JP2003509629A - Flow control and filtration method and apparatus - Google Patents

Abstract

(57) [Summary] The porous material valve 18 is arranged in the fluid transport path of the fluid distribution device 2. By selecting a particular porous material thickness, pore size, pore volume, and hydrophilic / hydrophobic balance of the material, a given actuation / closure pressure and flow rate is achieved.

Description

Detailed Description of the Invention

This application claims the benefit of US Provisional Application No. 60 / 153,647, filed September 13, 2000, the entire disclosure of which is incorporated by reference.

FIELD OF THE INVENTION The present invention relates to flow control and filtration methods and devices applicable to medical devices, drug delivery devices, food dispensing devices, aerosol generators and the like.

BACKGROUND OF THE INVENTION Fluid dispensing devices are used in a variety of applications including, for example, drug delivery, food dispensing, cleanser or hair spray dispensing, and the like. Such devices typically include an aerosol-generating surface and a fluid-transporting channel, the channel comprising:
An inlet is in fluid communication with the tank and an outlet is located above the aerosol generating surface. The fluid to be delivered is contained in a tank.

However, conventional fluid dispensing devices lacked a low cost, suitable method and device for controlling fluid flow. In addition, conventional fluid dispensing devices, particularly drug delivery devices, suffer from the lack of effective mechanisms to control evaporation and contamination of the fluid tank. Mechanical devices do not seem a viable option due to their high cost and lack of reliability (high failure rate).

Thus, controlling the flow of fluid, preventing evaporation and contamination of the fluid tank,
There is a need to develop a low cost and reliable shutoff valve.

SUMMARY OF THE INVENTION The present invention provides a novel and unique control of fluid flow in fluid dispensing systems used in medical devices, drug delivery systems, food dispensing, aerosol generation, and the like. Methods and apparatus are provided.

The present invention uses porous materials for both flow control regulators for fluid distribution and / or pressure dependent shutoff valves. The porous material can be used to prevent leaching of fluid from a pressurized fluid source, to minimize evaporation of fluid contained therein and / or to prevent contamination.

The present invention provides a closure and / or flow control valve for fluid distribution systems and the like. The fluid dispensing system according to the present invention delivers the fluid from the source tank to the dispensing location by creating a pressure drop.

A shutoff valve is provided in the fluid transport path to protect the source tank and minimize evaporation. Mechanical shutoff valves such as check valves, poppet valves, flapper valves and duck bill valves are too costly and unreliable.

Accordingly, the present invention provides a novel method and apparatus in which a porous medium inserted into a fluid transport path of a fluid distribution system serves as a shutoff valve, a fluid flow control mechanism, and a pollution control device. .

The porous medium has a predetermined actuation pressure (acti) to establish fluid flow.
vation pressure) Requires a lower or threshold pressure. At pressures below this working pressure, no fluid will flow. Therefore, when the pressure drop is below a certain level, the pressure drop of the porous medium acts as a shutoff valve. Such a pressure drop occurs in the inhalation drug delivery device due to the inspiration force of the user.

The size of the pores and the total volume of the pores, and to some extent the hydrophilic / hydrophobic balance of the porous material, determine the pressure value (ie, threshold pressure) required to initiate the flow. These variables also determine the flow through this material. For example, some porous media promotes free flow after reaching the threshold pressure. Once the threshold pressure is reached, the flow promoted in the other porous media increases as the pressure rises and reaches a certain maximum value.

The pore size also limits the size of particles in and out of the porous media. Therefore, the size of the particles exiting the fluid distributor is limited to a certain size, while at the same time fluid loss (fluid evaporation) due to vapor pressure in the fluid tank is substantially eliminated. Therefore, the porous valve can also be regarded as a filtering device that filters the fluid and distributes only fluid particles of a predetermined size.

The particle size limitation also results in substantially eliminating contamination of the fluid in the fluid tank. Biological contaminants do not pass through the pores of the porous valve, effectively preventing biological contamination from crossing the porous material. The pore size can be tailored to a particular pore size to prevent certain types of biological cells from contaminating the fluid tank.

