Abstract:
A pump-type dispenser for dispensing predetermined doses of medicament in droplets or in spray form to the nasal area incorporates a rigid vial for medicament, an expandable pouch located within the rigid vial, a nasal screen, a one-way actuation mechanism, a one-way valve mechanism in the nozzle area and a spring element, both the valve mechanism and the spring element being formed as integral portions of the pump body. The nasal screen aligns the dispenser nozzle with the nasal passage and also allows the user to discreetly hide the nasal area from public view. The one-way valve mechanism in the nozzle area ensures a one-way movement of medicament from the dispenser, thereby preserving substantially perfect sterility of the medicament in the dispenser regardless of the environment surrounding the dispenser, without requiring the use of preservatives. The one-way actuation mechanism enables the user to load and dispense a uniform quantity of medicament with a uniform actuation force and speed via a single continuous motion of the actuation mechanism upon application of a very small force on the actuation trigger mechanism by the user. By preventing the pump mechanism from being left in a loaded state for a prolonged period of time, the one-way actuation mechanism prevents the spring element from experiencing the “fatigue” phenomenon. The rigid vial/expandable-pouch combination facilitates improved long term use, as well as uniformity of dosage independent of the pump orientation.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to a system and method for dispensing liquid droplets or spray-pattern discharges and relates more particularly to a system and a method for dispensing droplets or spray-pattern discharges of medicinal liquids into the nasal passage, which system and method provide greater ease of application and privacy for the user, as well as increased mechanical efficiency and improved ability to prevent contamination of the stored medicinal liquids. 
     BACKGROUND OF THE INVENTION 
     Amongst various dispensers for applying medicament, a typical medicament container includes a flexible vial storage portion and a nozzle for dispensing medicament by squeezing the vial between its side walls. Another type of medicament dispenser is an accordion-like or piston-like pump dispenser which is actuated by squeezing the vial between a bottom wall and the nozzle so as to compress the vial in its longitudinal direction, rather than from its sides. An example of the piston-like dispenser which ejects precalibrated dosage of medicament is described in detail in U.S. Pat. No. 5,613,957, which is expressly incorporated herein by reference. 
     In recent years, pump-type dispensers have received attention for their use in accurately dispensing small doses of medicaments, e.g., for nasal applications. One persistent problem associated with pump-type dispensers for dispensing medicaments is preventing contamination of the medicament which can occur when the medicament that has been exposed to ambient air returns and/or remains in the outlet channel, e.g., within the nozzle. One solution to this problem is to simply add preservatives to the medicament being dispensed, thereby preventing bacterial growth. However, this solution has obvious disadvantages, e.g., added costs and toxicity of the preservatives. In order to prevent bacterial growth in medicament which does not contain preservatives while allowing dispensation of multiple doses of the medicament, the nozzle must prevent any medicament that has been previously exposed to ambient air from being reintroduced, or “sucked back,” into the outlet channel of the nozzle, i.e., prevent any “dead volume.” “Dead volume” is defined herein as the volume of space within the outlet channel of the pump where medicament can come into contact with the open air and remain. If any residual medicament remains within the dead volume, this residue could serve as a host environment for germ growth. 
     Another consideration involved in designing pump-type dispensers for medicaments is ensuring accurate dispensation of a predetermined quantity of medicament, e.g., ranging from 5 μl to greater volumes, upon each actuation of the dispenser, irrespective of the orientation of the dispenser or the force applied by the user to the actuation mechanism of the dispenser. While many pump-type dispensers provide an upper limit of the quantity of medicament dispensed upon each actuation of the dispenser, these pumps often dispense varying quantities of medicament as a function of the speed and/or force of actuation of the actuation mechanism of the dispenser. In the case of a pump-type dispenser which generates aerosol or spray-type discharges, not only will the dispensed dose of medicament vary with the speed and/or the force of actuation of the actuation mechanism, but the spray pattern, or the plume, of the dispensed medicament will also vary with the speed and/or the force of actuation. 
     It should also be noted that persons who suffer from asthmatic or allergic condition routinely need to carry a medicament dispenser with them for emergency situations, but both the existing pressurized medicament dispensers and non-pressurized dispensers have significant drawbacks. The pressurized dispensers are not always ready for use unless they incorporate a heavy glass bottle sustaining vacuum. The non-pressurized devices generally require a particular orientation for dispensing medicament, as well as suffering from a measurable dead volume in the nozzle area. 
     Yet another problem in designing pump-type dispensers for medicaments is ensuring the ease of applying the medicament. Conventional pump-type dispensers for nasal application, an example of which is shown in FIG. 2, are generally actuated by compression along the length of the dispenser. As shown in FIG. 2, the conventional nasal pump  200  is actuated by pushing down on the syringe arms  203  while supporting the bottom portion  202  with the thumb. The combined actuation motion leads to difficulty in holding the nasal pump in stationary position, and usually results in removal of the nozzle tip  204  from the nostril area. For those users who may have greater than average difficulty with the actuation motion, e.g., elderly patients with arthritis or young children, accidental application of the nasal medicament to the face or into the eye may occur. 
     Yet another problem associated with the pump-type medicament dispensers is manufacturing complexity: pump-type medicament dispensers are currently made of numerous parts and are highly delicate to assemble. As the number of components increases, the difficulty and cost of mass production increases correspondingly. For example, many of the pump-type dispensers incorporate springs, which pose problems in the manufacturing process because of the springs&#39; tendency to get intermingled. In addition, very small size of the gaskets and other components make relative movement of the parts difficult. Furthermore, increased number of components also increases the complexity of achieving stability and compatibility of the component materials with the medicament. 
     One attempt to solve the above-described problems associated with applying medicament from a dispenser is described in my U.S. Pat. No. 5,267,986, which discloses a system including a cartridge for actuating a piston-like or accordion-like vial-dispenser for applying medicament to an eye. The cartridge disclosed in U.S. Pat. No. 5,267,986 includes: a housing for holding the vial-dispenser, a telescoping cylinder for compressing the vial-dispenser in the longitudinal direction to load the vial with medicament; a locking mechanism for locking the telescoping cylinder and the vial-dispenser in the loaded position, against the urging of a spring mechanism of the vial-dispenser; and a trigger mechanism for releasing the telescoping cylinder and the vial-dispenser from the locked position to release the medicament loaded in the dispenser by means of the force of the spring mechanism. In order to obviate the need for a discrete spring element in the pump mechanism of the vial-dispenser, a portion of the vial-dispenser body is made of an elastic material which is compressible and provides spring force. The two-step process in which the cartridge disclosed in U.S. Pat. No. 5,267,986 loads and subsequently releases the medicament from a vial-dispenser defines the basic operation a “reverse pump,” an example of which is described in U.S. Pat. No. 5,613,957. 
     The dispensing system disclosed in U.S. Pat. No. 5,267,986 addresses some of the previously-mentioned problems by enabling a user to apply a predetermined dose of medicament independent of the physical force, or speed, applied to the dispensing system by the user: the releasing force or speed of the dispensed medicament is dependent on the integral spring element of the dispensing system. Whereas conventional pump-type dispensers often utilize compression along the longitudinal axis for release of medicament, the actuation motion of the release mechanism described in U.S. Pat. No. 5,267,986 is preferably achieved in a direction perpendicular to the longitudinal axis of the vial-dispenser to ensure enhanced leverage for the user. 
     While the dispensing system disclosed in U.S. Pat. No. 5,267,986 addresses some of the previously-mentioned problems, at least one significant problem remains: because elastic materials, particularly elastomeric materials and springs, tend to exhibit hysteresis, spring force decreases if the spring mechanism is kept in the compressed position, i.e., in the loaded, locked position. Although the deformation of spring is generally reversible if the spring is returned to, and maintained in, the unbiased state for some period, some of the deformation becomes irreversible, or experiences “creep,” if the spring is kept in the compressed state beyond a certain threshold period of time, which threshold period varies with the spring material. The amount of loss of spring force is dependent on the tendency of a particular spring material to “creep,” and it is known that metal springs tend to exhibit much less “creep” than plastic springs. The hysteresis of elastic materials used to form the spring mechanism of the pump described in U.S. Pat. No. 5,613,957 is due to loss of some of the spring property when the spring element remains in the compressed state for an extended, and often unexpected, period of time. 
     Two examples illustrate the practical implications of the above-mentioned hysteresis problem in connection with the dispensing system disclosed in U.S. Pat. No. 5,267,986. As a first example, a user places the dispensing system in the loaded state but does not actuate the release mechanism for several hours due to an interruption. When the release mechanism is finally actuated, hysteresis of the spring mechanism causes the dosage of released medicament to vary from the dosage calibrated to be released under normal conditions. As a second example, a user places the dispensing system in the loaded state but subsequently forgets about the loaded system; the user does not actuate the release mechanism for several weeks or months. In this situation, not only will the initially-released dosage vary from the calibrated dosage, due to lower actuation speed or force, but subsequently-dispensed dosages will also vary from the calibrated dosage due to a type of permanent deformation, or “creep,” that has occurred, i.e., a permanent change in the actuation stroke. In view of the above-described problem of spring deformation, it would be desirable to have a pump-type medicament-dispensing system which allows the user, by means of a single actuation motion, to load the vial with medicament and subsequently dispense the medicament, without any intervening locking step. 
     Pump-type dispensers for applying nasal medicaments are faced with yet another problem in providing the users with some level of discreetness: the sight of a conventional pump-type nasal dispenser positioned inside of a nostril is unseemly and often causes embarrassment for the user. Accordingly, it would be desirable to achieve dispensation of nasal medicament without presenting the unsightly appearance of the dispenser positioned inside the nostril. 
     Still another problem faced by pump-type dispensers is achieving a tight seal of the dispenser after filling it with liquid. The standard approach is to utilize plugs or lids which are formed to mechanically engage the filling opening of a pouch or a container. The main difficulty with this approach is that the allowable mechanical tolerances of the interacting parts of the plug or lid and the opening of the pouch or the container must be extremely small in order to achieve a tight, substantially hermetic seal. Furthermore, even if the interacting parts initially form a tight seal, the portions of the interacting parts which are under pressure tend to experience a “creep,” i.e., deformation of the material, over time. Accordingly, the “creep” phenomenon tends to reduce the tightness of the seal. Thus, there is a need for a mechanical closure system which achieves and maintains a hermetic seal of a pouch or a container over the life of the container. 
     Accordingly, it is an object of the present invention to provide a pump-type dispenser for dispensing medicament in droplets or spray form, which dispenser facilitates easy application of the medicament while ensuring positional stability of the dispenser during the actuation motion. 
     It is another object of the present invention to provide a pump-type dispenser for applying medicaments into the nasal passage, which dispenser provides the user with a nasal screen for discreetness. 
     It is yet another object of the present invention to provide a pump-type dispenser for applying medicaments into the nasal passage, which dispenser provides a guide for aligning the dispenser nozzle with the nasal passage. 
     It is yet another object of the present invention to provide a pump-type dispenser for applying medicament into the nasal passage, which dispenser ensures a one-way movement of medicament through the nozzle of the dispenser. 
     It is yet another object of the present invention to provide a pump-type dispenser which has a substantially zero “dead volume” in the nozzle portion so that no medicament which has been exposed to ambient air can remain, i.e., the medicament is completely released once it passes through the outlet nozzle, or the combined effect of the surface tensions of the medicament and the surrounding outlet nozzle forces any remaining medicament out of, and away from, the outlet portion. 
     It is yet another object of the present invention to provide a pump-type dispenser for dispensing nasal medicament, which dispenser minimizes the number of parts for manufacturing. 
     It is yet another object of the present invention to provide a pump-type dispenser for nasal medicament, which dispenser incorporates a nozzle adapted to generate an aerosol-type discharge by means of elastic, radial deformation along the circumference of the nozzle which simultaneously functions as an integral spring and an elastic valve, while substantially maintaining the physical profile in the direction of the longitudinal axis of the nozzle. 
     It is yet another object of the present invention to provide a pump-type dispenser for nasal medicaments, which dispenser does not require propellants such as CFCs, the release of which is harmful to the ozone layer, or the release pressure of which propellant is temperature dependent, thereby creating variations in dispensed dosages. 
     It is yet another object of the present invention to provide a pump-type dispenser for nasal medicaments, which dispenser emits a predetermined dose of medicament upon each actuation of the dispenser, irrespective of the orientation of the dispenser and the force applied by the user to actuation mechanism. 
     It is yet another object of the present invention to provide a pump-type dispenser for nasal medicaments, which dispenser emits a predetermined dose of medicament upon each actuation of the dispenser, irrespective of the force applied by the user to the actuation mechanism of the dispenser. 
     It is a further object of the invention to provide a nasal-medicament dispensing system which can accurately deliver a small, calibrated amount of medicament by means of a single actuation motion which loads the system with medicament and subsequently dispenses the loaded medicament immediately thereafter without any intervening locking step. 
     It is a further object of the invention to provide a nasal-medicament dispensing system having a single actuation motion for loading and dispensing the medicament, which system incorporates an elastomeric spring element as an integral portion of the body of the dispensing system. 
     It is a further object of the invention to provide a nasal-medicament dispensing system which includes an actuation mechanism for actuating a vial-dispenser of the type having a spring configuration, e.g., an accordion-like or piston-like vial-dispenser, which actuation mechanism requires minimal force for actuation. 
     It is a further object of the invention to provide a nasal-medicament dispensing system which substantially eliminates any possibility that spring elements of the dispensing system will exhibit hysteresis of spring characteristics. 
     It is a further object of the invention to provide a nasal-medicament system in which the actuation motion of the actuation mechanism for dispensing the loaded medicament is in the direction perpendicular to the longitudinal axis of the vial dispenser to ensure enhanced leverage for the user and to avoid the actuation motion being parallel to the compression axis of the spring element. 
     It is a further object of the invention to provide a method of accurately delivering a small, calibrated amount of medicament by means of a single actuation motion of a medicament-dispensing system which loads the system with medicament and immediately dispenses the loaded medicament thereafter without any intervening locking step. 
     It is a further object of the invention to provide a method of dispensing a small, calibrated amount of medicament by means of an actuation mechanism for actuating an accordion-like or piston-like vial-dispenser, which actuation motion requires minimal force for actuation. 
     It is another object of the present invention to provide a mechanical closure system for achieving a tight, substantially hermetic seal of a pouch or a container having an opening. 
     It is another object of the present invention to provide a method of mechanically sealing a pouch or a container having an opening to achieve a tight, substantially hermetic seal while simultaneously allowing delivery of gels or suspensions via an outlet nozzle. 
     It is yet another object of the present invention to provide a mechanical closure system for a pouch or a container having an opening, which mechanical closure system compensates for deformation of the interacting parts of the mechanical closure system and the pouch or the container. 
     It is yet another object of the present invention to provide a mechanical closure system for achieving a tight, substantially hermetic seal of a pouch or a container having an opening, which system does not require extremely small tolerances for the interacting parts. 
     It is yet another object of the present invention to provide a method of mechanically sealing an opening of a pouch or a container after having introduced liquid into the container through the opening, which method eliminates the need to provide vacuum conditions for filling the container and, thereby, substantially reduces the cost of the mechanical system for filling the container. 
     It is yet another object of the present invention to provide a method of mechanically sealing an opening of a pouch or a container, which method involves removably sealing the opening of the pouch or the container in a first configuration, and permanently sealing the opening of the pouch or the container in a second configuration. 
