CA2125665C

CA2125665C - Medicaments

Info

Publication number: CA2125665C
Application number: CA002125665A
Authority: CA
Inventors: Rachel Ann Akehurst; Anthony James Taylor; David Andrew Wyatt
Original assignee: Glaxo Group Ltd
Current assignee: Glaxo Group Ltd
Priority date: 1991-12-12
Filing date: 1992-12-04
Publication date: 2001-06-12
Anticipated expiration: 2012-12-04
Also published as: DE69205177T2; ES2079210T3; TW229159B; CY2008A; EP0616525B1; DE69205177D1; AU663906B2; DK0616525T3; WO1993011745A1; CA2125665A1; AU3085292A; US5817293A; EP0616525A1; HK79097A; GR3018168T3; AU663906C; JP3280974B2; MX9207200A; NZ246046A; JPH07501811A

Abstract

This invention relates to aerosol formulations of use for the administration of medicaments by inhalation, in particular a pharmaceutical aerosol formulation which comprises particulate medicament, a fluorocarbon or hydrogen-containing chloroflu-orocarbon propellant and up to 5 % w/w based upon propellant of a polar cosolvent, which formulation is substantially free of surfactant. A method of treating respiratory disorders which comprises administration by inhalation of an effective amount of a pharmaceutical aerosol formulation as defined is also described.

