U.S. patent application number 14/095885 was filed with the patent office on 2014-06-12 for device and system for mixing and dispensing components stored separately from one another.
This patent application is currently assigned to Nexmed Holdings, Inc.. The applicant listed for this patent is Nexmed Holdings, Inc.. Invention is credited to Daniel W. Frank, Yiping Wang, William S. Wei.
Application Number | 20140163464 14/095885 |
Document ID | / |
Family ID | 40626086 |
Filed Date | 2014-06-12 |
United States Patent
Application |
20140163464 |
Kind Code |
A1 |
Wang; Yiping ; et
al. |
June 12, 2014 |
DEVICE AND SYSTEM FOR MIXING AND DISPENSING COMPONENTS STORED
SEPARATELY FROM ONE ANOTHER
Abstract
Mixing devices and systems are disclosed for storing separate
components and for mixing and dispensing those Components on
demand. A mixing device includes a syringe having a generally
tubular housing formed with a mixing chamber. A plunger is fitted
to the tubular housing to form a first syringe. A dispensing
syringe is releasably connected to the mixing chamber. At this
point each syringe holds a desired amount of a mixture component.
The contents of one syringe are passed through the mixing chamber
to the other syringe, forming a usually incomplete mixture. The
mixture is then passed through the mixing chamber to the other
syringe. Multiple passes through the mixing chamber are continued
until the desired mixing result is achieved, and the mixture
material is contained in the second syringe that is used to
thereafter dispense desired amounts of the mixture.
Inventors: |
Wang; Yiping; (Howell,
NJ) ; Wei; William S.; (Belle Meade, NJ) ;
Frank; Daniel W.; (Broomall, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nexmed Holdings, Inc. |
San Diego |
CA |
US |
|
|
Assignee: |
Nexmed Holdings, Inc.
San Diego
CA
|
Family ID: |
40626086 |
Appl. No.: |
14/095885 |
Filed: |
December 3, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12734404 |
Apr 29, 2010 |
8596859 |
|
|
PCT/US2008/012591 |
Nov 6, 2008 |
|
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14095885 |
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61002391 |
Nov 8, 2007 |
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Current U.S.
Class: |
604/82 ;
366/176.3 |
Current CPC
Class: |
B01F 13/0023 20130101;
A61M 2205/6045 20130101; A61M 5/31596 20130101; A61J 1/2093
20130101; A61M 5/31563 20130101; A61M 5/008 20130101; B01F 13/002
20130101; B01F 5/0685 20130101; A61M 2005/3104 20130101; A61M
5/31505 20130101; B01F 5/0688 20130101; A61M 5/3156 20130101; A61J
1/2096 20130101; A61M 2205/6081 20130101; A61M 2005/31508
20130101 |
Class at
Publication: |
604/82 ;
366/176.3 |
International
Class: |
A61J 1/20 20060101
A61J001/20; A61M 5/315 20060101 A61M005/315 |
Claims
1.-8. (canceled)
9. A mixing device comprising: an integrally constructed body
having a housing and a mixing chamber integrally connected to a
distal end of the housing, the mixing chamber having a distal open
end; a plunger having a plunger body fitted at least partially
within the housing, the plunger axially moveable relative to the
housing; and an interior structure disposed within the mixing
chamber, wherein the interior structure cooperates with internal
walls of the mixing chamber to define multiple flow
passageways.
10. The mixing device of claim 9, wherein the interior structure is
positioned adjacent the hollow housing and spaced from the open
end.
11. A system for mixing and dispensing, comprising: the mixing
device of claim 9, further comprising a first engagement member
disposed in the mixing chamber of the mixing device; and a
dispensing syringe comprising: a tubular housing having a hollow
bore; a discharge nozzle extending from the tubular housing; a
dispensing syringe plunger disposed at least partially within the
tubular housing; and a second engagement member provided on the
discharge nozzle and adapted for direct mating with the first
engagement member.
