U.S. patent application number 11/241274 was filed with the patent office on 2006-02-09 for cleaning compound for and method of cleaning valves and actuators of metered dose dispensers containing pharmaceutical compositions.
Invention is credited to Pankaj Modi.
Application Number | 20060030509 11/241274 |
Document ID | / |
Family ID | 32506779 |
Filed Date | 2006-02-09 |
United States Patent
Application |
20060030509 |
Kind Code |
A1 |
Modi; Pankaj |
February 9, 2006 |
Cleaning compound for and method of cleaning valves and actuators
of metered dose dispensers containing pharmaceutical
compositions
Abstract
A method of cleaning a metered dose spray device, and a cleaning
composition for such cleaning, to prevent the device from becoming
clogged with medication. The method includes removing the aerosol
can containing the medication from the actuator, placing an aerosol
can containing a cleaning composition in the actuator, and
dispensing the cleaning solution through the actuator. The residual
medication is thereby removed from the actuator. A sufficiently
small quantity of cleaning composition remains in the actuator so
that the cleaning composition itself will not clog the actuator.
Additionally, the cleaning composition is non-toxic, so that
residual cleaning composition remaining in the actuator will not
harm the user when a subsequent dose of medication is
dispensed.
Inventors: |
Modi; Pankaj; (Ancaster,
CA) |
Correspondence
Address: |
HAMILTON, BROOK, SMITH & REYNOLDS, P.C.
530 VIRGINIA ROAD
P.O. BOX 9133
CONCORD
MA
01742-9133
US
|
Family ID: |
32506779 |
Appl. No.: |
11/241274 |
Filed: |
September 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10320045 |
Dec 16, 2002 |
6979668 |
|
|
11241274 |
Sep 29, 2005 |
|
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Current U.S.
Class: |
510/412 |
Current CPC
Class: |
C11D 7/22 20130101; A61M
15/009 20130101; C11D 7/50 20130101; B08B 9/00 20130101; C09K 3/30
20130101 |
Class at
Publication: |
510/412 |
International
Class: |
C11D 17/00 20060101
C11D017/00 |
Claims
1. An aerosol container removably insertable in a metered dose
dispenser for cleaning an actuator of the dispenser, the container
containing a cleaning composition comprising a propellant and
silicone.
2. The container of claim 1., wherein the propellant is selected
from the group consisting of tetrafluoroethane, heptafluoroethane,
dimethylfluoropropane, tetrafluoropropane, butane, isobutane,
dimethyl ether, hydrogen-containing chlorofluorocarbons,
hydrogen-containing fluorocarbons, and diethyl ether.
3. The container of claim 2, wherein the propellant is selected
from the group consisting of dimethyl ether, hydrogen-containing
chlorofluorocarbons, hydrogen-containing fluorocarbons, and diethyl
ether.
4. The container of claim 2, wherein the propellant is
1,1,1,2-tetrafluoroethane.
5. The container of claim 1, wherein the propellant is present in a
concentration of about 90 to 99 wt./wt. % of the total cleaning
composition and the silicone is present in a concentration of about
1 to 10 wt./wt. % of the total cleaning composition.
6. The container of claim 1, wherein the composition further
comprises an organic solvent.
7. The container of claim 6, wherein the organic solvent is an
alcohol solution.
8. The container of claim 7, wherein the alcohol solution is
ethanol.
9. A composition for cleaning an actuator of a metered dose
dispenser, the composition comprising a propellant, silicone, and
ethanol, wherein the propellant is selected from the group
consisting of tetrafluoroethane, heptafluoroethane,
dimethylfluoropropane, tetrafluoropropane, butane, isobutane,
dimethyl ether, hydrogen-containing chlorofluorocarbons,
hydrogen-containing fluorocarbons, and diethyl ether, and wherein
the propellant is present in a concentration of about 90 to 99
wt./wt. % of the total composition and the silicone is present in a
concentration of about 1 to 10 wt./wt. % of the total
composition.
10. The composition of claim 9, wherein the propellant is selected
from the group consisting of dimethyl ether, hydrogen-containing
chlorofluorocarbons, hydrogen-containing fluorocarbons, and diethyl
ether.