Description

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MEDI~'AMEh1'1'S
This invention relates to aerosol formulations of use for the administration of medicaments by inhalation.
'fhe use of aerosols'to administer medicaments has been known for several decades.
Such aerosols generally comprise the medicament, one or more chlorofluorocarbon propellants and either a surfactant or a solvent, such as ethanol. The most commonly used aerosol propellants for medicaments have been propellant 11 (CC1,F) and/or propellant 114 (CF.~C1CF,C1) with propellant 12 (CCI.,F~). However these propellants are naw believed to provoke'the degradation of stratospheric ozone and there~is thus a need to provide aerosol formulations for medicamentsc which employ so called "ozonetfriendly"
propellants.
A class of propellants which are believed. to have minimal ozone-depleting effects in comparison to conventional chlorofluorocarbons comprise. fluorocarbons and hydrogen-containing chlorofluorocarbons, and a number of medicinal aerosol formulations using such propellant systems are disclosed in, for example, EP
0372777, W091/04011, WrJ91/1 l 173, WC191/11495 and .W~91/14422. ~'hese applications are all concerned with the preparation of pressurised aerosols for the administration of medic~.ments and seek to overconne the problems associatedwwith the rise of the new class of pr~pellants; in particular the problems of stability associated with the pharmaceutical formulations prepared. The applications all propose the addition ol' ore orv snore of adjuvants such as alcohols, alk~nes, dimetlzyl ether; surfactants (including fluorinated and non-fluorinated surfactants, carboxylic acids, polyethoxylates etc) end even conventional chlorofluorocarbon propellants in small amounts intended to minimise potehtial ozone damage.
Thus, for example ~P 037277:7 rewires the- use of l, l',1,2-tetralluoroethane in combination with both a cosolvent h~vib~ ~re~tes polarity than 1,1,1,2-tetrafluorosthane (e.g. an alcohol or a lmwer alk~ne) and a surfactant in order to achieve a si:able formulation of x medicament powders In particular it: is noted in the specification at pale i. ~;,.
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~~ ~~/a i~~s ecrm~ziozmo 3, line 7 that "it has been found that the use of propellant 134a ( 1,1,1,2-tetrafluoroethane) and drug as a binary mixture or in combination with a conventional surfactant such as sorbitan trioleate does not provide formulations having suitable properties for use with pressurised inhalers". Surfactants are generally recognised by those skilled in the art to be essential components of aerosol formulations, required not only to reduce aggregation of the medicament but also to lubricate the valve employed, thereby ensuring consistent reproducibility of valde actuation and accuracy of dose dispensed. Whilst W091/11173, W091/11495 and WU91/14422 are concerned .with formulations comprising an admixture of drug. and surfactant, W091/04011 discloses medicinal aerosol formulations in which the particulate medicaments are pre-coated with surfactant prior to dispersal in 1,1,1,2-tetrafluoroethane.
We have now surprisingly found that, in contradistinction to these teachings, it is in fact possible to obtain satisfactory dispersions of medicaments in fluorocarbon or hydrogen-containing chlorofluorocarbon propellants such as 1,1,1,2-tetrafluoroethane without recourse to the use of any surfactant in the composition, or the necessity to pre-treat the medicament prior to dispersal in the propellant.
There is thus provided in one aspect of the invention a pharmaceutical aerosol formulation which comprises particulate medicament, a fluorocarbon ~ or hydrogen-containing chlorofluorocarbon propellant and up to 5% w/w based upon ~ propellant of a polar cosolvent, wtxich formulation is substantially free of surfactant. By ' "substantially free of surfactant" is msant~ formulations which contain no significant amounts of surfactant, for example less than 0.0001% by weight of the medicament. .
The particle size of the particulate (e.g. nnicronised) medicament should be such as to permit inhalation of substantially all of the medicament intovthe lungs upon administration of the aerosol formulation and will this be less than 100 microhs, desirably less than 20 microns, and preferably in the range 1 ~ 10 microns; e.g. 1-5 microns. .
Medicaments which may ~e administered in aerosol formulations according to the invention include any drug useful in inhalation therapy which may be presented in a form which is substantially completely insoluble in the selected propellant.
appropriate medicaments may thus be selected from, for example, ~ analgesics, e.g:
codeine, ~V~~ t.~:~l l 1'~~ih ~'~T/twP~~/02$1() ~1~~~~a dihydromorphine, ergotamine, fentanyl or morphine; anginal preparations, e.g.
diltiazem;
antiallergics, e.g. cromoglycate, ketotifen or nedocromil; anti-infectives, e.
g.
cephalosporins, penicillins, streptomycin, sulphonamides, tetracycfines and pentamidine;
antihistamines, e.g. methapyrilene; anti-inflammatories, e.g. beciomethasone, ~lunisolide, S budesonide, tipredane, triamcinolone acetonide or fluticasone; antitussives, e.g.
noscapine; bronchodilators, e.g. ephedrine, adrenaline, fenoterol, formoterol, isoprenaline, metaproterenol, phenylephrine, phenylpropanolamine, pirbuterol, reproterol, rimiterol, salbutamol, salmeterol, terbutaline, isoetharine, tulob.uteroi, orciprenaline, or (-)-4-amino..3,5-dichloro-a-[[[6-[2-(2-pyridinyl)ethoxy]hexyl]aminojmethyl]benzene-methanol; diuretics, e.g. amiloride; anticholinergics e.g. ipratropium, atropine or oxitropium; hormones, e.g. cortisone, hydrocortisone or prednisolone;
xanthines e.g.
aminophylline, choline theophyllinate,~ lysine theophyllinate or theophylline;
and therapeutic proteins and peptides, e.g. insulin car glucagon. It will be .clear to a person skilled in the art that, where appropriate, the rn~edicaments may be ~ used im the form of salts (e.g. as alkali metal or amine salts or as as:id addition salts) or as esters (e.g. lower alkyl esters) or as solvates (e.g. hydrates) to optimise the activity and/or stability of the medicament and/or to minimise the solubility of the medicament in thepropellant.
Particularly preferred medicaments for administration using aerosol formulations in accordance with the invention include anti-allergies, bronchodilators and anti-. inflammatory steroids of use in the treatment ~of respiratory disorders such as asthma by ' inhalation therapy, for example cromoglycate (e.g. as the sodium salt), salbutamoi (e.g. as .
the free base or as the sulphate salt), salmeterol. (e.g. as the xinafoat~
salt), terbutaline (e.g. as the sulphate salt), reproterol (e.g: as the hydrochloride salt), beclomethasone dipropionate, flutic~sone propionate or ~ (-)-4-amino-3,5-dichloro-cx-[[[6-[2-(z_pyridinyl)-ethoxy]hexyl)amino]- methyl] benzenemethanol. Salmeterol, salbutamol, fluticasone propionate, beclomethasone diprflpionate and physiologically at;ceptable salts and solvates thereof are especially preferred.