12. The system of claim 11, wherein the first and second engagement
members comprise a bayonet interlock, a threaded engagement, or
other interlocking arrangement.
13. The system of claim 11, wherein the first and second engagement
members provide releasable engagement between the mixing device and
the dispensing syringe, and wherein the engagement is sufficient to
withstand pressures generated during a mixing event without
requiring manual pressure to hold the mixing device and the
dispensing syringe together.
14. The system of claim 11, wherein the dispensing syringe plunger
comprises a plunger tip configured to provide wiping engagement
with interior walls of the tubular housing.
15. The system of claim 11, further comprising a unit dose
dial.
16. The system of claim 11, further comprising a stop collar,
wherein the dispensing syringe plunger is provided with a series of
engagement features each adapted to retain the stop collar at a
selected position along the dispensing syringe plunger.
17. The system of claim 11, further comprising: a cap fitted over
at least a portion of the discharge nozzle to occlude the orifice;
and a support base having an interior opening adapted to receive
the cap.
18. A method of mixing two flowable components, comprising:
introducing a nozzle of a dispensing syringe into a distal opening
of a mixing device, wherein the dispensing syringe comprises a
tubular housing having a hollow bore, a nozzle extending from the
tubular housing, and a dispensing syringe plunger disposed at least
partially within the tubular housing, wherein the mixing device
comprises a housing, a mixing chamber integrally connected to a
distal end of the housing, the mixing chamber having a distal
opening, a mixing device plunger fitted at least partially within
the housing and axially moveable relative to the housing, and an
interior structure disposed within the mixing chamber and
cooperating with internal walls of the mixing chamber to define
multiple flow passageways, and wherein a first liquid component is
stored in the housing of the mixing device and a second component
having a higher viscosity is stored in the tubular housing of the
dispensing syringe; interlocking a first engagement member disposed
within the mixing chamber with a second engagement member disposed
on the nozzle of the dispensing syringe such that the mixing device
and the dispensing syringe releasably engage in a free standing
manner that does not require manual pressure to maintain;
depressing the mixing device plunger so as to move the first liquid
component through the mixing chamber into the dispensing syringe to
contact the second component; and depressing the dispensing syringe
plunger so as to move the first liquid component and the second
component through the mixing chamber into the housing of the mixing
device.
19. A syringe comprising: a generally tubular housing having
opposing proximal and distal end portions, the distal end portion
terminating in a nozzle defining a mixing chamber, wherein the
tubular housing and mixing chamber are a unitary molded body; and a
plunger configured for axial movement with the tubular housing
wherein the mixing chamber includes at least one emulsifying
passageway formed by an internal structure disposed within the
mixing chamber and wherein the interior structure has opposed ends
that are flared in an inwardly extending or concave frustoconical
shape, wherein the plunger comprises a plunger tip configured to
provide wiping engagement with interior walls of the tubular
housing.
20. The syringe of claim 19, further comprising a stop collar,
wherein the plunger is provided with a series of engagement
features each adapted to retain the stop collar at a selected
position along the dispensing syringe plunger.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to a mixing device
including a container, such as a syringe, having an integral mixing
chamber, such as a chamber with one or more emulsifying
passageways, and provision for connection to a separate container.
The invention also relates to a system including the mixing device,
a disposable dispensing container for dispensing a medicament to a
targeted site, optionally including a unit dose dial for metering a
quantity of a unit dose to be dispensed from a multiple-dose
medicament container, and a support base for the dispensing
container.
BACKGROUND OF THE INVENTION
[0002] Certain medicaments and other materials are comprised of
components that are incompatible with one another as a previously
prepared mixture, and accordingly, must be mixed just prior to
dispensing. For example, emulsifying needles have been provided
with a single tubular passageway with a socket at each end for
connection between a pair of syringes carrying the separate
components. One example of incompatible components includes, for
example, an oil and an aqueous solution prepared on demand to form
an emulsion having a relatively short shelf life at room
temperature. The components may be considered to be "incompatible"
with one another for a variety of reasons. For example, certain
emulsified mixtures used in the health care field become unstable
upon mixing, with the resulting mixture having a limited shelf life
not suitable for storage, or for practical, commercial
distribution. Instability may arise due to chemical reactions as
well as interactions that do not involve chemical bonds.