11. The composition of claim 9, wherein the propellant is
1,1,1,2-tetrafluoroethane.
Description
RELATED APPLICATION
[0001] This application is a Divisional of U.S. application Ser.
No. 10/320,045, filed Dec. 16, 2002.
[0002] The entire teachings of the above application are
incorporated herein by reference.
FIELD OF THE INVENTION
[0003] The present invention relates to a method of cleaning
actuators or metered dose dispensers used to dispense
pharmaceutical compositions. The invention also relates to a
composition to be used in cleaning actuators of metered dose
dispensers.
DESCRIPTION OF THE RELATED ART
[0004] Metered dose spray devices are presently used to administer
many different medications to the mouth and lungs, for example,
asthma medication and nitroglycerin for treatment of heart disease.
A typical metered dose spray device includes a container, for
example, a can, for containing a solution or suspension of
medication, a metering valve, and an actuator. The can will contain
the medication to be dispensed, possibly a solvent for the
medication, and a propellant. The propellant is a substance having
a low boiling point and high vapor pressure, so that as liquid is
dispensed from the container the propellant evaporates, thereby
maintaining a constant pressure within the can. Actuation of the
metering valve causes the metering chamber within the valve to
close with respect too the can's interior, and open with respect to
the mouthpiece (the structure of the actuator to be positioned in
communication with the user's mouth). Propellant within the
metering chamber will evaporate due to the sudden decrease in
pressure then the valve is actuated, propelling the medication into
the user's mouth.
[0005] After repeated use, the actuator can become clogged with the
medication being dispensed. This can interfere with proper dosing
and delivery of the medication. It is desirable, therefore, to
provide a method of cleaning the actuator on a regular basis to
resist clogging and assure delivery of the desired amount of
medication.
SUMMARY OF THE INVENTION
[0006] The present invention provides a method of cleaning an
actuator of a metered dose dispenser containing a pharmaceutical
product, and also provides a chemical composition for performing
this cleaning.
[0007] Generally, the metered dose spray device consists of three
major components: an aerosol container (which in many preferred
embodiments will be a can) containing medication in liquified
propellant gas; a metering valve, which when depressed dispenses a
known quantity of the medication; and a buccal spray actuator which
when combined with the stem of the metering valve comprises an
expansion chamber, also called a sump, and a nozzle, often called a
spray orifice. The actuator itself is comprised of an actuator bot,
stem block, sump, spray orifice and mouthpiece. The actuator boot
keep the aerosol can fixed in place. The stem block is dimensioned
and configured to receive the stem of the metering valve, which is
fixed to the aerosol can, and whose purpose is to carry the
medication from the metering valve to the actuator sump, specially
designed to act as an expansion chamber and to redirect the aerosol
through the spray orifice.
[0008] In the rest position, the metering chamber of the valve is
connected directly to the aerosol can containing the medication,
permitting free flow from the metering chamber to the container.
The vapor pressure of the propellant therefore ensures that the
metering chamber remains full of the medication/propellant mixture,
and the capillary action of the passage from the container to the
metering chamber prevents fluid in the metering chamber from
exiting back into the container. Upon depression of the can towards
the actuator, the valve stem is pushed into the can. The connection
between the aerosol container and metering chamber is thereby
closed and the metered discharge process begins. The metered dose
is ejected from the metering chamber under the pressure of the
flashing liquid propellant. The medication then passes through the
valve stem orifice into the actuator sump where it undergoes
further boiling as it attempts to fill the chamber and displace the
air. Finally, a high-quality spray, particularly suited to buccal
delivery, emerges from the spray orifice and mouthpiece of the
actuator.
[0009] Cleaning is performed by first removing the aerosol can
containing the medication, and replacing it with an aerosol
container or can containing a cleaning composition. The cleaning
composition's can is then depressed towards the actuator to force
the valve stem into the container and discharge the cleaning
composition through the actuator's sump and orifice. Residue of the
pharmaceutical product present in the actuator is substantially
removed by the discharge of the cleaning composition therethrough,
by the force of the flowing cleaning composition and/or by being
dissolved in a solvent within the cleaning composition.