It will be .appreciated by those skilled in the art that the aerosol f~rmulations according to the invention may , if desired, contain a combination of two br more actide ~v~ ~~l ~ 1 ~~~~ rc-~m:~xiox» a o ingredients. Aerosol compositions containing two active ingredients (in a conventional propellant system) are known, for example, for the treatment of respiratory disorders such as asthma. Accordingly the present invention further provides aerosol formulations in accordance with the invention which contain two or more particulate medicaments.
S Medicaments may be selected from suitable combinations of the medicaments mentioned hereinbefore. Thus, suitable combinations of bronchodilatory agents include ephedrine and theophylline, fenoterol and ipratropium, and isoetharine and phenylephrine aerosol formulations.
Preferred aerosol formulations in accordance with the invention comprise (a) an effective amount of a particulate bronchodilatory medicament (b) an effective amount of a particulate antiinflammatory, preferably a steraidal antiinflamrnatory medicament (c) a fluorocarbon or hydrogen - containing chlorofluorocarbon prapellant~ and (d) up to 5%
wJw based upon propellant of a..palar casolvent. Particularly preferred aerosol formulations contain bronchodilators such as salbutamol (e.g. as the free.
base or as the sulphate salt), salmeterol (e.g. as the xinafoate s<~lt) or isoprenaline in combination with an antiinflammatory steroid such as a beclomethasone ester (e.g. the diproprionate)or a fluticasone ester (e.g. the propionate). Alternatively aerosol foi-mulati,ons may contain. a bronchodilator in combinatiowwith an antiallergic such as cromoglycate (e.g.
the sodium salt). Combinations of isaprenaline end sodium cromoglycate, salmeterol and fluticasorre propionate; or salbutamol and beclomethasone dipropionate are especiall~~
preferred.
' The final aerosol formulation desirably contains 0.005-10% w/w, preferably 0.005-5% w/w, especially 0.01-1.0% wlear, of medicament relative to the total weight of the formulation.
The propellants for use in the invention may be any ~luoracarban or hydrogen-containing chlorofluarocarbon or mixtures thereof having a suffrcierit vapour pressure to render them effective as propellants. Preferably the pr~pellant will be a non-solvent for the medicament. Suitable propellants include, ~ fox example, C,~hydrogen-containing chlorofluorocarbans such as CHzCIF, CC1F~CI~CIF, CF;CHC1F, CI-IF,CCIF2, Ck-IC1FCI-IF" CF~CIL,~1 and CCIFZCI-I3; C,~,hydrogen-containing ~0 V~L'~ ~~J1 ~"~clw ~yC~'/~:I'9x/11~8y0 ~~~~~~~) S
fluorocarbons such as CHF~CHF,, CF,CH,F, CI-IF~CH, and CF,CHFCF,; and perfluorocarbons such as CF3CF3 and CF3CF,CF3.
Where mixtures of the fluorocarbons or hydrogen-containing chlorofluorocarbons are employed they may be mixtures of the above identified compotands or mixtures, preferably binary mixtures, with other fluorocarbons or hydrogen-containing chloro-fluorocarbons for example CHCIFz, CH2F~ and CF3CH,. Preferably a single fluorocarbon or hydrogen-containing chlorofluorocarbon is employed as the propellant.
Particularly preferred as propellants are C,Ahydrogen-containing fluorocarbons such as 1,1,I,2-tetrafluoraethane (CF3CHzF) and I,1,1,2,3,3,3..heptafluoro-n-propane (CF,CHFCF3).
dt is desirable that the formulations of the invention contain no components which may provoke the degradation of strat~rspheric ozone. In particular it is desirable that the .
formulations are substantially free of chlorofluorocarbons such as CC1~F, CCI~F~ and CF,CCI,.
The propellant tnay additionally contain a volatile adjuvant such as a saturated hydrocarbon for ~ example propane, n-butane, isobutane, pentane and.
isopentane or a~
dialkyl ether for example dimethyl ether. In general, up to 50% wlw of the propellant may comprise a volatile hydrocarbon, for example 1 to 30% w/w. However, formulations which are substantially free of volatile adjuvants are preferred.
.
Polar cosolvents which may be incorporated into the formulations according to the present invention include (e.g. CZ$)aliphatic alcohols . and polyols Nuch as ethanol, ' isopropanol and propylene glycol and mixtures thereof. Preferably ethanol will be employed. Irt general only small quantities (e.g. 0.05 to 3.0°f°
w/w) of polar cosolvent are reguired to improve the dispersion and the use of quantatses in excess of 5%
w/w may disadvantageously tend to dissolve the medicament. Formulations preferably contain less than I% w/w, e.g. about 0.1% w/w of polar cosolvent. Polarity may be determined -For example, by the method described in European Patent Application ~'ublication No 0327777.
A particularly preferred embodiment of the invention provides a pharmaceutical aerosol formulation consisting essecatially of one or more particulate medicament, one or 1~1~f~ ~1/t t'/~S p'C:'1'/E~92/0~810 .~ ~' ~ ~ ~ '.) more fluorocarbon or hydrogen-containing chlorofiuorocarbon propellant and U.OI to 5%
w/w based upon propellant of a polar cosolvent.
The formulations of the invention may be prepared by dispersal of the medicament in the selected propellant in an appropriate container, e.g. with the aid of sanitation. It may S be preferred to add the cosolvent after the medicament and propellant have been combined in order to minimise any solubilising effects of the cosolvent and thereby enhance the dispersion. The process is desirably carried out under anhydrous conditions to obviate any adverse effects of moisture on suspension stability.
The formulations according to the invention form weakly flocculated suspensions on standing but, surprisingly, these suspensions have been found to be easily redispersed by mild agitation to provide suspensions with excellent delivery characteristics suitable for use in pressurised inhalers, even after prolonged storage. Minimising and preferably avoiding the use of formulation excipients e.g. surfactants in the aerosol formulations according to the invention is also advantageous since the formulations may be 15~ substantially taste and odour free, less irriitant and less toxic than conventional formulations.
The chemical and physical stability and the pharmaceutical acceptability of the aerosol formulations according to the invention may be determined by techniques well known to those skilled in the art. ~ Thus, far example, the chemical stability of the components may be determined by HPf.C assay, far example, after prolonged storage of ' the product. Physical stability data rn~ay be gained from other conventional analytical techniques such as, for example, by leak testing, by valve delivery assay (average shot weights per actuation), by dose reproducibility assay (active irigredient per actuation)) and spray distribution analysis.