Accordingly, practical applications of such materials require
devices and systems to prepare mixtures of components which must be
stored separately until the time of application or use, or stored
at a relatively lower temperature, for example by refrigeration,
prior to use.
[0003] Emulsifying needles have been proposed for mixing two
components (e.g. oil and water or other aqueous solution) carried
in their own respective general purpose syringes. Typically, the
contents of one syringe are passed through the emulsifying needle
to the other syringe to contact its contents. The receiving syringe
is then pumped to move the components in a reverse direction
through the emulsifying needle to the now empty syringe. Successive
iterations of the pumping operations are carried out until the
desired mixture condition is reached. For example, one common
mixture condition is the emulsification of the two components.
Other types of mixtures other than emulsifications may be prepared
in a similar manner. Mixing arrangements employing an
emulsification needle and general purpose syringes may be
unsuitable for certain applications, as where a disposable mixing
device is preferred.
[0004] As will be appreciated by those skilled in the art, the
components frequently have substantially different viscosities and
other physical properties either in their separate stored state or
when combined in a mixture, so as to require substantial pressures
to be developed by the syringes, when passing the mixtures back and
forth through the emulsifying needle. In the presence of elevated
pressures, the emulsifying needle may become dislodged from one or
both syringes, unintentionally, thereby compromising the
preparation process.
[0005] Prior art arrangements suffer from another disadvantage in
that the emulsifying needles, in order to reduce costs, include
separable connectors for joinder to common, general purpose
syringes. Thus, the arrangement does not provide a control to
restrict the syringes which can be used in the process.
[0006] As a further drawback, the emulsifying needles require a
fairly expensive construction since they utilize surgical stainless
steel materials processed according to familiar standards required
in the medical industry. The emulsifying needles present a
substantial capital investment and hence are adapted for re-use,
requiring an intervening cleaning and sterilization procedure, at a
minimum. This accordingly presents questions of cross contamination
or other questionable conditions, adding to the complexity of the
work environment.
[0007] As an another drawback, the single emulsifying passageway
(or single passage) emulsifying needles in the art require many
iterative back and forth passes to achieve uniform mixing,
especially for higher viscosity medicaments such as gels. This
drawback may cause potential non-uniform multiple-dose medicament.
Non-uniform multiple-dose medicament may pose risk to patients
either by under- or over-dose.
SUMMARY OF THE INVENTION
[0008] The present invention provides a novel and improved mixing
device and system in which a syringe is provided with a generally
tubular housing having opposed proximal and distal end portions.
The distal end portion terminates in a mixing chamber such as a
unitary nozzle defining one or more emulsifying passageways. Also
included is a plunger configured for axial movement within the
tubular housing.
[0009] In one example, a system is provided in which the nozzle is
adapted to interlock with a second container such as a dispensing
syringe or a pump like device, so as to receive a component such as
a liquid infusion carried in the second syringe. The components of
the syringes are passed through the mixing chamber, alternately
from one syringe to the other, to provide a mixture of a desired
condition, such as an emulsification of the two components.
[0010] In one example, the mixing device is comprised of a unitary
molded body defining a tubular housing and mixing chamber. Thus the
mixing device can be commercially provided in an economical manner,
using only two components including the plastic molding containing
the tubular housing and mixing chamber and a plunger configured to
fit within the tubular housing for reciprocal axial movement
therewithin. Further, the mixing device can be pre-filled to
provide convenient storage of a first component.
