Patent Application
20130118638
The present invention relates to the field of pharmaceutical capsule filling technology. Specifically, the present invention relates to a method and device designed for filling capsule shells with minitablets, also known as minitabs or microtabs. More specifically, the present invention relates to an apparatus that works in conjunction with known capsule shell filling technology to provide an exact number of minitabs per capsule in an efficient, rapid and cost effective manner.
Capsules are solid pharmaceutical dosage forms in which a drug substance or pharmaceutical composition, i.e., a drug alone or combined with excipients, is enclosed in a hard or soft soluble shell or container. Capsules may be classified as either “hard” or “soft” depending upon the nature of the shell. A detailed description of hard and soft capsule products is provided on pages 395-440 of Modern Pharmaceutics, 3rd ed. © 1996, ed. by Banker et al. and on pages 885-891 of Remington, The Science and Practice of Pharmacy, 20th ed. © 2000. Capsule shells consist of a cap and a body. Most commercially available capsule shells are sold in a “prelock” form wherein the capsule cap and body are joined together in an easily separated fashion. Preparation of a final capsule product involves separation of the cap and body portions, placing or filling the drug substance or pharmaceutical composition into the capsule body and replacing and locking the cap onto the filled capsule body.
The separation, filling and closing of the capsule shell to form a capsule product has been performed by hand and by mechanical means. Some of the prior art capsule filling machines employ systems wherein a prelocked capsule shell is fed from a hopper, and the capsule body and cap are separated. The capsule body is indexed to a position to enable the filling of the capsule body with the drug substance or pharmaceutical composition, and the capsule cap is then oriented over the filled capsule body and locked onto the capsule body to create the final filled capsule product. Most of the known capsule-filling machines employ turntables or carousels which can intermittently rotate between alternate work stations. Generally, one work station separates the empty capsule shells, another fills the capsule body, another may compress or weigh the encapsulated material and, finally, the capsule cap is locked onto the filled capsule body and the final complete capsule is ejected from the capsule filling machine. Some known capsule filing machines are described in U.S. Pat. Nos. 3,978,640; 4,163,354 and 4,731,979, which are incorporated herein by reference.
Most of the known prior art technology for filling capsule shells focused on techniques designed for filling capsules with very small particles such as powders, beads or pellets. These small particles typically exhibit a mean particle diameter of less than 0.5 mm. The amount of material to be placed in the empty capsule shells was generally determined by a total fill weight or volume because it is impractical and/or unnecessary to count the actual amount of particles contained within a capsule.
Minitabs, also described in the literature as microtabs or minitablets, are small tablets typically having a diameter (or length) of about 0.5 mm to about 10 mm. Minitabs are generally prepared by techniques known in the art, such as wet or dry granulation followed by compression of the granules; direct compression of blended materials, or any other tableting techniques known in the art. A primary distinction between minitabs and conventional tablets is purely one of size.
It has also been discovered that because of the greater size of the minitabs compared with conventional beads or particles employed in capsule formulations, it is critical that an exact number of minitabs are placed into a single capsule. The difference between nine minitabs versus ten minitabs in a capsule can be the difference of 10% or more of the effective dose. Such a variation in dosage strength is outside the allowable limits for pharmaceutical preparations. In contrast, with conventional capsule filling technology it is possible to have hundreds or thousands of particles in a single capsule, wherein the dosage strength difference between 999 and 1000 particles is offset by minor fluctuations in the weight of the individual particles.
Systems that disclose methods and devices for filling capsule shells with minitabs are also known in the art. One particular system is described in U.S. Published Application No. 2009/0241482. The described apparatus fills individual columns with a set number of tablets, ensuring their exact orientation within the columns, and then drops the tablets into prepared capsule bodies. The apparatus employs techniques which fill columns using a presser pin to maintain the specific orientation of the tablets within the columns and a horizontally rotating pan to drop the minitabs into the columns.
Other techniques for filling minitabs into capsules have been developed and are currently in use to prepare products such as Kremers Urban Development Company's delayed release omeprazole capsule product. The method employed by Kremers to place minitabs into a capsule shell employs a horizontally rotating plate that relies upon gravity to drop and stack a number of minitabs into a column and dispense the stacked minitabs from the column into a capsule body. This process is slow and can result in a number of improperly filled capsules. The improperly filled capsules can result from the minitabs not falling into the column quickly enough and/or the minitabs not being oriented in the column in the correct manner such as in an end-to-end manner rather than a top-to-bottom manner.