     It is yet another object of the present invention to provide a system of mechanically sealing an opening of a pouch or a container, which system provides a single-piece sealing element consisting of a mechanical plug detachably coupled to a crimping element via a flange for removably sealing the opening of the pouch or the container, and the system further providing that the crimping element may be detached from the mechanical plug to permanently seal the opening of the pouch or the container. 
     It is yet another object of the present invention to provide a spray-type dispensing system having a swirling chamber in the region of the nozzle for generating a spray pattern, which system substantially minimizes the head loss in the swirling chamber and in the outflow channels surrounding the swirling chamber. 
     It is yet another object of the present invention to provide method of generating a spray-type emission from a medicament dispensing system having a swirling chamber in the region of the nozzle for generating a spray pattern, which method substantially minimizes the head loss in the swirling chamber and in the outflow channels surrounding the swirling chamber. 
     SUMMARY OF THE INVENTION 
     In accordance with the above objects, the present invention provides a pump-type dispenser for dispensing predetermined doses of medicament in droplets or in spray form to the nasal area, which pump-type dispenser incorporates a nasal screen, a pump mechanism, a one-way valve mechanism in the nozzle area, a one-way actuation mechanism and an integral spring element. The nozzle area, which includes the one-way valve mechanism, is adapted to minimize the head loss experienced by the liquid in the nozzle area, thereby achieving more efficient fluid mechanics. The nasal screen not only guides and correctly aligns the dispenser nozzle with the nasal passage, but the screen also serves the important function of allowing the user to discreetly apply the nasal medicament from the dispenser without exposing the nasal area to the public. Furthermore, the one-way valve mechanism in the nozzle area ensures a one-way movement of medicament from the dispenser, thereby preserving substantially perfect sterility of the medicament in the dispenser regardless of the environment surrounding the dispenser, without requiring the use of preservatives. 
     The one-way actuation mechanism enables the user to sequentially load and dispense the medicament with a single continuous motion of the actuation mechanism upon application of a very small force on the actuation trigger mechanism by the user. The use of the one-way actuation mechanism also enables design simplification by allowing replacement of the traditional metallic spring element with a spring element formed as an integral part of the dispensing system and made from the same elastomeric material as the valve material. The actuation mechanism operates transversely to the length of the dispenser, thereby minimizing the risk that the user will accidentally remove the dispenser nozzle from the nose during use. In addition, the integral spring element formed as a portion of the pump body minimizes the number of component parts for the dispenser, thereby minimizing the manufacturing complexity and the likelihood of mechanical failure during use. Furthermore, the one-way actuation mechanism and the integral spring element provide the dispenser according to the present invention with the unique characteristic of delivering the same precise quantity of medicament at the same actuation force and speed, regardless of the actual force applied to the actuation trigger by the user. 
     As can be seen from the above, the pump-type dispenser according to the present invention provides a safe, stable and easily operable mechanism for applying medicament to the nasal area. As an additional advantage, the pump-type dispenser according to the present invention for dispensing nasal medicament may be used with substantially all types of liquid formulations, e.g., solutions, suspensions and gels. An exemplary pump mechanism incorporated in the dispenser according to the present invention has: a) a pump body having a front end or tip on the fluid outlet side, the front end comprising an outlet orifice sealed off by an elastic membrane, and continuing backwards through a pump duct with a fluid inlet orifice; and b) a movable piston fitted inside the pump body, the relative displacement of the end of the piston in relation to the pump body between the inlet orifice and a stop position located towards the outlet orifice thus determining the quantity of fluid expelled on displacement, the end of the piston fitting hermetically by slight friction against the duct, the inlet orifice being of a sufficient size for only the preset quantity of fluid or gel to be trapped at the end of the pump duct for its expulsion through the outlet orifice, the pump body and the piston being totally enveloped by an elastic phial, with the exception of the front end of the pump body. 
     The front end of the pump body, i.e., the tip or “nose,” incorporates an outlet orifice preferably in the form of, for example, a cylindrical channel, opening into a pump duct, the latter being, for example, a cylindrical tube, the outlet orifice or channel and pump duct preferably lying in the same general direction. The outlet orifice is preferably a channel advantageously positioned essentially axially along the length of the pump. However, as is clear to those skilled in the field, the channel may be of any shape, e.g., an elbow shape, so as to ensure a projection perpendicular to the axis of the pump. 
     The elastic membrane may be made of any well-known state-of-the-art elastic material, for example rubber, an elastomer, and preferably thermo-elastic materials such as polyurethane, Adrian®, or those available from AES under the name of VISKAFLEX®, from DUPONT under the name of ALCRYN® or HYTREL®, from DSM under the name SARLINK®, from SHELL under the name KRATON®, and from Monsanto under the name Santoprene®. The elastic membrane has, at the outlet orifice, a sufficient thickness to form a one-way valve towards the outlet. In other words by working the piston towards the outlet orifice, the force exerted on the piston enables the said valve to open thus enabling the fluid to be expelled. By contrast, after expelling the liquid, if the piston is then drawn back the valve becomes hermetically sealed and, in the pump duct, a reduced pressure or vacuum is created. 
     The pump duct has a fluid inlet orifice enabling the fluid to fill through the latter. This inlet orifice may be of any shape, rounded, elongated, and may be in the shape of a channel, a slit, a groove, etc. 
     Similar to a syringe, the pump mechanism according to the present invention incorporates a movable piston fitted inside the pump body; the piston is preferably fitted along the length of the device. “Movable” simply indicates that the piston is movable in relation to the body in which it is housed, without prejudicing which element, i.e., the piston or body, moves. This piston can move between a stop position located towards the fluid outlet orifice, and a position beyond the fluid inlet orifice. The stop may be, as in a conventional syringe, the end of the pump duct on the outlet side. However, another stop may be made, if desired, before this end. In the first case, after the fluid is expelled by the relative working of the piston and pump body, the volume of fluid held between the outlet valve and the piston end will be reduced merely to the volume of the evacuation channel. In the second case, the volume of fluid held between the outlet valve and the piston end will include a certain portion of the pump duct in addition to the evacuation channel. 
     As in a conventional syringe, the end of the piston of the pump according to the present invention fits hermetically by slight friction against the pump cylinder. It will thus be understood that when the piston is drawn in the opposite direction to the outlet orifice, a reduced pressure is created in the pump duct, the said reduced pressure being “broken” when the end of the piston reaches the level of the fluid inlet orifice. At this point the fluid is sucked into the pump duct which it fills. During the relative displacement of the piston towards the outlet orifice, when the piston goes beyond the inlet orifice, it thus traps in the pump duct a certain volume of fluid. The set volume between this position and the most extreme, stop position of the movable piston corresponds to the preset quantity of fluid which will be expelled by the pump. The compression of the fluid by the piston, the compression being achieved, for example, and preferably with the aid of an elastic, or by pressure with the aid of the thumb on the piston, enables the elastic membrane forming a valve to open and the fluid to be expelled. 
     The volume of formulation to be delivered by the exemplary phial-pump incorporated in the present invention is small, for example in the order of 5 μl. 
     As can be seen from the above, the rest position of the pump according to the invention is the position where the piston is at the stop. This is why preferably the pump according to the invention has an elastic means of returning the piston to the stop position. These elastic means are well known to those skilled in the field and are such as a spring, the said spring being fitted inside or outside the pump, along the piston&#39;s axis of displacement; the spring may be made of a metal or plastic material, the nature of the spring being adapted to the fluid contained in the bottle when the said spring is fitted inside the phial in contact with the fluid. 
     The above-mentioned elastic means may be formed as a part of the envelope of the elastic phial itself, for example, in the form of a concertina, or annular convex part of sufficient thickness to form a mean of return. The envelope is for example at this level integral on one side with the pump body and on the other side with the piston by means of rings with which these element may be fitted. These rings can cooperate with corresponding slots which in this cage are made in the envelope. If desired, in order to strengthen the means of return it is possible to use, for example, two return element such as concertinas located more particularly on either side of the retaining ring, integral with the piston a illustrated below. The elastic membrane may be alternatively a separate piece from the elastic phial. However, in preferred conditions of embodiment of the pump mechanism described above, the elastic membrane and the elastic phial form a single piece. The number of pieces of the pump mechanism according to the invention may therefore be remarkably reduced. Indeed, according to the invention, it is possible to have a pump mechanism incorporating just three pieces: a phial made of an elastic material; the pump body and the piston. 
     The exemplary pump mechanism according to the present invention has a pump body with a frontal ring, fitted close to the fluid outlet. Such a frontal ring enables the elastic phial to be hermetically fixed to the pump body. Such a ring also enables the embodiment of elastic means for returning the piston to the stop position. The pump body may also include a rear ring, which can perform several functions. The rear ring is preferably an incomplete ring, i.e., portions of the ring are cut out. 
     The above-described piston has the general conformation of an elongated element, corresponding to conventional piston, the elongated element having a plurality of elements, preferably three, in the shape of a ship&#39;s anchor, each thus forming a radial element, at the end of which is an arc-shaped element. The plurality of arcs then forms the incomplete ring referred to above. In such a case, for example, the pump body comprises a cylindrical element, comprising at its front end a ring and at its rear end another cylindrical ring, of larger diameter than the diameter of the arcs described above, the front base of the rear cylindrical ring being cut away so that the above anchors can pass through the base of the cylinder thus enabling, by means of slots corresponding to the above radial elements, and made in the cylinder comprising the pump body, the longitudinal displacement of the piston. 
     The slots made in the pump body perform two functions: a) on the one hand, they enable the displacement of the piston, by the radial elements sliding along the axis of the slots; and b) on the other hand, the end of the slots on the front side constitutes the fluid inlet orifice enabling the fluid to reach the final pump duct corresponding to the preset volume of fluid to be expelled. 
     The above-described shape of the piston facilitates the following: a) enable the nozzle portion to be integral with the rear portion of the pump body; b) eliminates the need for the nozzle portion to be snapped into the housing when the piston is moved towards the rear; and c) enables the pump mechanism to be interchangeable within the same housing. The shape of the piston also enables the piston to be actuated through the bellows portion serving as the spring element, without causing or resulting in any motion of the rear vial portion of the pump mechanism. One advantage resulting from the lack of motion involving the rear vial portion is that the pump mechanism does not experience any momentum change as a function of the fluid-content level of the vial, i.e., the pump mechanism exhibits the same momentum characteristics whether the rear vial portion is full or nearly empty, thereby ensuring substantially constant dosage. 
     In addition to the above-noted advantages, the pump mechanism according to the present invention may also incorporate two O-shaped rings which are secured around the circumference of the pump piston, such that the O-shaped rings provide a fluid-tight seal between the piston and the surrounding sleeve portion of the pump body. The O-shaped rings, which may be made of silicone, polyisoprene, Kraton™, Adrian™, butyl or any rubber-like material, maintain the bellows chamber free of fluid by providing a fluid-tight seal between the pump piston and the surrounding sleeve portion of the pump body. In turn, the absence of fluid in the bellows chamber substantially eliminates the possibility of fluid hindering the elastic deformation of the rear bellows portion. 
     The dynamics of a pump according to the present invention are summarized below. Let us assume that the equilibrium position is the position in which the piston is at the stop. As is clear for the man skilled in the art, the displacements referred to in the present application are in general relative displacements. Indeed preferably, the piston may be kept stationary and the pump body moved as illustrated below, or the pump body kept stationary and the piston moved to achieve the outlet of the fluid. When the piston draws back, it creates a cavity whose state of pressure is a partial vacuum, indeed the outlet orifice is blocked off by the elastic membrane, preventing the entry of air into the pump. On drawing back further, the piston ends up by reaching the level of a fluid inlet orifice. At this point the pump duct, also referred to as a “drop cavity” or “dose chamber,” quickly fills with fluid. The piston can then be pushed back or left to move on to the stop position. When the piston again reaches the level of the fluid inlet orifice, on reaching the end of the latter, it traps a preset volume of fluid. The volume between this extreme position and the stop position of the piston then determines the quantity of fluid expelled. From this moment, ejection of the fluid occurs. As soon as the annular piston lip contacts the compression chamber, the valve opens. 
     A pump mechanism according to the invention has many advantages which it also confers to an elastic phial fitted with such a pump. The preset volume proposed for the pump may be adjusted by altering both the cross-sectional area of the cavity or pump duct and the length of this cavity by changing the depth of the inlet orifice. The dose is constant and depends neither on gravity nor the activation speed of the pump. It can only depend on the spring effect given to the relative pump body/piston movement, and this for a given viscosity and orifice diameter. 
     The use of an elastic wall for the envelope makes it possible to achieve in one piece the following functions. First, a one-way valve function is facilitated, enabling operation without drawing in air or the actual substance being delivered; the pump also makes it possible to dispense formulations without preservative which may be used repeatedly without the risk of contamination of the inside of the phial. Second, a phial function is facilitated: the elasticity of the wall in fact enables the wall to cave in gradually as the liquid is evacuated by the pump. Third, the elastic wall functions as an integral spring element. 
     The injection or filling of the above-described pump mechanism may be associated with a suction which precedes and/or accompanies and/or follows filling so as to eliminate any residual gas in the phial after filling. The dose delivered on each activation of the pump mechanism does not vary, whatever the ambient pressure, because substantially no gas exists inside the system, and the expulsion force applied to the liquid is not dependent on the manual force applied by the user. 
     The pump-type dispenser mechanism according to the present invention may further incorporate an inner pouch made of an elastic material, e.g., Kraton™, and located within the vial portion. The vial portion, in this case, may be made of a rigid material which substantially eliminates ingress of air into the vial portion. The interior of the inner pouch contains varying volume of air, depending on the amount of liquid contained in the vial portion. The elastic inner pouch is collapsible such that its bottom exterior surface conforms to the liquid level in the vial portion. Accordingly, when the vial portion is completely filled with fluid, the inner pouch is substantially completely collapsed and the volume of the interior is substantially zero. As the liquid in the vial portion is gradually depleted as the result of the pump operation, the inner pouch expands correspondingly, drawn by the suction pressure in the vial portion, thereby substantially eliminating the residual air inside the vial portion, which residual air may adversely affect the operation of the pump. The volume of air in the inner pouch is in turn regulated via air holes. 
     One embodiment of the pump-type dispenser mechanism according to the present invention may also incorporate a nozzle mechanism for generating an aerosol-type liquid discharge, which nozzle mechanism ensures one-way movement of liquid and also has a substantially zero “dead volume” at the tip of the nozzle. The nozzle mechanism according to the present invention is not only suitable for dispensing nasal medicaments, but may be also adapted for use with a variety of types of liquid-dispensing apparatuses, for example, medicament dispensers which channel liquid from a liquid reservoir through the nozzle mechanism by application of pressure via a pump mechanism. 
     One embodiment of the nozzle mechanism includes a flexible nozzle portion with an outlet and fluid channels, a rigid shaft received within the flexible nozzle portion, and a rigid housing surrounding the flexible nozzle portion and exposing the outlet. The rigid shaft interfaces the outlet to form a second normally-closed, circumferential valve as well as to define a collecting chamber, or a “swirling chamber,” for temporarily collecting the liquid which has been channeled from the liquid reservoir, prior to being discharged via the outlet. The outlet has an elastic outer wall, the thickness of which decreases along the elongated axis of symmetry of the outlet from a bottom portion of the outlet toward the tip of the outlet, thereby facilitating one-way movement of liquid through, and out of, the outlet. 