For example, the pores can be sized to prevent the following organisms from entering the fluid path or tank. Virus: 0.05-0.1 micron, bacterium: 0.5-1.5 micron, red blood cell: 5 micron, and lymphocyte: 5-8 micron.

Further, in many fluid distribution systems, sizing the particles exiting the fluid tank is important. For example, in drug delivery systems, especially inhalers, drugs administered into the body of a patient are relatively easily absorbed at a particular particle size.

By adjusting the hydrophilic / hydrophobic balance and porosity of the porous material, evaporation of fluid from the source tank through the porous media valve can be minimized. The porous valve according to the present invention has a loss of evaporation of 60 compared to mechanical valves.
% Reduced.

Thus, a myriad of actuating / closing pressures and / or flow rates are achieved by varying parameters such as porous material thickness, pore size, pore volume, hydrophilic / hydrophobic balance of the material. be able to.

Accordingly, in one aspect of the invention, the pressure valve at the fluid tank outlet of the fluid distribution device comprises a porous medium.

In another aspect of the invention, a pressure valve for a fluid distribution device comprises a fluid transport channel having an inner diameter, and an outlet and an inlet in fluid communication with a fluid tank. This valve also comprises a porous medium located adjacent the outlet.

In another aspect of the invention, the distribution pipe of the fluid distribution device comprises a fluid transport channel having an inner diameter, the channel comprising an outlet located above the aerosol generating surface;
An inlet in fluid communication with the fluid tank. The distribution pipe also comprises a pressure valve adjacent the outlet, the valve comprising a porous medium.

In another aspect of the invention, the pressure regulator at the fluid tank outlet of the fluid distribution device comprises a porous medium.

In another aspect of the invention, a fluid dispenser regulator comprises a fluid transport channel having an inner diameter with an outlet located above the aerosol generating surface and an inlet in fluid communication with a fluid tank. This conditioner also comprises a porous medium located adjacent the outlet.

In another aspect of the invention, the porous media of the fluid distribution device comprises a porous plastic having a pore size of approximately 0.02 micron to 0.80 micron.

In another aspect of the invention, a pressure valve system for a fluid dispensing device includes a means for transporting fluid from a fluid tank to an aerosol generating surface and a porous means in fluid communication with the transport means. With. When a pressure drop is generated, this porous means allows the flow of fluid onto the aerosol generating surface.

In another aspect of the invention, a method of dispensing fluid in a fluid dispensing device is provided. The liquid dispensing device includes a fluid tank having an outlet located adjacent the aerosol generating surface, an airflow flowing over the surface, and a valve disposed adjacent the outlet and having a porous medium. This porous medium has a predetermined working pressure. The method comprises the steps of applying a predetermined actuation pressure on a porous medium, distributing a drug to an aerosol generating surface, and entraining aerosolized particles generated at this surface into an air stream. .

In another aspect of the invention, a system for dispensing fluid in a fluid dispensing device is provided. The fluid distribution device includes a fluid tank having an outlet disposed adjacent an aerosol generating surface, an airflow flowing over the surface, and an outlet disposed adjacent the outlet.
A valve with a porous medium. This porous medium has a predetermined working pressure. The system comprises means for exerting a predetermined operating pressure on the porous medium, means for distributing the drug to an aerosol generating surface, and entraining the aerosolized particles generated at this surface into the air stream. And means for.

In another aspect of the invention, a method of dispensing a drug in a drug delivery device is provided. The drug delivery device includes a drug tank having an outlet located adjacent the aerosol generating surface, an airflow flowing over the surface, and a valve disposed adjacent the outlet and having a porous medium. This porous medium has a predetermined working pressure. The method comprises the steps of applying a predetermined actuation pressure on a porous medium, distributing a drug to an aerosol generating surface, and entraining aerosolized particles generated at this surface into an air stream. .

