US2868691A - Self-propelling compositions for inhalation therapy containing a salt of isoproterenol or epinephrine - Google Patents

Description

United States Patent SELF-PROPELLING COMPOSITIONS FOR INHALA-I TION THERAPY CONTAINING A SALT OF ISO- PROIERENOL R EPINEPHRIYE Claims. (Cl. 167-54) This invention relates to novel medicament-containing,

self-propelling compositions for inhalation'therapy.'-

A number of previous eflorts have been directed to the preparation of medicament-containing, pharmaceutical preparations for use in inhalation therapy. Thes'e preparations suffer from one or more shortcomings. In many cases they require cumbersome mechanical devices to dispense the medicament. Some of these devices employ a rubber airbulb to aspirate the medicament. This often requires substantial physical effort on the "part of the user. In other cases the vehicle for the medicament may possess irritating properties which mitigate against the use of the compositions for inhalation therapy where delicate mucous membranes may be aflected. In some cases Where a fixed dosage is required these'compositions are not conveniently dispensed in measured, constant amounts. For these reasons, as well as others, the benefits of inhalation therapy have not'been fully realized and progress in this mode of medication has lagged.

It is, therefore, one object of this invention to overcome the disadvantages of the prior art compositions invide a self-propelling therapeutic composition for inhalation therapy which maybe packaged with safety in suitable low pressure containers,;such as frangible containers, or in containers having a dispensing valve construction which will permit dispensing jmeasui'ed, constant doses of "the medicament.

Still another object of the present invention is to provide a stable therapeutic composition containing a liquified non-toxic propellent material which is not subject to erratic pressure variations and which imparts easily controlled pressures at room or ambient temperatures to the container in which the composition is stored and dispensed from.

Other objects will be apparent to those skilled in the .art from reading the description which follows.'

The self-propelling compositions of the present invention comprise a medicament dissolved in a non-toxic,

liquid propellant in thenature of a fluorinated or fluorochlorinated lower aliphatic hydrocarbon, preferably with the aid of a co-solvent for both the medicament and the a medicament in aerosol form for inhalation therapy.

'monochlorotrifluoromethane (Freon l3) "ice In carrying out the invention it is contemplated that the non-toxic, liquid propellant shall be a fluorinated or a fluorochlorinated lower saturated aliphatic hydrocarbon, and preferably a halogenated alkane containing not more than 2 carbon atoms and at least 1 fluorine atom, or mixtures thereof. The preferred halogenated lower alkane compounds may be represented generally by the formula C H Cl F wherein an integer less than 3, n is an integer or zero, yis aninteger or zero, and z is an integer, such that n+y+z=2m+2. The propellants shall possess a boiling point of less than F. at 760 mm. pressure. Examples of the propellantsare dichlorodifiuoromethane (Freon 12), dichlorotetrafluoroethane (Freon 114) CCIF CClF trichloromonofluoromethane (Freon 11), dichloromonofiuoromethane (Freon 21), and Propellants with improved vapor pressure characteristics may be obtained by using certain mixtures of these compounds, e. g., Freon 11 and Freon 12, or Freon 12 and Freon 114, For example, dichlorodifluoromethane, which has a vapor pressure of about 70 pounds per square inch .gauge and 1,2-dichloro-1,1,2,2-tetrafluoroethane (Freon 114), with a vapor pressure of about -13 pounds per square inch. gauge at 70 F., may be mixed in various proportions to form a propellant having an intermediate vapor pressure which is well suited for use in relatively low pressure containers.

It is desired that the vapor pressure of the propellant employed shall itself be between about 25 and 65 pounds per square inch gauge at 70 F., and preferably between about 30 and 40 pounds per square inch gauge at that temperature. A one-component propellant defined'for use in thecomposition was found to give a'composition with gaugepressures in the rangeof 55to 65 pounds per square inch at 70 F., which are usable safely with metal containers. The two-component propellants, such as equalweight mixtures of Freon 12 and "Freon 11, were found to give gauge pressures in the range of 2 0 to 40 pounds per square inch at 70 F., which are usable safely with specially reinforced glass containers.