     In the above-described embodiment of the nozzle mechanism, the fluid channels, which define a portion of a fluid communication path between the liquid reservoir and the collecting chamber, are positioned at various radial edge or circumferential points within the flexible nozzle portion. The radially positioned fluid channels provide uniform pressure with a minimum of “head loss” which will be explained later. As a result, the liquid pressure is uniformly applied at the entry point of the swirling chamber once the pressure within the radially positioned fluid channels reach a threshold pressure sufficient to radially deform a first normally-closed, annular or circumferential valve forming a portion of the fluid communication path between the liquid reservoir and the collecting chamber, which first normally-closed valve is described in further detail below. It should be noted that while the first normally-closed valve is positioned annularly, i.e., applies even pressure at all points of the circumference, the fluid channels extend along the longitudinal axis of the flexible nozzle portion and occupy only small sections of the circumference of the second normally-closed valve. 
     The above-mentioned swirling chamber is used to create a spray pattern for the discharged liquid. The greater pressure differential between the outside and the inside of the pinhole opening of the swirling chamber, the greater the homogeneity and the smaller the spray-particle size. In order to minimize the source of resistance, also referred to as “head loss” in fluid mechanics, the length of the fluid channel incorporated in the present invention is minimized, as well as the rate of reduction of the fluid-channel width (if any) and the rate of change of the fluid-channel angle relative to the swirling chamber. 
     The above-described embodiment of nozzle mechanism according to the present invention may be coupled to a flexible body portion which has a substantially tubular shape and a wall thickness which decreases from the bottom of the body portion toward the flexible nozzle portion, along the elongated axis of symmetry of the body portion. The rigid shaft received within the flexible nozzle portions extends down into the flexible body portion so that a second portion of the rigid shaft interfaces the flexible body portion to form the first normally-closed, radially-positioned valve in the fluid communication path between the liquid reservoir and the collecting chamber. As with the second normally-closed, radially-positioned valve, the first normally-closed, radially-positioned valve is opened when the pressure on the liquid in the fluid communication path reaches a threshold pressure sufficient to radially deform the portion of the flexible body portion forming the first normally-closed, radially-positioned valve. 
     One advantage of the nozzle mechanism according to the present invention is that the configuration of the outlet portion substantially eliminates the possibility that liquid in the nozzle mechanism will come in contact with ambient air and subsequently return and/or remain in the interior portion of the nozzle mechanism. The nozzle mechanism achieves this result by means of the second normally-closed valve, which facilitates one-way movement of liquid from the nozzle mechanism through the outlet portion during discharge. Due to the second normally-closed valve, the outlet portion has a substantially zero “dead volume”, i.e., a space in which liquid that may have been exposed to ambient air can remain. 
     In addition to the second normally-closed valve, the first normally-closed valve positioned along the fluid communication path between the liquid reservoir and the nozzle mechanism adds further assurances that liquid in the liquid reservoir will not be contaminated by the ambient air and subsequently reintroduced into the nozzle mechanism. Because the first and second normally-closed valves are positioned along the fluid communication path to open asynchronously during fluid communication leading to discharge through the outlet, failure of either one of the valves will not affect the integrity of the nozzle mechanism to prevent contamination of the liquid in the liquid reservoir. 
     Another advantage of the nozzle mechanism according to the present invention is that the nozzle mechanism experiences substantially no deformation along the direction of the discharge path through the outlet, i.e., the elongated axis of symmetry for the outlet. As a result, the physical profile of the fluid channel, which induces swirling action of the liquid in the collecting chamber of the nozzle mechanism, is maintained during liquid discharge. 
     Another advantage of the nozzle mechanism according to the present invention is that the number of parts which constitute the nozzle mechanism and, in turn, the dispensing system which includes a pump mechanism in combination with the nozzle mechanism, is significantly reduced in comparison to conventional nozzle mechanisms. The reduced number of parts reduces costs and complexity of assembly. 
     The pump-type nasal medicament dispenser according to the present invention incorporates an exterior housing and a cartridge positioned within the housing, which cartridge is in turn particularly adapted for actuating an accordion-like or piston-like vial-dispenser mechanism. The vial-dispenser has an accordion-like front bellows portion near the anterior end, a rear vial section or liquid storage chamber at the posterior end, and a rear bellows portion located between the front bellows portion and the rear vial section. A drop cavity or a dosage cavity, which may be located within either the front bellows portion or the rear bellows portion, holds a precalibrated amount of medicament loaded from the liquid storage chamber. In addition, an internal piston mechanism within the vial-dispenser acts in concert with the front and rear bellows portions to expel the medicament contained in the drop cavity. 
     The cartridge includes a generally elongated body portion which is adapted to receive the vial-dispenser between an anterior wall and a posterior wall of the cartridge. The posterior wall of the cartridge may form a portion of a rear chamber of the cartridge, in which case the rear chamber of the cartridge receives the rear vial section of the vial-dispenser. The anterior wall of the cartridge has an aperture for exposing the nozzle of the vial. 
     Located on top portion of the cartridge is a trigger mechanism which, when depressed, acts via, and in concert with, a notched lever located in the interior portion of the housing to extend the front bellows portion and compress the rear bellows portion of the vial-dispenser in the longitudinal direction, away from the anterior wall of the cartridge and towards the rear chamber. In the case of the exemplary embodiment of the vial-dispenser described herein, extension of the front bellows portion and compression of the rear bellows portion cause a precalibrated dose of medicament to enter the dosage cavity located in the front of the dispenser, thereby “loading” the dosage cavity. 
     Continuing with the triggering motion, once the notched lever located in the interior portion of the cartridge has extended the front bellows portion of the vial-dispenser a predetermined distance, the notched lever is disengaged from the front bellows portion by a wedge-shaped arm extending from the rear wall of the cartridge. Upon disengagement from the notched lever, the front bellows portion contracts and the rear bellows portion extends towards the anterior wall of the cartridge. In concert with the movements of the front and rear bellows portions, movement of the internal piston mechanism creates pressure which forces the medicament from the dosage cavity via the anterior nozzle of the vial-dispenser. 
     The present invention also provides an exemplary embodiment of a mechanical lid or a plug which interacts with an opening of the rear vial section of the vial-dispenser mechanism, as well as with a rigid ring placed inside the vial opening. The mechanical plug is snapped into the vial opening such that the mechanical plug compresses both the outside of the opening and the inner face of the ring placed inside the vial opening, thereby forming a tight seal of the opening. 
     The opening area of the vial has an annular recess configured to accommodate the rigid ring, where the rigid ring is snapped into the annular recess. After the rigid ring has been snapped into the annular recess of the opening region of the vial, the mechanical plug is snapped both into the rigid ring and around the outside edge of the vial opening so that the vial opening is compressed between the rigid ring and the mechanical plug. The radial edge of the inner face of the mechanical plug is formed as an arch-shaped region which extends around the plug such that the radial edge of the plug is adapted to “hug” the perimeter of the vial opening. In addition, attached to the inner face of the mechanical plug are two or more legs which extend perpendicular to the lower surface of the mechanical plug. The ends of the legs are hook-shaped to engage the bottom of the rigid ring/radial groove combination. The annular recess and the legs of the mechanical plug facilitate both vertical and radial compression of the opening region of the vial and the rigid ring. In this manner, a tight seal of the vial opening is ensured. 
     In addition, the outside surface of the opening region of the vial and the interior surface of the annular recess of the mechanical plug each has one or more protrusions, or “interferences.” Once the mechanical plug has been snapped into the vial opening, the resulting compression of the vial material tends to cause displacement, or “creep,” of the compressed material towards areas of lesser compression. The protrusions limit the range of displacement of the compressed vial material, i.e., force the vial material displaced by compression to remain within a defined area, thereby ensuring the tightness of the seal for a prolonged period of time. 
     The central inner surface of the mechanical plug may be equipped with an extension or a plunger which is adapted to extend into the liquid content of the vial in such a way that the mechanical plug snaps tightly into the vial opening after, and only after, the plunger has displaced the surface level of the liquid up to the upper edge of the vial opening, thereby obviating the need for a vacuum condition normally utilized for an airless filling process. In this manner, the plunger substantially reduces the residual air bubbles which may otherwise remain between the surface of the liquid and the inner surface of the mechanical plug. 
     As an alternative to the above-described mechanical closure system, the present invention also provides a rigid crimping element detachably coupled via a breakaway flange to a rigid mechanical plug. These elements may be molded as a single piece in order to simplify the manufacturing and assembly process. 
     The mechanical plug is first inserted into an opening of a neck of the rear vial section of the vial-dispenser mechanism. The mechanical plug and an interior portion of the neck of the vial interact to maintain the mechanical plug within the neck of the vial. However, a predetermined amount of force may dislodge the mechanical plug from the neck of the vial. This detachable engagement between the mechanical plug and the neck of the vial allows the vial to be temporarily sealed for some operations and open for other operations. 
     In order to permanently and effectively seal the vial, the crimping element is then repositioned relative to, e.g., detached from, the mechanical plug and slipped over the neck of the vial, which action results in compression of the neck of the vial between an inner face of the crimping element and an external face of the mechanical plug, thereby providing a tight, hermetic seal of the vial. 
     The neck of the vial may be annular and has an inner wall and configured to engage the mechanical plug. A first semicircular protrusion extends substantially around the entire circumference of the inner wall of the neck to engage a first groove on the mechanical plug so that, when the mechanical plug is inserted into the opening of the neck, the first protrusion on the mechanical plug “snaps” into the first groove on the mechanical plug. This first step of “snapping” the first protrusion into the first groove is reversible so that sterilization of the vial using β or γ radiation can take place with the first protrusion snapped into the first groove, and the plug can be detached from the neck, i.e., by releasing the first protrusion from the first groove, for subsequent filling of the vial. 
     A second protrusion extends around an outer wall of the neck of the vial and is configured to engage the crimping element. The second protrusion consists of a semicircular portion extending substantially around the entire circumference of the outer wall of the neck to engage a second groove on the crimping element. When the crimping element is slipped over the neck of the vial, the second protrusion on the neck of the vial “snaps” into the second groove on the crimping element to securely couple the crimping element to the neck of the vial. Once the crimping element is “snapped” into place, the neck of the vial is then compressed between the crimping element and the mechanical plug to provide a tight seal of the vial. This second step of “snapping” the crimping element onto the vial is irreversible, thereby forming a permanent seal. 
     The interacting surfaces of the crimping element and the neck of the vial have complementary contours which ensure distribution of the compressive force over the entire region of the interacting surfaces when the crimping element is engaging the neck of the vial. In this manner, the present invention substantially eliminates the “creep” phenomenon exhibited by prior art closure mechanisms. 
     In order to further maintain the crimping element on the neck of the vial, the mechanical plug may further include an overhanging shoulder that extends around the entire circumference of the outer face of the mechanical wall. The crimping element may then have a conical-shaped brim that extends underneath the shoulder of the mechanical plug when the crimping element is slid over the neck of the vial. Thus, any upward movement of the crimping element would be further constricted since the brim of the crimping element would then come into contact with the shoulder of the mechanical plug. 
     A plunger or extension may also be provided on a bottom surface of the mechanical plug so that, when the mechanical plug is inserted into the neck of the vial, the plunger may extend into a liquid content of the vial in order to raise the surface level of the liquid. Thus, the plunger may substantially reduce the residual air bubbles which may otherwise remain between the surface of the liquid and the inner surface of the mechanical plug. 
     Yet another exemplary embodiment of a mechanical plug effectively seals the opening of the rear vial section of a vial-dispenser mechanism which incorporates an inner pouch within the rear vial section for minimizing the presence of air inside the rear vial section. A rear portion of the inner pouch has an inverted U shape, and the rear portion radially clasps the opening area of the rear vial section. A radial protrusion of the inner pouch is seated in a complementary recess formed in the opening area of rear vial section, and the rear plug, which also has an inverted U shape, slides over, and radially clasps, the rear portion of the inner pouch and the opening area of the rear vial section to provide a tight seal along both the radial and vertical directions. 
     Still another exemplary embodiment of a mechanical plug has an annular protrusion which is snap-fitted into a complementary annular recess formed in the opening area of the rear vial section, thereby providing a radial seal along the annular recess. The mechanical plug also has an annular flange which rests against an annular flange of the opening area of the rear vial section. The annular protrusion of the mechanical plug and the annular flange of the opening area act in concert to provide vertical compression of the opening area of the rear vial section. 
     The pump-type dispenser system according to the present invention for dispensing nasal medicament has several distinct advantages. First, the dispenser system according to the present invention substantially eliminates ingress of air into the pump mechanism, thereby providing not only a sterile environment for the nasal medicament, but also facilitating consistency of the dispensed dosage by minimizing disruption of pump operation caused by air. Second, because the pump-type dispenser according to the present invention is substantially airless, the operation of the pump, as well as the dispensed dosage, is completely unaffected by the orientation of the pump-type dispenser during use. Third, the present invention provides a one-way valve in the nozzle area to further ensure a sterile environment for the nasal medicament inside the dispenser. The valve facilitates only one-way movement of medicament from the interior of the nozzle to the exterior, thereby substantially eliminating the possibility that medicament which has been exposed to ambient air or the exterior of the nozzle may be “sucked back” into the interior of the nozzle, and, in turn, substantially eliminating the possibility of contamination of the medicament inside the dispenser. 
     In addition to the above-noted advantages, the pump-type dispenser according to the present invention also provides a mechanism by which aerosol-type discharges of uniform dosage is achieved without any propellant gas such as CFC. This is achieved by utilizing a combination of the above-mentioned airless pump mechanism, a “one-way actuation release mechanism,” which facilitate loading and ejection of a uniform dose of medicament with a single actuation motion, and an aerosol-generating nozzle mechanism which achieves a very low “head loss” for the fluid discharge. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an exemplary embodiment of the pump-type dispenser for nasal medicaments in accordance with the present invention. 
     FIG. 2 is a front-elevation view of a prior art pump-type dispenser. 
     FIG. 3 is a perspective view of an embodiment of a piston to be incorporated as a part of an embodiment of the pump-type dispenser for nasal medicaments according to the present invention. 
     FIG. 4 is a perspective view of an embodiment of a pump body to be incorporated as a part of an embodiment of the pump-type dispenser for nasal medicaments according to the present invention, which pump body is intended to cooperate with the piston illustrated in FIG.  3 . 
     FIG. 5 is a lateral cross-sectional view of the piston shown in FIG. 3 fitted into the pump body shown in FIG.  4 . 
     FIG. 6 is a lateral cross-sectional view of an embodiment of an envelope intended to cooperate with the piston shown in FIG.  3  and the pump body shown in FIG. 4 to form an embodiment of a phial-pump incorporated in the pump-type dispenser for nasal medicaments according to the present invention. 
     FIG. 7 is a cross-sectional view of an assembled phial-pump incorporating the piston, the pump body and the envelope shown in FIGS. 3,  4  and  6 , respectively. 
     FIGS. 8A-8E show a sequence of cross-sectional views of the phial pump shown in FIG. 7, the sequence illustrating the operation of the phial-pump. 
     FIG. 9 is a cross-sectional view along the length of aerosol dispenser including one embodiment of a nozzle mechanism according to the present invention. 
     FIG. 10 is a cross-sectional view illustrating the flow path of liquid through the fluid communication path between the liquid reservoir and the nozzle mechanism of the aerosol dispenser shown in FIG.  9 . 
     FIG. 11 is a cross-sectional view along line A—A shown in FIG.  9 . 
     FIG. 12A is an enlarged cross-sectional view showing one stage of deformation of a valve in the nozzle mechanism according to the present invention shown in FIG.  9 . 
