GB2388843A - A metered dose inhaler containing a pharmaceutical formulation of fluticasone propionate - Google Patents

Abstract

A metered dose inhaler comprises a canister filled with a metering valve which contains a pharmaceutical solution aerosol formulation which comprises: <SL> <LI>(i) fluticasone propionate and <LI>(ii) a hydrofluoroalkane (HFA) propellant, </SL> characterised in that the fluticasone propionate is completely dissolved in the formulation; wherein the canister is fitted into a channelling device which comprises a mouthpiece actuator having an actuator exit orifice of diameter 0.25mm or less. The pharmaceutical formulation may further contain a low volatility component e.g. glycerol or propylene glycol and/or a solubilisation agent e.g. ethanol or dimethoxymethane.

Description

A Metered Dose Inhaler Containing a Pharmaceutical Formulation of

Fluticasone ProDionate Background of the invention

Field of the invention

5 The present invention relates to a pharmaceutical formulation for use in the administration of medicaments by inhalation. In particular, this invention relates to a pharmaceutical formulation of fluticasone propionate for use in metered dose inhalers (MDl's). The invention also relates to methods for their preparation and to their use in therapy. Description of the background art

Inhalers are well known devices for administering pharmaceutically active materials to the respiratory tract by inhalation. Such active materials commonly delivered by inhalation include bronchodilators such as p2 agonists and anticholinergics, 15 corticosteroids, anti-allergies and other materials that may be efficiently administered by inhalation, thus increasing the therapeutic index and reducing side effects of the active material. (6a, 11 b, 1 6a, 1 7a)-6, 9-difluoro-11 -hydroxy-1 6-methyl-3oxo-17-(1 -oxopropoxy) 20 androsta-1, 4-diene-1 7-carbothioic acid, Sfluoromethyl ester was described as an anti inflammatory steroid by US Patent No. 4,335,121. This compound is also known by the generic name of fluticasone propionate and has since become widely known as a highly effective steroid in the treatment of inflammatory diseases, such as asthma and chronic obstructive pulmonary disease (COPD).

Metered dose inhalers (MDl's) are the most common type of a wide range of inhaler types and utilise a liquefied propellant to expel droplets containing the pharmaceutical product to the respiratory tract as an aerosol. MDI formulations are generally characterized as solution formulations or suspension formulations.

The most commonly used aerosol propellants for medicaments have been Freon 11 (CCI3F) in admixture with Freon 12 (CCI2F2) and Freon 114 (CF2CI. CF2CI). However, these propellants are now believed to provoke the degradation of stratospheric ozone

and their use is now being phased out to eliminate the use of all CFC containing aerosol propellants. There is thus a need to provide an aerosol formulation for medicaments which employ so called 'ozone- friendly' propellants.

5 Hydrofluoroalkanes (HFAs; known also as hydrofluorocarbons or HFCs) contain no chlorine and are considered less destructive to ozone and these are proposed substitutes for CFCs. In particular, 1,1,1,2tetrafluoroethane (HFA 134a) and 1,1,1,2,3,3,heptafluoropropane (HFA227) have been acknowledged to be the best candidates for nonFC propellants.

The efficiency of an aerosol device, such as an MDI, is a function of the dose deposited at the appropriate site in the lungs. Deposition is affected by several factors, of which one of the most important is the aerodynamic particle size. Solid particles and/or droplets in an aerosol formulation can be characterized by their mass median 15 aerodynamic diameter (MMAD, the diameter around which the mass aerodynamic diameters are distributed equally).

Particle deposition in the lung depends largely upon three physical mechanisms: 1. impaction, a function of particle inertia; 20 2. sedimentation due to gravity; and 3. diffusion resulting from Brownian motion of fine, submicrometer (c1 pm) particles.

The mass of the particles determines which of the three main mechanisms predominates. The effective aerodynamic diameter is a function of the size, shape and density of the particles and will affect the magnitude of forces acting on them. For example, while inertial and gravitational effects increase with increasing particle see and particle density, the displacements produced by diffusion decrease. In practice, diffusion plays 30 little part in deposition from pharmaceutical aerosols. Impaction and sedimentation can be assessed from a measurement of the MMAD which detemmines the displacement across streamlines under the influence of inertia and gravity, respectively.

/ Aerosol particles of equivalent MMAD and GSD (geometric standard deviation) have similar deposition in the lung irrespective of their composition. The GSD is a measure of the variability of the aerodynamic particle diameters.

5 For inhalation therapy there is a preference for aerosols in which the particles for inhalation have a diameter of about 0.5 to 51lrn. Particles which are larger than 5rUT in diameter are primarily deposited by inertial impaction in the orthopharynx, particles 0.5 to 5pm in diameter, influenced mainly by gravity, are ideal for deposition in the conducting airways, and particles 0.5 to Bern in diameter are desirable for aerosol 10 delivery to the lung periphery. Particles smaller than 0.5pm may be exhaled.

Respirable particles are generally considered to be those with aerodynamic diameters less than 5pm. These particles, particularly those with a diameter of about 3pm, are efficiently deposited in the lower respiratory tract by sedimentation.

It has been recently demonstrated in patients with mild and severe airflow obstruction that the particle size of choice for a,B2 agonist or anticholinergic aerosol should be approximately Burn (Zaanen, P. et al, Int. J. Pharm. (1994) 107, 211-217, Int. J. Pharm. (1995) 114, 111-115, Thorax (1996), 51, 977-980.) Many of the factors relevant to the MMAD of particles are relevant to droplets and the additional factors of rate of solvent evaporation, and surface tension are also important.

In suspension formulations, particle see in principle is controlled during manufacture by 25 the see to which the solid nedicament is reduced, usually by micronisation. However, if the suspended drug has the slightest solubility in propellant, a process known as Ostwald Ripening can lead to particle sme growth. Also, particles may have tendency to aggregate, or adhere to parts of the MDI eg. canister or valve. The effect of Ostwald ripening and particularly of drug deposition may be particularly severe for potent drugs 30 (including fluticasone propionate) which need to be formulated in low doses. Solution fommulations do not suffer from these disadvantages, but suffer from different ones in that particle or droplet see is both a function of rate of evaporation of the propellant from the formulation, and of the time between release of formulation from canister and

the moment of inhalation. Thus, it may be subject to considerable variability and is generally hard to control.

Besides its impact on the therapeutic profile of a drug, the size of aerosol particles has S an important impact on the side effect profile of a drug. For example, it is well known that the orthopharynx deposition of aerosol formulations of steroids can result in side effects such as candidiasis of mouth and throat. Accordingly, throat deposition of such aerosol formulations is generally to be avoided. Furthermore, a higher systemic exposure to the aerosol particles due to deep lung penetration can enhance the 10 undesired systemic effects of certain drugs. For example, the systemic exposure to certain steroids can produce side effects on bone metabolism and growth.