The particle size distribution of the aerosol farmi~lations according to the invention is particularly impressive and may be measured by conventional technidues, for example by cascade impaction or by the'"Tverin Impinger" anai~rtidal process: As used.herein reference to the "Twin Impinger" assay means "l~etern~aination of the deposition of the emitted dose in pressurised inhalations using apparatus A°, as defined in l3ritash Pharmacopoeia 19~~, pages A204-20'7, Appendix ~C~/II C. Such techniques enable the '°respirable ~rabtion" of ~t~ <~~ut i~:~~ r~c-~v~c~zioz»~a the aerosol formulations to be calculated. ~1s used herein reference to "respirable fraction" means the amount of active ingredient collected in the lower impingement chamber per actuation expressed as a percentage of the total amount of active ingredient delivered per actuatian using the twin impinger method described above. The Y
farmulations according to the invention have been found to have a respirable fraction of 20% or more by weight of the medicament, preferably 25 to 70%, for example 30 to 60%.
t)ptionally, the medicament may be surface-modified prior to its dispersion in the propellant by trea~~tment with a substantially non-polar liquid medium which is a non-solvent for the medicament. There is thus provided in a further aspect of the invention an aerosol formulation comprising particulate, surface.-modified medicament, as defined herein, a fluorocarbon or hydrogen-containing chlorofluorocarbon propellant and up to 5% w/w based upon propellant of a polar cosolvent, which formulation is substantially free of surfactant. By "surface-modifred medicament" is meant particles of medicament which have been w surface-modified. by admixture with a 'substantially non-polar non-solvent liquid, followed by removal of the liquid. The substantially non-polar non-solvent liquid medium is conveniently an aliphatic hydrocarbon, e.g. a lower alkane, which is sufficiently volatile to permit its ready evaporation, e.g, at ambient temperature and pressure, after slurrying with the medicament. The use of isopentane as liquid medium is particularly advantageous in this respect.
The .medicament is desirably slurried with the liquid medium under anhydrous conditions to obviate any adverse effects of moisture on suspension stability.
The slurry may advantageously be sonicated to maximise the surface-modifying . ePFect of the treatment. The liquid may be removed by any convenient means for example by 2~ evaporation or by filtration (allowed by evaporation, provided that following treatment the medicament is substantially free of the liquid. The formulations of the invention wilt be substantially fires of the non-solvent non-polar liquid:
The formulations according to the invention may be filled into canisters suitable for delivering pfarmaceutical aerosol formulations. Canisters generally comprise a b~ntainer capable of withstanding the vapour pressure of the propellant used such as a plastic or i~!(:D 91/ 11 ~~i~ t't,'f/ EI'92/02~ 10 ~~~~~~rs plastic-coated glass bottle or preferably a metal can, for example an aluminium can which may optionally be anodised, lacquer-coated and/or plastic-coated, which container is closed with a metering valve. 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-acrylonitrile rubbers, butyl rubber and neoprene. Suitable valves are commercially available from manufacturers well known in the aerosol industry, for example, from Valois, France (e.g. DF10, DF30, DF60), Bespak plc, UK (e. g.
BK300, BK356) and 3M-Neotechnic Ltd, "IJJK (e.g. SpraymiserTM).
t;onventional bulk manufacturing methods and machinery well known to those skilled in the art of phar~rr~aceutical aerosol manufacture may be employed for the preparation of large scale batches for the commercial production of filled canisters. Thu s, for example, in one bulk manufacturing method a metering valve is crimped onto an aluminium can to 1 S form an empty canister. The particulate medicament is added to a charge vessel and a mixture of the polar cosolvent and liquifaed propellant is pressure filled through the charge vessel into a manufacturing vessel. 'The drug suspension is mixed before recirculation to a filling machine and an aliquot of the drug suspension is then ~Iled through the metering valve into the canister. Alternatively, where the drug is particularly soluble in the polar cosolvent, the particulate medicament may be suspended in 50 - 30% w!w of the propellant before the cosolvent is added and then made up to weight with propellent before pressure filling into canisters. 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.
Bach f Iled 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 ar nasal cavity of a patient. Suitable channelling devices comprise for example a valve actuator and a cylindrical or c~ne-like passage trough which medicament may be delivered from the filled canister via the metering valve to the nose or mouth of a patient e.g. a mouthpiece actuator. Metered dose anhalers are designed tc~ deliver a fixed unit ~Y(3 ~~3/ ~ 1 '~~1~ t'C't'/ ~a'92/02810 c) dosage of medicament per actuation or "puff', far example in the range of 10 to 5000 microgram medicament per puff.
Administration of medicament may be indicated for the treatment of mild, moderate or severe acute or chronic symptoms or for prophylactic treatment. It will be appreciated that the precise dose administered will depend on the age and condition of the patient, the particular particulate medicament used and the frequency of administration and will ultimately be at the discretion of the attendant physician. When combinations of medicaments are employed the dose of each component of the combinatifln will in general be that employed for each component when used alone. Typically, administration may be one or more times, far example from 1 to'8 times per day, giving for example 1,2,3 or 4 puffs each time.
Thus, for example, each valve actuation may deliver 25 microgram.salsneterol, microgram salbutamoi, 25, 50, 125 or 250 microgram fluticasone propionate or 50, 100, 200 or 250 microgram beclomethasone .dipropionate. Typically each filled.
canister for use in a metered dose inhaler contains 100, 160 or 240 metered doses or puffs 'of medicament.
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, ~ which comprises administration by ' inhalation of an effective amount of a formulation as herein described.
The following non-limitative Examples serve to illustrate the invention.
Example 1 t 25 lVlicronised salmeterol xinafoate (9.57mg) was weighed directly into an open aluminium can. 1,1,1;2-Tetrafluoroethane ( 13.2g) was added from a vacuum flask together with ethanol ( 182mg) and a rxaetering valve was crimped irate place.
The resulting aerosol contained g.57mg salmeterol xinafoate ( 1.0% w/w ethanol]
and delivered 25 microgram salmeterol per actuation.