The above aspects of the invention will be further clarified by reference to the following drawings and written description.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A-1F show various views of an assembled three-part fluid distribution system 2 with a porous valve according to the present invention. The system has a rear portion 4, a central portion 6 and a jet 8 including a jet 10 and a jet end 12.

2A-2F include a jet with a porous material valve according to the present invention, FIG.
3A-3F show various views of the end of the fluid distribution system shown in FIGS.

3A-3G show various views of the central portion of the fluid distribution system shown in FIGS.

4A-4F show various views of the rear of the fluid distribution system shown in FIGS.

FIG. 5 is a side sectional view of distribution pipe 14 of a fluid distribution system having a porous material valve 18 at a tip 16 of distribution pipe 14 in fluid communication with a fluid tank.

[0035]   FIG. 6 shows various views of a porous valve according to the invention.

FIG. 7 is a graph showing the efficiency of a fluid distribution system using a porous valve according to the present invention with respect to particle size. The x-axis represents the size of the particles that could pass through the porous filter and the y-axis represents the efficiency of the device in percentage. This graph shows that as the particle size increases, so does the efficiency of the device. In the present invention, the efficiency when using the porous valve according to the present invention exceeds the average value when simply using the long tube. On average, the efficiency increase exceeds 7%.

FIG. 8 is a graph showing the performance of a porous valve according to the present invention used in an open mouthpiece of an inhaled drug delivery device, compared to the same device without the valve. The graph shows the inhalation rate as a percentage, the inhalation amount as μg and the device efficiency as a percentage. It can be seen that all items are improved when the porous valve is used.

FIG. 9 is a table outlining the performance of a drug delivery device using a porous valve according to the present invention. The table shows specific specifications, target values, original values obtained by using a long metal tube in a fluid distribution system, measured values using a porous filter according to the present invention, and best-in-class latest commercial products. The benchmark obtained from is described.

As is apparent from the table of FIG. 9, the following results can be obtained by arranging the porous valve in the fluid transportation path.

Increased efficiency of the fluid distribution system. Deliver a more stable and uniform fluid to the aerosolization mechanism (piezoelectric horn) of the inhaler. -Reduce evaporation loss by approximately 60%. -Improving weighing accuracy by almost 4%. And-the cost is relatively low.

FIG. 10 is a table showing the flow rate of water with respect to the pipe size for distributing the fluid from the fluid tank. The columns of the table include tube inner diameter (in inches and cm), tube flow rate (in cm ³ / sec and μL / sec), droplet diameter (in cm), droplet mass (in grams), and finally , The force (in grams) required to pass a droplet through the porous material.

FIG. 11 is a table showing the pipe pressure drop of the pipe inner diameter shown in FIG. For a given tube inner diameter, the pressure drop or the pressure required to move the fluid through the porous material is described (in mbar and psi).

[0043]   FIG. 12 shows the calculation of the maximum pressure of the flow in the porous medium. The maximum force generated is
20 N and the maximum pressure generated at the tip of the cannula is 2,571 lbf / in ^Two It can be seen that it is.

Examples of porous materials include polysulfone, polyether sulfone, cellulose acetate, nylon, polyvinylidene fluoride, polytetrafluoroethylene, and polyolefins. Specific examples of porous materials that can be used include Sa
rtorious 0.2 or 0.45 micron cellulose acetate CA125
87, Millipore 0.20 micron GVPH2935, Milli
pore 0.22 micron GSW P096, or Pall 0.22 micron nylon media.

The pore size is about 0.05 to 1.0 micron, more preferably about 0.15 to 0.90 micron, and most preferably about 0.20 to 0.8 micron.
It can be 0 micron.

A preferred porous valve structure for a drug delivery device according to the present invention is 2.0 mm above the piezoelectric aerosolization device (a device that produces aerosolized particles from a fluid),
A 0.5 mm inner diameter fluid transport channel with a 0.5 mm gap is provided.

