Pressurized Portable Dispenser

Abstract

A portable powder dispensing device has a medicament chamber in which a dose of powdered medicament in an open capsule shell is introduced and an outlet to cooperate with a human body cavity, such as a mouthpiece or a nozzle for inserting in a nostril. A jet of gas under pressure, from a propellant tank is introduced into the chamber at a swirl angle. The shell containing the medicament vibrates and spins thereby breaking up the particles or aggregates.

Parent Case Text

CROSS REFERENCES

This application is a continuation-in-part of copending application Ser. No. 11,555, filed Feb. 16, 1970, now U.S. Pat. No. 3,653,380, dated Apr. 4, 1972. The references in the prosecution thereof are hereby incorporated by this reference thereto.

Description

BACKGROUND OF THE INVENTION

A number of medicaments are introduced either orally or nasally. For instance, there are a number of nasal inhalators and there are also some devices for introducing finely divided medicament into the oral cavity and thence on into the respiratory system. In the past there were two general types. The nasal inhalator had a medicament chamber, openings to the atmosphere, and a nozzle which was introduced into the nostril. On inhaling, air was sucked into the chamber, picked up medicament, and was inhaled by the user. The dispensers for the oral cavity not only had a different shaped mouthpiece but often had a container feeding into a venturi tube through which air or a gas flowed, picking up the medicament. Some used a squeeze bulb or compressed air source to suspend the powder.

Where there was no reason to measure the dose accurately, these types of dispensers were quite satisfactory and are used on a large scale, particularly the nasal inhalators. It was difficult or impossible to introduce a definitely measured dose, with most of these devices.

It is with improved dispensing devices which can dispense accurately measured doses that the present invention deals.

SUMMARY OF THE INVENTION

The present invention departs from prior designs in several important respects. First, there is a medicament chamber into which gas or air under pressure is introduced at a swirl angle to create turbulence so that the entire dose in the chamber is carried on into the body cavity, e.g., nose or mouth, and thence into the respiratory system, or vagina, ear or wound for local therapy. An important feature is a loose element in the medicament chamber such as half of the shell of a capsule carrying a dose of medicament. This shell spins, vibrates and collides with the powdered medicament thus preventing the formation of or breaking up any coarser aggregates. Adhering of medicament to the walls of the dispensing chamber is greatly reduced and for the most part completely eliminated, and more importantly is consistent for any given system.

The present invention permits discharging finely divided solid particles from an accurately predetermined dosage either into the nose or mouth or similar body cavity. No problem of over dosage is presented, which was a problem with some dispensers used in the past. With medicaments which in excessive amounts have undesirable effects, complete safety is assured.

In one form, the dispenser of the present invention at first glance appears somewhat similar to a nasal inhalator. However, the air passages are sealed up and a gas duct carries gas under pressure into a side of the mixing chamber. As the gas comes in at an angle, called the swirl angle, there is high turbulence and a very thorough distribution of the medicament results. A measured dose of medicament is ordinarily introduced in a half of a capsule. The capsule half vibrates violently, which results in complete emptying of medicament dose and also breaks up aggregates, giving a fine aerosol or smoke, defined as a suspension of solid particles in gas.

Ordinarily the gas duct enters the medicament chamber at an angle which is not a right angle. The particular angle is not critical so long as it is a sufficient angle to produce a high degree of turbulence. A liquid may be introduced in the capsule half shell, if the medicament is more readily administered in liquid form. The most important use for the present invention is to introduce a medicament into the respiratory system, but it is possible to introduce small doses of medicament into the nasal passages without their being driven into the lungs. Also, while the nose and mouth are the cavities in which the dispensers of the present invention are primarily used, other bodily cavities can also receive accurately predetermined dosages of finely divided medicament; and therefore, in its broader aspects the present invention is not strictly limited to dispensers to be used in oral or nasal use.

The source of the gas under pressure is not a critical part of the present invention. It is convenient to form the gas introducing tube for the mixing chamber so that it can be pressed on the discharge valve of an ordinary aerosol container or pressure tank which contains a volatile liquid or gas, such as Freon, of suitable boiling point.