The medicament employed in a composition according to this invention can be one which is therapeutically ef fective when administered'by inhalation and which may be brought into stable solution in any of the above defined liquified propellants, if necessary, with the aid of a cosolvent and/ or stabilizing substance. One type of medicament which can be employed satisfactorily is the vasoconstrictive amines and their acid-addition salts. However, other types of medicaments, such :as hormones, enzymes, alkaloids, steroids, analgesics, broncho-dilators,. antihistamines, 'antitussives, anginal preparations, antibiotics and sulfonamides and synergistic combinations of these,v

may be employed successfully. Examples of the medicaments which may be employed in producing the compositions of this invention are: isoproterenol hydrochloride [u-(isopropylaminomethyl) protocatechuyl alcohol], phenylephrine, epinephrine, ephedrine, narcotine, codeine, atropine, ergotamine, scopolamine, colchicine, cortisone and alkyl nitrites, such'as amyl nitrite or octyl nitrite.

The co-solvent maybe any liquid substance which assists in. dissolving the medicament in the liquified propellant and which is chemically inert to the medicament in the sense that it does not promote the decomposition of this substance. Suitable co-solvents are intermediate in polarity between the propellant and the medicament.

The co-solvents have the property of being a solvent for the medicament and soluble in the propellants prescribed for use in this invention. The co-solvent beside being chemically inert toward the medicament, should benontoxic andwithout undesirable effects on inhalation in the amount present in the aersol produced. The co-solvent shall have as low a boiling point as possible and prefer-. ably not higher than 212 F. at atmospheric pressure. Examples of satisfactory co-solvents include non-toxic loweralcohols and eth ers, e. g., ethanol, diethyl ether, chloroform, mixtures of ethanol and wate r, and mixtures of chloroform and ethanol.

The stabilizers or anti-oxidants which .may be employed are stronger reducing agents than the medicament and which are non-toxic, such as the alkali-metal bisu'lfites (sodium bisulfite), alkali-metal ascorbates (sodium ascorbate), ascorbic acid, nordihydroguaiaretic acid, 2- tertiarybutyl-4-hyd'roxy anisole, 3-tertiarybutyl-4-hydroxy anisole, butylated hydroxytoluene' (sold under the trademark Tenox BHT), ethylhydro-caffeate, etc. It is normallynot necessary to employ -a stabilizer in an amount in excess'of 0.25% by-weight ofthe composition.

One of the important features of this invcntionisthe discovery that the components 'ofthe compositions must be present within certain critical proportions, as otherwise the benefits of the invention are not obtained. One of the most important characteristics of a spray product is the spray pattern. Spray pattern involves the delivery rate, the particle size distribution and the spray angle. The spray pattern is affected by mechanical factors, e. g., valve construction and orifice size and shape, and by the characteristics of the composition, e. g., viscosity, vapor pressure, type and percentage of propellant. For example, where less than the minimum proportion of pro= pellant is employed, thecomposition lack-suificient propellent force and consequently the'inadequate aerosolization of the medicament results in a particle size distribution which is not efiiciently absorbed in-the' bronchioles and alveoli. Where more than the allowable maximum proportion of propellant is employed, the composition may become unstable during storage and-the medicament may precipitate from the composition. Also, thecompositions may develop undesirably high pressures.

into an open container. The open container and its contents are then cooled, preferably to a temperature below the boiling point of the propellant to be employed. A temperature of 25 F. is usually satisfactory. A measured quantity of the liquified propellant which also has been cooled below its boiling point is then introduced into the container and mixed with the solution already present. The quantities of the components introduced into the container are calculated to provide the desired concentration of each in the final composition. Without permitting the temperature of the container and its contents to-rise above the boilingpoint of the propellant, the container is sealed with a closure equipped with asuitable dispensing valve arrangement. Upon warming to room temperature the Q mnts of the container are mixed by agitation of the containerto insure complete solution of the medicament. The sealed container is then ready to dispense the composition and provide the medicament naerosol form- In prder more clearly to disclose the nature of the present invention, the following examples illustrating compositions in accordance with the invention will now be described. ;It sohuld be understood, however, that this is done, solely by way of example and is intended neither to delineate the scope of the invention nor limit the. ambitofthe appended claims. .In the examples which follow, the processdescribed above was employed. In the cxampleswhich follow and throughout the specification, the quantities of material are expressed in termsof One I of the essential characteristics of the compositions of'this I invention is that the medicament shall remain'dissolved and uniformly dispersed throughout the composition. To this end a co-solvent is often necessary in order to maintain the medicament in the dissolved, uniformly dispersed state, both at the time the compositions are prepared and during normal periodsand conditions of storage.

