴；

R⁶And R⁷Each independently is H or C₁-C₆Alkyl or, together with the nitrogen atom to which they are attached, represents azetidinyl, pyrrolidinyl or piperidinyl, wherein said azetidinyl, pyrrolidinyl and piperidinyl groups are optionally substituted by C₁-C₆Alkyl substitution;

R⁸is (i) azetidin-1-yl, pyrrolidin-1-yl, piperidin-1-yl, morpholin-4-yl, piperazin-1-yl, homopiperidin-1-yl, homopiperazin-1-yl, or tetrahydroisoquinolin-1-yl, each of which is optionally substituted on a ring carbon atom with a substituent as follows: c₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, C₁-C₆Alkoxy radical- (C₁-C₆) -alkyl, R⁹R⁹N-(C₁-C₆) -alkyl, fluoro- (C)₁-C₆) -alkyl, -CONR⁹R⁹、-COOR⁹Or C₂-C₅Alkanoyl optionally substituted on a ring carbon atom not adjacent to a ring nitrogen atom with the following substituent: fluoro- (C)₁-C₆) -alkoxy, halogen, -OR⁹Cyano, -S (O)_mR¹⁰、-NR⁹R⁹、-SO₂NR⁹R⁹、-NR⁹COR¹⁰or-NR⁹SO₂R¹⁰And said piperazin-1-yl and homopiperazin-1-yl are not substituted with C₂-C₆To ring nitrogen atoms linked by C₁-C₆Alkyl, phenyl, C₁-C₆Alkoxy radical- (C₂-C₆) -alkyl, R⁹R⁹N-(C₂-C₆) -alkyl, fluoro- (C)₁-C₆) Alkyl radical, C₂-C₅Alkanoyl, -COOR¹⁰、C₃-C₈Cycloalkyl, -SO₂R¹⁰、-SO₂NR⁹R⁹or-CONR⁹R⁹Is substituted, or

(ii)NR¹¹R¹²；

R⁹Is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or phenyl;

R¹⁰is C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or phenyl;

R¹¹is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl or benzyl;

R¹²is H, C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, benzyl, fluoro- (C)₁-C₆) -alkyl, -CONR⁹R⁹、-COOR¹⁰、C₂-C₅Alkanoyl or-SO₂NR⁹R⁹；

R¹³Is (a) phenyl, pyridin-2-yl, pyridin-3-yl or pyridin-4-yl, each optionally substituted with C₁-C₆Alkyl radical, C₁-C₆Alkoxy, - (C)₁-C₃Alkylene group) - (C₁-C₆Alkoxy), halogen, cyano, - (C)₁-C₃Alkylene) -CN, -CO₂H、-(C₁-C₃Alkylene) -CO₂H、-CO₂(C₁-C₆Alkyl), - (C)₁-C₃Alkylene) -CO₂(C₁-C₆Alkyl), - (C)₁-C₃Alkylene) -NR¹⁴R¹⁴、-CONR¹⁴R¹⁴Or- (C)₁-C₃Alkylene) -CONR¹⁴R¹⁴Or (b) azetidin-2-yl, azetidin-3-yl, pyrrolidin-2-yl, pyrrolidin-3-yl, piperidin-2-yl, piperidin-3-yl, piperidin-4-yl, homopiperidin-2-yl, homopiperidin-3-yl or homopiperidin-4-yl, each optionally substituted with C₁-C₆Alkyl radical, C₃-C₈Cycloalkyl, phenyl, benzyl, or het;

R¹⁴is H or C optionally substituted by cyclopropyl₁-C₆An alkyl group;

m is 0, 1 or 2;

y is CO, CS, SO₂Or C ═ n (cn); and

at R⁴And R¹³"het" as used in the definition is a C-linked, 4-to 6-membered heterocyclic ring having 1 to 4 ring nitrogen heteroatoms, or having 1 or 2 nitrogen ring heteroatoms, and 1 oxygen or 1 sulfur ring heteroatom, optionally substituted by C₁-C₆Alkyl radical, C₃-C₈-cycloalkyl, C₁-C₆Alkoxy radical, C₃-C₈Cycloalkoxy, hydroxy, oxo, or halo.

2. A combination according to claim 1 wherein adenosine A of formula (I)_2aThe receptor agonist is 6- [ (2, 2-diphenylethyl) amino]-9- { (2R, 3R, 4S, 5S) -5- [ (ethylamino) carbonyl]-3, 4-dihydroxytetrahydro-2-furanyl } -N- {2- [ ({ [1- (2-pyridinyl) 4-piperidinyl)]Amino } carbonyl) amino]Ethyl } -9H-purine-2-carboxamide or a pharmaceutically acceptable salt or solvate thereof.

3. A combination according to claim 1 or 2 wherein the adrenergic β 2 receptor agonist is salmeterol, or a pharmaceutically acceptable salt or solvate thereof.

4. A combination according to claim 1 or 2 wherein the adrenergic β 2 receptor agonist is formoterol or a pharmaceutically acceptable salt or solvate thereof.

5. A combination according to any one of the preceding claims for use as a medicament.

6. A combination according to any one of claims 1 to 4 for simultaneous, sequential or separate administration in the treatment of obstructive airways and other inflammatory diseases.

7. A pharmaceutical composition comprising adenosine a of general formula (I) as defined in claim 1_2aA receptor agonist, an adrenergic β 2 receptor agonist and a pharmaceutically acceptable excipient, diluent or carrier, for administration by inhalation in the treatment of obstructive airways and other inflammatory diseases.

8. The pharmaceutical composition of claim 7, wherein adenosine A of formula (I)_2aThe receptor agonist and the adrenergic beta 2 receptor agonist are as defined in any one of claims 2 to 4.

9. Adenosine A of the general formula (I) as defined in claim 1_2aUse of a receptor agonist or an adrenobeta 2 receptor agonist in the manufacture of a medicament for the administration of two active ingredients simultaneously, sequentially or separately by inhalation in the treatment of obstructive airways and other inflammatory diseases.

10. Use according to claim 9, wherein adenosine a of formula (I)_2aThe receptor agonist and the adrenergic beta 2 receptor agonist are as defined in any one of claims 2 to 4.

11. A method for the treatment of obstructive airways and other inflammatory diseases which comprises simultaneously, sequentially or separately administering to a mammal in need of such treatment by inhalation an effective amount of adenosine a of formula (I) as defined in claim 1_2aReceptor agonists and adrenergic beta 2 receptor agonists.

12. As claimed in claim11, wherein adenosine a of formula (I)_2aThe receptor agonist and the adrenergic beta 2 receptor agonist are as defined in any one of claims 2 to 4.

13. An inhalation device for the simultaneous, sequential or separate administration of adenosine a of formula (I) as defined in claim 1 in the treatment of obstructive airways and other inflammatory diseases_2aReceptor agonists and adrenergic beta 2 receptor agonists.

14. A device as defined in claim 13, wherein adenosine a of formula (I)_2aThe receptor agonist and the adrenergic beta 2 receptor agonist are as defined in any one of claims 2 to 4.