The present invention solves the problems associated with filling capsules with minitabs by providing a device and method that ensures an exact amount of minitabs are encapsulated in an efficient, rapid and cost effective manner. The present invention comprises the use of a rotary drum, preferably a vertically rotating rotary drum, which collects, arranges and distributes a set number of minitabs into a capsule shell body.
In one embodiment of the present invention, the minitab rotary drum feeder is a component of a “sidecar” for use with conventional capsule filling technology. The sidecar is capable of attaching to conventional and commercially available capsule filling machines. The sidecar is capable of supporting one or more of the minitab rotary drum feeder devices for distributing a set number of minitabs into a capsule shell in an efficient, rapid and cost effective manner. The term “minitab rotary drum feeder” as used in the present application refers to an entire device as exemplified in
The present invention also provides a method and apparatus that is capable of delivering multiple types of minitabs to a single capsule through the use of multiple minitab rotary drum feeders on a single capsule filling machine carousel.
A further embodiment of the present invention is capable of monitoring the deployment of the minitabs to the rotary drum to ensure an exact number of minitabs is being delivered to each and every capsule; this embodiment is also capable of interrupting the process if an error in filling is discovered.
The present invention relates to a device and method for supplying a predetermined number of minitabs to a capsule shell body. The device and method employ a rotary drum, preferably a vertically rotating rotary drum that collects a predetermined number of minitabs from a supply hopper and dispenses the predetermined number of minitabs into a capsule shell body.
As used throughout this specification, the term “minitab” encompasses a pharmaceutical composition, preferably a compressed composition, that has an average diameter of at least about 0.5 mm to about 15 mm, preferably at least about 1 mm to about 10 mm, and most preferably at least about 2 mm to about 5 mm. The minitabs should contain a drug and may further contain one or more pharmaceutically acceptable excipients. The minitabs may also comprise coatings such as aesthetic coatings, enteric coatings and/or sustained or controlled release coatings. Examples of minitabs that can be used in the present invention are described in U.S. Pat. No. 6,159,499 which is incorporated herein by reference.
The device and method of the present invention are designed to deliver a predetermined number of minitabs to a capsule shell body. The predetermined number of minitabs can range from 1 to 100 and will depend upon a number of factors such as the size of the capsule shell and the size of the minitab. Generally, the predetermined number of minitabs will range from 2 to 50, and preferably from about 2 to about 25, per capsule body.
As shown in
The plurality of cavities (15) may be arranged in a filling grid (18), i.e., rows and columns. The number of columns (17) in the filling grid (18) may correspond to the number of capsule shell bodies (19) that need to be filled per rotation or indexing of the capsule filling machine carousel (20). For example, if the capsule filling machine carousel (20) employs a capsule filling block (32) with twenty-seven capsule shell bodies, the number of columns (17) in each filling grid (18) on the rotary drum (10) should be twenty-seven. Similarly, if the number of capsules (19) in the capsule filling block (32) is, e.g., twenty-one, then the number of columns (17) in each filling grid (18) is twenty-one. The number of rows (38) in each column (17) corresponds to the predetermined number of minitabs (16) that need to be placed or filled into each capsule shell body (19). For example, if the number of minitabs (16) to be placed or filled into a capsule shell is two, the number of rows (38) per filling grid (18) is two. Similarly, if the number of minitabs (16) to be placed or filled into a single capsule body (19) is nine, the number of rows (38) per filling grid (18) is nine.
The rotary drum (10) may contain more than one filling grids (18). The number of filling grids (18) will depend upon the size of each filing grid (18) and the size of the rotary drum (10). The smaller the filling grid (18), the more filling grids that may be incorporated onto the surface of the rotary drum (10). Similarly, the larger the rotary drum (10), the more filling grids (18) that may be incorporated onto the surface of the rotary drum (10).
