the intrapulmonary delivery device 5 shown in fig2 comprises a mouthpiece 10 , a flow rate controller 14 , and a container 18 . details of the mouthpiece 10 are illustrated in fig1 and 3 . the mouthpiece is a unitary structure of flexible material having an annular flat flange portion 10 a , a bulbous intermediate portion 10 b , the diameter of which is slightly less than the diameter of flange portion 10 a , a cylindrical portion 10 c and a nipple portion 10 d . nipple portion 10 d has an orifice 12 at the distal end away from flange portion 10 a . the mouthpiece 10 is elongated and generally tubular and is made of a flexible material that can withstand sterilization via hot water , e . g . latex or silicone rubber . preferably , the mouthpiece is made of a clear silicone rubber - type material so that deposits of medicament or other substances within the mouthpiece can be easily viewed and removed . the orifice 12 of the mouthpiece 10 has a diameter of approximately about 3 . 1 mm to 8 mm and a relatively circular shape . the mouthpiece 10 has a wall thickness of approximately about 0 . 5 mm to 5 mm . the container 18 is shown in fig2 , 4 b and 4 c . container 18 comprises a hollow cylinder of approximately about 140 mm to 160 mm in length for holding a quantity of medicament . the container 18 has a first cross sectional area and a neck portion 24 of a second cross sectional area which is less than the first cross sectional area . it is to be noted that the container wall transitions from the first to the second cross sectional area by forming an angle of approximately 45 °. the container further comprises an outlet opening 23 at the end of the neck portion 24 that allows for medicament to pass through . the mouthpiece 10 is sized to fit snugly over and around the neck portion 24 of the container and is held in place by a combination of friction and elasticity . the opposite end of the container is closed by a boot 20 . boot structure 20 comprises an integral closure for the end of the container and includes side walls 20 a and 20 b which cooperate with a central portion 20 c to present a slot 20 d that frictionally engages the wall of container 18 . central portion 20 c also mounts a membrane valve 26 having a plurality of slits 26 a so as to accommodate the insertion of a supply tube 27 ( fig2 ). it will be appreciated that valve 26 is integral with the body of the boot 20 . as best illustrated in fig2 , 4 a , 4 b and 6 c , a baffle structure 22 is coupled with neck portion 24 . baffle structure 22 comprises four vanes 23 , mounted about an axial hub 25 . each of vanes 23 is spaced approximately 90 ° from an adjacent vane . the outboard surface of each vane has a straight section 23 a which merges into an angled section 23 b so that this surface generally follows the contour of container 18 . an end wall 21 rigid with the vanes 23 blocks the flow of medicament from the container 18 . the axial hub 25 presents a through passage 16 along its length . the diameter of passage 16 is approximately 1 . 5 mm to 4 mm and the length is approximately 26 mm to 32 mm . end wall 21 ( fig6 a and 6c ) mounts baffle structure 22 rigidly with the container 18 inside the neck portion 24 . it is preferred that the diameter of the mouthpiece orifice 12 is about double the diameter of passage 16 . in operation , the device of fig2 is easy to use and effectively delivers medicament to the lungs of a patient . the mouthpiece 10 is connected to the neck portion 24 of the container 18 and medicament is supplied to container 18 via supply line 27 . a tight fit between the mouthpiece 10 and the container 18 is essential because the transference of negative inspiratory pressure will not occur if there is a leak between the mouthpiece 10 and the container 18 . the mouthpiece 10 is configured to conform to the mouth of the user as he purses his lips around the conical section 10 c so that an airtight seal is formed . in this regard it will be appreciated that bulbous portion 10 b forms a “ stop ” for the user &# 39 ; s lips when moving in one direction , and the nipple 10 d being larger in diameter than section 10 c , works against accidental withdrawal of the mouthpiece when in use . once the user forms a seal with his or her lips around mouthpiece 10 , medicament within container 18 will move into the lungs as the user inhales . because of the specific design of baffle structure 22 , greatly reduced negative pressure is required to initiate the flow of medicament through passage 16 and through orifice 12 . this reduced effort results in a relatively low inspiratory flow rate which , as explained above , is desirable for maximum efficacy of the medicament . the preferred flow rate is between about 25 . 8 and 30 . 2 liters per minute ( 0 . 43 to 0 . 51 liters per second ). while the physics of the device 5 according to the present invention are not fully understood , it is believed that the combination of the upper portion of container 18 , as shown in fig6 c , together with baffle structure 22 form a flow rate controller 14 which promotes laminar flow and creates a type of poiseuille gauge . the relatively high negative inspiratory pressure which is required to effect low emitted flow through passageway 16 is explained by the poiseuille equation : where f = flow rate ; r = radius of the constriction ; l = length of the constriction ; δp = pressure difference driving the flow ; and η = is the viscosity of air . one alternative to the mouthpiece orifice 12 and axial hub passage 16 of the preferred embodiment described above is to make both the orifice and passage the same diameter . the passage 16 in baffle structure 22 is about 28 mm to 30 mm in length with a diameter of about 1 . 5 to 4 mm . the mouthpiece orifice 12 has a diameter of about 3 . 1 and 8 mm . even with an orifice 12 that is the same diameter as passage 16 , the effect on flow rate is only about 10 % ( i . e ., the change in flow rate is negligible ). however , doubling the size of the orifice 12 relative to the diameter of the passage 16 will produce a theoretical 16 fold increase in flow rate . while not intending to be bound by any particular theory , it may be that human physiology is better adapted to hard sucking action on an object with the geometry of a nipple as described herein , as compared to the cylindrical or elliptical configuration of a spacer or holding chamber device of the prior art . it may also be that use of a flexible material for the mouthpiece 10 according to the present invention is better suited with respect to human physiology than a non - flexible mouthpiece in terms of generating maximum negative inspiratory pressure with minimal force . additionally , while the mouthpiece orifice 12 of the present invention is shown in a relatively circular configuration , it will be appreciated by one skilled in the art that other configurations such as oval and elliptical can be utilized as well . the mouthpiece 10 in combination with the flow