While the proportions of components may varysomewhat depending upon the specific medicament and liquificd propellant employed, in general it has been found desirable that the liquid propellant constitute at least about 50% by weight of the total composition upward to about 90%. It is preferred that the propellant constitute between about 55% or 60% and 80% by weight of the total composition. The amount and constitution of the co-solvent is largely dependent upon the solubility characteristics of the medicament employed. In most cases it has been found that satisfactory results are obtained where the co-solvent constitutes between about 5% or 10% and 40%, and preferably between abont 20% and 40%'-- v we hto the t a .cQmP s t Qn- .lf to! to ch c -so n s s e hanol; is us th int rnattern ,is affected, resulting-in a wetsprayor stream rather thanan aerosol cloud. The amout of medicament shall generally constitute from about 0.1% to 20%, and preferably from about 0.1% to 2% by weight of the'composition. Desirably the propellant makes-upthe difference 'betwen the proportions of medicamennco-solvent, stabilizer and 100%.

"The novel compositions of the-invention maybe-prepared and containers filled with them by-means of-the following process:

Asuitable measured quantity-of the medicament-is mixed with, and dissolved in, a measured amountof the co-solvent. .A stabilizer, if desired,- is added. A- measured quantity-zof the resultingsolution isythea ntra used percentages bysweight of the total composition.

E le

P s-.4 1 Isoproterenol H61 0.25 ate 11.

thane? wer I fluerqmohaa wn 211-.-

Example 2 v Percent Isoproterenol HCl 2 0.25 Water V i 1. 5 Ethanol (absolute) 33.25 Dichlorotetrafluoroethane (Freon 114) 40 Dichlorodifluorornethane (Freon 12) 25.0

Example 3 I Percent Isoproterenol l ICl ate Ethan We Trichloromonotiuoromethane (Freon 1-1) Example 6 g 1 V H Percent Narcotine v 1 Water 0.65 Ethanol (absolute) a 12.35 Chloroform 20.6 Dichlorodifiuorornethane (Freon 12) i f-'3 4.8 Dichlorotetrafluoroethane (Freon 114) 30.6

' -Example 7 p t A Percent Nicotine "1 Ethanol 95% T 34 Dicblorodifiuoromethane (Freon 12) 25 Dichlorotetrafluoroethane (Freon 114) 40 g 100 --Example 8 i r Q 'Percent Isoproterenol HCl 0.25 Water 1 1.5 Ethanol (absolute) 33.25 Dichlorotetrafluoroethane-(Freon- -1 14) 45.5 Dichlorodifluor ometha'ne (Freon 12.) 19.5

Example 9 I Percent Octyl nitrite 0.1- Ethanol 95% p 20 Dichlorotetrafluoroethane (Freon 114) 49.2 Dichlorodifluoromethane (Freon '12) 30.7

Example 10 I I I P ercent Atropine 0.1 Ethanol 95% a 9.9 Dichlorodifluoromethane (Freon 12) 45 Dichlorotetrafluoroethane (Freon 114) 45 1 100 Example 11 i t Percent Octyl nitrite 0.1 Ethanol 95 9.9 Dichlorotetrafiuoroethane .(Freon 114) 55.4 Dichlorodifiuoromethane (Freon 12) 34.6

Y 100 Example 12 Percent O ctyl nitrite 0.1 Diethyl ether 14.9 'Dichlorotetrafluoroethane (Freon 114) 45 Dichlorodifluoromethane (Freon 12) 40 Other medicaments than those employed in the above examples may be used, such as ergot-amine, scopolamine,

" colchicine, cortisone, amyl nitrite, etc.

' is liquified and cooled at 25 F., added to the chilled concentrate and mixed in. Keeping it at the same temperature, the mixture is measured into the container to 4' be filled and the container is sealed with a closure equipped with a suit-able dispensing valve arrangement. An alternative process, known as pressure filling," is paricularly suitable where the closure employed has, a special valve construction, for'example, that of the type disclosed .in U. S. Patent 2,721,010, issued Octoberl8, 1955. Such a valve' construction permits dispensing a measured dose of medicament'in aerosol form;