[0010] A cleaning composition, to be used in the above method, is
also provided in the present invention. The cleaning composition is
itself non-toxic and leaves little or no residue in the actuator,
and thus does not interfere with subsequent delivery of the
pharmaceutical product. The cleaning composition is preferably
comprised of silicone and a propellant, and optionally, an organic
solvent.
[0011] It is therefore an object of the present invention to
provide a method of cleaning an actuator of a metered dose spray
device used in delivery of pharmaceutical agents.
[0012] It is another object of the present invention to provide a
cleaning composition for preventing clogs within the actuator of a
metered dose spray device.
[0013] It is a further object of the present invention to provide
an efficient and economical method of cleaning a metered dose spray
device.
[0014] It is another object of the present invention to provide an
apparatus for cleaning a metered dose spray device that is easy to
use.
[0015] It is a further object of the present invention to provide a
safe cleaning composition for use with metered dose spray
devices.
[0016] These and other objects of the present invention will become
more apparent through the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The foregoing and other objects, features and advantages of
the invention will be apparent from the following more particular
description of preferred embodiments of the invention, as
illustrated in the accompanying drawings in which like reference
characters refer to the same parts throughout the different views.
The drawings are not necessarily to scale, emphasis instead being
placed upon illustrating the principles of the invention.
[0018] FIG. 1 is a front isometric view of a metered dose spray
device.
[0019] FIG. 2 is a side view of a can and metering valve assembly
for a metered dose spray device.
[0020] FIG. 3 is a cross-sectional side view of an actuator, can
and metering valve for a metered dose spray device showing the
metering valve closed.
[0021] FIG. 4 is a side cross-sectional view of an actuator, can
and metering valve for a metered dose spray device showing the
metering valve open.
[0022] FIG. 5 is a cross-sectional view of a can and valve
assembly, taken along the lines 5-5 in FIG. 3.
[0023] Like reference numbers denote like elements throughout the
drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A description of preferred embodiments of the invention
follows.
[0025] The present invention provides a method of cleaning a
metered dose spray device, and a chemical composition for
performing this cleaning.
[0026] Referring to the figures, the metered dose spray device 10
includes an actuator 12, an aerosol can 14, and a metering valve
16.
[0027] The aerosol can 14 is best illustrated in FIGS. 2-4. The
aerosol can 14 is preferably cylindrical having an open end 18. The
open end 18 is dimensioned and configures to mate with the ferrule
(described below) of the metering valve 16. A preferred material
for the can 14 is aluminum, but stainless steel or other suitable
materials can also be used.
[0028] Referring to FIGS. 3-4, the metering valve 16 includes a
housing 20, having a plurality of slots 21 (FIG. 5) with a stem 22
slidably contained therein. A preferred material for the 3-slot
housing and stem is polyester, but acetyl resins or other suitable
materials can be used as well. The metering valve 16 also includes
a ferrule 24, dimensioned and configured to fit around the outside
of the open end 18 of the aerosol can 14, being crimped around the
end 18 to secure the metering valve 16 to the can 14. A preferred
material for the ferrule is aluminum. A sealing gasket 26 provides
a seal between the can's open end 18 and the ferrule 24. A
preferred material for the sealing gasket 26 is nitrile (buna)
rubber. A metering chamber 28 within the 3-slot housing 20 is
defined between the upper annular stem gasket 30 and the lower
annular stem gasket 32. A preferred material for the first and
second stem gaskets 30, 32 is nitrile (buna) rubber. The stem 22
includes an upper stem and a lower stem, with the lower stem having
a U-shaped retention channel 34 having ends 36 and 38, and an upper
stem having a channel 40 having ends 42 and 44. The principle of
retention lies in the particular geometry at the base of the stem
22, which allows the passage of the fluid under the differential
pressure from the aerosol can 14 to valve metering chamber 28 after
actuation, but resists the return (due to gravity) of the fluid to
the aerosol can 14 by the capillary action of the retention channel
34.