The minitabs (16) are supplied to the cavities (15) of the rotary drum (10) by any conventional supply means such as a bulk product hopper (24) which supplies the minitabs to the direct supply hopper (107) via conduits or product chutes (24A) and (24B). The bulk supply hopper (24) may be located above or adjacent to the minitab rotary drum feeder (1) and may comprise a means to assist in the feeding of the minitabs (16) to the direct supply hopper (107) such as a vibration means (not shown in the drawings). The direct supply hopper (107) is located above or adjacent to the rotary drum (10) to allow direct contact or feeding of the minitabs (16) to the surface of the rotary drum (10). To assist in the feeding of the minitabs (16) into the cavities (15) of filling grids (18), the direct supply hopper (107) may employ a means to assist in the feeding of the minitabs (16) such as rotating pegs (25) or a vibration means (not shown in the drawings). The supply hoppers (107) and (24) may also employ anti-static devices (108) to dissipate any static electric charges created by the movement of the minitabs (16). Antistatic devices may also be employed at other locations on the device of the present invention as needed. It has been discovered that antistatic devices are particularly useful when enteric coated minitabs are employed with the present invention.
In one embodiment of the present invention, the rotary drum (10) rotates on it axis towards the horizontally rotating capsule filling machine carousel (20). An empty filling grid (18) (i.e., no minitabs in the cavities) is indexed or moved into position under the direct supply hopper (107) at which time a single minitab (16) is deposited into each cavity (15) of the filling grid (18). The depositing of the single minitabs (16) into each cavity (15) may be accomplished by gravity or may be aided by the use of a vacuum. The vacuum is created by drawing air into an air opening (21) formed in the cavities (15). The air may be drawn into the air opening (21) by a vacuum means (22).
Once the minitabs (16) are located in the cavities (15) of the filing grid (18), the rotary drum (10) continues its vertical rotation whereby the filled filling grid (18) passes under a retention means that retains and/or prevents any excess minitabs (16) from exiting the direct supply hopper (107). The retention means may be any device known in the art such as a rotary brush (26) as shown in
After passing the retention means, the filled filling grid (18) may pass under a preservation plate (27) as shown in
The present invention further comprises a funnel block (28) located below the rotary drum (10). The funnel block (28) is designed to receive the minitabs (16) from the rotary drum (10). As shown in
For example, if the filling grid (18) contains twenty-seven columns (17) with nine rows (38) in each column, the funnel block (28) will contain twenty-seven funnels (33) which correspond to each of the twenty-seven columns (17) of the filling grid (18). In operation, the filled filling grid (18) will rotate to a position wherein the nine minitabs (16) in each of the filled rows (38) of the particular column (17) will be dislodged, removed or expelled from their cavity (15) on the rotary drum and deposited into the specific funnel (33) that corresponds to the particular column. The minitabs (16) may be dislodged from the cavities (15) by gravity. The minitabs (16) may also be dislodged with the aid of a jet of air or a push pin. The air jet may be provided by air openings (21) which create a vacuum at the apex of the rotary drum (10) but which is converted or reversed to provide an air jet at the discharge location of the rotary drum (10). Alternatively, the vacuum may be stopped at or near the discharge location (i.e., just prior to the indexing of the filling grid (18) above the funnel block (28) or just above the funnel block (28)), and an outwardly directed stream of air is provided by a second air opening in the cavity (15) at or near the discharge location.
The present invention also comprises a magazine block (29) located below the funnel block (28). The magazine block (29) may be a separate and distinct structure from the funnel block (28) or it may be a part of the funnel block (28). The magazine block (29) contains a plurality of receiving channels (34) which are designed to correspond with the funnels (33) of the funnel block (28) so that as the minitabs (16) exit the cavities (15) of the rotary drum (10), they pass through the funnels (33) and proceed into the receiving channel (34). The receiving channels (34) collect and store the minitabs (16) until they are discharged into the capsule shell body (19). It is preferred that the lower portion of the receiving channels (34) be of a size and shape to vertically stack the predetermined number of minitabs (16) until discharged into the capsule shells. This preferred design of the lower portion of the receiving channels (34) in the magazine block (29) may be accomplished during the creation, i.e. drilling, of the receiving channels (34) into the magazine block (29) or by a separate unit that is attached to the bottom of the magazine block and forms part of the magazine block. The separate unit allows for a straight or direct passageway and temporary storage area for the predetermined number of minitabs (16).