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Example 2 Micronised salmeterol xinafoate (9.57mg) was weighed directly into an open aluminium can. 1,1,1,2-Tetrafluaraethane ( I 8.2g) was added from a vacuum flask together with ethanol {0.4SSg) and a metering valve was crimped into place.
The S resulting inhalers contained 9.5Img salmeterol xinafoate~ (2.5% w/w ethanol) and delivered 50 microgram salmeterol per actuation.
:~~amnles 3 and a Micronised fluticasone propionate (66mg or 6.6m~g) is weighed directly into each of 10 100 open aluminium cans and a metering valve is then crimped into place on each can.
Ethanol (0.182g) and 1,1,1,2-tetrafluoroethane (18.2g) is then added to each canister under pressure, through the valve, and each filled canister shaken to disperse the drug.
The resulting inhalers contain 66 or 6.6mg flutic;asone propionate ( 1 %. w/w ethanol) and deliver 250 or 25 microgram fluticasone propionate . per actuation {Examples 3 and 4 respectively).
Exam~e,~5 and 6 Micronised salbutamol (24mg or 48mg) is weighed directly into each of 3 open aluminium cans. 1,1,1,2-Tetrafluoroethane {18.2g) is added to each can from a vacuum ~ flask together with ethanol {0.364g), and a metering valve is then crimped into place.
' Each filled canister is then shaken in an ultrasonic bath for 8 minutes.
'The resulting inhalers contain 24mg or 48mg salbutamol (2% w/w ethanol) and deliver 100 or microgram salbutamol per actuation (Examples S and 6 respectively).
Example 7 Micronised salbutamol sulphate ( 1 Smg) was weighed directly into an open aluminium can. 1,1,1,2-Tetrafluoroethane { 18.2g) was added from a vacuum flask together with ethanol (0. i 82g) and a rrretering valve was them crimped into place: The f lied canister was then shaken in an ultrasonic bath for 5 minutes. 'rhe resulting inhaler contained l5rng salbutamol sulphate ( 1 % w/w ethanol).

