Aerosol Powder Dosage Dispensing Device

Abstract

A dispensing device is described with a mixing chamber in which a dose of powder or other medicament is introduced through an outlet for a human body cavity, such as a mouthpiece or a hollow projection suitable for inserting in a nostril. A source of gas under pressure, for example from an aerosol can, is introduced into the chamber at an angle, and there is present in the chamber a larger movable element, such as a steel ball, which vibrates and breaks up the particles or aggregates. In one modification a half capsule containing the dosage may be introduced into the chamber and the capsule after emptying itself constitutes the moving element.

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 of course a projecting hollow member which was introduced into the nostril. On inhaling, air was sucked into the chamber, picked up medicament, which in some cases was liquid and other cases was sublimed from crystals. The type of dispenser for introducing finely divided medicament into the oral cavity not only had a different shaped mouthpiece but usually had a container feeding into a venturi tube through which air or a gas flowed, picking up the medicament.

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. However, for many purposes it is desireable to introduce a definitely measured dose, and this was difficult or impossible with the devices which were used in the past. 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 an angle to create turbulence so that all of the dosage introduced into the chamber is carried on into the human body cavity, e.g., nose or mouth, and thence on into the respiratory system.

Another important feature of the present invention is that in the medicament chamber there is present a loose element, such as a steel ball or, in another modification, half of the shell of a capsule carrying a dosage of medicament. These movable elements vibrate, collide with the medicament being atomized, and prevent formation of or break up any coarser materials such as coarser aggregates of a powdered medicament. Also, adhering of medicament to the walls of the dispensing chamber is greatly reduced and for the most part completely eliminated.

The present invention, therefore, permits discharging a finely divided spray of liquids of 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 the dispensers used in the past; and so even with medicaments which in excessive amounts have undesirable effects, complete safety is assured.

In general, the principles of the present invention can be incorporated into two somewhat different shaped devices. In one device, which is particularly usable with finely divided solid medicaments for oral use, a chamber is formed with a plug and sealer and a funnel-shaped entrance to a mouthpiece. Preferably a conical screen is also provided further to assure that larger aggregates are not dispensed. Gas under pressure is then introduced into the chamber substantially at right angles. High turbulence results, and if there is present a steel ball or other element which can vibrate and move, thorough and complete breaking up of aggregates results and the exactly predetermined dose is introduced in the best form. In a preferred modification of this type of dispenser, the gas under pressure is introduced through two openings which direct a large volume of lower velocity gas directly into the chamber and a smaller volume of higher velocity gas into another part of the chamber to increase the turbulence.

The second general type of dispenser of the present invention at first glance appears somewhat similar to a nasal inhalator. However, the air passages are sealed up and a tube or conduit carries gas under pressure into a side of the mixing chamber. As the gas comes in at an angle, there is high turbulence and a very thorough distribution of the medicament results. The medicament is ordinarily introduced in a half of a capsule, the capsule half vibrating violently, which results in complete emptying of medicament dose and also breaks up larger aggregates.

In the second type of dispenser referred to above, ordinarily the conduit enters at an angle which is not quite a right angle, whereas in the first type described above the gas is usually introduced at right angles to the flow through the mouthpiece. The particular angle is not critical so long as it is a sufficient angle to produce a high degree of turbulence. While it is theoretically possible to introduce liquids or suspensions in either type of dispenser, a liquid is much more readily introduced in the second type, so that the first type is primarily effective for medicament in the form of finely divided solids, although the invention is not strictly limited thereto and even in this type it is possible to introduce liquids although less readily than in the second type.

Reference has been made to introducing the medicament into the respiratory system. This is the most important field for the present invention, but it is possible to introduce small doses of medicament into the nasal passages in the second type of dispenser 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 nature of the gas under pressure actually forms no part of the present invention. However, it is desirable to form the gas introducing tube to the mixing chamber so that it can be pressed on the discharge valve of an ordinary aerosol container which contains a volatile liquid or gas, such as Freon, of suitable boiling point. This 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 an aerosol can it should be pressed for a short but still 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 dispensing chamber for oral use;

FIGS. 2, 3 and 4 show separate elements of the dispenser, FIG. 4 being an exploded view of all of the elements;

FIG. 5 shows the elements of FIG. 4 assembled and connection to an aerosol container;

FIG. 6 is a cross-section through a nasal inhalator of the prior art, and

FIG. 7 is a similar cross-section through a nasal inhalator of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 5 relate to a dispenser for oral use. The dispenser has a housing 1 forming part of a medicament chamber, with a mouthpiece 2 and a funnel-shaped inlet 3 to the mouthpiece in the housing 1. A chamber is formed by a plug 5 with a conical end and a sealing O-ring 7. There is also provided a conical screen 4, which can be seen in the exploded view in FIG. 4 and in the assembled view in FIG. 5.