Summary of the invention

Thus, according to the present invention we provide a pharmaceutical aerosol 15 formulation for use in a metered dose inhaler, comprising (i) fluticasone propionate and (ii) a hydrofluoroalkane (HFA) propellant; and characterized in that the fluticasone propionate is completely dissolved in the formulation.

Detailed description of the invention

20 The formulation according to the invention will generally contain a solubilisation agent to aid solubilisation of the fluticasone propionate in the formulation. Suitable solubilisation agents indude propylene glycol and ethanol, preferably ethanol. Other suitable solubilisation agents include ethers (eg dimethyl ether). Alkanes may also be of use.

A further solubilisation agent of interest is dimethoxymethane (methylal) which has good 25 solvency properties. We have also found ethylacetate to be a solubilising agent with good solvency properties.

As a particular aspect of the present invention we provide a pharmaceutical aerosol formulation comprising (i) fluticasone propionate, (ii) a hydrofluoroalkane (HFA) 30 propellant, (iii) a low volatility component to increase the mass median aerodynamic diameter (MMAD) of the aerosol particles on actuation of the inhaler and (iv) a solubDisation agent in sufficient quantity to solubilise the fluticasone propionate in the formulation.

The presence of the low volatility component in the solution formulation increases the fine particle mass (FPM) as defined by the content of stages 5 of an Andersen Cascade Impactor on actuation of the formulation relative to solutions formulations 5 which omit this component. Solution formulations which omit the higher volatil ty component generally give rise to a particle she distribution which have a higher content of finer particles; such distributions generally do not match the distribution of the existing commercialized suspension formulations which contain CFC's and may therefore not be big-equivalent. Examples of HFA propellants indude 1, 1,1,2-tetrafluoroethane (HFA134a) and 1,1,1,2,3,3,3-heptafluoron-propane (ItFA227) and mixtures thereof. The preferred propellant is 1,1, 1,2-tetrafluoroethane (HFA134a) An alternative propellant of interest is 1,J,1,2,3,3,3-heptafluoro-n-propane (HFA227).

The preferred low volatility component is glycerol, propylene glycol or polyethyleneglycol (eg PEG 200 or PEG 400), especially glycerol. Polyethylene glycol is also of particular interest, especially PEG400. Preferably it is present in an amount of 0.5 to 3% (who), especially around 1% (w/w).

The preferred solubilisation agent is ethanol.

More specifically, the present invention can be defined as a pharmaceutical aerosol formulation which comprises: (i) fluticasone propionate; (ii) 1,1,1,2-tetrafluoroethane (HFA 134a); (iii) 0.3% (w/w) glycerol; and (iv) a solubilisaffon agent (particularly ethanol) in sufficient quantity 30 to solubilise the fluticasone propionate in the formulation.

We prefer the formulation to be suitable for delivering a therapeutic amount of fluticasone propionate in one or two actuations. Preferably, the formulation will be

( 6 suitable for delivering 22501lg per actuation, especially 259, 509, 1259 or 2509 per actuation. However, as mentioned in the foregoing, the amount of ethanol required to dissolve high concentrations of fluticasone propionate may tend to depress the vapour pressure of the propellant to an undesirable degree. The vapour pressure 5 should desirably remain above around 50psi. Therefore the formulation is most suitable for delivering 25-125119 per actuation, especially 25-509 per actuation.

The formulation according to the invention will be used in association with a suitable metering valve. We prefer that the formulation is actuated by a metering valve capable 10 of delivering a volume of between 501 and 1001, eg 50111 or G31l1. 1001 is also suitable. When a 501 metering volume is used, the final concentration of fluticasone propionate delivered per actuation would be 0.1% w/v (which equates to 0. 19 of fluticasone propionate per 100ml of formulation) or approx. 0.083% w/w (which equates to 0.0839 of fluticasone propionate per 100g of formulation) for a Song dose, 0.25% 15 (w/v) or approx. 0.21% (wlw) for a 125pg dose, 0.5% (w/v) or approx. 0.42% (w/w) for a 250pg dose and 0.05% (w/v) or approx 0.042% (w/w) for a 25119 dose. VVherein a 631 metering volume is used, the final concentration of fluticasone propionate delivered per actuation would be 0.079 /0 (w/v) or approx. 0.067% (w/w) for a song dose, 0.198% (wet) or approx. 0.167% (w/9v) for a 125119 dose, 0.397% (w/v) or approx. 0.333% (wow) 20 for a 25OIlg dose and 0.04% (w/v) or approx. 0.033% (w/w) for a 259 dose. When a 1001 metering volume is used, the final concentration of fluticasone propionate delivered per actuation would be 0.05% who (which equates to 0.059 of fluticasone propionate per 100ml of formulation) or approx. 0.042% watt (which equates to 0.0429 of fluticasone propionate per 10Og of formulation) for a 50pg dose, 0.125% (w/v) or 25 approx. 0.11 (w/w) for a 1251lg dose, 0. 25% (win) or approx. 0.21% (wow) for a 2509 dose and 0.025 6 (win) or approx 0.021 % (w/w) for a 259 dose. The previously quoted w/w figures are approximate in that they do not compensate in the mismatch in density between HFA134a and ethanol, however the prease figures may be readily detemnined.

30 The formulation is most suitable for concentrations of fluticasone propionate in the range 0.025 to 0.25 % (we), preferably 0.025 to 0.15 % (why), more preferably 0.035 to 0.15 % (we), particularly 0.04 to 0.1 % (w/v). A concentration of 0.025 to 0.04 % (w/v) is also of particular interest. Formulations of the present invention containing

( 7 such low concentrations of fluticasone propionate may have particular physical stability advantages relative to suspension formulations containing the same wherein particles of fluticasone propionate may be susceptible to Ostwald ripening or to chug deposition on the canister wall or on parts of the valve as discussed above. Drug deposition is 5 especially problematic in low strength fluticasone propionate suspension formulations because the amount of drug lost through deposition on internal surfaces of the metered dose inhaler can represent a significant proportion of the total available drug and therefore have a significant effect on dosing uniformity through the life of the product.

The solution formulations of the present invention overcome or substantially mitigate 10 such disadvantages.

Use of a larger metering chamber eg 100111 will generally be preferred.

We prefer the formulation to contain between 0.5 and 2% w/w, more preferably behveen 15 0.8 and 1.6% w/w, particularly between 1.0 and 16% w/w glycerol. Another range of particular interest is 0.5-1% (w/w) glycerol. We especially prefer to use 1.3% (w/w) glycerol. We also especially prefer to use 1.0% w/w glycerol.