[0011] Numerous other advantages and features of the present
invention will become readily apparent from the following detailed
description and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings,
[0013] FIG. 1 is a schematic elevational view, shown partly in
cross section, of a mixing device illustrating the present
invention;
[0014] FIG. 2 is an elevational view, shown partly in cross
section, of a dispensing syringe for use with the device of FIG. 1;
and
[0015] FIG. 3 shows the dispensing syringe fitted to a support base
and provided with a unit dose dial for dispensing a unit dose
amount from a multiple-dose medicament container.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] The invention disclosed herein is, of course, susceptible of
embodiment in many different forms. Shown in the drawings and
described herein below in detail are the preferred embodiments of
the invention. It is to be understood, however, that the present
disclosure is an exemplification of the principles of the invention
and does not limit the invention to the illustrated
embodiments.
[0017] For ease of description, mixing devices and systems
embodying the present invention are described herein below in their
usual assembled position as shown in the accompanying drawings and
terms such as proximal and distal, front, rear, upper, lower,
horizontal, longitudinal, etc. may be used herein with reference to
this usual position. However, the mixing devices and systems may be
manufactured, transported, sold, or used in orientations other than
that described and shown herein.
[0018] Referring now to the drawings, and initially to FIG. 1, a
mixing device is generally indicated at 10. Included is a body
generally indicated at 12 which is preferably made of one-piece
integral construction utilizing molding or other fabrication
techniques. Preferably, body 12 is made of a rigid plastic
material, clear, translucent or opaque, such as polyolefin,
including polyethylene, polypropylene, and the like, suitable for
injection molding.
[0019] Preferably, body 12 is hollow, or at least partially hollow
throughout its entire length. Body 12 includes a hollow generally
tubular housing 14 having a proximal end portion 16 and a distal
end portion 18. Body 12 further includes a unitary or integral
mixing chamber 20 at the distal end 18 of tubular housing 14 and
connected thereto by an optional frustoconical transition 24.
Mixing chamber 20 has a nozzle or open free end 26, preferably
fitted with an outwardly extending flange 28, disposed about an
opening 30. A separate closure 34 includes a plug-like body 36 that
is dimensioned so as to be received within opening 30, and an
enlarged head 38 to facilitate its withdrawal from the open end of
body 12, once fitted thereto so as to seal open end 30.
[0020] In a preferred embodiment, mixing chamber 20 is adapted to
emulsify components that are passed through the mixing chamber.
Accordingly, one or more interior channels are formed in the mixing
chamber. In a particularly preferred embodiment illustrated in FIG.
1, an internal structure 40 is disposed within the hollow interior
of mixing chamber 20 having multiple passageways. As can be seen in
FIG. 1, the opposed ends of interior structure 40 are flared in an
inwardly extending or concave frustoconical shape. Also, as shown
in FIG. 1, interior structure 40 is located adjacent the tubular
housing 14 and is spaced from the open end 30. Interior structure
40 preferably cooperates with the mixing chamber walls to define
multiple flow passageways. Most preferably, the mixing chamber
cooperates to emulsify the components. Accordingly, the structure
40 is dimensioned so as to cooperate with the walls of the mixing
chamber 20 to form a high shear flow for efficient emulsification
of components with a minimum number of iterations as the contained
contents are combined with an aqueous vehicle, or the like, and
pumped back and forth through the mixing chamber. The present
invention also contemplates mixing to achieve results other than
emulsification, and accordingly, a wide variety of interior
structures, e.g., static mixers, or arrangements with no
intermediate interior structure, are contemplated as well by the
present invention.
[0021] The present mixing chambers can be of virtually any length,
internal dimensions and constructions as may be desired. The
present mixing chamber be provided with one or more interior
dividing members or partitions defining one or more mixing channels
of desirable length and cross sectional size within mixing chamber
20. Most preferably, the interior structure is integral with the
mixing chamber housing and the remainder of body 12, but can be
added during or after molding of body 12, if desired.