The chamber is assembled by first introducing the conical screen 4, which is slightly larger at its base than the internal diameter of the housing 1. This conical screen is introduced with its apex into the throat of the mouthpiece 2, as can be seen best in FIG. 5. A steel ball 6 is then introduced and the plug 5 inserted to a depth to produce a chamber of the desired dimensions. Chambers of various dimensions can be produced with the same equipment by varying the distance that the plug 5 is inserted into the housing 1. It will be seen that the dispensing chamber is between the conical end of the plug 5 and the screen 4.

In use a dose of medicament, for example finely powdered medicament, is introduced through the mouthpiece, the housing 1 being held so that the mouthpiece points up. The finely divided medicament passes through the screen 4 and, if necessary, some tapping of the instrument may be used in order to be sure that all of the medicament enters the chamber. Then an extension 8 on the housing 1 with a central conduit 9 is pushed onto the valve mechanism 10 of a conventional aerosol container, as is shown in FIG. 5. This container is of somewhat simplified design as it is not required that it contain material to be sprayed.

When pressed down on the valve, the Freon gas in the container flows into the chamber through two openings, which can be seen in the cross-section view of FIG. 1. Opening 12 is the larger one and opening 13 is the smaller one. Most of the Freon enters through the larger opening 12 and because of the size of the opening has relatively low velocity. A smaller portion at much higher velocity enters through the opening 13 and the two streams of gas strike each other and further enhance the turbulence. The steel ball 6 vibrates and bounces around, which assures further fineness of subdivision and also breaks up any larger aggregates of the powder so that everything is blown out through the screen 4 and the mouthpiece 2 and the whole of the predetermined dosage is introduced. A single steel ball 6 is shown, but, of course, more than one may be present and they may be made of other materials.

FIGS. 6 and 7 show nasal inhalators. In FIG. 6 the inhalator 14, with a hollow extension 15 which goes into the nostril, communicates with a medicament chamber 16. The element 15 is screwed onto a boss on the inhalator 14 or can be a friction fit in the conventional manner. When the inhalator is introduced into a nostril and the patient inhales, air flows in through the tubes 17 and a portion of the medicament in the chamber 16 is introduced into the nostril. This type of inhalator is very satisfactory where an accurately predetermined dose is not needed and can be used many times where materials such as sublimable anticongestants are present. However, exact predetermined dosage cannot be provided.

FIG. 7 shows the present invention, in which the openings 17 are completely eliminated and a tube 19, which at its other end attaches to the valve of the aerosol can enters into the chamber 16 at a right angle. In use the nasal portion 15 is removed by unscrewing at 18, or removing it when it is a friction fit, and a half capsule 20 is introduced into the medicament chamber. The inhalator element 15 is then fastened on by screwing or by friction fit and the tube 19 is brought into contact with the valve 10 of an aerosol can, as is shown for the other form of dispenser in FIG. 5. The blast of Freon enters at an angle, causes high turbulence in the chamber 15, which is further advanced by the vibration and spinning of the half capsule 20, resulting in complete emptying thereof and in further turbulence, so that the whole dose is introduced into the nostril.

While in the type shown in FIGS. 1 to 5 it is usually preferable to introduce the exact dosage through the mouthpiece, it is, of course, possible to remove the plug 5 and introduce a half capsule as in FIG. 7 into the chamber, replacing the plug and proceeding then as has been described above in connection with FIGS. 1 to 5.

Claims

I claim:

1. A dispenser for dispensing single doses of finely divided powdered medicament for oral use, comprising

a mouthpiece and an integral housing, a converging funnel-shaped entrance in the housing leading to the mouthpiece,

a conical screen element fitting into said entrance,

a plug with a conical end introducible into the housing from the end opposite the mouthpiece and provided with sealing means, whereby a medicament chamber of predetermined size is formed by introducing the plug a predetermined distance into said housing,

at least one movable ball in the medicament chamber, which ball vibrates or spins when gas pressure is introduced, whereby turbulence results,

pressure means for introducing gas into the chamber at an angle to the chamber,

and an extension on the housing at right angles to the mouthpiece axis and shaped to receive gas from said pressure means, which extension and housing is provided with a plurality of conduits to the medicament chamber, one of larger cross-section than the others, the conduits being positioned so that gas flowing through them produces streams which contact each other in the chamber.

2. A dispensing device according to claim 1 in which one of the conduits is of greater cross-section than the other so that a larger volume of gas through the larger is struck by a smaller volume of gas through the smaller opening, thereby agitating said ball and inducing high turbulence, and both conduits are about tangential to the housing.