Below the magazine block (29) is a movable plate, or discharge plate (31), which is capable of moving horizontally or generally perpendicular to the direction of the receiving channels (34). The discharge plate (31) acts as a gate below the magazine block (29) that meters and controls the dispensing of the predetermined number of minitabs (16) into the capsule shell bodies (19). The discharge plate (31) contains a plurality of discharge passageways (36) that correspond with the receiving channels (34) and are capable of matching up with the exit or bottom of the receiving channels (34) on the bottom of the magazine block (29). The discharge plate (31) also contains a blocking area (30) which, depending upon the location of the discharge plate (31), will block or prevent the minitabs (16) in the receiving channels (34) from discharging or existing from the apparatus.
In operation, the discharge plate (31) is moved to an engaged position so the blocking area (30) is under the exit or bottom portion of the receiving channels (34). The minitabs (16) are released or discharged from the cavities (15) of the rotating drum (10) and collected by the funnels (33) of the funnel block (28) for collection in receiving channels (34). Once the predetermined number of minitabs are collected in the receiving channels (34) and the capsule filling carousel (20) has rotated a capsule block (32) with a set of capsule bodies (19) into alignment under the discharge plate (31), the discharge plate (31) is moved or disengaged, thereby causing the discharge passageways (36) to align with the bottom of the receiving channels (34) and the top of the capsule shell bodies to create a continuous passage for the predetermined number of minitabs (16) from the device of the present invention to the capsule shell body. Once the predetermined number of minitabs (16) has been dispensed into the capsule shell bodies (19), the discharge plate (31) is returned to the engaged position thereby blocking the receiving channels (34). The capsule filling carousel (20) is horizontally rotated away from the device of the present invention and thereby moves the filled capsule shell body away from the filling area and indexes a new set of empty capsule shell bodies (19) into position under the discharge plate (31). The rotary drum is also rotated so the empty filling grid (18) is returned to the direct supply hopper (107) to collect another set of minitabs (16) for filling into another set of empty capsule shell bodies (19). If there is more than one filling grid (18) on the rotary drum (10), the rotation of the rotary drum (10) will allow a subsequently filled filling grid (18) to discharge the predetermined number of minitabs (16) into the funnels (33) of the funnel block (28), store the predetermined number of minitabs (16) in the receiving channels (34) of the magazine block (29) and discharge the predetermined number of minitabs (16) through the discharge passageways (36) of the disengaged discharge plate (31) once a new set of capsule shell bodies (19) have been indexed to the appropriate location below the discharge plate (31).
Once the predetermined number of minitabs (16) is filled into a capsule shell body (19), the capsule shell body may be capped or sealed with the capsule shell cap, or the capsule shell body may be indexed to an additional filling location(s) for receiving additional minitabs (16) such as a predetermined number of a different type of minitab (116). The different type of minitab may be immediate release minitabs, enteric coated minitabs, or sustained release minitabs. The different type of minitabs (16) may also include minitabs with a different drug from the first set of predetermined minitabs, thereby allowing for combined drug delivery from a single capsule.
One embodiment of the present invention further employs a means for monitoring the filling of the correct number of minitabs (16) into the individual capsule shell bodies (19). The means for monitoring comprises a detection device, such as an optical detection device, which is located at a point after the filling grid (18) of the rotary drum (10) rotates past the retention means (26) and prior to the filling grid (18) discharging the minitabs (16) into the funnels (33) of the funnel block (28). The detection device will inspect each cavity (15) in a filling grid (18) to insure that each cavity (15) contains a minitab as it rotates from the direct supply hopper (107) to the funnel block (28). If one or more of the cavities (15) in the filling grid (18) does not contain a minitab (16), the detection device will prevent the capsule filling carousel (20) from indexing a new capsule block (32) with a set of capsule shell bodies below the discharge plate. The detection device may further direct the incompletely filled filling grid (18) to discharge the inaccurate number of minitabs (16) into a rejected retention or waste bin. The rejected retention bin may be located below the discharge plate (31). Because the rejected minitabs (16) are not encapsulated, they may be collected and returned to the supply hoppers (107) or (24) for reuse.
One embodiment of the present invention will be further illustrated by the following example which is not intended to limit the scope of the present invention.
The frame assembly (13) of the minitab rotary drum feeder (1) is also connected to a frame base (37). The frame base (37) possesses a linear slide (39) which is designed to removably attach to a capsule filling machine carousel (20). The minitab rotary drum feeder (1) connects to the carousel (20) via a linear slide (39). The linear slide (39) allows the minitab rotary drum feeder (1) to be moved to various positions on the capsule filling machine carousel (20).