Depending on the final concentration of fluticasone propionate in the formulation, the 20 propellant, and the precise amount of low volatility component, the concentration of solubilisabon agent (eg ethanol) required will vary. So as not to suppress the vapour pressure of the propellant to an undesirable extent, the amount of ethanol should preferably not exceed around 35%. The amount of ethanol will more preferably be in the range 5 to 30%, particularly 5 to 20%, more particularly 10 to 20%. A range of 7 to 25 16% whir is also particularly preferred, more particularly 7 to 1 1% w/w.

When the concentration of fluticasone propionate is around 0. 1% wiv and the propellant is 1,1,1,2-tetrafluoroetnane, an amount of ethanol of 124% w/w eg 118% w/w, especially around 16% who is particularly suitable but is more preferably 20-22% w/w 30 especially around 21% w/w. When the concentration of fluticasone propionate is around 0.05% who and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 7-11% who eg 7% who, especially around 7 h wow is particularly suitable but is more preferably 11% vhv especially around 10% wow. When the concentration of

( 8 fluticasone propionate is around 0.079% who and the propellant is 1,1, 1,2 tetrafluoroethane, an amount of ethanol of 15-17% wow especially around 16% is suitable. When the concentration of fluticasone propionate is around 0.198% w/v and the propellant is 1,1,1,2-tetrafluoroethane, an amount of ethanol of 34 36% w/w eg 5 around 35% is suitable. When the concentration of fluticasone propionate is around 0.025% why and the propellant is 1, 1,1,2-tetrafluoroethane, an amount of ethanol of 7 9% wow especially around 8%, more preferably around 7% is suitable.

When the concentration of fluticasone propionate is around 0.025% w/v and the 10 propellant is 1,1,1,2,3,3,3-heptafluoro-n-propane, an amount of ethanol of 13-15% w/w especially around 14% is suitable. When the concentration of fluticasone propionate is around O.Q5% who and the propellant is 1,1,1,2,3,3,3-heptafluorn-propane, an amount of ethanol of 17-19% w/w especially around 18% is suitable 15 When the concentration of fluticasone propionate is around 0.05% w/v and the propellant is 1,1,1,2tetrafluoroethane, an amount of ethylacetate as solubilisation agent of 13-16% whir especially around 15% is suitable. When the concentration of fluticasone propionate is around 0.05% we and the propellant is 1,1,1,2tetrafluoroethane, an amount of dimethoxymethane (methylal) as solubilisation agent of 13-16% w/w 20 especially around 15% is suitable.

The above generally described formulations are particularly preferred in conjunction with 1.0-1.6% w/w glycerol, particularly 1.0% who glycerol or 1.3% w/w glycerol.

25 Formulations according to the invention which are free of surfactants are preferred.

Formulations according to the invention which are free of all exdpients besides the solubilisation agent (eg ethanol), low volatility component (such as glycerol) and the propellant are particularly preferred.

30 Formulations according to the invention will preferably contain fluticasone propionate as the only medicament. However formulations which contain medicaments in addition to fluticasone propionate such as beta adrenergic agonists and anti-cholinergic compounds may also be contemplated.

The pharmaceutical composition according to the present invention may be filled into canisters suitable for delivering pharmaceutical aerosol formulations. Canisters generally comprise a container capable of withstanding the vapour pressure of the HFA 5 propellant, such as plastic or plastic coated glass bottle or preferably a metal can, for example an aluminium can which may optionally be anodised, lacquer coated andlor plasticoated, which container is closed with a metering valve. It may be preferred that canisters be coated with a fluorocarbon polymer as described in WO 96/32151, for example, a co-polymer of polyethersulphone (PES) and polytetrafluoroethylene (PTFE).

10 Another polymer for coffing that may be contemplated is FEP (fluorinated ethylene propylene). The metering valves are designed to deliver a metered amount of the formulation per actuation and incorporate a gasket to prevent leakage of propellant through the valve. The gasket may comprise any suitable elastomeric material such as for example low density polyethylene, chlorobutyl, black and white butadiene 15 acrylonitrile rubbers, butyl rubber and neoprene. Thermoplastic elastomer valves as described in WO92/11190 and valves containing EPDM rubber as described in WO95/02651 are especially suitable. Suitable valves are commercially available from manufacturers well known in the aerosol industry, for example, from Valois, France (eg.

DF10, DF30, DF60), Bespak pie, UK (eg. BK300, BK356, BK357) and 3MNeotechnic 20 Ltd. UK (eg. SpraymiserA). The DF31 valve of Valois, France is also suitable.

Valve seals, espemally the gasket seal, and also the seals around the metering chamber, will preferably be manufactured of a material which is inert to and resists extraction into the contents of the formulation, especially when the contents include 25 ethanol. Valve materials, especially the material of manufacture of the metering chamber, will preferably be manufactured of a material which is inert to and resists distortion by contents of the fommulation, especially when the contents include ethanol. Particularly 30 suitable materials for use in manufacture of the metering chamber include polyesters eg polybutyleneterephthalate (PBT) and acetals, especially PBT.

( 1o Materials of manufacture of the metering chamber and/or the valve stem may desirably be fluorinated, partially fluorinated or impregnated with fluorine containing substances in order to resist drug deposition.

5 Valves which are entirely or substantially composed of metal components (eg Spraymiser, 3M-Neotechnic) are especially preferred for use according to the invention.

Conventional bulk manufacturing methods and machinery well known to those skilled in the art of pharmaceutical aerosol manufacture may be employed for the preparation of 10 large scale batches for the commercial production of filled canisters. Thus, for example, in one bulk manufacturing method a metering valve is crimped onto an aluminium can to form an empty canister. The medicament is added to a charge vessel and a mixture of ethanol, low volatility component and liquefied propellant is pressure filled through the charge vessel Into a manufacturing vessel. An aliquot of the formulation is then filled 15 through the metering valve into the canister. Typically, in batches prepared for pharmaceutical use, each filled canister is check-weighed, coded with a batch number and packed into a tray for storage before release testing.

In an alternative process, an aliquot of the liquified formulation is added to an open 20 canister under conditions which are sufficiently cold that the formulation does not vaporise, and then a metering valve crimped onto the canister.

In an alternative process an aliquot of medicament dissolved in the solubilising agent and any low-volatility component is dispensed into an empty canister, a metering valve 25 is crimped on, and then the propellant is filled into the canister through the valve.

Typically, in batches prepared for pharmaceutical use, each filled canister is check-

weighed, coded with a batch number and packed into a tray for storage before release testing. Each filled canister is conveniently fitted into a suitable channelling device prior to use to form a metered dose inhaler for administration of the medicament into the lungs or nasal cavity of a patient. Suitable channelling devices comprise, for example a valve

( actuator and a cylindrical or cone like passage through which medicament may be delivered from the filled canister via the metering valve to the nose or mouth of a patient eg. a mouthpiece actuator.