[0029] The stem 22 moves between the rest (closed) position and an
open position. Within the rest position, shown in FIG. 3, the inlet
end 36 of the retention channel 34 is above the first stem gasket
30, so that the contents of the aerosol can 14 may enter the
retention channel 34. The outlet end 38 of the retention channel 34
is below the first stem gasket 30 and within the metering chamber
28. Both the inlet end 42 and outlet end 44 of the channel 40 are
outside the metering chamber 28, thereby resisting passage of fluid
from the metering chamber 28 to the channel 40. In the open
position, shown in FIG. 4, both the inlet end 36 and outlet end 38
of the retention channel 34 are above the first stem gasket 30 of
the metering chamber 28, thereby resisting any fluid flow from the
aerosol can 14 to the metering chamber 28. At the same time, the
inlet end 42 of the channel 40 is above the second stem gasket 32
and inside the metering chamber 28, thereby permitting passage of
fluid from the metering chamber 28 through the passage 40. The stem
22 is biased by the spring 46 into the rest position of FIG. 3.
[0030] The actuator 12 is best illustrated in FIGS. 1, 3 and 4. The
actuator 12 includes mouthpiece 50, a stem block 48 and an actuator
sump 52. The actuator sump 52, which is located in the stem block
48, includes an inlet end 54, dimensioned and configured to receive
the lower end 56 of the valve stem 22, and an outlet end 58, called
a spray orifice. The spray orifice 58 of the actuator sump 52 is
dimensioned and configured to direct medication towards the back of
the throat. The spray orifice 58 may have a generally round
configuration. The sump volume is preferably sufficient to generate
a high-pressure stream of fluid upon actuation of the metered dose
spray device.
[0031] The actuator 12 may also include a cap 60, surrounding the
actuator 12 and aerosol can 14. The cap 60 is preferably slidably
and removably secured to the actuator 12. One method of slidably
and removably securing the cap 60 to the actuator 12 is by
friction, thereby permitting removal or reattachment of the cap 60
and actuator 12 by merely pulling upward on the cap 60. The
actuator 12 may also include a dust cover 68, dimensioned and
configured to cover the mouthpiece 50.
[0032] The cleaning composition of the present invention includes a
mixture of silicone and an appropriate propellant, and may
optionally include an organic solvent. Preferably, silicone is
about 1-10 wt./wt. % of the total cleaning composition, and
propellant is about 90-99 wt./wt. % of the cleaning
composition.
[0033] Propellants commonly used in conjunction with drug delivery
via metered dose spray devices are also appropriate for use with
the present cleaning composition. Such propellants include
tetrafluoroethane, heptafluoroethane, dimethylfluoropropane,
tetrafluoropropane, butane, isobutane, dimethyl ether and other
non-CFC and CFC propellants. The preferred propellants are
hydrogen-containing chlorofluorocarbons, hydrogen-containing
fluorocarbons, dimethyl ether and diethyl ether. Even more
preferred is HFA-134a (1,1,1,2-tetrafluoroethane).
[0034] Suitable organic solvents for use with the cleaning
composition of the present invention include alcohol solutions,
such as ethanol.
[0035] Use of the metered dose spray device 10 begins with the
valve 16 in its rest position. When the valve 16 is in its rest
position as shown in FIG. 4, medication within the aerosol can 14
is free to move through the slots 21 within the metering valve's
housing 20, through the U-shaped retention channel 34, and into the
metering chamber 28. The propellant, specifically selected for its
high vapor pressure, evaporates to the maximum extent permitted by
the volume of the aerosol can 145. The medication within the
aerosol can 14 is thereby forced through the retention channel 34
until the metering chamber 28 is full. The elongated and curved
shape of the retention channel 34 keeps the medication in the
metering channel 28 from traveling back into the aerosol can 14.
The location of the channel 40 below the second stem gasket 32
resists medication from exiting the metering chamber 28
prematurely.