In the drug delivery device according to the present invention, the drug is dispensed by applying a pressure drop over the porous medium of the drug distribution tube. Such pressure drop occurs as a result of the inspiratory force of the user of the drug delivery device, which also causes airflow within the device. Concurrently with or immediately after the onset of the pressure drop, the drug is dispensed onto the aerosol-generating surface of the drug delivery device. The drug is aerosolized and then entrained in the air stream produced by the inspiratory force.

[0048]   The following example illustrates the invention.

Commercially available porous filtration material was inserted into the small diameter cannula of the drug delivery device. This material has hydrodynamic holes with a diameter of 0.45 micron (preferably 0.2 micron or more) and a total thickness of less than 0.010 inches (about 0.3 mm). The surface area and pressure drop characteristics of this material are such that a drug delivery device can deliver 3 psi at 10 psi pressure drop.
It was suitable for dispensing a fluid flow of 00 microliters. This porous material is permeable to particles and fluids with an average diameter of less than 200 nanometers.

[Brief description of drawings]

1A-1F show an assembled three-part fluid distribution system.

2A-2F are diagrams showing the ends of the fluid distribution system shown in FIGS. 1A-1F.

3A-3G are views of the central portion of the fluid distribution system shown in FIGS.

4A-4F are views of the rear of the fluid distribution system shown in FIGS. 1A-1F.

[Figure 5]   1 is a side sectional view of a distribution pipe equipped with a porous material valve according to the present invention.

[Figure 6]   FIG. 3 is a diagram of a porous valve according to the present invention.

FIG. 7 is a graph showing the efficiency of a fluid distribution system using a porous valve according to the present invention.

[Figure 8]   3 is a graph showing the performance of the porous valve according to the present invention.

FIG. 9 is a table outlining the performance of a drug delivery device using a porous valve according to the present invention.

[Figure 10]   It is a table which shows the flow volume of water with respect to a pipe dimension.

FIG. 11   11 is a table showing the pipe pressure drop of the pipe inner diameters shown in FIG. 10.

[Fig. 12]   3 is a table showing pressure calculation of an inhaler.

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] July 5, 2001 (2001.7.5)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Contents of correction]

This application claims the benefit of US Provisional Application No. 60 / 153,647, filed September 13, 1999, the entire disclosure of which is incorporated by reference.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01D 71/36 B01D 71/64 71/64 71/68 71/68 B01J 4/00 101 B01J 4/00 101 F16L 55/00 L (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA , BB, BG, BR, BY, BZ, CA, CH, CN, CR, CU, CZ, DE, DK, DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX , MZ, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW (71) Applicant 425 South Woodsmill Road, Suite 270, St. Louis, Missouri 63017-3441, United States of America (72) Inventor Pubkov, Lichyard M United States of America, Michigan 48170, Plymouth, Birchwood 39819 (72) Inventor Armor, Thomas A. United States of America, California 95014 Cupertino, Tailson Avenyu 19000 F term (reference) 3H025 BA14 4D006 GA07 GA44 HA41 HA91 HA95 KA72 KB30 MA03 MA22 MC18 MC22 MC30 MC54 MC62 MC63 PA01 PB24 PC41 4G068 AA02 AA03 AB07 AB15 AC20 AD12 AD40 AF01 AF36

Claims (29)