5 In a typical arrangement the valve stem is seated in a nozzle block which has an orifice leading to an expansion chamber. The expansion chamber has an exit orifice which extends into the mouthpiece. Actuator (exit) orifice diameters in the range 0. 15 0.45mm particularly Q.2.45mm are generally suitable eg 0.15, 0.22, 0.25, 0.30, 0.33 or 0.42mm. We have hound that it is advantageous to use a small diameter eg 0.25mm or 10 less, particularly 0.22mm since this tends to result in a higher FPM and lower throat deposition 0.15mm is also particularly suitable. The dimensions of the orifice should not be so small that blockage of the jet occurs.

Actuator jet lengths are typically in the range 0.30-1.7mm eg 0.30, 0.65 or 1.50mm.

15 Smaller dimensions are preferred eg 0.65mm or 0.30mm.

Metered dose inhalers are designed to deliver a fixed unit dosage of medicament per actuation or'puff'' for example in the range of 25 to 250 p9 medicament per puff.

20 Administration of medicament may be indicated for the treatment of mild, moderate or severe acute or chronic symptoms or for prophylactic treatment. Treatment may be of asthma, chronic obstructive pulmonary disease (COPD) or other respiratory disorder. It will be appreciated that the precise dose administered will depend upon the age and condition of the patient, the quantity and frequency of administration will ultimately be at 25 the discretion of the attendant physician. Typically, administration may be one or more times, for example from 1 to 8 times per day, giving for example 1,2,3 or 4 pubs each time. The preferred treatment regime is 1 or 2 puffs of 25, 50, 125 or 25O'lg/puff fluticasone propionate, 2 times per day.

30 The filled canisters and metered dose inhalers described herein comprise further aspects of the present invention.

( A still further aspect of the present invention comprises a method of treating respiratory disorders such as, for example, asthma or chronic obstructive pulmonary disease (COPD), which comprises administration by inhalation of an effective amount of a formulation herein before described.

A further aspect of the present invention comprises the use of a formulation herein before described in the manufacture of a medicament for the treatment of respiratory disorders, eg. asthma or chronic obstructive pulmonary disease (COPE,).

10 As mentioned above the advantages of the invention include the fact that formulations according to the invention may be more environmentally friendly, more stable, less susceptible to Oswald ripening or drug deposition onto internal surfaces of a metered dose inhaler, have better dosing uniformity, deliver a higher FPM, give lower throat deposition, be more easily or economically manufactured, or may be otherwise 15 beneficial relative to known formulations.

The invention is illustrated with reference to the following examples: Example 1 and 2 Formulations may be prepared with compositions as follows: 20 Fluticasone propionate: 0.1% who 0.05% w/v Ethanol: 16% whir 7% Glycerol: 1.3% wow 1.3% 1, 1,1,2-tetrafluoroethane: to 100% to 100% 25 These solution formulations may be filled into an aluminium canister under pressure and fitted with a metering valve having a 50 pI metering chamber.

These formulations are suitable for delivering 50 119 or 25 log fluticasone propionate per actuation respectively.

30 Example 3

Formulations were prepared with compositions as follows: Form. 3a Form. 3b Form. 3c Fluticasone propionate: 0.1% we 0.079% w/v 0.05% w/v

( Ethanol: 21% who 16% w/w 10% Glycerol: 1.0% w/w 1.0 6 whir 1.0% 1,1,1,2tetrafluoroethane: to 100% to 100 h to 100% S These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chambers of volume 50 pI, 63 Al and 100 A respectively. These formulations are suitable for delivering 50 p9 fluticasone propionate per 1 0 actuation.

Example 4

Formulations were prepared with compositions as follows: Form 4a Form. 4b Form. 4c 1 Fluticasone propionate: 0.1% w/v 0.079% w/v 0.05% w/v Ethanol: 21% w/w 16% w/w 10% 1,1,1,2-tetrafluoroethane: to 100% to 100% to 100% These solution formulations were filled into aluminium canisters (120 20 actuations/canister, overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chambers of volume 50 PI, 63 pi and 100,ul respectively. These formulations are suitable for delivering 50 fug fluticasone propionate per actuation. Example 5

A formulation was prepared with compositions as follows; Pluticasone propionate: 0.198% w/v Ethanol: 35% w/w 30 Glycerol: 1.0% who 1,1,1,2tetrafluoroethane: to 100%

( 14 This solution formulation was filled into an aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 63 A. This formulation is suitable for delivering 125 Ho Fluticasone propionate per actuation.

Example 6

A formulation was prepared with compositions as follows: Fluticasone propionate: 0.198% we Ethanol: 35% w/w to 1,1,1,2-tetrafluoroethane: to 100% This solution formulation was filled into an aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 63 PI.

15 This formulation is suitable for delivering 125 119 fluticasone propionate per actuation.

Example 7

Formulations were prepared with compositions as follows: Form. 7a Form. 7b Form. 7c 20 Fluticasone propionate: 0.05% wiv 0.05% wiv 0.05% w/v Ethanol: 10% w/w 10% w/w 10% w/w Glycerol: 0.5% watt 2% who 3% w/w 1,1,1, 2-tetrafluoroethane: to 100% to 100% to 100% 25 These solution formulations were filled into aluminium canisters (120 actuations/canister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 100 pi.

These formulations are suitable for delivering 50 '9 fluticasone propionate per actuation. Example 8 Formulations were prepared with compositions as follows: Fluticasone

propionate: 0.025% who 0.025% w/v

( 15 Ethanol; 8% wall 7% w/w Glycerol: 1.0% war 1.0% whip 1,1,1,2tetrafluoroethane: to 100% to 100% 5 These solution formulations were filled into an aluminium canisters (120 actuationslcanister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 100 Hi.

These formulations are suitable for delivering 25 ilg Fluticasone propionate per actuation. Example 9

Formulations were prepared with compositions as follows: Formulation 9a: Fluticasone propionate: 0.05% w/v 15 Dimethoxymethane: 15%w/w 1,1,1,2tetrafluoroethane: to 100% Formulation 9b: Fluticasone propionate: 0.05% w/v Ethylacetate: 15% w/w 20 1, 1,1,2-tetrafluoroethane: to 100% Formulation 9c: Fluticasone propionate: 0.05% who Dimethoxyrnethane: 15% w/w Glycerol: 1% who 25 1,1,1,2-tetrafluoroethane: to 100 K Formulation 9d: Fluticasone propionate: 0 05% why Ethylacetate: 15% w/w Glycerol: 1% w/w 30 1,1,1,2-tetrafluoroethane: to 100%

( 16

These solution formulations were filled into aluminium canisters (120 actuationscanister; overage of 40 actuations) under pressure and fitted with a metering valve (Valois DF60) having metering chamber of volume 100 pi.