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a f Example 8 lsopentane (20m1) was added to micronised salmeterol xinafoate (O.Sg) to form a slurry, which was sonicated far 3 minutes. The resulting suspension was dried by evaporating the isopentane at ambient temperature to yield surface-modif ed salmetero) xinafaate. Samples of this product (9.57mg) are weighed into aluminium aerosol cans, ethanol (~ 1 mg) and 1,1,1,2-tetrafluaroethane ( 18.2g - 99.95% w/w of total fill weight) is added and suitable; metering valves are. crimped onto the cans. The filled canisters are then each sonicated far 5 minutes. The resulting aerosols contained salmeterol in an amount equivaient~to 240 actuations at 25 microgram per actuation (0.5% w/w ethanol) Micronised beclomethasone diprapionate manahydrate (68 mg) is weighed into a clean, dry, plastic-coated glass bottle, 1,1,1,2-tetrafluoraethane (ta 18.2g) is added from a vacuum flask together with ethant~l (0.182g) and the bottle is quickly sealed with a metering valve. The resulting aerosol dispensed 250 microgram beclomethasone dipropianate (as the monohydrate) per 75.8mg actuation ( 1 % w/w ethanol).
Example 10 Micranised sodium cromaglycate ( 1.2g) is weighed directly into ara aluminium can, 1;1,1,2-tetralluorethane (ta 18.2g) added from a vacuum flask together with ethanol (455mg). A metering valve is crimped into place and the filled canister sonicated for five minutes. The aerosol vdeliv~rs 5rng sodium cramaglycz~te per actuation (2.5%
w/w ethanol).
Example 11 Micronised terbutaline sulphate (60mg) is weighed directly into an alixminium can, 1,1;1,2-tetrafluorethane .(ta 1~:2g) added frarn a vacuum flask together with ethanol (9l mg). A metering valve is crimped into place and the filled canister sbni~cated for five w~~ ~:;~~ ~~~~ s~crm~nxiox~>lo ~~.~~~~::i minutes. The aerosol delivers 250 microgram terbutaline sulphate per actuation (0.5%
w/w ethanol).
.~~-~-,2 Micronised reproterol hydrochloride ( 120mg) is weighed directly into an aluminium can, 1,1,1,2-tetrafluorethane (to 18.2g) added from a vacuum flask together with ethanol (364mg). A metering valve is crimped into place and the filled canister sonicated for five minutes. The aerosol delivers 500 microgram reproterol hydrochloride per actuation (2%
w/w ethanol).
>~,~~m Ip ~ 13 1',~Iicronised terbutaline sulphate (60mg) is weighed directly into an aluminium can, 1,1,1,2,3,3,3-heptafluoro-n-propane (to ~21.4g) added from a vacuum flask together with ethatnol (214mg). A metering valve is crimped into place and the filled canister sonicated I S . far five minutes. The aerosol delivers 250 microgram terhutaiine sulphate per actuation ( 1 % w/w ethanol):
Exam~l~ 14 l~icronised salmeterol xinafoate (9.5'7mg) is weighed directly into an aluminium can and 1, I,1,2,3,3,3-heptafluoro-n-propane (to 21.4g) added from a vacuum flask .together ' with ethanol (428mg)~. A metering valve is crimped into place and the filled canister sonicated for five minutes. The aerosol delivers 25 microgram salmeterol xinafaate per actuation (2% wJw ethanol).
Example I S
l~icronised fluticasane propionate ( i 3.3mg) is weighed direcily into ~n aluminium can, l,1,1,2,3,3,3-heptafluoro-n-propane (to 21.4g) added from a vacuum flask together with ethanol ( 107mg). A, metering valve is crirraped into piece and the filled canister sonicated for five minutes. The aeros~1 delivers SO microgram fluticasone propionate ~~r actuation (0.5% w/w ethanol):