[0022] Mixing device 10 further includes a plunger 46 having a body
portion 48, adapted to fit within tubular housing 14 in a known
manner so as to cooperate with tubular housing 14 to function as a
dispensing actuator for a syringe-like device. In the preferred
embodiment, tubular housing 14 is employed to hold a desired amount
of a first component for the mixture, such as water, an aqueous
gel, or an aqueous or other liquid solution as may be desired to
serve as a delivery vehicle for active ingredient or ingredients
contained in a separate compartment. If desired, the plunger 46 may
be withdrawn and temporarily removed from body 12, with the tubular
housing 14 being filled with the first component, as desired.
Alternatively, the open end 30 may be immersed in a supply of the
first mixture component and plunger 46 withdrawn in a known manner
so as to pull liquid into tubular housing 14, ready for a mixing
event. If desired, a filling needle or the like can be fitted to
the mixing device to withdraw material from conventional sterile
containers, or the like.
[0023] Turning now to FIG. 2, a dispensing syringe, containing one
or more active ingredients in a suitable not aqueous carrier, is
generally indicated at 50. Included is a tubular housing 52 having
a hollow bore for receiving a plunger 54. Tubular housing 52 is
preferably hollow throughout and terminates in a discharge nozzle
portion 56 orifice 55 connected to tubular housing 52 through an
optional transition member 58, usually having a frustoconical
shape. The dispensing syringe 50 is preferably made in a manner
similar to that of body 12, as discussed above.
[0024] Plunger 54 includes an elongated body 62 having an enlarged
head 64 at one end that provides a convenient, manually graspable
end portion, as is known. A seal such as piston 68 is carried at
the free end of body 62 and is preferably of a material more
resilient than body 62, so as to provide wiping engagement with the
interior walls of tubular housing 52, as plunger 54 is reciprocated
within the tubular housing and piston mover axially therewithin. If
desired, seal piston 68 can be omitted in favor of a free end
portion of body 62 forming a wiping or other sealing engagement
with tubular housing 52.
[0025] That portion of the seal or piston that comes in contact
with the contents of tubular housing 52 must be compatible
therewith. To that end, seal or piston 68 can be provided with a
fluorocarbon (e.g., Teflon.RTM.) coating, a silicone coating, or
the like, or made from an inert material such as silicone rubber,
and the like.
[0026] A second component to be added to form the mixture is
preferably stored in the hollow interior of tubular housing 52. In
the preferred embodiment, the material stored in tubular housing 52
has the form of an oil or a non-runny semi-solid material, such as
an oil paste, ointment, gel, oil suspension, viscous solution, or
colloidal suspension, salve, paste, or the like. In one instance,
tubular housing 52 holds an oil paste with alprostadil, used to
form VITAROS.TM. male erectile dysfunction treating formulations
that are stable at room temperatures.
[0027] It may not be necessary in all instances to provide a
resilient seal or piston 68 of the type described above however.
Rather, an outwardly protruding ring of the same material as body
62 or a featureless plunger tip may be sufficient for some
applications.
[0028] A separate closure in the form of a cap 72 is fitted over
the generally cylindrical end portion 56 so as to occlude orifice
55 Cap 72 can be provided with a flexible liner 73, e.g., a
fluorocarbon liner, that contacts and seals orifice 55 when in
place. An engagement member 76 is provided on end portion 56 for
mating with a complementary engagement member 80 formed adjacent
the discharge opening 30 of mixing device 10. The cooperating
engagement members 76, 80 may comprise, for example, a bayonet
interlock, or a threaded engagement or other conventional
interlocking arrangement as may be desired. The purpose of
engagement members 76, 80 is to provide a releasable engagement
between mixing device 10 and dispensing plunger 50 that is
sufficient to withstand pressures generated during a mixing event,
without requiring manual pressure to hold the members 10, 50,
together.