These formulations are suitable for delivering 50 119 Fluticasone propionate per 5 actuation. Example 10

Formulations were prepared with compositions as follows: Formulation 10a: 10 Fluticasone propionate: 0.05% why Ethanol: 10% w/w Glycerol: 1% who 1, 1,1,2-tetrafluoroethane: to 100% Formulation 10b: 15 Fluticasone propionate: 0.05% w/v Ethanol: 10% w/w PEG 200: 1% w/iv 1, 1,1,2tetrafluoroethane: to 100% Formulation 10c: 20 Fluticasone propionate: 0. 05% w/v Ethanol: 10% whip PEG 400: 1% whir 1,1,1,2-tetrafluoroethane: to 100% Formulation 10d: 25 Fluticasone propionate: 0.05% w/v Ethanol: 10% w/w Propylene glycol: 1% whir 1,1,1,2-tetrafluoroethane: to 100% Formulation 10e: 30 Fluticasone propionate: 0.05% w/v Ethanol: 18% w/w 1, 1,1,2,3,3,3 heptafluoro-n-propane: to 100% Formulation 10f:

Fluticasone propionate: 0.05% why Ethanol: 18% wAv Glycerol: 1% w/w 1,1,1, 2,3,3,3-heptafluoro-n-propane: to 100% 5 Formulation 1 Og: Fluticasone propionate: 0.025% why Ethanol: 14% w/w 1,1,1,2,3,3,3-heptafluoro-npropane: to 100% Formulation 10h: 10 Fluticasone propionate: 0.025% w/v Ethanol: 14% wJ\v Glycerol: 1 % wAv 1,1,1,2,3,3,3-heptafluoro-n-propane: to 100% Formulation 10i: 15 Fluticasone propionate: 0.025% w/v Ethanol: 7% w/w 1,1,1,2-tetrafluoroethane: to 100% Formulation 10j: Fluticasone propionate: 0.025% w/v 20 Ethanol: 7%whu Glycerol: 1 % who 1,1,1,2tetrafluoroethane: to 100% 25 These.solut;ion formulations were filled into aluminium canisters (120 actuations/canister, overage of 40 actuations) under pressure and fitted with a metering valve Lois DF60) having metering chamber of volume 63 pi.

These formulations are suitable for delivering 31.5 p9 (10a-10e) or 15.75 p9 (10f,10g) fluticasone propionate per actuation. However the performance of these formulations is 30 a model for formulations that would deliver SO 9 and 25 p9 Fluticasone propionate using a metering valve of 100 pi.

Andersen Cascade Impaction Data

Formulations as described in Examples 3, 4, 5 and 6 were profiled using an Andersen Cascade Impactor, using a 0.22mm (orifice) x 0.6Smm (jet length) actuator from Bespak (BK621 variant). Testing was performed on canisters at Beginning of use" (BoU) and 5 delivered drug from 10 actuations was collected in the instrument after 4 priming actuations were fired to waste. Results are shown in Tables 1-4 and Figures 14 and 11. For comparison, data from a Flixotide Evohaler (trademark) (particulate fluticasone propionate suspensed in HFA134a (excipient free) 50 119 per actuation) product is also shown in some figures.

The 0.079% w/v fluticasone propionate products of Examples 3 and 4 (50 lug per actuation; 63111 metering chamber) were profiled using an Andersen Cascade Impactor in a study to see the effect of actuator orifice diameter and length.

15 Three actuators were used: 0.50mm diameter orifice x 1.50mm jet length 0.33mm diameter orifice x 1.50mm jet length 0.22mm diameter orifice x 0. 65mm jet length 20 Results are shown in Table 5 and Figures to 9. For comparison, data from a Flixotide Evaha!er (trademark) (particulate fluticasone propionate suspensed in HFA134a (excipient flee) 50,ug per actuation) product is also shown in some figures.

The results show the best performance (as indicated by highest FPM) in products 25 containing a relatively low concentration of ethanol (say around 10%) and containing glycerol (say around 1 %). A small actuator orifice diameter (say around 0.22mm) is also seen to be preferred.

The solubility of fluticasone propionate in ethanol in the presence of HFA134a is shown 30 in Figure 10 A study was performed on the 0.05% who fluticasone propionate formulations (HFA134al10% ethanol) of Examples 3 (Formulation 3c), 4 (Formulation 4c) and 7

(Formulaffons 7a, 7b and 7c) with a O.Zmm x 0.65mm actuator using an Andersen Cascade Impactor to consider the effect of glycerol content on the following properties: (i) MMAD, (ii) throat deposition, and (iii) stage 3-7 deposition. The results are shown in figures 12-14. For maximum deposition in the desired region without excessive throat 5 deposition the optimal glycerol concentration appears to be around 0.8-1.6 % who, particularly 1.1.6 % w/w.

A study was performed using an Andersen Cascade Impactor to compare the properties of formulations containing different solubilising agents. An actuator of dimensions 10 0 22mm x0.65 mm was used for the study. The results of the analysis of the formulations of Example 9 Formulations 9a, 9b, 9c and 9d and a comparison with the formulations of Example 3 Formulation 3c and Example 4 Formulation 4c are shown in Table 6 and Figure 15. The ethanol with glycerol profile clearly appears the most attractive since it demonstrates the highest FPM content in view of the high dosing in 15 stages 4 and 4 relative to the other profiles. Nevertheless the methylal profiles also looked of significant interest in view of the very low throat deposition. The addition of 1% glycerol shifted the methylal profile to lower stages only to a small extent, perhaps in view of its greater volatility than ethanol. A higher percentage of glycerol would be expected to increase the magnitude of the shift.

A study was performed using an Anderson Cascade Impactor to compare the properties of formulations containing different low volatility components. An actuator of dimensions 0.22mm x0.65 mm was used for the study. The results of the analysis of the formulations of Example 10 Formulations 10a to 10d are shown in Table 7 and 25 Figure 16. Particularly good profiles are shown by glycerol and PEG400 which demonstrate relatively low throat deposition and high dosing in stages 4 and 5.

A study was performed using an Andersen Cascade Impactor to study the properties of 0.0S% fluticasone propionate formulations containing 1,1,1, 2,3,3,3-heptafluoro-n 30 propane (HFA227) as propellant. An actuator of dimensions O.22mm x0.65 mm was used for the sbudy. The results of the analysis of the formulations of Example 10 Formulations 10e and 10f are shown ir; Table 8 and Figure 17. Comparison with the HFA134a aerosol formulation of Formulation 10a is shown.