Chlorofluoroalkanes and mixtures of them give propellants with preferred pressure characteristics. Dichlorodifluoromethane, sold under trademarks such as Freon 12 or Genetron 12, is conveniently commercially obtainable in small pressure tanks having a depressable stem valve. Such pressure tanks are used as power units for spray paints, noise devices, signaling systems, and many other purposes.

In the quantities used for powder dispensing, dichlorodifluoromethane is essentially non-toxic. In larger quantities, it dilutes the oxygen in the air to such an extent that it can become suffocating. Other propellants such as carbon dioxide in cylinders, or compressed air or compressed oxygen from tanks or a supply line may be used as a power source. Where fixed compressed gases such as oxygen or air are used as a power source, the complexity of pressure reducing devices to give a uniform pressure for the dispensing of the medicament introduces a cost and weight that is unacceptable for some usages. For use in a doctor's office or under hospital conditions where a large number of doses are to be dispensed and skilled maintenance is available and weight is not critical, such compressed gas, particularly oxygen, is quite advantageous as the oxygen can aid breathing performance and is frequently used in respiratory therapy to reduce the load on the heart and lungs, and is readily available.

The use of dichlorodifluoromethane or other of the haloalkanes permits a very compact and readily portable package and may be considered as the preferred form of use of the invention. It should be understood that when the dispenser is pressed onto the discharge valve of a pressure tank it should be pressed for a short but sufficient time to assure that the full dosage of medicament in the dispensing chamber is ejected into the desired body cavity. This presents no problem as an exact time measurement is not needed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section through a nasal inhalator of the present invention.

FIG. 2 is a cross-section through a nasal inhaler which fits axially on the pressure tank and discharges powder at an angle.

FIG. 3 is a cross-section on line 3--3 of FIG. 2 showing a cross-section of the dispenser, particularly the swirl angle of the gas duct.

FIG. 4 is a modification of the dispenser showing radial pressurization and axial discharge with threaded assembly.

FIG. 5 is a drawing on a smaller scale showing the use of a dilution chamber for the dispersed aerosol.

FIG. 6 is a cross-section of a simplified two-piece assembly in which the propellant tank feeds directly into the medicament chamber.

FIG. 7 is a cross-section along lines 7--7 of FIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a powder dispenser in which a gas duct 13, which at its other end attaches to the valve of the aerosol can or propellant tank 14 enters at a swirl angle into the medicament chamber 12 in the dispenser housing 11. In use, the nasal nozzle 15 is removed by unscrewing at the threaded nozzle coupling 16 and half of a hard shell capsule 17 containing a powdered medicament 18 is introduced into the medicament chamber 12. The nasal nozzle 15 is then fastened on by screwing or by friction fit and the gas duct 13 is brought into contact with the valve stem 19 of an aerosol can or propellant tank 14. The blast of Freon enters at a swirl angle, causes high turbulence in the medicament chamber 12 which is further enhanced by the vibration and spinning of the half capsule 17, resulting in complete emptying thereof and in further turbulence, so that the whole dose of powdered medicament 18 is introduced through the nasal nozzle 15 into the nostril of the user.

The medicament to be dispensed may be any of the therapeutic agents which are desirably administered in finely divided powdered form. While not restricted to such powder size, materials having a particle size of 90 percent smaller than 5 microns are conveniently administered by the present type of portable powder dispenser. Larger powders may be administered, but usually less elegant techniques are satisfactory with the larger powders. Among the finely powdered medicaments are penicillin or salts or derivatives thereof, steroids or a therapeutically effective salt or derivative thereof, and isoproternol as well as live virus materials. Some such live viruses materials are disclosed in U.S. Pat. No. 2,798,835, Markham and Cox, NEWCASTLE DISEASE AND INFECTIOUS BRONCHITIS VACCINES AND PRODUCTION THEREOF, and U.S. Pat. No. 2,798,836, Bird and Markham, INHALABLE LIVE VIRUS VETERINARY VACCINE. For some uses, such as with poultry, live virus vaccines can be dispensed as a finely divided material to be inhaled by poultry. With other materials depending on the patient, live virus products may be administered to humans or other mammals. The present type of dispenser is particularly advantageous with medicaments which are sensitive to moisture or storage conditions. The medicament may be stored under conditions most advantageous for storage, and yet readily transferred to the present dispenser for the most advantageous methods of dispersion on administration.

