Agitating – With specified discharge means – By suction or compressed air
Reexamination Certificate
1999-09-14
2001-01-09
Soohoo, Tony G. (Department: 1723)
Agitating
With specified discharge means
By suction or compressed air
C366S194000, C366S144000, C366S226000, C366S241000, C422S270000, C422S283000, C073S866000
Reexamination Certificate
active
06170980
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to tablet dissolution testing and more particularly to a novel tablet dissolution apparatus.
In the pharmaceutical industry, it is commonplace, during pharmaceutical formulation development, stability determination, analytical development, quality control, or otherwise, to ascertain the rate at which a drug in solid form (hereinafter referred to as a “tablet”) dissolves under certain well-defined conditions. In this manner, one can gauge or predict the dissolution rate of the tablet in the human stomach. Historically, tablet dissolution testing has been performed largely manually; however, recently, certain automated tablet dissolution apparatuses have been developed.
For example, in commonly-assigned U.S. Pat. No. 5,816,701, inventors Martin et al., which issued Oct. 6, 1998, and which is herein incorporated by reference, there is disclosed one such automated tablet dissolution apparatus. In a preferred embodiment, the apparatus of the aforementioned patent includes a dissolution vessel removably seated within an aluminum platen. The apparatus also includes an assembly for automatically measuring a desired volume of media, heating and degassing the volume of media and then dispensing the volume of media into the dissolution vessel. In addition, the apparatus includes a carousel having a plurality of compartments, the carousel being rotatably mounted on a stage, the stage being alignable with the vessel. According to one mode of operation, an open-top, cage-type basket is placed in one or more compartments of the carousel, each basket containing a tablet intended for dissolution. The apparatus additionally includes a shaft aligned with the vessel, the bottom end of the shaft being adapted to frictionally fit together with a basket. The shaft is rotatable and vertically movable so that it can fit together with a basket, pick the basket up out of the carousel, lower the basket into the vessel, rotate the basket within the media and remove the basket from the media. The apparatus further includes a catheter automatically movable in and out of the vessel for sampling the media at desired times, an automated mechanism for loading and replacing a depth filter on the input end of the catheter, an automated mechanism for removing the basket from the end of the shaft after testing has been completed and an automated mechanism for removing media from the vessel after testing has been completed. The apparatus also includes a paddle shaft which may be used interchangeably with the basket shaft if tablets are placed directly in the compartments of the carousel and are then dispensed from the carousel into the vessel through an opening in the bottom of each carousel that is alignable with an opening in the stage.
Although the aforementioned automated tablet dissolution apparatus works well with tablets whose dissolution is typically effected using a rotatably-driven, cage-type basket and also works well with tablets that do not float on top of the media and whose dissolution is typically effected using a rotatably-driven paddle, the above-described automated apparatus cannot be used to test tablets that float on top of the media and whose dissolution is typically effected by placing such a tablet in a weighted “sinker” and then using a rotatably-driven paddle to cause the dissolution of the tablet in the sinker. One reason why the above-described automated tablet dissolution apparatus cannot be used with tablets requiring the use of sinkers is that said apparatus is not designed for the automated retrieval of a sinker from the dissolution vessel following the testing period.
Typically, when sinkers are used with conventional non-automated testing equipment, they are retrieved manually. The present inventor is aware of one automated tablet dissolution apparatus in which a specially-designed sinker is retrieved with a robotic assembly. However, as can readily be appreciated, the aforementioned automated tablet dissolution apparatus comprising the foregoing robotic assembly is limited in its usefulness to testing those tablets for which use of the specially-designed sinker is accepted. Consequently, because certain tablets have dissolution protocols that require the use of specific sinkers, the foregoing robotic system does not have broad applicability.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel tablet dissolution apparatus.
It is another object of the present invention to provide a novel tablet dissolution apparatus that overcomes at least some of the shortcomings of the apparatuses described above.
It is still another object of the present invention to provide a tablet dissolution apparatus that is adapted for use with a variety of sinkers (although not limited to use therewith) and that can be used to automatically remove a sinker from a dissolution vessel (if one is present therein) following testing.
According to one aspect or feature of the invention, there is provided a tablet dissolution apparatus, said tablet dissolution apparatus including a dissolution vessel and a novel automated mechanism for emptying the contents of said dissolution vessel, said automated emptying mechanism preferably comprising (a) a waste media receptacle, said waste media receptacle having an inlet opening and defining a media chamber; (b) tubing means having a first end insertable into the dissolution vessel and a second end attached to said inlet opening of said waste media receptacle; (c) automated means for moving said first end of said tubing means into and out of, respectively, the dissolution vessel; (d) automated vacuum means for creating a vacuum drawing from within said waste media receptacle to said first end of said tubing means, said vacuum being sufficiently strong to empty the contents of said dissolution vessel; and (e) a sinker strainer disposed between said first end of said tubing means and said media chamber.
According to a first embodiment, said sinker strainer is disposed in-line between said waste media receptacle and said first end of said tubing means.
According to a second embodiment, said sinker strainer is disposed within said waste media receptacle.
REFERENCES:
patent: 3860394 (1975-01-01), Tepas, Jr. et al.
patent: 4464340 (1984-08-01), Lennox, Jr. et al.
patent: 4578244 (1986-03-01), Cosgrove, Jr. et al.
patent: 4792434 (1988-12-01), Metzger et al.
patent: 4856909 (1989-08-01), Mehta et al.
patent: 4879917 (1989-11-01), Eppelmann et al.
patent: 4924716 (1990-05-01), Schneider
patent: 5639974 (1997-06-01), Hanson et al.
patent: 5682001 (1997-10-01), Hanson et al.
patent: 5816701 (1998-10-01), Martin et al.
patent: 6006777 (1999-12-01), Renslow
Article entitled, “A fully automated, benchtop dissolution testing workstation,” by Richard Buechsenschuetz, published before present application.
Sales literature for Zymark Corp.'s Multidose workstation, published before present application.
Sales literature for Scientific Instruments and Technology Corp.'s Pharma Test dissolution baths, published before present application.
Kriegsman & Kriegsman
Soohoo Tony G.
Source For Automation, Inc.
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