     FIG. 12B is an enlarged cross-sectional view showing another stage of deformation of the valve in the nozzle mechanism according to the present invention shown in FIG.  9 . 
     FIG. 13A is an enlarged cross-sectional view showing one stage of deformation of a valve in the body portion of the aerosol dispenser shown in FIG.  9 . 
     FIG. 13B is an enlarged cross-sectional view showing another stage of deformation of the valve in the body portion of the aerosol dispenser shown in FIG.  9 . 
     FIG. 14A is a cross-sectional view showing a second embodiment of the nozzle mechanism according to the present invention. 
     FIG. 14B is a cross-sectional view along line B—B shown in FIG.  14 A. 
     FIG. 15 is a detailed cross-sectional side view of a the dispensing system including the cartridge and the vial-dispenser in accordance with the present invention, which dispensing system is shown in a rest position. 
     FIG. 16 is a detailed cross-sectional side view of the dispensing system including the cartridge and the vial-dispenser in accordance with the present invention, which dispensing system is shown in an intermediate position during actuation of the trigger mechanism. 
     FIG. 17 is a detailed cross-sectional side view of the dispensing system including the cartridge and the vial-dispenser in accordance with the present invention, which dispensing system is shown in a release position during actuation of the trigger mechanism. 
     FIG. 18 is an exploded view of components of one preferred embodiment of the mechanical closure system incorporated in the dispensing system according to the present invention. 
     FIG. 19 is an exploded cross-sectional view of components of the preferred embodiment of the mechanical closure system according to the present invention shown in FIG.  18 . 
     FIG. 20 is a cross-sectional view of assembled components of the preferred embodiment of the mechanical closure system according to the present invention shown in FIG.  18 . 
     FIG. 21 is an exploded cross-sectional view of components of another preferred embodiment of the mechanical closure system according to the present invention. 
     FIG. 22 is a cross-sectional view of assembled components of the preferred embodiment of the mechanical closure system according to the present invention shown in FIG.  21 . 
     FIG. 23 a  is a perspective view of a neck of a container of an exemplary embodiment of the mechanical closure system according to the present invention. 
     FIG. 23 b  is a cut-away view of the neck of the container of FIG. 23 a  taken along line A—A. 
     FIG. 24 a  is a perspective view of a mechanical plug and crimping element in accordance with the exemplary embodiment of the mechanical closure system according to the present invention. 
     FIG. 24 b  is a cut-away view of the mechanical plug and crimping element of FIG. 24 a  taken along line B—B. 
     FIG. 25 is a cross-sectional view showing an interaction of the container of FIG. 23 a  with the mechanical plug of FIG. 24 a  in accordance with the present invention. 
     FIG. 26 is a cross-sectional view showing an interaction of the container of FIG. 23 a  with the mechanical plug and crimping element of FIG. 24 a  in accordance with the present invention. 
     FIG. 27 a  shows a first step in an exemplary process for filling and sealing the container of FIG. 23 a  with the exemplary embodiment of the mechanical closure system according to the present invention shown in FIG.  25 . 
     FIG. 27 b  shows a second step in the exemplary process for filling and sealing the container of FIG. 23 a  with the exemplary embodiment of the mechanical closure system according to the present invention shown in FIG.  25 . 
     FIG. 27 c  shows a third step in the exemplary process for filling and sealing the container of FIG. 23 a  with the exemplary embodiment of the mechanical closure system according to the present invention shown in FIG.  25 . 
     FIG. 27 d  shows a fourth step in the exemplary process for filling and sealing the container of FIG. 23 a  with the exemplary embodiment of the mechanical closure system according to the present invention shown in FIG.  25 . 
     FIG. 27 e  shows a fifth step in the exemplary process for filling and sealing the container of FIG. 23 a  with the exemplary embodiment of the mechanical closure system according to the present invention shown in FIG.  25 . 
     FIG. 28 is a perspective view illustrating the difference in height between a portion of the swirling channel and a converging fluid channel in an exemplary embodiment of the nozzle mechanism according to the present invention shown in FIGS. 9 and 11. 
     FIG. 29 a  is a cross-sectional view taken along the longitudinal axis of another exemplary embodiment of a phial pump in accordance with the present invention. 
     FIG. 29 b  is a cross-sectional view of the rear plug mechanism for sealing the vial portion of the phial pump shown in FIG. 29 a.    
     FIG. 30 a  is a cross-sectional view taken along the longitudinal axis of yet another exemplary embodiment of a phial pump in accordance with the present invention. 
     FIG. 30 b  is a cross-sectional view of the rear plug mechanism for sealing the vial portion of the phial pump shown in FIG. 30 a.   
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIG. 1, an exemplary embodiment of the pump-type dispenser system  100  for dispensing nasal medicaments in accordance with the present invention has an exterior housing  101 , an actuation trigger mechanism or button  103  on one side of the housing  101 , a screen lid  102  hinged to the top portion of the housing  101  by means of an articulation hinge  105 , and a nozzle housing portion  104 . The screen lid  102  serves three primary functions. First, the lid serves as a guide for aligning the axis of the nozzle housing portion  104  with the axis of the nasal passage: by simply placing the interior surface of the lid  102  against the nasal ridge, the user is able to easily center the nozzle housing portion  104  within the nasal passage. Second, the lid  102  serves as a screen for hiding the nasal area from the public view, thereby enabling the user to apply the nasal medicament in a discrete manner. Third, when the lid  102  is folded down, it serves as a cover which isolates the nozzle housing portion  104  from the germs and other pollutants which may surround the nozzle housing portion  104 . Furthermore, because the lid is not detachable from the exterior housing, this arrangement eliminates the possibility of misplacing the lid and risking contamination of the nozzle housing portion. In this manner, the lid  102  provides an excellent hygienic protection for the nozzle housing portion  104 . 
     In the exemplary embodiment shown in FIG. 1, the actuation trigger button  103  is connected to a one-way actuation mechanism within the housing  101 , and the one-way actuation mechanism is in turn connected to a pump mechanism. The one-way actuation mechanism and the pump mechanism are explained in further detail below. By depressing the actuation trigger button  103  transverse to the axis of the nozzle housing portion  104 , the pump mechanism is operated in such a manner that the pump mechanism sequentially loads and dispenses a precalibrated amount of nasal medicament, all within a single continuous motion of the trigger mechanism. Because the one-way actuation mechanism accomplishes loading and dispensation of medicament in a single continuous motion of the trigger mechanism, there is no possibility of locking the pump mechanism in a compressed state, which would lead to “creeping,” or permanent deformation, of the pump mechanism. Because the actuation trigger button  103  is operated transverse to the axis of the nozzle housing portion  104 , there is substantially no risk of accidentally removing the nozzle housing portion  104  from the nasal area during operation of the pump-type dispenser  100  according to the present invention. 
     An exemplary pump mechanism which may be incorporated in the pump-type dispenser system according to the present invention is a three-piece phial-pump. The exemplary phial-pump, which will be explained further in connection with FIGS. 3-6E, is designed to eliminate the presence of air or the need for preservatives in the retained formulation and still prevent the contamination of this formulation. In addition, this type of exemplary phial-pump should be able to benefit from almost zero exposure to the air whilst the phial is being filled with the formulation, thus ensuring the sterility of the content without requiring preservatives. 
     As shown in FIG. 3, the exemplary phial-pump has a piston which features: a large longitudinal plunger  1 , at the front end of which is a flange  2  designed to ensure the seal of the cavity of the pump body when the piston increases the pressure therein; and ship&#39;s-anchor-shaped fins  3 , of which there are three in this configuration. Each of the fins  3  has a spoke  4  at the end of which is an arc  5 . 
     As shown in FIG. 4, the exemplary phial-pump has a pump body made up of three main parts: the front part, or “nose”  6 ; the middle part, or “sleeve”  7 ; and the rear part, or “body”  8  of the pump. Nose  6  may have a purely cylindrical or truncated-cone configuration; here, it comprises a small cylinder  9  at the tip followed by a truncated-cone area  10 , itself perforate by the evacuation orifice  11  of the pump. Behind the truncated-cone part is another cylindrical part  12  and, behind this cylindrical part  12 , an annular groove  13  serving to seal an elastic envelope which will be described in further detail below; this annular groove separates the nose proper from a disc or “frontal disc”  13   a.    
     As shown in FIG. 4, sleeve  7  is a cylindrical sleeve, inside of which is the pump cavity. The cylindrical wall of sleeve  7  is perforated by longitudinal slots  14 , in each of which slides a corresponding piston spoke  4 . Each slot has two portions: a wider rear portion  14  for the piston spokes  14  to slide along; and a narrower front portion constituting the communication orifice between the external liquid and the pump cavity, and forming an inlet orifice  15 . The height of this pump cavity determines the level at which the piston will effect compression upon the fluid, and the height therefore determines the volume of the dose to be ejected. 
     On the inner wall of this sleeve, in its frontmost part following the pump nose, is stop  16  comprising an annular undercut, shown in FIG. 5, which houses the annular flange of the piston when the pump is in the at-rest or closed position. This undercut  16  enables the front annular flange  2  of the piston to exert a very slight compression after initial assembly, so as to keep the rest of the pump in perfect occlusion without causing the front flange of the piston to creep whilst storing the pump prior to its use. It is thus impossible for the air or liquid contained in the evacuation orifice  11  of the nose, here an ejection channel, to come into contact with the liquid contained in the rest of the pump or phial. 
     Continuing with FIG. 4, the pump body  8  comprises a cylindrical cavity in continuity with the sleeve, and of a decidedly larger diameter, and will itself be housed in the rear ring of the envelope in order to activate the pump. In the front part of this element there are cutaway sections  17  enabling fins  3  to pass through so as to fit the piston into the pump body. In the example illustrated here, the pump body is movable whereas the piston will be held in a stationary position. 
     As shown in FIG. 5, the piston of FIG. 3 is fitted inside the pump body of FIG.  4 . In addition to the elements described previously, the front stop  16  of the piston with its undercut is shown. Also shown is the inlet orifice  15 , and the position of the piston inside the body is such that if the piston moves forward, it will block off, in a cavity (or “pump duct”)  18 , the preset volume of fluid admitted through orifice  15 . Also shown is the spoke  4 , installed in a longitudinal slot in which it is adapted to slide. In addition, on the rear side of the pump body, a cutaway section  17  enables a fin to pass through. It can be seen from above that the pump mechanism according to the present invention has three annular parts  12 ,  5  and  8 . 
     As shown in FIG. 6, the exemplary elastic envelope has three rings: a front ring  19 , a middle ring  20  and a rear ring  21 , amongst which are confined a front concertina  22  and a rear concertina  23 . The front ring  19  cooperates with the ring  13   a  of the pump body, the middle ring  20  cooperates with the incomplete ring formed by the arcs  5  on the piston, and the rear ring  21  cooperates with the rear ring  8  of the pump body. These rings of the elastic envelope securely retain the rings of the other two pieces, i.e., the pump body and the piston; in particular, the assembly at the level of rings  13   a  and  19  is perfectly hermetic. Moreover, at the frontmost level of the envelope is an elastic membrane  24  forming a one-way valve towards the outlet which is defined by at least the elastic membrane and the complementary parts of the small cylinder  9  of the truncated-cone area  10 . 
     It will also be seen from FIG. 6 that, in this exemplary configuration, the envelope comprises two parts which have been designed to enable the passage of hollow needles in an alternative method of filling the phial-pump with a fluid, liquid or gel, i.e., areas  25  and  26 . These parts have a greater thickness than that of the surrounding areas, and filling needles penetrate these areas if the rear vial or phial section of the phial-pump doesn&#39;t have a filling opening and doesn&#39;t employ a mechanical closure element. Moreover, these areas each comprise a small cylinder capable for example of being heat-sealed under pressure between two heated jaws. Such a cylindrical device may be replaced for example by an extra thickness raised towards the outside of the envelope, thus protruding onto the outer wall, and onto which a heated piece may be applied so as to melt this raised part in order totally to seal the orifice having enabled the penetration of a needle. Lastly, it will be noted that in FIG. 6, the rear part of the envelope serving solely as a receptacle has not been shown here. 
     The above-described components of the exemplary phial-pump is assembled as follows. First, the piston is fitted into the pump body until the front annular flange reaches the stop, and the partially assembled “pump” is thus in the at-rest closed position. The partially assembled “pump” is then fitted into the elastic envelope whilst jets of compressed gas dilate the elastic envelope during assembly enabling the latter with a minimum of friction. 
     As shown in FIG. 7, an alternative embodiment of the phial-pump incorporates three pieces similar to the above pieces, but with a few minor differences. The embodiment of FIG. 7 incorporates the rings  13   a ,  5  and  8  respectively in the rings of the envelope numbered  19 ,  20  and  21 . Also shown are the front  22  and rear  23  concertina springs. As can be seen from comparing FIGS. 5 and 7, length L corresponds to the backward travel of the piston inside the body enabling on the one hand the introduction of fluid into duct  18  of the pump and on the other determining, on the basis of the inside diameter of duct  18 , the volume of fluid to be expelled. Furthermore, as shown in FIG. 7, fluid from a vial portion  77  is in communication (as indicated by the bidirectional arrow “F”) with a bellows chamber contained within the bellows portion  23 . 
     FIG. 7 also shows the phial-pump fitted inside a rigid shell  27 . Also more clearly distinguishable is the annular undercut. In the cases illustrated above, for projecting each individual dose of an ophthalmic liquid, the dimensions may be, for example, as follows: a) diameter of the channel constituting the outlet orifice, and its length—approximately 1.0 mm and 2.0 mm, respectively; b) thickness of the Kraton™ envelope at the level of valve  24  is approximately 0.8 mm, decreasing towards the fluid outlet end; and c) thickness of the Kraton envelope at the level of concertina 23 is 1 mm, and at concertina  22 , 0.75 mm. Lastly, we can see that the rear part of the envelope, at the top of FIG. 7, has been enclosed for example by sealing, so that the pump body and piston are totally enveloped with the exception of the front end of the pump body. 
     It should be noted that two different types of phial-pump systems may be implemented in accordance with the present invention: a) a relative arrangement of the housing and the phial-pump vial which allows the rear part of the vial to be movable; or b) a relative arrangement in which the rear part of the phial-pump vial is fixed relative to the housing, and only the piston is movable. It should be noted that a given phial-pump may be incorporated as a part of either one of the above-described relative arrangements. Illustrated in connection with FIGS. 8A-8E are various steps involved in the operation of the first type of phial-pump system described above. In this series of FIGS. 8A-8E, the phial-pump has been assembled as shown in FIG. 7, inside a rigid shell. In the phial-pump described here, by using this rigid shell, the pump body is movable whilst the piston is held in a stationary position. 
     In FIGS. 8A-8E, “F” represents the fluid with which the elastic envelope has been filled. In the at-rest position shown in FIG. 8A, the piston is held in a stationary position by receptacle  27  of the pump, i.e., by a different structure to the three elements of the actual phial-pump. In the phial-pump system described here, the piston rings are held secure by the compression of rear concertina spring  23 . In FIG. 8B, on activating the pump, the pump body is thrust forwards by its rear part  8  and transmits this thrust to the nose which is made integral with it by means of the sleeve. The effect of this is to create a cavity of drops in pump duct  18  in this space, which remained virtual during the pump&#39;s at-rest period and which is then of a volume determined by the height of the bottom lip of front groove  14  from sleeve  7 , which places this cavity of drops  18  in communication with the cavity limited by the front concertina. This cavity of drops  18  is limited at the front by pump stop  16 , at the sides by the front cylindrical par  18  of the sleeve not opened by the lateral slots  14  and, a the rear, by the front part  2  of the piston limited by front annular flange  2  of this piston. 