( A study was performed using an Andersen Cascade Impactor to study the properties of 0.025% fluticasone propionate formulations containing 1, 1, 1,2-tetrafluoroethane (HFA134a) or 1,1,1,2,3,3,3-heptafluoro-n-propane (HFA227) as propellant. An actuator 5 of dimensions 0.22mm x0.65 mm was used for the study. The results of the analysis of the formulations of Example 10 Formulations 1Og to 10j are shown in Table 9 and Figures 18 and 19. The HFA134a product with ethanol shows a particularly attractive profile eg as shown by a high total delivered dose and a relatively low throat deposition.

Brief descnpffon of the drawings: Table 1: Effect of valve on FPM in fluticasone propionate HFA134a solution aerosols (50pg/actuation) Table 2: Effect of different levels of ethanol on FPM in fluticasone propionate/HFA1 34a 15 solution aerosols Table 3: Effect of different levels of ethanol on FPM in fluticasone propionate/HFA1 34a solution aerosols (valve see effect ignored) Table 4: Cascade impaction analysis of fluticasone propionate/HFA1 34a solution aerosols (125pg/actuation) containing 35% ethanol or 35% ethanol and 1% glycerol 20 Table 5: Cascade impaction analysis of fluticasone propionate/HFA1 34a solution aerosols (50pg/actuation) containing 16% ethanol or 16 h ethanol and 1% glycerol Table 6: Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (SO'lglactuation) containing various solubiling agents with and without 1% glycerol 25 Table 7: Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (50,g/actuation) containing various low volatility components Table 8: Cascade impaction analysis of fluticasone propionate solution aerosols (SOIlg/actuation) containing various propellants Table 9: Cascade impaction analysis of fluticasone propionate solution aerosols 30 (25pg/actuation) containing various propellants Figure 1: Effect of valve see and glycerol on FPM in fluticasone propionate solution aerosols in HFA134a (50pg/actuation)

Figure 2: Effect of level of ethanol on FPM in various fluticasone propionate/HFA1 34a solution aerosols with no addition of glycerol Figure 3: Effect of level of ethanol on FPM in various fluticasone propionate/HFA134a solution aerosols with addition of 1 glycerol 5 Figure 4: Effect of glycerol on FPM in fluticasone propionate 1259 /HFA134a solution aerosols containing 35% ethanol or 35% ethanol and 1% glycerol Figure 5: Effect of actuator dimensions on FPM and throat in fluticasone propionate/HFA134a solution aerosols (50pg/actuation) containing 16% ethanol Figure 6: Effect of actuator dimensions on FPM and throat in fluticasone 10 propionate/HFA134a solution aerosols (50pg/actuation) containing 16% ethanol and 1% ethanol Figure 7: The effect of addition of glycerol on FPM in fluticasone propionate 50pg/ltFA134a solution aerosols containing 16% ethanol or 16% ethanol and 1% glycerol (0.22mm diameter actuator orifice) 1 5 Figure 8: The effect of addition of glycerol on FPM in fluticasone propionate 50pg/HFA134a solution aerosols containing 16% ethanol or 16% ethanol and 1% glycerol (0.33mm diameter actuator orifice) Figure 9: Effects of addition of glycerol and actuator dimensions on FPM in fluticasone propionate 50pg/HFA134a solution aerosols containing 16% ethanol or 16% ethanol 20 and 1% glycerol (all actuator variants) Figure 1 0: Solubility of fluticasone propionate in ethanoUHFA1 34a.

figure 1 1: Effects of addition of glycerol and actuator dimensions on FPM in fluticasone propionate 50pg/HFA1 34a solution aerosols containing 1 0% ethanol or 1 0% ethanol and 1% glycerol 25 Figure 12: Effects of addition of glycerol on MMAD in fluticasone propionate 50pg/HFA134a solution aerosols containing 10% ethanol Figure, 13: Effects of addition of glycerol on throat deposition in fluticasone propionate 50pg/HFA134a solution aerosols containing 10 h ethanol Figure 14: Effects of addition of glycerol on stage 7 deposition in fluticasone 30 propionate 5O'lg/HFA134a solution aerosols containing 10% ethanol Figure 1 5: Cascade impaction analysis of fludicasone propionate/HFA1 34a solution aerosols (50pg/actuation) containing ethanol, methylal or ethylacetate as solubilising agent, wig and without 1% glycerol

1 22

Figure 16: Cascade impaction analysis of fluticasone propionate/HFA134a solution aerosols (SOg/actuaffon) containing various bw volatility components and 10% ethanol Figure 17: Cascade impaction analysis of fluticasone propionatetHFA227 solution aerosols (song actuation) containing 18% ethanol with and without 1% glycerol and 5 comparison with HFA134a aerosol Figure 18: Cascade impaction analysis of fluticasone propionate in HFA227 or HFA134a solution aerosols (25pg actuation) containing ethanol Figure 19: Cascade impaction analysis of fluticasone propionate in HFA227 or HFA134a solution aerosols (251lg actuation) containing ethanol and 1% glycerol Throughout the specification and the claims which follow, unless the context requires

otherwise, the word 'comprise', and variations such as 'comprises' and comprising', will be understood to imply the inclusion of a stated integer or step or group of integers but not to the exclusion of any other integer or step or group of integers or steps.

Above mentioned patents and patent applications are hereinbefore incorporated by reference Abbreviations 20 FPM fine particle mass FP fluticasone propionate mic metering chamber BoU beginning of use PEG polyethyteneglycol 25 Form. Formulation MMAD mass median aerodynamic diameter

_ _ _ _ _ CD a, _ cot lo O rat 0. u'm-o-ma,_-o'o -= m _ _ o _ o _ (D (D 00 CD r_ E 3 us o o cat us u, _ o o U=, o o r u, _ _ _ _ _ u a1 (77 CD O r O -

o 3 ' o o r, in.- o to r a, 4) _ _ _ _ _ ii 0 r _ iD u c" o 3 u, t9 o _, oo - o 4 o c 3 o cn 0 _ C U,

_ _ _ _ _ {q 03 C O O CO -CD C O 3 u o o o.- r u oo to u.

o _ I O O c cq 4- _ _ _ _ c (D n oo r,o to c"L U, O O O O C (D CO (D u gx 3 o _ P _ V, 5 to 5 o 0 _ _ _ _ c a (D U r u 0 a E 3 u, i o o o o ai tn i un _ c C E c o _ _ o" c 0 0,o UJ _ _ U,.

0 _ _ _ _ _ uor ≥,o _ 'U>++ _ 0- x ' E 0.u O u c, c,, _ _.