The rotary drum (10) possesses an exterior surface (14), which contains multiple minitab cavities (15) for receiving minitabs (16). Preferably, the minitab cavities (15) are organized into filling grids (18) which comprise a set of columns (17) running vertically along the rotary drum exterior surface (14). Each minitab cavity column (17) contains a set number of minitab cavities (15) in a row (38). As shown in
The number of minitab cavities columns (17) will correlate with the number of capsules (19) per capsule block (32) that will ultimately be filled with minitabs (16). The minitab cavities rows (38) will correlate with the number of minitabs (16) to be filled into each capsule (19).
The minitab cavities (15) can be formed in the rotary drum exterior surface (14) in such a manner that they are connected by air openings (21) that generally run the length of the rotary drum (10) allowing for application of a vacuum or air jet depending upon the location of the filling grid (18) on the rotation cycle of the rotary drum (10). The application of a vacuum/supply means (22) while the rotary drum (10) is circulating through the direct supply hopper (107) assists in filling the cavities (15) of the filling grid (18) with individual minitabs (16). If the vacuum is maintained after the filling grid exits the direct supply hopper (107) area, the vacuum will aid in holding the individual minitabs (16) in the individual cavities (15) during the transportation to the funnel block (28). The vacuum should be stopped prior to the filling grid (18) arriving at the funnel block (28) or when the filling grid (18) arrives at the funnel block (28). The vacuum/supply means (22) can also be reversed at the appropriate time to force air through the air openings (21) to assist in ejecting the individual minitabs (16) from the minitab cavities (15) on the rotary drum (10) and into the funnels (33) of the funnel block (28). While the vacuum/supply means (22) can be used to secure the minitabs (16) in the minitab cavities (15) and assist in the ejection of the minitabs (16) by either loss of the vacuum seal and/or use of compressed air forcing the ejection of the minitab (16), it is not a necessary component. This is because the unique vertical rotation of the rotary drum (10) allows gravity to hold the minitab (16) in place when it is embedded in the minitab cavity (15) near the apex of the rotation of the rotary drum (10), and gravity further provides release of the minitab (16) from the minitab cavity (15) near the nadir of the rotation of the rotary drum above the funnel block (28).
The rotary drum exterior surface (14) can also be designed to contain air cavities (23) located on the rotary drum exterior surface (14). The air cavities (23) contain openings on the rotary drum exterior surface that are smaller than the smallest minitab diameter that are encapsulated using the minitab rotary drum feeder (1) of the present invention. This ensures that minitabs (16) will not be unintentionally embedded in the air cavities (23). These air cavities (23) are located between the previously described filling grids (18). The air cavities assist in creating a vacuum seal to secure the minitabs (16) in the minitab cavities (15) or provide an air jet to eject the minitabs (16) from the minitab cavities (15).
Located above the rotary drum (10) is a direct supply hopper (107), which is connected to the frame assembly (13). The direct supply hopper (107) stores and then distributes the minitabs (16) to the rotary drum (10). A lower portion of the direct supply hopper (107) is open to the rotary drum exterior surface (14) in such a manner that the minitabs (16) will come in direct contact with the minitab cavities (15). The direct supply hopper (107) further contains a means for agitation of the minitabs, such as rotating pegs (25), which are capable of agitating and moving the minitabs (16) to facilitate their distribution across the rotary drum exterior surface (14). The direct supply hopper (107) can also contain a static electric discharge device (108) for dissipating and/or removing the electrical charge that can form during movement of the minitabs (16)
As the rotary drum (10) passes underneath the direct supply hopper (107), the minitabs (16) are distributed across the rotary drum exterior surface (14) and embedded in the minitab cavities (15).
As the rotary drum (10) begins its downward rotation towards the capsule filling machine carousal (20), it passes a retention means such as a rotating brush (26), which sweeps excess minitabs (16) from the rotary drum exterior surface (14). The swept, non-embedded minitabs (16) remain in the direct supply hopper (107) and will be retained for distribution during the next set degree of rotation of the rotary drum (10). Retaining the unused minitabs (16) in the direct supply hopper (107) allows for the reuse of the minitabs (16).