     Continuing with FIG. 8C, when the nose is pushed sufficiently far forward so that front flange  2  of the piston is then behind the front lips  15  of the front grooves of sleeve  7 , the depression in the cavity of drops  18  is then made up for by the arrival of fluid F. The pump is then said to be in the filled or open position. This filled position may be locked by a ratchet system on receptacle  27  which itself will be unlocked if the user applies pressure to a pawl. The pawl may form a part of the receptacle case  27  in which this pump is housed. The locking/unlocking mechanism and operation will be explained in detail in a separate section below. During activation, rear spring concertina  23  is under compression and front concertina  22  is extended. Subsequently, as shown in FIG. 8D, during the stage of ejecting the drops of fluid F, i.e. when the nose and body return to their initial at rest position, rear spring concertina  23 , initially compressed, extends and the assembly resumes the at-rest position shown in FIG.  8 E. 
     Illustrated in FIG. 29 a  is another exemplary embodiment of a type of phial pump in which the piston portion is movable and the rear part of the vial is fixed relative to the housing. The operation of the pump  7000  shown in FIG. 29 a  is similar to that of the phial pump illustrated in FIGS. 3-7 and  8   a - 8   e , but several mechanical features distinguish the pump  7000 . The pump  700  includes a main piston  7001  which is slidably engaged within a sleeve formed by a collet  7026  and longitudinally-extending portions  7014  and  7016 . The piston  7001  is coupled via a radially-extending flange  7005  to an elastic envelope  7300  having a front concertina portion  7022 , a rear bellows portion  7023 , a rear portion  7028 , a front ring  7029 , an exterior nozzle portion  7006  and a front cone  7025 . The front concertina portion  7022  and the rear bellows portion  7023  provide spring action to the coupled piston  7001 . The rear portion  7028  of the elastic envelope  7300  securely retains the collet  7026  and the rear segment  7016   a  of the longitudinally-extending portion  7016 , and in turn, rear portion  7028  is securely retained within the front segment of a vial portion  7027 , inside of which defines a fluid reservoir  7077 . The vial portion is made of a rigid material which substantially eliminates ingress of air into the fluid reservoir  7077 . 
     Continuing with the exemplary embodiment of the pump shown in FIG. 29 a , a fluid-outlet valve  7024  is defined by the interface of the exterior nozzle portion  7006  and a rigid interior nozzle portion  7004  which is secured via a radial protrusion  7030  to a complementary ring portion  7029  of the elastic envelope  7300 . The exterior nozzle portion  7006  has a radial thickness that decreases along the longitudinal axis from the base of the nozzle portion to the tip. When the pump  7000  is at its ambient position, the piston  7001  rests against a base segment  7007  of the rigid interior nozzle portion  7004 . During operation of the pump  7000 , a cavity (or “pump duct”)  7018  is defined between the base segment  7007  and a front end of the piston  7001  when the piston is initially withdrawn relative to the base segment  7007 . Furthermore, an outlet orifice  7011  provides a fluid communication channel between the cavity  7018  and the fluid-outlet valve  7024 . 
     The longitudinally-extending sleeve portion  7014  shown in FIG. 29 a  has an elongated slot  7015  which serves as the inlet orifice to the cavity  7018  and which is substantially similar to the slot  15  shown in FIG.  5 . Furthermore, two O-shaped rings  7003   a  and  7003   b  are secured, or molded, around the circumference of the piston  7001  as shown in FIG. 29 a , such that the O-shaped rings provide a fluid-tight seal between the piston  7001  and the surrounding sleeve formed by the collet  7026  and longitudinally-extending portions  7014  and  7016 . The O-shaped rings  7003   a  and  7003   b  may be made of silicone, polyisoprene, Kraton™ or any rubber-like material. In addition, the base segment  7007  delimits the forward compressive movement of the piston  7001  and its front flange  7002  which ensures the seal of the cavity  7018  during the compressive movement. 
     Operation of the pump  7000  may be substantially similar to the operation illustrated in FIGS. 8 a - 8   e . From the ambient position of the piston  7001  depicted in FIG. 29 a , the relative movement of the piston away from the base segment  7007  of the rigid interior nozzle portion  7004  creates a suction, or depression, within the cavity  7018  defined by the space between the base segment  7007  and the front end of the piston  7001 . The maximum relative movement of the piston  7001  away from the base segment  7007  is predefined. When the flange  7002  of the piston  7001  is positioned behind the slot  7015 , a fluid communication channel is established through the slot  7015 , and the depression in the cavity  7018  draws in the fluid to the cavity from a surrounding cavity  7008  defined between the front concertina portion  7022  and the front sleeve portion  7014 . During this “filling” stage in which the pump piston  7001  is moved rearward relative to the base segment  7007 , the front concertina  7022  is extended and the rear bellows portion  7023  is compressed. 
     During the fluid-ejection stage, the piston  7001  urged forward by the spring action of the front concertina  7022  and the rear bellows portion  7023 . When the front flange  7002  has moved forward of the elongated slot  70015 , the fluid in the cavity  7018  is compressed by the forward movement of the piston  7001 , and the compressed fluid is channeled through the outlet orifice  7011  to the fluid-outlet valve  7024 . When sufficient fluid pressure exists at the fluid-outlet valve  7024 , the exterior nozzle portion  7006  is radially deformed and separated from the rigid interior nozzle portion  7004  to pass the fluid. Because the exterior nozzle portion  7006  has a radial thickness that decreases along the longitudinal axis from the rear or the base of the nozzle portion to the front or the tip, the front segment of the fluid-outlet valve  7024  is closed when the base segment of the valve is initially opened, and as the fluid passes through the valve  7024 , the base segment of the valve is closed by the time the front segment of the valve  7024  is opened to emit the fluid. At the completion of the fluid-ejection stage, the piston  7001 , the front concertina  7022  and the rear bellows  7023  return to the ambient position shown in FIG. 29 a.    
     In the above-described pump  7000 , the two O-shaped rings  7003   a  and  7003   b  provide a fluid-tight seal between the piston  7001  and the surrounding sleeve formed by the collet  7026  and longitudinally-extending portions  7014  and  7016 , thereby maintaining the bellows chamber  7023   a  free of fluid. The absence of fluid in the bellows chamber substantially eliminates the possibility of fluid hindering the elastic deformation of the rear bellows portion  7023 . 
     As previously noted above, the interior of the vial portion  7027  defines the fluid reservoir  7077 . The interior of the vial portion  7027  also contains, however, an inner pouch  7100  made of an elastic material, e.g., Kraton™. As shown in FIG. 29 a , the inner pouch  7100  is secured to the vial portion  7027  by means of a rear plug  7200 , which will be described in further detail below. The interior  7078  of the inner pouch  7100  contains varying volume of air, depending on the amount of liquid contained in the fluid reservoir  7077 . FIG. 29 a  depicts the fluid reservoir  7077  containing an amount of fluid which is about a third of the reservoir&#39;s maximum capacity. The elastic inner pouch  7100  is collapsible, or expandable, such that the exterior surface  7100   a  of the inner pouch conforms to the liquid level in the fluid reservoir  7077 , i.e., when the vial portion  7027  is completely filled with fluid, the inner pouch is substantially completely collapsed and the volume of the interior  7078  is substantially zero. 
     As the liquid in the reservoir  7077  is gradually depleted as the result of the pump operation, the pouch  7100  expands correspondingly, drawn by the suction pressure in the reservoir  7077 , thereby substantially eliminating the residual air inside the reservoir  7077 , which residual air may adversely affect the operation of the pump. The volume of air in the interior  7078  is in turn regulated via air holes  7201  formed in the rear plug. In the above manner, the inner pouch functions as an effective air-regulation mechanism for the fluid reservoir  7077 . 
     As shown in detail in FIG. 29 b , the rear of the vial portion  7027  of the phial pump  7000  shown in FIG. 29 a  is sealed by means of the rear plug  7200 . Furthermore, the inner pouch  7100  is secured to the vial portion  7027  by the rear plug  7200 . As previously noted, the rear plug  7200  has a plurality of air holes  7201  which regulate the volume of air in the interior  7078  of the inner pouch  7100 . A rear portion  7103  of the inner pouch  7100  has an inverted U shape, and the rear portion  7103  radially clasps the rear of the vial portion  7207 . A radial protrusion  7101  of the inner pouch  7100  is seated in a complementary recess  70271  formed in the rear of the vial portion  7207 . In addition, the rear plug  7200 , which also has an inverted U shape, radially clasps the rear portion  7103  of the inner pouch  7100 . 
     The rear plug  7200  has two notch portions  7201  and  7202  which protrude radially inward, and the notch portions  7201  and  7202  interact with a notch portion  7102  of the rear portion  7103  of the inner pouch and a notch portion  70272  of the rear of the vial portion  7207 , respectively. When the rear plug is being placed into the sealing position, one interior surface of the rear plug compressively engages the radial protrusion  7101  of the rear portion  7103  of the inner pouch  7100 , and the notch portions  7201  and  7202  of the rear plug slide over the notch portions  7102  and  70272 , respectively, to firmly engage the underside of the notch portions  7102  and  70272 . For this reason, the rear plug is also referred to as a “sliding plug.” In this manner, the rear plug  7200  provides compression along both the radial and vertical directions to the rear portion  7103  of the inner pouch  7100  and the rear of the vial portion  7207  to provide a tight seal of the rear of the vial portion  7207  along both the radial and vertical directions. 
     Illustrated in FIG. 30 a  is yet another exemplary embodiment of a type of phial pump in which the piston portion is movable and the rear part of the vial is fixed relative to the housing. The pump  8000  illustrated in FIG. 30 a  is substantially similar to the pump illustrated in FIG. 29 a , except for a couple of differences. First, the pump  8000  does not have an inner pouch  7100 . Instead, the elastic envelope portion  7300 , which include the front concertina portion  7022  and the rear bellows portion  7023 , extends into the rear to form a vial portion  7301 . The vial portion  7301  is substantially enclosed within a rigid exterior housing  8027 . Second, the rear plug  8200  incorporated in the exemplary embodiment of FIG. 30 a  is simpler than the rear plug  7200  incorporated in the pump  7000  shown in FIG. 29 a.    
     As shown in further detail in FIG. 30 b , the rear plug  8200  cooperates with the rear segment  7301   a  of the vial portion  7301  to provide a tight seal. The rear plug  8200  has an annular protrusion  8201  which is snap-fitted into a complementary annular recess  7302  formed in the rear segment  7301   a  of the vial portion  7301 , thereby providing a radial seal along the annular recess  7302 . The rear plug  8200  also has an annular flange  8202  which rests against an annular flange  7302  of the rear segment  7301   a  of the vial portion  7301 . The annular protrusion  8201  and the annular flange  8202  act in concert to provide vertical compression of the rear segment  7301   a . In this manner, the rear plug  8200  provides a tight seal of the rear segment  7301   a  of the vial portion  7301  along both the radial and vertical directions. 
     Turning to FIGS. 9 and 11, shown in these figures is a first exemplary embodiment of an aerosol tip or nozzle mechanism  32  which may be incorporated in the nasal dispenser system according to the present invention indicated generally by numeral  31 . The first exemplary embodiment of the aerosol tip mechanism  32  includes a flexible nozzle portion  310  having an outlet portion  3108  and fluid channels (or feed channels)  3104 , a rigid shaft  3102  received within the flexible nozzle portion  310 , and a rigid external housing  3101  surrounding the flexible nozzle portion  310  and exposing the outlet portion  3108 . The rigid shaft  3102  interfaces the interior of the outlet portion  3108  to form a first normally-closed valve  3105 , as well as to define a swirling chamber or collecting chamber  3103  for liquid which has been channeled from a liquid reservoir, e.g., a vial container, prior to being discharged via a pinhole formed at the end of the outlet portion  3108  of the aerosol tip mechanism  32 . 
     As shown in FIGS. 9 and 11, for the first exemplary embodiment of the aerosol tip mechanism, the fluid channels (also referred to as “feed channels”)  3104  initially extend longitudinally (vertically) along the walls  31021   a ,  31021   b  and  3102   c , which walls circumferentially surround the rigid shaft  3102 , then the fluid channels continue horizontally (radially) to deliver fluid into the swirling chamber  3103 . It should be noted that wall  31021   c  is only shown in FIG. 11, and not shown in FIG. 9, for the sake of clarity of illustration. The vertical portion of the feed channels is designated as  3104   a , and the horizontal portion is designated as  3104   b . The fluid channels  3104  are described in further detail in later sections. 
     A brief description of the fluid mechanics involved in the fluid channels  3104  and the swirling chamber  3103  is helpful here. The swirling chamber  3103  is used to create a spray pattern for the discharged medicament, and several factors affect the physical characteristics of discharged spray pattern. First, the length of the pinhole formed at the end of the outlet portion  3108  is the main parameter controlling the cone angle of the spray pattern, i.e., the shorter the length of the pinhole at the end of the outlet portion  3108 , the wider the spray pattern. Second, the greater the pressure differential between the outside and the inside of the pinhole opening at the end of the outlet portion  3108 , the greater the homogeneity of the particles and the smaller the particle size. Third, the smaller the diameter of the pinhole at the end of the outlet portion  3108 , the smaller the particle size in the spray. 
     In order to increase the homogeneity of the spray-particle size and generally reduce the particle size, the dispensing system according to the present invention maximizes the relative pressure differential between the outside and the inside of the pinhole opening at the end of the outlet portion  3108  by means of minimizing the resistance sources in the fluid path, also referred to as “head loss” in fluid mechanics. In this regard, the length of the fluid channel  3104  incorporated in the present invention is minimized, as well as the rate of reduction of the fluid-channel width as the fluid channel approaches the swirling chamber  3103 , and the rate of change of the fluid-channel angle relative to the swirling chamber, i.e., the transition from the vertical portion  3104   a  to the horizontal portion  3104   b  is made as gradually as possible without unduly extending the overall length of the fluid channel  3104 . Using the embodiment of the dispensing system incorporating the fluid channels and the swirling chamber shown in FIGS. 9 and 11, the average particle size of the discharged spray pattern was 40 μm. 
     As shown in FIGS. 9 and 11, three separate horizontal channel portions  3104   b  merge into the swirling chamber  3103 . In this configuration, additional reduction in head loss can be achieved by creating a relative difference in ramp slope α between the swirling chamber  3103  and the converging channel portions  3104   b , as shown in FIG. 28, such that the liquid  2801  already swirling in the swirling chamber  3103  is already halfway to the top of the swirling chamber when this liquid merges with the liquid  2802  entering the swirling chamber  3103  from an adjacent horizontal channel portion  3104   b.    
     A second exemplary embodiment of the aerosol tip or nozzle mechanism  32  according to the present invention is shown in FIGS. 14A and 14B. The second exemplary embodiment is substantially similar to the first exemplary embodiment, with one exception. In contrast to the first exemplary embodiment shown in FIGS. 9 and 11, the second exemplary embodiment of the aerosol tip or nozzle mechanism does not include walls  31021   a ,  31021   b  and  31021   c  circumferentially surrounding the rigid shaft  3102 , and the feed channel  3104  solely consists of obliquely vertically oriented channel extending along the interface of the exterior of the second portion  3102   a  of the rigid shaft and the interior surface of the flexible body portion  3107 . Accordingly, in the second embodiment, the obliquely vertically oriented feed channel  3104  is connected directly to the swirling chamber  3103 . 