[0029] As mentioned, the system comprising mixing device 10 and
dispensing syringe or device 50 is provided to mix, on demand, two
or more components unsuitable for pre-mixing and prolonged storage
together. In a preferred embodiment, mixing device 10 is pre-filled
and shipped with a desired quantity of an aqueous or other liquid
component, while dispensing syringe or device 50 is pre-filled and
shipped with a semi-solid flowable component, such as a paste
material, stored in dispensing syringe 50. As mentioned, the liquid
component may also be introduced into the mixing device just prior
to the mixing event.
[0030] Preparations for the mixing event include removing the
closures 34, 72 from mixing device 10 and dispensing device 50 and
thereafter introducing end portion 56 of dispensing syringe 50 into
orifice 30 of mixing device 10. The interlocking engagement members
76, 80 are thereafter configured so as to releasably hold the
mixing device 10 and dispensing syringe 50 together in a
"hands-off" free standing manner that does not require manual
pressure. As indicated in the preferred embodiments of FIGS. 1 and
2, the orifice 54 of dispensing syringe 50 extends past engagement
member 80 of mixing device 10 so as to be located generally
proximal to interior structure 40.
[0031] One of the plungers 46, 54 is depressed so as to move its
contents through mixing chamber 20 to contact the contents of the
other container. For example, plunger 46 may be depressed so as to
discharge the contents of mixing device 10 through mixing chamber
20, so as to enter the interior of dispensing syringe 50, to
thereby mix with its contents. It is anticipated that the mixture
may not be completed to the desired condition, e.g.,
emulsification. Accordingly, plunger 54 is then depressed so as to
discharge the mixture back through mixing chamber 20 so as to enter
the empty, or substantially empty, tubular housing 14 of mixing
device 10. Thereafter, plunger 46 is depressed so as to again pass
the mixture through mixing chamber 20. Successive iterations are
carried out, as required to produce the desired end result. For
example, when an emulsification is desired, successive iterations
are carried out to pass the mixture a desired number of times
through mixing chamber 20, and through the one or more
emulsification passageways formed by the cooperation of interior
structure 40 with the hollow tubular exterior of the mixing
chamber. Upon attainment of the desired mixture condition, plunger
46 is depressed a final time, so as to move the mixture into the
hollow interior of dispensing syringe 50.
[0032] The dispensing syringe is thereby filled with a recently
produced mixture of the desired components. As mentioned above, two
components are combined by mixing to form a mixture such as an
emulsion. If desired, additional components may be added to the
mixture by replacing the mixing device 10 or dispensing syringe 50
with a similar member containing an additional component. The
mixing operation is then continued in the manner described above
until the desired mixing condition is achieved, and the mixture is
stored within dispensing syringe 50. The dispensing syringe is now
available for dispensing a precisely controlled, desired quantity
of mixture. For example, the dispensing syringe 50 may be employed
to deliver a desired amount of medicament to a targeted site.
[0033] It will be appreciated by those skilled in the art that the
dispensed amount of mixture from dispensing syringe 50 can be
accurately controlled in a customary manner. If desired, a unit
dose dial such as a stop collar 90 may be fitted to body 62 of
plunger 54 so as to limit the travel of plunger 54 within tubular
housing 52. In a preferred embodiment, body 62 of plunger 54 is
provided with a series of recesses 92 so as to provide convenient
selectable engagement with stop collar 90. If desired, the recesses
92 can be replaced with other conventional engagement features so
as to retain stop collar 90 at a desired position along body 62.
For example, recesses 92 could be replaced with a series of blind
holes dimensioned so as to receive a resilient pin (not shown)
disposed on the interior of stop collar 90.
[0034] Referring again to FIG. 3, a system for dispensing mixtures
is provided with an optional support base 96 having an interior
opening 98 that receives cap 72. Thus, with a single hand
available, an operator can conveniently insert dispensing syringe
50 in a temporary position that seals the opening of the dispensing
syringe, shielding its free end against contamination caused by
inadvertent contact with the dispensing orifice 54 and free end 56
of dispensing syringe 50 (see FIG. 2).