Cot _ _ _ _ _ up - 0 0 to. cs, o, a, 0 0 0 cc' V Ed ID up - - Cut - - O 1_ on' o 3:=.

o o _ _ _ _ _ _ _ (D 0 rut 0 [D cat O I- rat o 0 3 a: co tD _ _ co c u,,, _ o _ tD _ , s O c E _ 3 _ _ _ i,D o Oo aO, cn CD a -o tn o _ o s &m _ _ _ 0 > _ _ _ _ 0 u' -' O -' U) ' ' - o a, U o 3 _, __ oco-m ._ s o E=CF _.

5,_ C +

'3 CJ O O _ >

t" G E o u e O =- -

2S _ _ _ _ _ o l In o' 0 r a l -. - t9 a e 0 0 t9 I O O

_ _ _ _ _ {D - O O a, cn a' 0 0 0 co 3 o i In _ _ _ _ _ o 1 n - O _ _ _ _ i L0 (D CD i (D. o, {D iD 3 O to l - - f- O O - o cna tn o, 3 _ U' 0m _ _ _ _ CD O. r CD -..+ O. r O CO CD (D - - U. c _ O - CD -

o 3 _ _ o cn c s = c o: _ _ _ _ 0 - m o 3 _ a, o _ o tD ci _ o o o.3 _ o O t O CS O CD U) O O U, Cn O, a:, _ 1- 4 U 3i tD o o o tD OO r r 3 _

o o eo a, {D (D CD _ U' O. - - r,o tom 3o a o o o 4 er _ Lt g r 4-

_ c 3_ E i" Q O O v rl n mC _ _ _ 0 0 0 0 +. U) . . g n a, v, 3 _ I o _ U7 O X _ _ _ _ CD r c co 0 c r a O {C' O O C" O O O - CO (D O CO O 0, 0

o 3 o_ o,x c E - .

o s U' t =3 c u> ++ o o tf 7 + + 0 4- o v' u - x m iI 1;! C o v O o ( c o q:

_ _ (00 '0o Dn O | u 1 = w - O u, 0 0 Us O a, -

u <5 L,. to =,. =' id l Llil. =. o I V1: - O _ up cad Lf3 Ad- - {he red red -

o, Is 0 c 0 r; cci u, hi r O cc' Ad | E lu E O C r 0 n u u n t; it E 33 3 an 0 u aS

_ g, _ _ _ o _ - 3 u, E. 5 oE C _ _ _ _ _ _ _ o a) a, {q {D O U) 0 o o _. o m _ E. --- i u, u, o. +. a, tD --o. o r) o mE r e o o r " _ o o a, IL C; E tD c; o c o-r o. r, c o E _ q. _ _ o _ _ _ _

- O O -' Q O- =. o -. O. 2 O _ _ t U t n U) o u r 00.0 u o E i̳ - o o - o o o i a, c 0 = o tL _ _ r 0 r r CD O O CD U) U, O O (D Ll o E D _ 0 0 - 0 0 co co u) c $ o 0 tD C {, (.D Ln I_ O O r 4 _ i O O O O CD (D O4 ' ,0 _ r _ r i a, 0 0 r _ 0 q u 0 0 0 0 o to - v _ C '' r 1 - O O {D O O Ui C O O O O {D tD (D r {D t' [,L _ _ _ _ U) _ _ Q m _ _ U) O 0 i _ t - O O O O r) C" tl, 01 "> 0 0 - _ a u O {D ID-O O._ , 8 _ o o o o o 0 "u 0 Q 2

r - o. - - - -i, (D. _ _ 0 0 C 8 _ o o o o i 0 o E _ ci u _ _ _ 0 o o o _ r {D i i _ 0 0 0 0 - _ _ _ u L O _ E r4 _ _ _ 0 tD 0 0 0 _ 0i - 0 0 0 0 _ _ _ i 0 d -n O Qu -_E c i. o. _ aq u a r 0 0 0 3 - c - - O en e 4J- Ul C E. O X.> o o (D Ou d U D _ tVIVl e 0 E J 2 2,.E v o. t:n 6, t IE' E

( _ _ _ _ _ t O O CO - 0 1- 10 N {O o U. CO C ' O N _ _ _ <) N N) N N a w) 0 Ct) o o O _ N O O O O {D CO N N 1

=, 01 W oC, O O _ 0- iD 00 tL m O. _ a, _ _ _ _ _ (D (D a) 1- 0 N N N O O O O - - N O N

C, O W

4) 0 _ ze u, IJ) _ _ _ O) N lo 1O 0 0, 0 O 1-

O fD O) O O - O - 1 t CV) N 0 o 8 m Q w o u ' _ ae g O r m O U) D O _ _ _ _ _ c c o a: h tD O o 0 _ toE tD<Dmooom Nlt70)- 3 rlD _ x _ 8 c 0= at E _ e.

IL _ _ _ 0 5) tD a, 0 0 0 N er W 0 O W O O O - tD t0 0 3 o,:n 1; 0, c ID 'oo w E c 0 0 m 0. u, <D 0 E-o o' $cto o3 0 0 a 3 o, J9 J? 3 0 0- O

_ _ _ _ _ _ lD r r iD i 0 <D a _O_O-O:;j" _ 2 0.

n O O O Z _ _ _ O o U' r a, O O N N -

, 2 O _ _ 0

m o F _ = _ _ _ _

-, - t O 0 N 1_ 0 0 0 1_ 0 0 CD - O - i tD _ N _ O N 0 t') O 8 O O G 1L E z _ o Ll O al N ID 0 tl O O O Ul i T O Oo O N ID O O O N U {D _ _ O - U t > D _ _ 8]J

3 o e o 0 a o _ _ _ 1'- 0 0 O 0 Y1 0 h_ N _ al 0 CO 0 _ 0 _ l 0 N _ O C0 _ J2 O O1 O

E _ - o o e _ K III _ _ -tO O a) l 0 N O E 0 8 _ N O O O 0 N N -

c' O r _ c' & 0) ul =e :' LL m $o _ O _ _ _ _ _ io D _ io oa' r- 0 o r o. _ o.:- 8 3 _ _ o_ _ _ C=' o C 2 Z o _ _ _ r7 r, - 'fD-0 O, r U _ O 3 N 1- 0 0 0 0 r 0 _ _ 0 N _ O O _ n O _ G _ 0. O

o _ ii ae o0 _ C n O 0 O O O _

g t a 0 e 0 _ N tl t 0 0 2 O O O O - - - - 11

u,:: 15 0 a, lu' di;

( - - - - - - - - - - -

8 N 0 - O 0 0 Oi. O O to _ r nail oE O - _ _ _ i-u rut 0 us us fir co Al O^ _ _ A) O O U) _ O O U)

I 0 8 m w at _ _ _ _ _ 0 (D O U' 0 o _ 2, O _ con O _ O O _ 0 =- 0

m cn x z He n _ _ _ r a r 0 N 0 O O O O O

CO C 0 o o, t O cn t; 0 8 o== lo o, o L m o _ _ m 0 a) C m tv) CD 0 CO N 03 CD 0 O t' O N 0 O O O O Oi _ O U) O O =.