It is desirable to enclose the composition in accordance with this invention in apressure-tight container having a suitable outlet valve secured in an opening in the top wall of the container. With the compositions of the invention the pressure rangeis such that it is permissible to use glass bottles instead of metal containers. The compositions and the bottles are characterized by a clear, sparkling appearancewith the advantage that it is easy to observe when the'container is nearly empty. It is recommended for added safety that the glass bottles be coated with a plastic film, preferably clear. 'Aldip-tube of suitable material may be connected with the opening containing the valve arrangement and extendingfto the bottom of the container or an inverted system without a dip-tube may be'-used.-- Upon opening the valve the composition is expelled through the opening in the form of a fine stream to form an aerosol of the medicament. Toaccomplish suitable aerosolization of the medicatnent the opening is desirably constructed to provide a small orifice so as to expel a fine spray of the composition., The container just described is typical of thesecalled aerosol bomb. One typical form of device which iseminently satisfactory for dispensing accurately measured quantities of the medicament in a suitable aerosol form and insuring eflective administration is that disclosed in our copending' application entitled, Aerosol Dispensing Apparatus, Serial No. 572,965,--filed concurrently with this application. I "The terms and expressions which we have employed are used as terms-of description and not of limitation, and we have no intention, in the use of suchterms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scop of the invention claimed.

, .What is claimed is: a

1. A self-propelling pharmaceutical composition capable of providing a medicament in aerosol formsuitable for inhalation therapy, comprising as the medicament a water-soluble acid-addition salt of a bronchodi lator amine selected from the class consisting of isoproterenol and epinephrine, said medicament comprising between about 0.1% and 2% of the composition, as a co solvent for said medicament, an aqueous ethanol mixture in an amount comprising between about 20% to 40% of the composition, the water in said cosolvent comprising between about 1.5% and 2% 'of the total com'-' position, and as a liquefied non-toxic propellant componut 21 halogenated lower alkane containing at least 1 fluorine atom and not more than 2 carbon atoms and having a vapor pressure of between about 20 and 65 pounds per square inch gauge at F., said liquefied propellantfcomponent comprising substantially the re mainder of the composition.

2.- A self-propelling pharmaceutical composition as defined by claim 1, wherein the liquefied non-toxic propellantcomponent comprises a mixture of said halogenated lower alkanes.

3. A self-propelling pharmaceutical composition as defined by claim 1, wherein the liquefied non-toxic propellant component has a vapor pressure of between about a 20 and 40 pounds per square inch gauge at 70 F.

4. A self-propelling pharmaceutical composition as defined by claim I, wherein the liquefied non-toxic propellant component is selected from the group consisting of dichlorodifluoromethane and a mixture of dichlorodifiuoromethane and dichlorotetrafiuoroethane.

'5. A self-propelling pharmaceutical composition as deinedby c im. 1, whe e h m c m compr se a water s'oliibleiacid addition salt of epinephrine.

Aseiep o onia pharmaceutical composition as defined by claim 1, wherein the medicament comprises isoproterenol hydrochloride.

,8 A s lfr e lin ha a tica c m osi as. efi y fs i .1. he e n th h q sam nt om ses epinephrine hydrochloride.

se -swellin Ph r aceut ca o po t on si efined by claim '1, containing about 0.2% isoproterenol hydrochloride, about 2% wate about 37.8% ethanol, 3 91 .39 li uefied tsi hls qmh ofluorom hane. and shq li e i d. is lomdiflu sm th .A- Ql -Pmps in pharm seu l mp sition as defined'by claim 1, containing about 0.25% epinephrine, about 0.5%,oj a 3% .normal solution ofhydrochloric acid, about 0.15% ascorbic acid, about; 1% a ditional-water, about 33. 1%, ethanol, about 25% liquefiedv dichlorodisfiuoromethane, and about 40% liquefied ,dichlorotetra: fluoroethane.

11 A self-propelling pharmaceutical composition as defined by claim .1 containing about 0.25% ,isoprotera enol hydrochloride, about-1.5% water, about 33.25%- ethanol, and the remainder being a liquefied'non-toxie propellant as ,defi ne d by claim 1.

12. Asel-f-propelling pharmaceutical composition as definedby claim 11, containing about 0.25%l.isoproter-. enol hydrochloride, about 1.5% water, about "33.25% ethanol, and the remainder being liquefied dichlorodifluoromethane. i 13. A self-propelling pharmaceutical composition as defined by claim 11, containing about 0.25% isoproterenol hydrochloride, about 1.5 water, about 33.25% ethanol, about 40% liquefied dichlorotetrafiuoroethane, and-about 25% liquefied dichlorodifluoromethane. V

14. A package comprising a pressure-tight container having a valve-controlled opening and containing a selfpropelling pharmaceutical composition capable of providing a medicament in aerosol form suitable forinhal-ation therapy, comprising as a medicament a water-soluble acid-addition salt ofa bronchodilator' amine selected from the. class consisting of. isoproterenol and epinephrine,- said medicament comprising between about 0.1% and 2% of the composition, as. a .cosolvent-for said medicament an aqueous ethanol mixture. in an. amount comprising- -betwee about 20%. and 40% of the composition, the waterin said cosolvent comprising between about 1.5% and 2% of the total. composition, and as a liquefiedinontoxic propellant component a halogenated lower allgane containing at least '1 fluorine atom and not more that-n2 carbon atoms and. having a vapor pressure ofbetween abqutZO: and 65 pounds per square inch gauge at- 70" =F.',

8 said liquefied propellant component comprising substantia l lythe remainder of the composition.