[Claims] 1. A pressure actuated valve for a fluid tank outlet of a fluid distribution device having a porous medium. 2. The valve of claim 1, wherein the valve supplies fluid to an aerosol generating surface. 3. The porous medium comprises a porous plastic.
Valve described in. 4. The valve according to claim 3, wherein the porous plastic comprises a polysulfone or polyethersulfone material. 5. The porous plastic comprises a cellulose acetate material,
The valve according to claim 3. 6. The valve according to claim 3, wherein the porous plastic is made of a nylon material. 7. The valve according to claim 3, wherein the porous plastic comprises a polytetrafluoroethylene material. 8. The porous plastic is made of a polyolefin material.
The valve according to claim 3. 9. The valve of claim 3, wherein the porous plastic comprises a nylon medium. 10. The pore size of the porous plastic is approximately 0.
The valve of claim 3, which is between 15 microns and 0.80 microns. 11. The valve of claim 1, wherein the pressure drop applied to the outlet causes a fluid flow from the tank through the porous medium. 12. The valve according to claim 11, wherein the pressure drop is a predetermined value. 13. The valve according to claim 1, wherein the porous medium acts as a filtration element. 14. The valve of claim 11, wherein the amount of pressure drop that allows fluid flow is determined by the pore size of the porous medium. 15. The valve of claim 11, wherein the amount of pressure drop that allows fluid flow is determined by the volume of pores in the porous medium. 16. The valve of claim 11 wherein the amount of pressure drop that allows fluid flow is determined by the hydrophilic / hydrophobic balance of the porous medium. 17. The valve of claim 1, wherein the porous medium prevents leaching of fluid from the tank. 18. The valve of claim 1, wherein the porous medium minimizes evaporation of fluid from the tank. 19. The valve of claim 1, wherein the porous medium prevents contamination of the fluid tank. 20. The valve of claim 1, wherein the fluid is a drug and the fluid dispensing device is an inhaled drug delivery device. 21. A pressure valve for a fluid distribution device, the fluid transport channel having an inner diameter, an outlet located above the aerosol generating surface, and an inlet in fluid communication with a fluid tank, said outlet. And a porous medium disposed adjacent to the pressure valve. 22. A distribution pipe for a fluid distribution device, the fluid distribution channel having an inner diameter, an outlet located above the aerosol generating surface, an inlet in fluid communication with a fluid tank, and adjacent to the outlet. And a pressure valve provided with a porous medium that 23. A pressure regulator at the fluid tank outlet of a fluid distribution device comprising a porous medium. 24. A fluid distribution device regulator comprising: a fluid transport channel having an inner diameter, an outlet located above the aerosol generating surface, an inlet in fluid communication with a fluid tank, and adjacent to the outlet. And a porous medium disposed in the regulator. 25. A porous medium for a fluid distribution device, the porous medium comprising a porous plastic having a pore size of approximately 0.15 micron to 0.80 micron. 26. A pressure valve system for a fluid dispensing device comprising: means for transporting fluid from a fluid tank to an aerosol generating surface; and porous means in fluid communication with the transport means. A pressure valve system wherein the porous means allows the flow of fluid onto the aerosol generating surface by generating a pressure drop. 27. A method of distributing fluid in a fluid distribution device, the fluid distribution device comprising: a fluid tank having an outlet disposed adjacent an aerosol generating surface; an airflow flowing over the surface; A valve disposed adjacent the outlet, the valve having a porous medium, the porous medium having a predetermined working pressure, the method applying the predetermined working pressure on the porous medium. A method comprising: delivering the drug onto the aerosol-generating surface; and entraining aerosolized particles generated at the surface into the air stream. 28. A system for distributing fluid in a fluid distribution device, the fluid distribution device comprising: a fluid tank having an outlet positioned adjacent an aerosol generating surface; and an airflow flowing over the surface. A valve having a porous medium disposed adjacent to the outlet, the porous medium having a predetermined working pressure, the system having the predetermined working pressure on the porous medium. A system comprising means for adding, means for dispensing the drug onto the aerosol generating surface, and means for entraining aerosolized particles generated at the surface into the air stream. 29. A method of dispensing a drug in a drug delivery device, the drug dispensing device comprising: a drug tank having an outlet disposed adjacent an aerosol generating surface; an airflow flowing over the surface; A valve disposed adjacent the outlet, the valve having a porous medium, the porous medium having a predetermined working pressure, the method applying the predetermined working pressure on the porous medium. A method comprising: delivering the drug onto the aerosol-generating surface; and entraining aerosolized particles generated at the surface into the air stream.