     As shown in FIG. 9, the first exemplary embodiment of the aerosol tip or nozzle mechanism  32  according to the present invention is coupled to a flexible body portion  3107  which has a substantially tubular shape and a wall thickness which decreases from the bottom of the body portion toward the flexible nozzle portion  310 , along the elongated axis of symmetry of the body portion. The rigid shaft  3102  received within the flexible nozzle portion  310  extends down into the flexible body portion  3107  so that a second portion  3102   a  of the rigid shaft interfaces the flexible body portion  3107  to form a second normally-closed valve  3106 . 
     Referring generally to FIGS. 9 and 10, the fluid communication path  3201  of liquid from the liquid reservoir to the outlet portion  3108  successively traverses the first normally-closed valve  3106  and the second normally-closed valve  3105 . A pump mechanism  3110  of the nasal dispenser system generally indicated by reference numeral  31 , acting in concert with a pump-body portion  3111  of the dispenser system, channels the liquid from the liquid reservoir along the fluid communication path  3201  by application of pressure. A segment of the pump-body portion  3111  defines a portion of the first normally-closed valve  3106 , which prevents the outflowing liquid from reversing direction and flowing back towards the liquid reservoir. It should be noted that the nozzle mechanism according to the present invention is intended to be used in conjunction with a wide variety of liquid dispensing systems, one example of which was illustrated previously in connection with FIGS. 3-8E. It should be understood that the pump mechanism  3110  and the pump-body portion  3111  of the dispenser system shown in FIGS. 9 and 10 are merely exemplary and generic representation of a wide variety of dispensing systems. 
     As shown in FIGS. 9 and 10, the liquid from the liquid reservoir is initially channeled along the fluid communication path  3201  to the entrance point of the first normally-closed valve  3106  which regulates the liquid flow to the vertical portion  3104   a  of the feeding channel  3104  formed along the interface of the exterior of the second portion  3102   a  of the rigid shaft and the interior surface of the flexible body portion  3107 . Once the pressure on the liquid in the fluid communication path reaches a threshold pressure sufficient to radially deform the flexible body portion  3107 , a portion  3501  of the flexible body portion  3107  forming a lower segment of the first normally-closed valve  3106  is radially deformed by the liquid, thereby opening the first normally-closed valve  3106 , as shown in FIG.  13 A. As the liquid passes through the first normally-closed valve  3106  toward the vertical portion  3104   a  of the feeding channel  3104 , sequential segments of the flexible body portion  3107  forming the first normally-closed valve  3106  are radially deformed, as shown in FIGS. 13A and 13B, until the liquid finally traverses the upper-most segment  3502  of the flexible body portion  3107  forming the first normally-closed valve  3106  and passes into the vertical portion  3104   a  of the feeding channel  3104 . 
     As shown in FIGS. 13A and 13B, because the wall thickness of the flexible body portion  3107  decreases from the lower segment  3501  to the upper segment  3502  of the first normally-closed valve  3106 , i.e., along the elongated axis of symmetry S of the nozzle mechanism, the lower segment  3501  of the valve  3106  is substantially closed by the time the liquid has reached the upper segment  3502 . FIG. 13A illustrates the initial opening action of the segment  3501 , and FIG. 13B illustrates the subsequent opening of the upper segment  3502 . Because the energy required to open the lower segment  3501  of the valve  3106  is greater than the energy required to open the upper segment  3502 , the liquid is naturally biased to maintain its forward movement through the first valve  3106  in the flexible body portion  3107  once the lower segment  3501  has been opened. In this manner, the first normally-closed valve  3106  ensures liquid movement only in the direction towards the vertical portion  3104   a  of the feeding channel  3104 . 
     Once the liquid in the fluid communication path  3201  has traversed the first normally-closed valve  3106 , the liquid then enters the vertical portion  3104   a  of the feed channel  3104  extending along the interface of the exterior of the second portion  3102   a  of the rigid shaft and the interior surface of the flexible body portion  3107  of the first embodiment of the aerosol tip mechanism  32 , as shown in FIGS. 9,  10  and  11 . The feed channel  3104  defines the portion of the fluid communication path  3201  between the first normally-closed valve  3106  and the swirling chamber  3103 , and the vertical portion  3104   a  of the feed channel is connected to a horizontal, i.e., radial, portion  3104   b  of the feed channel which in turn is connected tangentially to the cylindrical swirling chamber  3103  within the flexible nozzle portion  310 , as shown in FIGS. 11,  13 A and  13 B. The tangential connector of the horizontal portion  3104   b  of the feed channel  3104  to the cylindrical swirling chamber  3103  creates a swirling action of the liquid in the swirling chamber as indicated in FIG. 11 by the directional arrow  3301 . 
     In the second embodiment of the aerosol tip mechanism shown in FIGS. 14A and 14B, the feed channel  3104  consists of only the obliquely vertical portion, designated  3104   c , extending along the interface of the exterior of the second portion  3102   a  of the rigid shaft and the interior surface of the flexible body portion  3107 . Accordingly, in the second embodiment of the aerosol tip mechanism, the liquid directly enters the swirling chamber  3103  via the obliquely vertically oriented feed channel  3104   c  once the liquid in the fluid communication path  3201  has traversed the first normally-closed valve  3106 . The swirling action of the liquid, which is indicated by the directional arrow  3301  and is induced by the tangential (oblique) orientation of the feed channel  3104   c  relative to the swirling chamber  3103 , is maintained in the swirling chamber until the liquid is discharged via the outlet portion  3108 , the mechanics of which discharging action is described in detail below. 
     Referring generally to FIGS. 9,  12 A and  12 B, the liquid in the swirling chamber is discharged via the outlet portion  3108  when the liquid pressure reaches a threshold pressure sufficient to radially deform the outlet portion  3108  forming the second normally-closed valve  3105 . As with the first normally-closed valve  3106  described above, the liquid movement through the second normally-closed valve  3105  involves sequential deformation of segments of the outlet portion  3108 . As shown in FIG. 12A, a portion  3401  of the outlet portion  3108  forming a lower segment of the second normally-closed valve  3105  is radially deformed by the liquid, thereby opening the second normally-closed valve  3105 . As the liquid passes through the second normally-closed valve  3105  toward the tip of the outlet portion  3108 , sequential segments of the outlet portion  3108  forming the second normally-closed valve  3105  are radially deformed, as shown in FIGS. 12A and 12B, until the liquid finally passes through the upper-most segment  3402  of the outlet portion  3108  forming the second normally-closed valve  3105 . 
     As shown in FIGS. 9,  12 A and  12 B, the wall thickness of the outlet portion  3108  decreases from the lower segment  3401  towards the upper segment  3402  of the second normally-closed valve  3105 , i.e., along the elongated axis of symmetry S of the aerosol tip or nozzle mechanism. Due to this steady decrease in wall thickness, the lower segment  3401  of the valve  3105  is substantially closed by the time the liquid has reached the upper segment  3402 , as shown in FIGS. 12A and 12B. Because the energy required to open the lower segment  3401  of the valve  3105  is greater than the energy required to open the upper segment  3402 , the liquid is naturally biased to maintain its forward movement through the second valve  3105  in the outlet portion  3108  once the lower segment  3401  has been opened. Accordingly, the valve  3105  ensures liquid movement only in the direction towards the exterior tip of the nozzle portion  310 . 
     During the discharge of liquid through the outlet portion  3108 , the only segment of the flexible nozzle portion  310  which experiences deformation along the elongated axis of symmetry S of the aerosol tip or nozzle mechanism is the outlet portion  3108 . The remaining segments of the flexible nozzle portion are prevented by the rigid housing  3101  from deformation along the elongated axis of symmetry S. Even the outlet portion  3108  experiences only minimal deformation along the axis S; the significant deformation is along the radial direction. Furthermore, the outlet portion  3108  does not exert a force along the axis S on the rigid shaft  3102 , i.e., the outlet portion  3108  does not rub the rigid shaft during opening or closing of the second valve  3105 . Accordingly, because of the absence of any rubbing contact between the outlet portion  3108  and the rigid shaft  3102 , the chances of contaminants entering the swirling chamber  3103  are minimized. 
     One advantage of the aerosol tip or nozzle mechanism according to the present invention is the above-described prevention of axial deformation of the flexible nozzle portion  310  by the rigid housing  3101 . Because the flexible nozzle portion  310 , with the exception of the outlet portion  3108 , experiences substantially no deformation along the elongated axis of symmetry S shown in FIG. 12A, the physical profile of the fluid channel  3104 , which induces swirling action of the liquid channeled into the swirling chamber  3103 , is maintained during liquid discharge. An axial deformation of the flexible nozzle portion  310  along the direction of liquid discharge would deform the fluid channel  3104 , which in turn would prevent the swirling action from occurring. 
     In the above-described embodiment of the aerosol tip or nozzle mechanism according to the present invention, the flexible nozzle portion  310 , the flexible body portion  3107  and the pump-body portion  3111  may be made of any one of several materials well known in the art, including butadiene polyethylene styrene (KRATON™), polyethylene, polyurethane or other plastic materials, thermoplastic elastomers or other elastic materials. KRATON™ is particularly well suited for this purpose because of its characteristic resistance to permanent deformation, or “creep,” which typically occurs with passage of time. 
     Another advantage of the aerosol tip or nozzle mechanism according to the present invention is that the number of parts which constitute the nozzle mechanism and, in turn, the nasal dispenser system which includes a pump mechanism in combination with the nozzle mechanism, is significantly reduced in comparison to conventional nozzle mechanisms. As can be seen from FIG. 9, a nasal dispenser system incorporating the nozzle mechanism according to the present invention can be made using only three discrete parts: the rigid housing  3101 ; an integral, flexible piece encompassing the flexible nozzle portion  310 , the flexible body portion  3107  and the pump-body portion  3111 ; and the rigid shaft  3102  formed integrally with the pump mechanism  3110 . Because only three discrete parts are required, the cost and complexity of manufacturing the nasal dispenser system is significantly reduced. 
     Yet another advantage of the aerosol tip or nozzle mechanism according to the present invention is that the second normally-closed, one-way valve  3105  with its decreasing wall thickness of the outlet portion  3108  substantially eliminates the possibility that liquid in the nozzle mechanism will come in contact with ambient air and subsequently return to the interior portion of the nozzle mechanism, i.e., that the liquid will be “sucked back.” Due to the decreasing wall thickness of the outlet portion  3108 , the liquid is naturally biased to maintain its forward movement through the second valve  3105  in the outlet portion  3108  once the thicker base portion of the valve has been opened. Accordingly, the outlet portion  3108  has a substantially zero “dead volume,” i.e., a space in which liquid that has been previously exposed to ambient air can remain. 
     Still another advantage of the aerosol tip or nozzle mechanism according to the present invention is that the outlet portion  3108  does not rub the rigid shaft  3102  during opening or closing of the second valve  3105 . Accordingly, because of the absence of any rubbing contact between the outlet portion  3108  and the rigid shaft  3102 , the chances of contaminants entering the swirling chamber  3103  are minimized. 
     Still another advantage of the aerosol tip or nozzle mechanism according to the present invention is the presence of multiple valves along the fluid communication path leading to the outlet portion  3108 . In addition to the second normally-closed valve, the first normally-closed valve positioned along the fluid communication path between the liquid reservoir and the outlet adds further assurances that liquid in the liquid reservoir will not be contaminated by liquid that may have been accidentally exposed to ambient air and subsequently reintroduced into the nozzle mechanism. Because the first and second normally-closed valves are positioned along the fluid communication path to open sequentially, and hence asynchronously, during fluid communication leading to discharge through the outlet, failure of either one of the valves will not affect the integrity of the nozzle mechanism to prevent contamination of the liquid in the liquid reservoir. 
     The medicament-dispensing system according to the present invention also incorporates a one-way actuation release mechanism, shown in FIGS. 15-17, in connection with the housing  101 , shown in FIG. 1, which is adapted to house and work in conjunction with the accordion-like or piston-like vial-dispenser  4200 , also shown in FIGS. 15-17. It should be understood that the vial-dispenser  4200  depicted in FIGS. 15-17 is a generalized representation of a system combining the pump system shown in FIGS. 3-8 and the nozzle mechanism shown in FIGS. 9-14, and the description of the components shown in FIGS. 15-17 will also be a generalized description of the corresponding components shown in FIGS. 3-14. Although the present invention is described in conjunction with the vial-dispenser generally depicted in FIGS. 15-17 and specifically depicted in FIGS. 3-14, the present invention is not limited to this particular type of dispenser, i.e., the pump system and the nozzle mechanism may be different from the ones described herein. 
     As shown in FIG. 15, the vial-dispenser generally depicted at  4200  includes a nozzle  42 , a front ring  43 , a front bellows portion  44 , a rear ring  46 , a rear bellows portion  47  and a rear vial section or liquid storage chamber  48  containing a storage supply of liquid medicament. The vial-dispenser  4200  is compressible in the longitudinal direction along the bellows. For this purpose, the front and rear bellows portions  44  and  47 , respectively, are constructed of a soft flexible plastic material such as Kraton®. Resiliency of the dispenser is provided by the spring action of the front and rear bellows made of Kraton®, which has an excellent memory and serves as an excellent spring. It should be noted that the rear bellows portion  47  shown in FIG. 15 has a dome shape, and this dome shape may be incorporated into the front bellows portion  44 . Similarly, the shape of the front bellows portion  44  shown in FIG. 15 may be incorporated into the rear bellows portion  47 . 
     As shown in FIG. 16, the vial-dispenser  4200  further includes a drop cavity, or dosage cavity,  431  therein which holds, when the dispensing system is activated, a predetermined volume of fluid to be emitted through the nozzle  42 . In addition, a pump piston  49  within the vial-dispenser is anchored to the rear ring  46  such that the piston  49  moves in unison with the rear ring  46 . Furthermore, as shown in FIGS. 15 and 16, conduit channels  410 , which connect the rear vial section  48  to the front bellows portion  44 , and circumferential channels  411  within the front bellows portion  44 , are provided to serve as conduits for supplying medicament to the drop cavity  431  upon actuation of the dispensing system. As will be described in further detail below, a single actuation motion of the trigger mechanism of the dispensing system sequentially accomplishes filling, or loading, of the drop cavity with medicament from the rear vial section  48 , and subsequent discharge of the medicament from the drop cavity via the nozzle  42 . 
     As illustrated in FIG. 15, which represents a cross sectional view taken along the longitudinal axis of the dispensing system shown in FIG. 1, contained within the housing exterior housing  101  (not shown) is a cartridge  4101  of the dispensing system that includes an anterior wall  4104  which has an aperture  4106  for the discharge of medicament from the nozzle  42 , a posterior wall  4105 , wedge-shaped arms  4103  which extend internally from the posterior wall  4105 , a trigger  1103  and an internal notched lever  4102  which acts in concert with the trigger  1103 . It should be noted that although this particular embodiment is illustrated as having a separate external housing  101  and an internal cartridge  4101 , some or all components of the external housing and the internal cartridge may be combined, e.g., the trigger button  103  of the external housing  101  shown in FIG. 1 may be the same component as the internal trigger  1103  shown in FIG.  15 . 