An axial-feed, angular-dispensing modification of the invention is shown in FIG. 2. Here the dispenser housing 21 is a massive plastic block in which is formed the medicament chamber 22. A gas duct 23 is formed in the dispenser housing, conveniently by drilling, so that one wall is nearly tangent to the medicament chamber, as shown in FIG. 3. This gives a highly effective swirl angle so that as the dispersing propellant is introduced into the medicament chamber a high degree of spin and turbulence is attained. The nasal nozzle 25 is a press fit into the medicament chamber and has a discharge duct 26 leading axially from the medicament chamber, with a bend of approximately 45.degree., so that the finely divided powder being dispersed is dispensed at a convenient angle for oral or nasal administration. Half of a hard shell capsule 27 containing a powdered medicament 28 fits into the medicament chamber 22 to be dispersed at time of use.

One configuration which gives excellent results for powdered steroids is for the inner chamber to be about 0.28 inches in diameter and about 0.5 inch depth with a radius at the bottom of the chamber. The larger portion of a number 5 hard shell capsule which is approximately 0.38 inches long and approximately 0.19 inches in diameter fits loosely into the medicament chamber. With this size, the half of a hard shell capsule cannot turn over but is maintained in a somewhat upright position where it can rotate and vibrate but not turn over. If the chamber diameter is too small, the half capsule shell forming the medicament container will not rotate and vibrate and if it is too large, the capsule shell can become tilted and jammed and hence prevent rotation. The gas pressure through the gas duct should be such that the half capsule shell has a high rotational velocity, but not so high as to fracture. If too much pressure is fed in, the half capsule shell itself may be disintegrated. Stroboscopic observation shows that a rotational and vibrational rate of about 1,200 to 2,000 cycles per minute gives excellent results. For such rotational speeds the rotation and vibration dislodges the finely divided powder from the capsule shell, causing the powder to be picked up by the moving gas, and the entire suspension, now known as an aerosol or smoke, is discharged through the discharge duct for administration, such as inhalation by the subject.

While shown as a nasal nozzle, the orifice can be adapted to suit the site of application, for instance the mouth, the ear, the vagina, or a surface to which the powder is to be applied.

The dispenser housing is shown as fitting tightly into an outer dispenser holder 29. The space between the outer dispenser holder 29 and the dispenser housing 21 acts as a damping chamber 30 which smooths out any vibrations or variations in the propellant flow, aids in preventing liquid portions of the propellant being fed into the medicament chamber, and enhances smooth operation. A pressure chamber adapter 31 has a size and shape to fit over the stem 32 of a discharge valve on a propellant tank 24. Conveniently the pressure chamber adapter has a size such that from about 10 to about 15 cubic feet per minute of propellant gas flow into the damping chamber. The size of the pressure chamber adapter is critical to the extent that it must fit smoothly over the stem of the dispensing valve on the propellant tank without excess gas leakage but other than mating to each other, there are no critical limitations on such dimensions. Preferably the pressure chamber adapter fits current commercial valve stem standards.

In FIG. 4 is shown a modification in which the dispenser housing 34 has female threads 35 to receive male threads 36 on the end of an axial nasal nozzle 37. In this configuration, there is less chance of the nasal nozzle being blown out of the medicament chamber 38. The dispenser housing 34 is also adapted to be retained by screw threads 39 in the outer dispenser holder 40. A pressure adapter 41 fits over the stem 42 of the valve on a propellant tank 43. Here the propellant tank and stem are radial, and hence adapted to be held vertically while the nasal nozzle 37 is held horizontal to dispense a medicament into the mouth, ear or nose of a user. Because of the nature of the device, the complete assembly may be held in any angle which is convenient for administration. Some valves on the propellant tank operate more effectively if held above the surface of any propellant in the tank which may be in liquid form, but other valves work satisfactorily when held in any position.