[0035] While the mixing devices and dispensing syringes may be made
to virtually any dimension desired, representative examples of
typical applications can be given. For example, in one embodiment,
the mixing chamber, when adapted to an emulsification operation,
preferably has one or more emulsification channels or pathways
having an internal diameter of about 0.01 to about 0.05 inches, and
more preferably are in the range of about 0.02 to about 0.04
inches.
[0036] The syringe component of mixing device 10, that is, tubular
housing 14 and plunger 46, are preferably dimensioned so as to hold
about 1 milliliter (ml) of the formulation. In one example, tubular
housing 14 has an internal diameter ranging about 0.3 to about 0.7
inches and more preferably about 0.5 to about 0.6 inches. For
multiple milliliter size dose capacity, the ranges for the tubular
housing are multiplied by the number of milliliters of dose
desired. For example, for an X milliliter formulation content, the
internal diameter of tubular housing 14 ranges about 0.3X to about
0.7X inches, and more preferably about 0.5X to about 0.6X
inches.
[0037] A relatively large ratio of internal diameter of tubular
housing 14 with respect to the internal diameters of the
emulsification channels in the mixing chamber makes the mixing of
the two components more efficient. Preferably the ratio of the
internal diameter of tubular housing 14 to the internal diameter of
a emulsification channel is at least about 6:1, more preferable, in
the range of about 15:1 to about 30:1.
[0038] For a dispensing syringe holding a 1 ml of formulation, the
internal diameter of the tubular housing 52 preferably ranges
between 0.3 and 0.7 inches, most preferably between 0.3 and 0.4
inches. For multiple milliliter capacity, a formulation content of
X ml is accommodated by tubular housing 52 having an internal
diameter ranging between 0.3X and 0.7X inches, and most preferably
between 0.3X and 0.4X inches. A relatively small internal diameter
for the dispensing syringe (with an extended length) improves the
accuracy of dispensing of the resultant mixture.
[0039] As will be appreciated, a number of advantages are provided
by the present invention, over emulsification needles and similar
devices. For example, whereas prior art emulsification needles
provide a single mixing channel, the present invention provides one
or more mixing channels to increase mixing efficiency, thereby
reducing the number of iterations or passes through the mixing
chamber. Further, with multiple mixing channels, pumping resistance
from high viscosity formulations is effectively reduced.
[0040] By configuring the mixing chamber with a tubular housing
forming a first syringe, separation of mixing chamber and a first
syringe is eliminated. This is an important feature when elevated
pumping pressures are associated with a mixing event. Whereas
emulsifying needles employed a plug-in engagement, the present
invention provides a secure interlock between the mixing device and
the second dispensing syringe to prevent unintentional separation,
especially during mixing events having elevated pumping
pressures.
[0041] As an additional advantage, the emulsifying needles employed
heretofore are, for reasons of economy, adapted for use with
general purpose syringes having standard interfitting features.
While attractive from the point of view of cost savings, general
purpose syringes may be made from a variety of materials, some of
which are unsuitable for a particular application. For example, the
resilient plungers fitted to many disposable syringes may be made
of an elastomeric material that is incompatible or otherwise
unsuitable for use with certain mixture components. With the
present invention, economical disposable mixing devices and
dispensing plungers are provided that are readily adaptable for use
with special purpose applications, thereby ensuring materials
compatibility throughout a mixing and dispensing system.
[0042] As an additional advantage, whereas emulsifying needles are
adapted for reuse without regard to the particular components
involved, mixing devices and dispensing syringes according to
principles of the present invention can be made from specially
selected materials and may be color coded for different materials.
Alternatively, the free end of the dispensing syringe may be keyed
with a particular shape that can be mated only with mixing devices
having a complementary key shape, to ensure that the two are
suitable for use, one with the other.
[0043] The foregoing description and the accompanying drawings are
illustrative of the present invention. Still are the variations in
arrangements of parts are possible without departing from the
spirit and scope of this invention.
* * * * *