     As shown in FIG. 15, the vial-dispenser  4200  is positioned within the cartridge  4101  such that in resting position the front ring  43  rests against the anterior wall  4104 , the rear vial section  48  rests against the posterior wall  4105 , and the notched lever  4102  engages the rear ring  46 . Preferably, the cartridge  4101  is dimensioned such that the dispenser  4200  can fit snugly within the cartridge, with the nozzle  42  completely receded within the aperture  4106  of the anterior wall  4104 , thereby preventing accidental contact of the nozzle  42  with the eye, as well as preventing contamination of the outside of the nozzle. In addition, the posterior wall  4105  may form, in conjunction with the wedge-shaped arms  4103 , a rear chamber for accommodating the rear vial section  48 . 
     From the rest position illustrated in FIG. 15, the dispensing system according to the present invention is actuated by depressing the trigger  1103 . In concert with the depression of trigger  1103 , the notched lever  4102  moves laterally towards the posterior wall  4105  while engaged to the rear ring  46 , thereby extending the front bellows portion  44  and compressing the rear bellows portion  47  along the longitudinal axis of the vial-dispenser  4200 , as shown in FIG.  16 . As can be seen from FIGS. 15 and 16, when the front bellows portion is extended by the notched lever  4102  which is engaged to the rear ring  46 , the internal pump piston  49  is also moved laterally towards the posterior wall  4105 . The combined movement of the front bellows  44 , the pump piston  49  and the rear bellows  47  causes drop in pressure in the drop cavity  431 , and the drop cavity is filled, or “loaded,” with medicament channeled from the rear vial section  48  via the conduit channels  410  and circumferential channels  411 . 
     Continuing with the actuation sequence, further depression of the trigger  1103  causes the notched lever  4102  to eventually reach a position where the notched lever comes in contact with the wedge-shaped arm  4103 . At this point, the wedge-shaped arm engages the notched lever  4102  and lifts the notched lever clear of the rear ring  46 , as shown in FIG.  17 . Upon release from the notched lever  4102 , the spring action of the front bellows portion  44  and the rear bellows portion  47  causes the rear ring  46  and the pump piston  49  to move towards the anterior wall  4104 , as shown in FIG.  17 . The movement of the pump piston  49  creates pressure which forces the medicament to be discharged from the drop cavity  431  via the nozzle  42 . Subsequently, when the trigger  1103  is released, the notched lever  4102  is disengaged from the wedge-shaped arm  4103 , and the spring action of the notched lever  4102  allows the notched lever to snap back into the resting position shown in FIG.  15 . 
     As can be seen from the above description, one advantage of the dispensing system according to the present invention is that there is virtually no possibility of the front and rear bellows portions exhibiting hysteresis of spring characteristics since the front and rear bellows portions are never “locked” in a deformed state for an extended period of time. Accordingly, the dispensing system according to the present invention ensures that the discharged dosages do not substantially deviate from the calibrated dosage. The consistency of the dispensed dosages is also ensured by the fact that the actuation spring force is independent of the force applied to the actuation mechanism by the user. 
     Another advantage of the dispensing system according to the present invention is that the actuation motion of the trigger  1103  is perpendicular to the longitudinal axis of the dispensing system. Accordingly, there is little danger of accidental poking of the nasal passage with the nozzle  42  since the motion to depress the trigger is not in the direction of the nasal passage. 
     Yet another advantage of the dispensing system according to the present invention is that a single actuation motion of the trigger  1103  perpendicular to the longitudinal axis of the dispensing system enables the user to both load the drop cavity and subsequently discharge the precalibrated amount of medicament. The dispensing system according to the present invention is particularly useful for arthritic patients and young children because the trigger mechanism is a lever which allows for very easy actuation and release of a medicament drop, thereby enabling more accurate delivery of the medicament drop to the nasal passage. 
     In order to facilitate fast, efficient and aseptic filling, the nasal dispenser system according to the present invention may incorporate a mechanical closure system for the liquid container portion of the system, e.g., the rear vial section generally indicated by reference numeral  48  in FIG.  15 . As shown in FIG. 18, which is an exploded view of a first exemplary embodiment of a mechanical closure system according to the present invention, the first embodiment includes a mechanical lid or plug  5101  and a rigid annular ring  5102 , both of which interact with a neck region  5103   d  near an opening  5103   b of a pouch or container  5103  to tightly seal the opening  5103   b . The pouch or container  5103  may be made of any one of several materials well known in the art, including butadiene polyethylene styrene (KRATON™), polyethylene, polyurethane or other plastic materials, thermoplastic elastomers or other elastic materials. As shown in FIG. 18, the container  5103 , which has a nozzle  5103   a , is a generalized representation of a medicament dispensing system with a nozzle, for example, the vial dispenser  4200  shown in FIG.  15 . However, it should be noted that the neck region  5103   d  near the opening  5103   b  of the nozzle  5103  is a more detailed, exemplary depiction of the corresponding portion of the rear vial section  48  shown in FIG. 15, i.e., the end portion facing the wall  4105 , which end portion is shown without a mechanical closure element. 
     As shown in FIG. 18, which is an exploded cross-sectional view of the first embodiment of the mechanical closure system according to the present invention, the contour of the rigid ring  5102  is complementary to the inside contour  5103   c  of the neck region  5103   d  of the container  5103  near the opening  5103   b , thereby allowing the rigid ring  5102  to be snapped into the inside contour  5103   c  of the neck region  5103   d . Similarly, as shown in FIGS. 18 and 19, radial edge  5101   a  of the mechanical plug  5101  is formed as a U-shaped region which extends around the plug and complements the exterior contour of the combination of the rigid ring  5102  and the neck region  5103   d . After the rigid ring  5102  has been snapped into the inside contour  5103   c  of the neck region  5103   d , the mechanical plug  5101  is subsequently snapped into place around the container opening  5103   b  such that the U-shaped region  5101   a  tightly engages the neck region  5103   d  of the pouch  5103  and the interior surface of the rigid ring  5102 . 
     As shown in FIG. 19, the U-shaped region  5101   a  of the mechanical plug  5101  has protrusions  51013 ,  51014  and  51015 , and at least one recess  51016 . Similarly, the exterior surface of the neck region  5103   d  of the mechanical plug has protrusions  51031  and  51033 , and the interior surface of the neck region has a protrusion  51035 . In addition, the rigid ring  5102  has recesses  51021  and  51022  at the vertical interior surface  5102   a  and the bottom surface, respectively. The recess  51022  of the rigid ring  5102  accommodates the protrusion  51035  of the neck region  5103   d , thereby securely engaging the rigid ring to the neck region of the container  5103  once the rigid ring has been snapped into place. The protrusions  51013 ,  51014  and  51015 , as well as a portion  51018 , of the U-shaped region  5101   a  of the mechanical plug engage the recess  51021  of the rigid ring and portions  51034 ,  51036  and  51037  of the exterior surface of the neck region  5103   d , respectively. In addition, the protrusions  51031  and  51033  of the exterior surface of the neck region  5103   d  engage a portion  51017  and the recess  51016  of the U-shaped region  5101   a  of the mechanical plug. 
     In addition to the above-described combinations of interlocking protrusions and recesses, attached to the lower surface of the mechanical plug  5101  are at least two legs  51011  which extend perpendicularly to the lower surface of the mechanical plug, as shown in FIG.  19 . Each of the legs  51011  has a hook-shaped end portion  51012  adapted to engage a recess region  51032  at the bottom interior of the assembled combination of the rigid ring  5102  and the neck region  5103   d  of the mechanical plug. The legs  51011  are flexible enough such that, during assembly of the mechanical closure system according to the present invention, the legs  51011  slide down the vertical interior surface  5102   a  of the rigid ring and snap into place at the recess region  51032 , against a portion  51038  of the neck region  5103   d  of the container. 
     The combination of the U-shaped region  5101   a  and the legs  51011  of the mechanical plug  5101  facilitates both vertical and radial compression of the neck region  5103   d  of the container and the rigid ring against the mechanical plug. For example, as shown in FIG. 19, the portion  51012  of the legs  1011  interact with the portion  51023  of the rigid ring and the portion  51038  of the neck region  5103   d  of the container, and portions  51014  and  51018  of the mechanical plug interact with portions  51034  and  51037  of the neck region  5103   d  of the container, respectively, to vertically compress the neck region between the mechanical plug  5101  and the rigid ring  5102 . Similarly, the portions  51013 ,  51015  and  51017  of the U-shaped region  5101   a  of the mechanical plug  5101  interact with the portions  51021 ,  51036  and  51031 , respectively, to radially compress the neck region  5103   d  between the mechanical plug and the rigid ring  5102 . In this manner, a substantially hermetic seal of the container opening  5103   b  is achieved, as shown in FIG.  20 . 
     As can be understood from the above description and FIGS. 19 and 20, the first embodiment of the mechanical closure system according to the present invention achieves two types of mechanical seals. First, a seal extending along the horizontal direction of the neck region, e.g., the area extending between the portions  51034  and  51037 , as well as the interface of the regions  51022  and  51035 , is achieved by the vertical compression of the neck region  5103   d  by the mechanical plug against the rigid ring  5102 . Second, a seal extending along the vertical direction, e.g., the area extending between the portions  51036  and  51034 , as well as the interface of the regions  51021  and  51013 , is achieved by the horizontal compression of the neck region  5103   d  by the mechanical plug against the rigid ring  5102 . 
     Once the mechanical plug has been snapped into the container opening, the resulting compression of the container material tends to cause displacement, or “creep,” of the compressed material towards areas of lesser compression. The protrusions force the container material displaced by compression to be confined within a restricted area, thereby ensuring the tightness of the seal for a prolonged period of time. For example, the protrusions  51014  and  51015  of the mechanical plug  5101  delimits the protrusion  51031  on the exterior surface of the neck region  5103   d  of the container. Accordingly, when the material of the protrusion  51031  is initially compressed by the portions  51015  and  51017 , the displaced material of the protrusion  51031  is forced towards the protrusion  51014 , which limits any further movement of the displaced material, thereby maintaining a tight seal. In effect, the relative arrangement of protrusions  51014 ,  51015  and  51031  constructively guides the creeping phenomenon for sealing enhancement. 
     As shown in FIGS. 19 and 20, the central portion of a lower surface  51019  of the mechanical plug  5101  is preferably equipped with an extension or a plunger  51017  which is adapted to extend into the liquid content of the container before the mechanical plug  5101  has been snapped into place around the container opening  5103   b . The inserted plunger  51017  forces the liquid level to rise, hence allowing air or gas bubbles to rise along with the liquid level and escape through the container opening  5103   b  which is not yet sealed by the mechanical plug  5101 . In this manner, the plunger  51017  substantially reduces the residual air bubbles which may otherwise remain between the surface of the liquid and the lower surface of the mechanical plug. The configuration and dimensions of the mechanical plug  5101 , the neck region  5103   d  and the rigid ring  5102  are such that the U-shaped region  5101   a  and the legs  51011  of the mechanical plug interact with the neck region  5103   d  and the rigid ring  5102  to form a tight seal only after the plunger  51017  has forced the liquid level to rise to approximately the upper edge of the neck region  5103   d , thereby obviating the need for a vacuum condition normally utilized for an air-less filling process. 
     The lower surface  51019  of the mechanical plug  5101  is sloped in order to ensure that the air or gas bubbles which have been forced up to the surface level of the liquid by the insertion of the plunger  51017  are not trapped between the liquid level and the lower surface of the mechanical plug. The sloped surface  51019  facilitates radially upward movement of the air bubbles which eventually escape through the opening  5103   b  of the container, via the area between the two legs  51011 . 
     As shown in FIG. 21, which is an exploded cross-sectional view of a second exemplary embodiment of a mechanical closure system according to the present invention, the second embodiment of the present invention is substantially similar to the first embodiment and includes a mechanical plug or plug  5401  and a rigid annular ring  5402 , both of which interact with a neck region  5403   d  of a pouch or container  5403 . As in the first embodiment described in conjunction with FIGS. 18-20, the contour of the rigid ring  5402  is complementary to the inside contour of the neck region  5403   d  of the container  5403 , thereby allowing the rigid ring  5402  to be snapped into the inside contour of the neck region  5403   d . In addition, radial edge  5401   a  of the mechanical plug  5401  is formed as an arch-shaped region which extends around the plug and complements the exterior contour of the combination of the rigid ring  5402  and the neck region  5403   d . After the rigid ring  5402  has been snapped into the inside contour of the neck region  5403   d , the mechanical plug  5401  is subsequently snapped into place around the container opening  5403   b  defined by the neck region  5403   d  such that the arch-shaped region  5401   a  tightly engages the neck region  5403   d  of the pouch  5403  and the rigid ring  5402 , as shown in FIG.  22 . 
     As with the first embodiment of the mechanical closure system, the lower surface  54019  of the mechanical plug  5401  of the second embodiment is sloped, or tapered, in order to ensure that the air or gas bubbles which have been forced up to the surface level of the liquid by the insertion of the plunger  54017  are directed radially upward and eventually escape through the opening  5403   b  of the container, via the area between the two legs  54011 . 
     In addition, similar to the first embodiment of the mechanical closure system, the second embodiment shown in FIGS. 21 and 22 preferably have at least two legs  54011  attached to the lower surface of the mechanical plug  5401 , each of the legs having a hock-shaped region  54012  at the end. The hook-shaped region  54012  is adapted to engage a region  54023  at the bottom surface of the rigid annular ring  5402 . In addition, attached to the central lower surface of the mechanical plug  55401  is an extension or a plunger  54017  which is adapted to extend into the liquid content of the container before the mechanical plug  5401  is snapped into place around the container opening  5403   b , thereby substantially reducing the residual air bubbles which may otherwise remain between the surface of the liquid and the lower surface of the mechanical plug. 
     The second embodiment of the mechanical closure system according to the present invention utilizes fewer protrusions on the surfaces of the mechanical plug  5401  and the neck region  5403   d  than the number of protrusions found on the corresponding parts of the first embodiment. However, the unique arrangement of the interacting components, i.e., the mechanical plug  5401 , the rigid ring  5402  and the neck region  5403   d , ensures a substantially hermetic seal of the pouch  5403 . As shown in FIGS. 21 and 22, a protrusion  54015  and a region  54017  of the mechanical plug interact with a region  54031  of the neck region  5403   d , which region  54031  includes a protrusion from the regular contour of the exterior surface of the neck region  5403   d , and a portion  54016  of the mechanical plug interacts with the region  54022  of the rigid ring  5402 , thereby achieving radial compression of the rigid ring  5402  and the neck region  5403   d . In addition, portions  54016  and  54012  of the mechanical plug interact with regions  54022  and  54023  of the rigid ring  5402  to vertically compress the neck region  5403   d  and the rigid ring  5402 . 
     In order to ensure that the displacement or creep of the container material around the points of compression does not result in reduced tightness of the seal, the second embodiment of the mechanical closure system provides the protrusion  54015  at the radial edge of the mechanical plug  5401 . As shown in FIGS. 21 and 22, the protrusion  54015  forces the container material of region  54031  displaced by compression to be channeled upwards, towards a space  54018  delimited by the annular rigid ring  5402 . Accordingly, the protrusion  54015  and the rigid ring  5402  confine the displaced material of the region  54031  of the container  5403 , thereby maintaining a tight seal for a prolonged period of time. 
     As an alternative means of facilitating an efficient and aseptic filling and closure of the phial-type pump mechanism incorporated in the nasal dispenser system according to the present invention, a “self-crimping” mechanical closure system may be utilized. FIG. 23 a  shows a perspective view of a neck  6102  of a container or pouch  6100  adapted for use in connection with an exemplary embodiment of the self-crimping mechanical closure system. The container  6100  is another generalized depiction of the rear vial section  48  shown in FIG. 15, and the neck  6102  is a more detailed, exemplary depiction of the corresponding portion of the rear vial section  48 , i.e., the end portion facing the wall  4105 , which end portion is shown without a mechanical closure element. 