15. A method oi producing a measured dose ofimedicament in aerosol form suitable for inhalation therapy whi omprise f rm n a q d mposition oira' msdis mentqnthetorm o a atqrs luhleaci d ition altof abronchodilatoramine selected from the class consisting otisoproterenol and epinephrine, said medicamom. comprising between about 0.1% and 2% of the composition, said medicament being dissolved ina mixture of a co-solvent and a liquefied non-toxic propellant component, said co-solvent comprising an aqueous ethanol gniggtpre i n an amount comprising between about 2 1 and 49% oi the total. c mpos the Waterfih said nqns9lve n t comprising between about l.5'%.wand'2%' or the total composition, said liquefied non-toxic; propellant component comprising a halogenated lower alkane containing at least 1 fluorine atom and not more than 2 carbon atoms and having a--.v-ap,or pressure of between ab9u-t'20 and pounds per square inch gauge at F., said liquefied propellant component comprising substan-v a ly e .remainder ofthe. composition,v .and dispensing he. l iq isl .qq l position. from. a. pressure-tight. container through a control valve for-self-propelled delivery in the f rm of an. a lQS01' l'QSU1l1l1g from the rapidvaporization of...the propellant.

References Cited in thefile 'of this patent UNITED STATES PATENTS 2,232,976- Fox Nov. 26,1240,

Fulton: Propellents for Low-Pressure Liquefied Gas Aerosols, Ind. and Eng. Chem, vol. 40, No. 4, April 1948, pp. 699 and 700.

Fulton: Germicidal Aerosols, Soap and Sanitary Chemicals, May 1948, pp. -127, 157 and 1 59..

Mina-z Glass-Aerosols for Cosmetics, Amer. Peri. and'EsscOil Rev- Iune 1954, pp. 429-31;

Downing:- Formulation of- Aerosol Products, Soap and; Sanitary Chem., September 1953, pp. 142, 143, 145, 147; 149, 153, 155, 177 and 178.

U. S. Disp., 25th Ed., J; B. Lippincott Co., pp. 38 and 39,- Philadelphia, Pa.

Drugand Cos. Ind., vol. 65, No. 4, October 1949,. pp, 396-98-and- 470-73. I

New'and- Non-oificial Remedies, J. B; Lippincott Co.,v Philadelphia, Pa., 1955, pp. 225-227;

Merck Index, 6th ed., Merck and Co., Inc., 1952, pp. 72, 73, 387-89, 664 and, 674-75..

Claims (1)

1. A SELF-PROPELLING PHARMACEUTICAL COMPOSITION CAPABLE OF PROVIDING A MEDICAMENT IN AERSOL FROM SUITABLE FOR INHALATION THERAPY, COMPRISING AS THE MEDICANENT A WATER-SOLUBLE ACID-ADDITON SALT OF A BRONCHODILATOR AMINE SELECTED FROM THE CLASS CONSISTING OF ISOPROTERENOL AND EPINEPHRINE, SAID MEDICAMENT COMPRISING BETWEEN ABOUT 0.1% AND 2% OF THE COMPOSITION, AS A COSOLVENT FOR SAID MEDICAMENT, AN AQUEOUS ETHANOL MIXTURE IN AN AMOUNT COMPRISING BETWEEN ABOUT 20% TO 40% OF THE COMPOSITION, THE WATER IN SAID COSOLVENT COMPRISING BETWEEN ABOUT 1.5% AND 2% OF THE TOTAL COMPOSITION, AND AS A LIQUEFIED NON-TOXIC PROPELLANT COMPONENT A HALOGENATED LOWER ALKANE CONTAINING AT LEAST 1 FLUORINE ATOM AND NOT MORE THAN 2 CARBON ATOMS AND HAVING A VAPOR PRESSURE OF BETWEEN ABOUT 20 AND 65 POUNDS PER SQUARE INCH GAUGE AT 70* F., SAID LIQUEFIED PROPELLANT COMPONENT COMPRISING SUBSTANTIALLY THE REMAINDER OF THE COMPOSITION.