[0036] To use the metered dose spray device 10, the lower end 56 of
the stem 22 is first inserted into the inlet end 54 of the actuator
sump 52, located in the stem block 48 of the actuator 12. The cap
60 may also be secured to the actuator 12, thereby completely
concealing the aerosol can 14. The dust cover 68 is removed from
the mouthpiece 50. The mouthpiece 50 is inserted into the user's
mouth and the aerosol can 14 (possibly along with the cap 60) is
depressed towards the actuator 12. This action causes the metering
valve 16 to move from its rest position of FIG. 3 to its open
position of FIG. 4. When the stem 22 is moved from the rest
position of FIG. 3 to the open position shown in FIG. 4, the outlet
opening 38 of the retention channel 34 is moved above the first
stem gasket 30, thereby resisting medicine from moving from the
aerosol can 14 to the metering chamber 28. At the same time, the
inlet end 42 of the channel 40 is brought above the second stem
gasket 32, thereby providing a path from the metering chamber 28,
through the channel 40 and actuator sump 52, spray orifice 58,
through the mouthpiece 50, and into the user's mouth. Opening the
metering valve 16 also decreases the pressure within the metering
chamber 28, causing the propellant in the metering chamber 28 to
evaporate, thereby pushing the medication out through the channel
40 into the actuator sump 52, where it undergoes further
evaporation as it attempts to fill the chamber and displace the
air, and finally through spray orifice 58 and out the mouthpiece
50. Releasing downward pressure on the aerosol can 14 causes the
metering valve 16 to return to its rest position under pressure
from the spring 46, thereby permitting a new dosage of medication
to enter the metering chamber through the retention channel 34,
under pressure from the evaporated propellant within the aerosol
can 14.
[0037] To clean the actuator 12 of the metered dose spray device
10, the cap 60 is first removed. The can 14 containing the
medication is then removed, and is replaced with another can 14
containing the cleaning composition. As before, the lower end 56 of
the stem 22 is inserted into the inlet end 54 of the actuator sump
52, located in the stem block 48 of the actuator 12. The dust cover
68 should remain removed from the mouthpiece 50. The aerosol can 14
containing the cleaning composition is depressed towards the
actuator 12. This action causes the metering valve 16 to move from
its rest position of FIG. 3 to its open position of FIG. 4. When
the stem 22 is moved from the rest position of FIG. 3 to the open
position shown in FIG. 4, the outlet opening 38 of the retention
channel 34 is moved above the first stem gasket 30, thereby
resisting cleaning composition from moving from the aerosol can 14
to the metering chamber 28. At the same time, the inlet end 42 of
the channel 40 is brought above the second stem gasket 32, thereby
providing a path from the metering chamber 28, through the channel
40 and actuator sump 52, spray orifice 58, and through the
mouthpiece 50. Opening the metering valve 16 also decreases the
pressure within the metering chamber 28, causing the propellant in
the metering chamber 28 to evaporate, thereby pushing the cleaning
composition out through the cannel 40 into the actuator sump 52,
where it undergoes further evaporation as it attempts to fill the
chamber and displace the air, and finally through the spray orifice
58 and out the mouthpiece 50. As the cleaning composition passes
through the various portions of the actuator 12, it carries with it
any remaining medication within the actuator 12, thereby preventing
any clogs within the actuator sump 52. Releasing downward pressure
on the aerosol can 14 causes the metering valve 16 to return to its
rest position under pressure from the spring 46, thereby permitting
a new supply of cleaning composition to enter the metering chamber
through the retention channel 34, under pressure from the
evaporated propellants within the aerosol can 14. Upon completion
of cleaning, the aerosol can 14 containing the cleaning composition
should immediately be replaced with the aerosol can 14 containing
the medication. The cap 60 may again be place on the actuator 12,
so that the metered dose spray device 10 is ready to administer the
next dose of medication.
[0038] While a specific embodiment of the invention has been
described in detail, it will be appreciated by those skilled in the
art that various modifications and alternatives to those details
could be developed in light of the overall teachings of the
disclosure. Accordingly, the particular arrangements disclosed are
meant to be illustrative only and not limiting as to the scope of
the invention which is to be given the full breadth of the appended
claims and any and all equivalents thereof.
* * * * *