8 a w O Z. g --_ o C,4 N O ' t N _ > e, O 0 O' J N O O O O 0 N N N ^O IL C

C O. O IL m. 0 4,o _ _ _ _ _ u,, a < F "w l, _ -N m m a) U) 3 80 0 W C W" 0 WO O ''

C-) _ > J) a co a o u cn u.

( _ _ _ _ _ _ 10 0 O -10

a _ _ O O N _ ]0 O __

_ _ _ = - - - ", -

N O _ _ O O _ _ _ O O O 0 N t = o 3 8 E Z N N N N 0 0 N (D - U] 0

o, -T -,-----or,rq_ U' G o _ _ o o o o _ N. o N N _ _ _ _ _ r_ o N) U'l _ O U].

0 = _ N O O O. t0 N - O a} N 5 eE z e O u 5 O O _ _ O O O _ N _ O O 0 N _ _ _ 0

C. _ _ _ _ _ _ _ r4 0 0 0 ID O-.

c a N N O O O O O _ 0 U) E. E, E

o _ _. - O O O O O - N _ 0 0.

a 0 ' c E u o; ' '.

u e ' E i .' ;7i 0

Claims (1)

1. What is claimed is:

   1. A metered dose inhaler which comprises a canister fitted with a metering 5 valve which contains a pharmaceutical solution aerosol formulation which comprises: (i) fluticasone propionate and (ii) a hydrofluoroalkane (HFA) propellant, characterized in that the fluticasone propionate is completely dissolved in the formulation; wherein the canister is fitted into a channelling device which 10 comprises a mouthpiece actuator having an actuator exit orifice of diameter 0.25mm or less.

   2. A metered dose inhaler according to claim 1 wherein the formulation comprises: (i) fluticasone propionate; 15 (ii) a hydrofluoroalkane (HFA) propellant; (iii) a low volatility component to increase the mass median aerodynamic diameter (MMAD) of the aerosol particles on actuation of the inhaler; and (iv) a solubilisation agent in sufficient quantity to solubilise the ZO fluticasone propionate in the formulation.

   3. A metered dose inhaler according to claim 1 or claim 2 wherein the hydrofluoroalkane (HFA) propellant is 1,1,1,2-tetrafluoroethane (HFA134a).

   4. A metered dose inhaler according to any one of claims 1 to 3 wherein the formulation contains a low volatility component which is glycerol, propylene 25 glycol or polyethylene glycol.

   5. A metered dose inhaler according to claim 4 wherein the formulation contains a low volatility component which is polyethylene glycoi.

   6. A metered dose inhaler according to claim 4 wherein the formulation contains a low volatility component which is glycerol.

   30 7. A metered dose inhaler according to any one of claims 4 to 6 wherein the low volatility component is present in the formulation at a concentration of 0.5 to 3% wow.

   8. A metered dose inhaler according to claim 1 wherein the formulation comprises: (i) fluticasone propionate; (ii) 1,1,1,2-tetrafluoroethane (HFA 134a); 5 (iii) 0.5-3% (w/w)glycerol; and (iv) a solubilisation agent in sufficient quantity to solubilise the fluticasone propionate in the fommuiation.

   9. A metered dose inhaler according to claim 6 wherein the formulation contains between 0.8 and 1.6% (w/w) glycerol.

   10 10. A metered dose inhaler according to claim 9 wherein the formulation contains between 1.0 and 1.6% (w/w) glycerol.

   11. A metered dose inhaler according to claim 10 wherein the formulation contains 1.3% (w/w) glycerol.

   12. A metered dose inhaler according to claim 10 wherein the formulation 15 contains 1.0% (w/w) glycerol.

   13. A metered dose inhaler according to any one of claims 1 to 12 wherein the concentration of fluticasone propionate in the formulation is 0.025 to 0.15% wlv. 14. A metered dose inhaler according to claim 13 wherein the concentration of 20 fluticasone propionate in the formulation is 0. 035 to 0.15% w/v.

   15. A metered dose inhaler according to claim 14 wherein the concentration of fluticasone propionate in the fommulation is 0.04 to 0. 1% w/v.

   16. A metered dose inhaler according to claim 13 wherein the concentration of fluticasone propionate in the fomnulation is 0.025 to 0. 04% w/v.

   25 17. A metered dose inhaler according to any one of claims 1 to 16 wherein a solubilisation agent is present in the formulation which is ethanol or propylene glycol. 18. A metered dose inhaler according to any one of claims 1 to 16 wherein a solubilisation agent is present in the formulation which is an alkane or ether.

   30 1 g. A metered dose inhaler according to any one of claims 1 to 16 wherein a solubilisation agent is present in the formulation which is dimethoxymethane.

   20. A metered dose inhaler according to any one of claims 1 to 16 wherein a solubllisation agent is present in the formulation which is ethylacetate.

   21. A metered dose inhaler according to claim 17 wherein a solubilisation agent is present in the formulation which is ethanol.

   22. A metered dose inhaler according to claim 21 wherein the concentration of 5 ethanol in the formulation is 5 to 30% w/w.

   23. A metered dose inhaler according to claim 22 wherein the concentration of ethanol in the formulation is 10 to 20% w/w.

   24. A metered dose inhaler according to claim 22 wherein the concentration of ethanol in the formulation is 7 to 16% w/w.

   10 25. A metered dose inhaler according to claim 22 wherein the concentration of ethanol in the formulation is 7 to 11 % w/w.

   26. A metered dose inhaler according to claim 22 wherein the concentration of ethanol in the formulation is 7 to 8% w/w.

   27. A metered dose inhaler according to claim 19 wherein the concentration of 15 solubilisation agent in the formulation is 14 to 16% w/w.

   28. A metered dose inhaler according to any one of claims 1 to 27 comprising as canister an aluminium can which is anodised, lacquer-coated andlor plastic coated. 29. A metered dose inhaler according to claim 28 wherein the canister is coated 20 with a fluorocarbon polymer.

   30. A metered dose inhaler according to any one of claims 1 to 29 wherein the canister is fitted with a metering valve of metering volume 100 PI.

   31. A metered dose inhaler according to any one of claims 1 to 30 wherein the channelling device comprises a mouthpiece actuator having an actuator 25 orifice of diameter 0.15-0.22mm.

   32. Use of a metered dose inhaler according to any one of claims 1 to 31 in the manufacture of a medicament for the treatment of respiratory disorders by inhalation therapy.