A preferred embodiment of the minitab rotary drum feeder (1) can also contain a preservation plate (27) located over the exterior surface or the rotary drum exterior surface (14). The preservation plate (27) can be constructed to sit slightly above the top of the rotary drum exterior surface (14) and assist in retaining the minitabs (16) in the minitab cavities (15) during the downward rotation of the rotary drum (10). See
Located below the rotary drum (10) and connected to the frame assembly (13) is a funnel block (28). The funnel block (28) possesses funnels (33), preferably elliptical in shape, that allow the passage of the minitabs (16) from the minitab cavities (15) through the funnel block (28) and into a receiving channel (34) located in a magazine block (29). The magazine block (29) is located directly below the funnel block (28) and may be a single integral element of the funnel block (28) or a separate and distinct structure that is removably attached to the funnel block (28). The magazine block (29) contains receiving channels (34) that are designed to allow passage and temporary storage of the minitabs (16) from the funnel (33) in the funnel block (28) into the magazine block (29). More specifically, the openings or entrance of the receiving channels (34) on the top of the magazine block (29) are designed to match the lower opening or exit of the funnels (33) from the bottom of the funnel block (28).
The lower exit portion of the receiving channel (34) can be obstructed by a discharge plate (31). See
The capsule block (32) is designed to store empty capsules (19) to be filled in an opened and upright position. The capsule block (32) is further designed to contain capsule storage cavities in a pattern that matches with the openings on the bottom of the discharge plate (31). The capsule block (32) is connected to the capsule filling machine carousel (20) and is rotated horizontally into position below the discharge plate (31) wherein the discharge passageways (36) in the bottom of the discharge plate (31) are aligned with the open capsule shell bodies (19) in the capsule block (32). See
The funnels (33) in the funnel block (28) are designed to line up, i.e., spatially coordinate, with the minitab cavity columns (17) located on the rotary drum exterior surface (14). Therefore, for every minitab cavity column (17a, 17b, 17c, etc. . . . ) there will be a corresponding funnel (33a, 33b, 33c, etc. . . . ). See
The receiving channels (34) formed in the magazine block (29) are preferably cylindrical but can be any shape as long as the shape is generally uniform to avoid corners and edges that could obstruct the passage of the minitab (16) or damage the minitab (16). Because the minitabs (16) can be designed to provide very specific active release profiles, it is critical that these minitabs (16) are not damaged during the encapsulation process.
After the minitab (16) passes through the funnel block (28), it enters into the magazine block (29) and into the receiving channel (34). When the discharge plate (31) is positioned in the engaged or obstructed position, the minitabs (16) will be stored and collected in the receiving channel (34) until the discharge plate (31) is disengaged. Disengaging the discharge plate (31) moves it horizontally, allowing the discharge passageways (36) to complete a continuous channel and also allows passage of the predetermined number of minitabs (16), which are temporarily stored in the receiving channels (34), into the capsule block (32). The capsule block (32) will contain the open capsule shell bodies (19). See
As shown in
Additionally, as is shown in
The receiving channels (34) and discharge plate openings (36) are organized in a series of rows and columns designed to match. This organization also matches the location of the empty capsule shells (19) in the capsule block (32). See
A preferred embodiment of the present invention can contains a rotary drum as described above wherein the rotary drum (10) rotates forty-five degrees before stopping to allow for capsule filling. In this preferred embodiment, each capsule filling grid (18) contains twenty-eight columns (17), and each column has nine or eighteen rows (38) of minitab cavities (15). After each forty-five degree rotation, a block containing twenty-eight capsules is filled wherein each capsule (19) contains nine or eighteen minitabs (16). These combinations of minitab cavity columns (17) and cavity rows (38) can be altered to produce different amounts of minitabs per capsule and different amounts of capsules per capsule filling grid (18).
The rotary drum (10), supply hoppers (107) and (24), funnel block (28), magazine block (29), discharge plate (31) and preservation plate (27) may be made of any suitably rigid material. In certain embodiments, these parts of the invention are prepared from steel, preferably stainless steel, and may optionally be coated with friction reducing materials such as TEFLON® or electroless nickel.
The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which are not specifically disclosed herein. Thus, for example, in each instance herein, any of the terms “comprising,” “consisting essentially of” and “consisting of” may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US10/44834 | 8/9/2010 | WO | 00 | 1/16/2013 |