rate controller 14 will work with any inhalation delivery device such as pmdis , nebulizers , medicine cups . the mouthpiece 10 in combination with the flow rate controller 14 of the invention may also he used with other inhalation delivery devices , such as the presently available exubera insulin delivery device . fig6 d illustrates a side view of the mouthpiece 10 coupled with flow rate controller 14 which may be used in conjunction with an inhalation delivery device . most children can inhale most of the medication in 3 - 4 seconds with the present invention , whereas with the prior art devices it takes a minimum of 6 - 8 seconds . further ; without the benefit of the invention , most children will inhale and exhale twice within the first 6 - 8 seconds . usually , with prior art devices , over time ( 20 - 30 seconds or more ) medication falls out of the aerosolized state , primarily due to gravity , into the portion of the spacer or holding chamber that is substantially parallel to the ground when the spacer or holding chamber is in use . this results in less medication being aerosolized , thus giving less chance for medication to be inhaled . with the present invention a greater amount of medication is inhaled in the first few seconds , before the medication falls out of its aerosolized state . normal tidal volume breathing ( less than 30 l / min ) has been shown to allow better drug deposition into the lungs . the present invention encourages young children and adults to inhale naturally at normal tidal volume rates . this is especially important with patients with chronic obstructive pulmonary disease (“ copd ”), who may have difficulty generating negative inspiratory pressure . in fact , it is well known by those skilled in the art of pulmonary medicine that these groups of patients unconsciously purse their lips to enhance their breathing . the mouthpiece of the present invention naturally accommodates these patients &# 39 ; tendencies , permitting better generation of negative inspiratory pressure . it will also be appreciated that the present invention encompasses a method for administering medicament via inhalation . the method is carried out utilizing a container as afore - described having a first cross sectional area and a neck portion which presents a second cross sectional area that is smaller than the first cross sectional area . the method comprises the steps of providing a flexible mouthpiece having an orifice for passage of medicament , providing a baffle structure coupled with the mouthpiece and having an axial through passage with the structure extending at least partially into the neck portion of the container . next , the user places the mouthpiece into his or her mouth and then moves the medicament through the axial passage by inhalation . by following the afore - described method steps , the mouthpiece and baffle structure cooperate to dispense a desired quantity of medicament to the user . preferably , the method includes providing a mouthpiece having a nipple with the orifice of the nipple having a diameter of approximately 3 . 1 to 8 mm . it is also preferred that the mouthpiece have a thickness of approximately 0 . 5 to 5 mm and that the baffle structure comprises at least three ( 3 ) vanes . the method further comprises providing a baffle structure with a through passage of approximately 1 . 5 to 4 mm in diameter and a length of approximately 26 to 32 mm . preferably , the method utilizes a container having a length of 140 to 160 mm with the container comprising a boot structure which closes the end of the container opposite the outlet opening . one of the concerns with the use of dpis is the need to generate enough negative inspiratory pressure to de - aggregate the powdered medication found in these devices . most patients need high negative inspiratory forces , greater than 30 l / minute to de - aggregate the medication , resulting in undesirable turbulent flow . turbulent flow , as contrasted with laminar flow , is undesirable because it results in more oral deposition ( deposition of the medicament in the mouth ) rather than intrapulmonary deposition ( deposition of the medicament in the lungs ). the use of the present invention solves this problem if a dpi device releases the medicament into a spacer or holding chamber , e . g ., the exubera device presently on the market . another advantage of the present invention is time efficiency . utilizing the prior art devices , it takes approximately 20 - 30 minutes to prepare and administer a single nebulization treatment . this does not take into account the time it takes to coax a relatively compliant child into submitting to the nebulization treatment . if the child is crying or combative , even more time is needed for the treatment . a crying child will have poor inspiration and will not receive the proper amount of medicament due to the poor inspiration . using the device of the present invention , it takes approximately 8 - 20 seconds to complete a full inhalation treatment . while the preferred flow rate is about 25 . 8 to 30 . 2 l / minute , it is to be understood for certain applications the flow rate may range from 15 to 60 l / minute . the method and device of the present invention are useful for delivering a wide variety of medicaments , drugs , biologically active substances , and the like , to a patient &# 39 ; s lungs . the present invention is particularly useful for delivering high value medicaments and drugs , such as proteins and polypeptides , where efficient delivery and proper dosage are of great concern . from the foregoing it will he seen that this invention is one well adapted to attain all ends and objectives herein - above set forth , together with the other advantages which arc obvious and which are inherent to the invention . since many possible embodiments may he made of the invention without departing from the scope thereof , it is to he understood that all matters herein set forth or shown in the accompanying drawings are to he interpreted as illustrative , and not in a limiting sense . while specific embodiments have been shown and discussed , various modifications may of course be made , and the invention is not limited to the specific forms or arrangement of parts and steps described herein , except insofar as such limitations are included in the following claims . further , it will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations . this is contemplated by and is within the scope of the claims .
this invention relates to a therapeutic device and method of administering precisely measured doses of a therapeutic substance via inhalation to pediatric and adult patients . more specifically , the invention relates to a therapeutic device and method of administering inhaled medication which delivers a controlled flow rate to a mouthpiece for administration of medicament to young children and adults with a diminished capacity , at a rate of about 25 . 8 l / minute to 30 . 2 l / minute .