     As shown in the cut-away view of the container  6100  illustrated in FIG. 23 b , the neck  6102  includes an inner face  6106  and an outer face  6108 . A substantially semicircular first recess or groove  6110  is provided on the inner face  6106  of the neck  6102  near an opening  6104  of the container  6100 . The first groove  6110  may extend substantially around the entire circumference of the inner face  6106  of the neck  6102 . 
     A first protrusion  6112  is provided on the outer face  6108  of the neck  6102 , and extends substantially around the entire circumference of the outer face  6108 . The first protrusion  6112  includes a substantially semicircular upper portion  6112   a  and a substantially angular lower portion  6112   b . The upper portion  6112   a  of the first protrusion  6112  may be substantially vertically aligned with the substantially semicircular first groove  6110  located on the inner face  6106  of the neck  6102  so that, in a cross-sectional view as shown in FIG. 23 b , a substantially semicircular shell is formed by the first groove  6110  and the upper portion  6112   a  of the first protrusion  6112 . 
     An annular rim  6114  may be provided on top of the substantially semicircular shell formed by the first groove  6110  and the first protrusion  6112 . The annular rim  6114  is outwardly offset in relation to the neck  6102  of the container  6100 , and the annular rim  6114  defines the opening of the container  6100 . 
     FIG. 24 a  shows a further perspective view of the exemplary embodiment of the self-crimping mechanical closure system according to the present invention, which includes a rigid mechanical plug  6200  and a rigid crimping element  6300 . As shown in the cut-away view of FIG. 24 b , the mechanical plug  6200  is coupled to the crimping element  300  via a breakaway flange  6400 . The mechanical plug  6200  includes a floor  6202 , and a plug wall  6204  that extends normal to and surrounds the entire circumference of the floor  6202 . 
     Since the mechanical plug  6200  is detachably coupled to the crimping element  6300  via the breakaway flange  6400 , the mechanical plug  6200  and crimping element  6300  may be manufactured as a single-piece element. This simplifies the handling process, and the sealing process since the mechanical plug  6200  and the crimping element  6300  may be handled together. The breakaway flange  6400  may be designed or constructed of a certain material to allow for the removal and reinsertion of the mechanical plug  6200 /crimping element  6300  combination from the neck  6102  of the container, and only breaking upon an application of a predetermined amount of force. Although this exemplary embodiment includes the mechanical plug  6200  and the crimping element detachably coupled together via the breakaway flange  6400 , those skilled in the art will understand that other coupling mechanisms, e.g., a hinged flange, may also be implemented without departing from the scope of the present invention. 
     The floor  6202  of the mechanical plug  6200  has a substantially flat top surface  6202   a  and a bottom surface  6202   b  that is tapered from a radial outer edge  6202   c  towards a center portion  6202   d  of the floor  6202 , so that the vertical thickness of the floor  6202  increases from the radial outer edge  6202   c  to the center portion  6202   d . As the mechanical plug  6200  is inserted in the container  6100 , the tapered shape of the bottom surface  6202   b  allows for any liquid content in the container to be directed towards the radial outer edge  6202   c  of the floor  6202 . A plunger  6500  may also be provided at the center portion  6202   d  of the bottom surface  6202   b  of the floor  6202 , extending substantially perpendicular to the floor  6202 . This plunger  6500  would allow for further displacement of the liquid content towards the radial outer edge  6202   c  of the floor  6202 . 
     As discussed above, the plug wall  6204  surrounds the circumference of the floor  6202 . A substantially semicircular second protrusion  6212  is formed in an exterior surface  6210   a  of a lower portion  6210  of the plug wall  6204 . The second protrusion  6212  may extend substantially completely around the entire circumference of the exterior surface  6210   a.    
     As shown in FIG. 24 b , an interior surface  6210   b  of the lower portion  6210  of the plug wall  6204  may be initially perpendicular to the top surface  6202   a  of the floor  6202 , and then curve away from a radial center  6250  of the floor  6202  to adjoin an interior surface  6220   b  of an upper portion  6220  of the plug wall  6204 . The upper portion  6220  of the plug wall  6204  is substantially parallel to but offset radially outward from the interior surface  6210   b  of the lower portion  6210  of the plug wall. 
     Continuing with FIG. 24 b , a cross-sectionally substantially triangular overhanging shoulder  6230  may extend from the top of the exterior surface  6220   a  of the plug wall  6204 . A breakaway flange  6400  may be provided on the overhanging shoulder  6230  to detachably couple the mechanical plug  6200  to the crimping element  6300 . 
     The crimping element  6300  includes a compressing ring  6302  and a conical-shaped brim  6304 . An exterior surface  6302   a  of the compressing ring  6302  may be substantially parallel to the upper portion  6220  of the plug wall  6204 . A bottom portion  6302   d  of the interior surface  6302   b  of the compressing ring  6302  may be tapered and adjoin a substantially semicircular second groove  6310  formed in the interior surface  6302   b  of the compressing ring  6302 . The second groove  6310  may extend substantially around the entire circumference of the interior surface  6302   b  of the compressing ring  6302 . 
     As shown in FIG. 24 b , the brim  6304  extends from the compressing ring  6302  of the crimping element  6300  and angles into the interior of the crimping element  6300 . The brim  6304  may have an inner diameter L 1  that is slightly smaller than an outer diameter L 2  of the overhanging shoulder  6230  on the mechanical plug  6200 . L 1  and L 2  should be dimensioned so that the brim  6304  may be slid over the overhanging shoulder  6230  of the mechanical plug  6200  with a sufficient downward force, but then the brim  6304  will then be positioned underneath the shoulder  6230  to prevent substantial upward movement of the crimping element  6300 . 
     As shown in FIG. 25, which is a cross-sectional view of the mechanical plug  6200  inserted into the opening  6104  of the neck  6102  of the container  6100 , the mechanical plug  6200  is inserted into the opening  6104  until the semicircular first groove  6110  on the interior surface  6106  of the neck  6102  is mated with the second protrusion  6212  on the exterior surface  6210   a  of the mechanical plug  6200 . As discussed above, the interior surface  6106  of the neck  6102 , including an interior portion  6114   a  of the rim  6114 , and the exterior surface  6210   a  of the mechanical plug  6200  have been designed and proportioned so that these elements interlock as shown in FIG.  25 . 
     The exterior surface portions  6210   a ,  6220   a  and the second protrusion  6212  of the mechanical plug  6200  may preferably be dimensioned so that, when the mechanical plug  6200  is inserted within the neck  6102  of the container, they directly abut the interior portions  6114 ,  6106  of the neck  6102  of the container  6100  and the first groove  6110  on the neck  6102  of the container is mated with the second protrusion  6212  of the mechanical plug. Thus, as shown in the configuration illustrated in FIG. 25, the rigidity of the mechanical plug  6200  provides substantial resistance to any inward compression of the neck  6102  of the container  6100 . In addition, the interaction between the first groove  6110  on the neck  6102  and the second protrusion  6212  of the mechanical plug  6200  provides resistance to any vertical movement of the mechanical plug  6200  within the neck  6102  of the container  6100 . 
     Of course, since the crimping element  6300  has not yet been locked into place in the configuration shown in FIG. 25, a predetermined amount of force in an upwards direction may dislodge the mechanical plug  6200  from within the neck  6102  of the container  6100 . This allows the container  6100  to be transferred through potentially contaminated areas and then opened for operations such as, for example, filling the container  6100 . Upon completion of the operation necessitating the removal of the mechanical plug  6200 , the mechanical plug  6200  may then be re-inserted into the neck  6102  of the container  6100  and “snapped” into place as shown in FIG.  25 . 
     In the process of inserting the mechanical plug  6200  into the neck  6102  of the container  6100 , the plunger  500  on the bottom surface  6202   b  of the floor  6202  will also be inserted into any material, e.g., liquid, disposed within the container  6100 . The insertion of the plunger  6500  into the material within the container  6200  will cause a displacement within the material which may be taken advantage of in an exemplary process according to the present invention by setting the amount of material in the container  6100  to a predetermined level so that the displacement caused by the insertion of the plunger  6500  causes the top level of the material to rise to a point directly adjacent to the bottom portion  6202  of the mechanical plug  6200 . Thus, the insertion of the mechanical plug  6200  with the plunger  6500  attached thereto may cause any air bubbles or excess gas to be displaced from within the container  6100 , thereby achieving a substantially airless condition within the container  6100 . 
     FIG. 26 shows a cross-sectional view of a sealed configuration of the mechanical closure system according to the present invention. Starting with the configuration as shown in FIG. 25, a sufficient downward force is applied to the crimping element  6300  to break the flange  6400  that couples the crimping element  6300  to the mechanical plug  6200 . The downward force applied to the crimping element  6300  should also be sufficient to slide the crimping element  6300  over the neck  6102  of the container  6100  and simultaneously “snap” the upper portion  6112   a  of the first protrusion  6112  on the neck  6102  of the container  6100  into the second groove  6310  on the interior surface  6302   b  of the crimping element  6300 . The tapered shape of the bottom portion  6302   d  of the crimping element  6300  facilitates sliding the crimping element  6300  over the upper portion  6112   a  of the first protrusion  6112 . Once the crimping element  6300  is slid over the neck  6102 , the bottom portion  6302   d  of the crimping element  6300  rests against the angular bottom portion  6112   b  of the first protrusion  6112  on the neck  6102 . 
     The crimping element  6300  may preferably be composed of a substantially rigid material and dimensioned to snugly encircle the neck  6102  of the container  6100 . Thus, as shown in FIG. 26, the neck  6102  of the container  6100  will then be compressed between the crimping element  6300  and the plug wall  6204  of the mechanical plug  6200 , thereby creating a tight, hermetic seal for the container  6100 . 
     In the configuration shown in FIG. 26, the substantially conical shape of the brim  6304  of the crimping element  6300  and the dimensions of the brim  6304  and the overhanging shoulder  6230  on the mechanical plug  6200  allow a top section  6304   a  of the brim  6304  to extend underneath the overhanging shoulder  6230 . This substantially prevents the crimping element  6300  from sliding up and off the neck  6102  of the container  6100 , thereby further maintaining the crimping element  6300  on the neck  6102  of the container  6100 . 
     FIGS. 27 a - 27   e  illustrate, via a sequence of cross-sectional views, an exemplary process for filling and sealing the container  6100  in accordance with the present invention. FIG. 27 a  shows a first step in the exemplary process in which a predetermined downward force F 0  is applied to the mechanical plug  6200  so that the mechanical plug  6200  (with the crimping element  6300  attached via the breakaway flange  6400 ) is inserted into the neck  6102  of the container  6100 . Although FIG. 27 a  shows the force F 0  being applied to the center of the mechanical plug  6200 , those skilled in the art will understand that the force may be applied to any portion(s) of the mechanical plug  6200 . This also applies to any forces illustrated in any of the drawings. Those skilled in the art will also understand that any “downward” and “upward” direction for applying the forces is relative to the orientation of the container  6100 . 
     Once the mechanical plug  6200  has been fully inserted, the container  6100  may then be irradiated to sterilize the container. The container  6100  with the mechanical plug  6200  inserted therein may then be conveyed to, for example, a filling machine, which is not shown. Since the mechanical plug  6200  is still inserted within the neck  6102  of the container  6100 , the interior of the container  6100  is protected from outside contaminants during the transfer. 
     In the next step, shown in FIG. 27 b , a predetermined upwards force F 1  is applied to the mechanical plug  6200  in order to remove the mechanical plug  6200  from the container  6100 . The removal of the mechanical plug  6200  is possible because the crimping element  6300  has not been slid over the neck  6102  of the container at this stage. Then, in the next step, shown in FIG. 27 c , a conventional needle  6600  of the filling machine, which is not shown, may be used to fill the container  6100  with whatever desired material. 
     In conventional filling machines, a diameter D N  of the needle  6600  needs to be minimized to reduce the size of the puncture point through the mechanical plug  6200  because the puncture point needs to be then sealed with an external sealing agent. However, since the mechanical plug  6200  is removable in the mechanical closure system according to the present invention and there is no puncture point, the diameter D N  of the needle  6600  can be almost as wide as the opening  6104  of the container  6100 . This enables faster filling times than in conventional systems, which allows for faster cycle times for filling multiple containers  6100 . 
     In the next step, shown in FIG. 27 d , a predetermined downward force F 2  is applied to the mechanical plug  6200  to re-insert the mechanical plug  6200  into the neck  6102  of the container  6100 . In the process of re-inserting the mechanical plug  6200 , the plunger  6500  that is provided on the bottom surface  6202   b  of the mechanical plug  6200  is also inserted into the material  6700  that has been received within the container  6100 . As a result, a surface level  6700   a  of the material  6700  is raised, which may be advantageously exploited to substantially eliminate the amount of air or excess gas in the container  6100 . 
     Subsequently, a predetermined force F 3  may be applied to the crimping element  6300  as shown in FIG. 27 e , which results in a separation of the crimping element  6300  from the mechanical plug  6200  at the flange  6400 . The force F 3  may also be sufficient to cause the crimping element  6300  to slide over the neck  6102  of the container  6100 . The interaction of the crimping element  6300 , the neck  6102  of the container, and the mechanical plug  6200 , as described above with respect to FIG. 26, may then provide the container  6100  with a tight, hermetic seal. 
     In this exemplary process, the detachable arrangement of the mechanical plug  6200  relative to the crimping element  6300  allows the container to be temporarily closed when only the mechanical plug  6200  is operatively engaging the neck  6102  of the container  6100 . This prevents contamination during transportation or transfers, and allows certain operations requiring access to the interior of the container  6100  to be performed before finally sealing the container  6100  with the crimping element  6300 . For example, the container  6100  may be exposed to heat or radiation to decontaminate the container  6100 , or the container  6100  may be filled with a liquid content. 
     As an alternative to the above-described exemplary process, the forces F 2  and F 3  may be replaced with a single force applied to both the mechanical plug  6200  and the crimping element  6300 , which would result in the simultaneous insertion of the mechanical plug  6200  into the neck  6102  of the container  6100  and sliding the crimping element  6300  over the neck  6102  of the container  6100 . 
     In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. For example, the cartridge or housing may be adapted for use in conjunction with various types of vial-dispensers not specifically described herein, for example the vial-dispenser which is described in my U.S. Pat. No. 5,613,957 which has been expressly incorporated herein by reference. Furthermore, the spring action provided by flexible plastic material forming the front and rear bellows, shown in FIG. 15, may be alternatively provided by a longitudinally disposed spring which urges the vial-dispenser to return to original position upon being released from the compressed state. In addition, although the vial-dispenser has been described in this specification as having an accordion-like front bellows portion and a rear bellows portion, the dispenser may alternatively incorporate any other spring configuration, e.g., a single spring element which is either integral with the dispenser body or separately formed. Furthermore, the specific arrangement of the trigger  1103 , the notched lever  4102  and the wedge-shaped arm  4103  may be modified, e.g., the trigger  1103  and the notched lever  4102  may be formed separately from one another and/or from the cartridge  4101 . Still yet, while the mechanical closure system according to the present invention have been described as being adapted for a container or vial having a circular opening, the mechanical closure system according to the present invention may be adapted for openings of other shapes, e.g., square or rectangle. The specification and drawings are accordingly to be regarded in an illustrative rather than a restrictive sense.