~v~ ~;~n i7~~ ~crr~~zr~zt~no Example l6 Micronised salbutamol sulphate (31.7mg) is weighed directly into an aluminium can, 1,1,1,2,3,3,3-heptafluoro-n-propane (to 21.4g) added from a vacuum flask together with S ethanol (535mg). A metering valve is crimped into place and the filled canister sonicated for five minutes. The aerosol delivers 100 microgram salbutamol sulphate per actuation (2.5% w/w ethanol).
Micronised . beclomethasane diproprionate ( 13 .6mg) is weighed directly .
into an aluminium can, 1,1,1,2,3,3,3-heptafluoro-n-propane (to 21.4g)' added from a vacuum flask together with ethanol ( 107mg). .A metering valve is crimped into place and the filled canister sonicated for five minutes. The aerosol delivers SO microgram beclomethasane dipraprianate per actuation (0.5% w/w ethanol). . .
i5 Example 18 Per Inhaler % w/w Per Actuation .
Salrneterol xinafaate 0.048 36.25 microgram Fluticasone propionate 0.132 100 microgram Ethanol 1.0 0.76mg 1,1,1,2-Tetrafluoraethane to 100 to 75.8mg Example 19 Per Inhaler % w/w Per Actuation Salmeterol xinaf~ate 0.048 36.25 microgram Fluticasone propionate 0.330 250 microgram Ethanol 2.5 1.9rng 1,1,1,2-Tetrafluoroethane to 100 to 75.8mg Exam ire 20 wt~a ~:~/ ~ ~ ~~~~
~~ri~ P~xiox~~o Per Inhaler % w/w Per Actuation Salmetero) xinafoate 0.048 35.25 microgram Fluticasone propionate 0.056 SO microgram Ethanol 0.5 0.38mg S 1,1,1,2-Tetrafluoroethane to 100 to 75.8mg Example 21 Per Inhaler % w/w Per Actuation Salmeterol xinafoate 0.048 3b.25 microgram Fluticasone propionate 0. I GS 125 microgram Ethanol I .0 0.76mg 1,1,1,2-Tetrafluoroethane to I00 to 75.8mg lfaxam lie 22 S Per Inhaler % w/w Per Actuation Salbutamol * 0. I32 I00 microgram Fluticasone propionate 0.132 100 microgram Ethanol 1.0 0.76mg I, I,1,2-Tetrafluoroethane to 100 to 75.8mg ~' as free base or an equivalent weight of salt e.g. sulphate .
ample 23 Per Inhaler % w/w Per Actuation Salbutamol * ' 0.264 200 microgram Fluticasone propionate 0.330 250 microgram lEthanol 2.0 I .S2mg 1,1,1,2-Tetrafluoroethane to 100 to 7S.8mg * as free base or an equivalent weight of salt e.g: sulphate Exarinple 24 ~v~~ =~*~n ~~r~~:~ ~~~r/cl~~x/oz~~o ~~.~'56~~
Per Inhaler % w/w Per Actuation Salmetero) xinafoate 0.048 36.25 microgram Beclomethasone dipropionate 0.066 50 microgram Ethanol 0.5 0.38mg 5 l, l, I,2-Tetrafluoroethane to 100 to 75.8mg Example 25 Per Inhaler % w/w Per Actuation Salmeteroi xinafoate 0.048 36.25 microgram 0 Fiuticasone prolanate 0.264 200 microgram Ethanol 0.5 0.38mg 1,1,1,2-Tetrafluoroethane to I00 to 75.8mg 15 iPer Inhaler % w/w Per Actuation Salbutamol * 0.132 100 microgram Beclomethasone dipropionate 0.066 50 microgram Ethanol 2.0 I .52mg 3,1,1,2-Teirafluoroethane to 100 to 75.8mg * as free base or an equivalent weight of salt e.g. sulphate Example 27 Per Inhaler % w/w Per Actuation Salbutamol ,* 0.264 200 mierograari Beciamethasone dipropionate 0.264 200 microgram Ethanol 2.S 1.9mg 1,1,1,2-Tetrafluoroethane to 100 to 75.8rng * as free base or an equivalent weight of salt e.g. sulphate !N~ ~a~/ d 175 PCTJEP92/02f310 ~~.~,~fi6'~
l6 In Examples 18 to 27 micronised medicaments are weighed into aluminium cans,1, l ,1,2-tetrafluoroethane ( 18.2g) is added from a vacuum flask, together with the ethanol, and metering valves are crimped into place.