A modification of the axial flow device in FIG. 4 is shown in FIG. 5 in which a shoulder 45 is formed on the dispenser housing 34 to cooperate with a dilution chamber 46. The dilution chamber is a hollow cylinder, conveniently with a housing coupling 47 which fits over and against the shoulder 45 to hold the dilution chamber in position. Vents 48 permit the flow of air into the dilution chamber. The discharge end of the dilution chamber has a mouthpiece 49 which can fit into the mouth of the user. A dust cap 50 may be removably placed over the mouthpiece to keep it clean when not in use.

In use, the dilution chamber permits the aerosol or smoke as it is emitted from the nozzle to be diluted with air, and aggregates or unground particles to settle out or fall against the wall of the dilution chamber, so that a more uniform, more dilute aerosol is served to the user whereby a deeper therapy is readily obtained by inhaling the smoke or aerosol deeper into the lungs. Such a dilution chamber also aids in maintaining a uniform dosage. Part of the dose in the capsule shell is lost in the dilution chamber but as the portion lost is consistent, a more consistent dosage may be administered to the user. A small but consistent loss to give a more uniform dosage is advantageous with those medicaments for which the dosage level is critical.

A simplified modification is shown in FIGS. 6 and 7 in which the dispenser housing 52 is a single rectangular block having a medicament chamber 53 formed therein with screw threads to hold the nasal nozzle 54. The nasal nozzle is axial with the medicament chamber and conveniently formed on automatic screw machines. At right angles an offset is the pressure chamber adapter 55 which fits over the stem of a propellant tank, not shown, and which feeds the pressurizing gas directly into the medicament chamber where the gas spins the half hard shell capsule 56 containing the medicament 57. This configuration may be smaller and lighter than those above shown and is thus adapted to be carried in the pocket of a user.

The assembly of a small pressure tank, the dispenser housing, the nasal nozzle and a supply of capsules containing medicaments may be put in a small case which fits into the pocket of and is carried by the user. For such uses, it is convenient to have the other half of the hard shell capsule emplaced over the half containing the medicament so that a complete hard shell capsule is carried by the user and opened just prior to administration. The top can be removed from the hard shell capsule, the half containing the medicament dropped into the medicament chamber, and the nasal nozzle screwed into retaining location, the stem of the pressure tank placed in the pressure chamber adapter, and a dose dispensed to the user with a minimum of time if the patient is subject to distress symptoms such that rapidity of administration becomes critical.

Other modifications of the present powder dispenser are within the scope of the invention which is defined by the following claims:

Claims

1. A dispenser system for introducing a finely powdered medicament into a body opening, comprising, in combination:

a dispenser housing having therein a medicament chamber, and removably attached thereto,

a nozzle having one end shaped to cooperate with a body cavity, and the other end attached to said dispenser housing and closing the medicament chamber, and having a central discharge duct therethrough from end to end,

said medicament chamber being adapted to hold a movable solid medicament container having therein a single powdered medicament dose which container vibrates and spins when gas under pressure is introduced into said chamber thereby increasing the inherent swirl and turbulence due to the introduction of gas under pressure,

in said medicament chamber a medicament container about the size and shape of half of a hard shell capsule, adapted to move freely in but not turn over in said medicament chamber, and a predetermined single dose of a powdered medicament in said container,

at least one gas duct passing through the wall of said dispenser housing and entering nearly tangent to the medicament chamber for introducing gas under pressure into the medicament chamber at a swirl angle to the chamber, whereby turbulence results,

means to introduce gas under pressure through said gas duct, whereby said powdered medicament in said container is efficiently dispersed in the turbulent gas and essentially completely administered at a single time of use, into the body cavity, said means including

an outer dispenser holder attached to said dispenser housing surrounding said gas duct and spaced from a portion of said dispenser housing forming a damping chamber between said outer dispenser holder and the dispenser housing, and a pressure chamber adapter passing through said outer dispenser holder to receive the stem of a dispensing compressed gas propellant tank, thereby permitting pressurization of the damping chamber, and the damped transfer of gas pressure through the gas duct into the medicament chamber.