IS

Claims

1. A pharmaceutical aerosol formulation consisting essentially of (i) particulate medicament, (ii) 1,1,1,2-tetrafluorethane, 1,1,1,2,3,3,3-heptafluoro-n-propane or a mixture thereof as propellant, and (iii) 0.01 to 5% w/w based on propellant of polar cosolvent being a C2-6 aliphatic alcohol or polyol or a mixture thereof, the particulate medicament being present in an amount from 0.005% to 5% w/w relative to the total weight of the formulation and having a particle size of less than 100 microns, and which formulation contains less than 0.0001 % surfactant by weight of the medicament.

2. A pharmaceutical aerosol formulation consisting of (i) particulate medicament (ii) 1,1,1,2-tetrafluoroethane, 1,1,1,2,3,3,3-heptafluoro-n-propane or a mixture thereof as propellant, and (iii) 0.01 to 5% w/w based on propellant of polar cosolvent being a C2-6 aliphatic alcohol or polyol or a mixture thereof, said particulate medicament being present in an amount from 0.005% to 5% w/w relative to the total weight of the formulation and having a particle size of less than 100 microns.

3. A formulation as claimed in claim 1, wherein the polar cosolvent is present in an amount of 0.05 to 5% w/w based on propellant.

4. A formulation as claimed in claim 1 or 2, wherein the polar cosolvent is present in an amount of 0.05 to 3% w/w based on propellant.

5. A formulation as claimed in claim 1 or 2, wherein the polar solvent is present in an amount of less than 1% w/w based on propellant.

6. A formulation as claimed in claim 1 or 2, wherein the polar cosolvent is present in an amount of about 0.1 % w/w based on propellant.

7. A formulation as claimed in claims 1 to 6, wherein the medicament is present in an amount from 0.01 to 1% w/w relative to the total weight of the formulation.

8. A formulation as claimed in claims 1 to 7, which has a respiriable fraction of 20% or more by weight of the medicament.

9. A formulation as claimed in any of claims 1 to 8, wherein the polar cosolvent is ethanol.

10. A formulation as claimed in claims 1 to 9, wherein the propellant is 1,1,1,2-tetrafluoroethane.

11. A formulation as claimed in claims 1 to 10, which contains two or more particulate medicaments.

12. A formulation as claimed in any of claims 1 to 11, wherein said medicament is an anti-allergic, a bronchodilator or an anti-inflammatory steroid.

13. A formulation as claimed in claim 12, wherein said medicament is selected from salmeterol, salbutamol, fluticasone propionate, beclomethasone diproprionate and physiologically acceptable salts and solvates thereof.

14. A formulation as claimed in claim 12, wherein said medicament is an anti-allergic selected from cromoglycate, ketotifin and nedocromil and physiologically acceptable salts thereof.

15. A formulation as claimed in claim 14, wherein said medicament is cromoglycate and physiologically acceptable salts thereof.

16. A formulation as claimed in claim 12, wherein said medicament is an anti-inflammatory medicament selected from flunisolide, budesonide, tipredane and triamcinolone acetonide.

17. A formulation as claimed in claim 16, wherein said medicament is triamcinolone acetonide.

18. A formulation as claimed in any one of claims 1 to 11, wherein said medicament is an anti-cholinergic medicament selected from ipratropium, atropine, oxitropium and physiologically acceptable salts thereof.

19. A formulation as claimed in any of claims 1 to 11, wherein said medicament is a xanthine selected from aminophylline, choline theophylline, lysine, theophyllinate, theophylline and physiologically acceptable salts thereof.

20. A formulation as claimed in any of claims 1 to 11, wherein said medicament is a bronchodilator selected from ephedrine, adrenaline, fenoterol, formoterol, isoprenaline, metaproterenol, phenylephrine, phenylpropanolamine, pirbuterol, repoterol, rimiterol, terbutaline, isoetharine, tulobuterol, orciprenaline, and (-)-4-amino-3,5-dichloro-.alpha.[[[6-[2-(2-pyridinyl)ethoxy]hexyl]amino]methyl]benzene-methanol and physiologically acceptable salts thereof.

21. A formulation according to claim 20, wherein said medicament is formoterol or a physiologically acceptable salt thereof.

22. A formulation according to any of claims 1 to 11, which contains a bronchodilator and an anti-inflammatory as medicament.

23. A formulation according to claim 22, which contains salmeterol xinafoate and fluticasone propionate.

24. A canister suitable for delivering a pharmaceutical aerosol formulation which comprises a container capable of withstanding the vapour pressure of the propellant used, which container is closed with a metering valve and contains a pharmaceutical aerosol formulation as claimed in any of claims 1 to 23.

25. A canister as claimed in claim 24, wherein the container is an aluminium container.

26. A canister as claimed in claim 24 or 25, wherein the container is anodised, lacquer-coated or plastics coated.

27. A canister as claimed in claim 24 or 25, wherein the container is anodised, lacquer-coated and plastics coated.

28. A metered dose inhaler which comprises a canister as claimed in any one of claims 24 to 27, fitted into a suitable channelling device.

29. The use of a pharmaceutical aerosol formulation as claimed in any one of claims 1 to 23, for the treatment of a respiratory disorder.

30. The use as claimed in claim 29, wherein the respiratory disorder is asthma.