Electric heating – Metal heating – By arc
Reexamination Certificate
2002-05-21
2004-10-26
Heinrich, Samuel M. (Department: 1725)
Electric heating
Metal heating
By arc
C219S121710, C219S121820
Reexamination Certificate
active
06809288
ABSTRACT:
FIELD OF THE INVENTION
This invention pertains to a method of and apparatus for forming cavities on solid formulations. More particularly, it pertains to a method of and apparatus for forming one or more cavities or holes on the surface of a solid formulation, such as a solid pharmaceutical dosage form, by employing a laser device.
BACKGROUND OF THE INVENTION
Solid formulations are used for the delivery of active agents to an environment of use. Active agents generally include medicines, nutrients, food products, pesticides, herbicides, germicides, algaecides, chemical reagents, and others known to those of ordinary skill. When a solid formulation includes a core coated with a composition that is partially or completely insoluble in an intended environment of use, its coat(s) may include one or more perforations to permit release of the active agent from the core. Exemplary devices include osmotic devices, coated tablets, coated capsules, coated pills, coated lozenges, coated pellets, coated pastille and others. Some of these exemplary dosage forms employ osmotic pressure to control the release of the active agent contained in the core of the dosage form. These dosage forms may also include one or more layers, external to the core, comprising one or more materials that are subject to erosion or that slowly dissolve in the environment of use thereby gradually dispensing the active agent.
U.S. Pat. No. 4,088,864 to Theeuwes et al. and U.S. Pat. No. 4,063,064 to Saunders et al. disclose a high speed process for forming outlet passageways in the walls of osmotic devices for release of the contents of the osmotic device comprising: a) moving the pills in succession along a predetermined path at a predetermined velocity; b) tracking the moving pills seriatim at said velocity with a laser of a wavelength which is absorbable by said walls by oscillating the optical path of the laser back and forth over a predetermined section of the pill path at said velocity; c) firing the laser during said tracking; d) adjusting the laser beam dimension at said wall, the laser power and the firing duration being such that the laser beam is capable of piercing the wall; and e) forming, with the laser beam, an outlet passageway 4 to 2000 microns in diameter in the wall. These patents also disclose an apparatus for forming outlet passageways in the walls of osmotic devices for release of the contents of the osmotic device comprising: a) a support frame; b) a laser operating in a pulse mode; c) a laser-based optical pill-tracking mechanism; d) a rotary pill indexer; and e) an electrical power supply to supply and control power for the laser, the tracking mechanism, and the indexer.
U.S. Pat. No. 5,783,793 to Emerton et al. discloses a laser apparatus used to drill multiple holes on each side of a tablet sequentially without having to move the tablet. The apparatus includes mirrors and an acousto-optic deflector to reflect and deflect laser beam, respectively. The apparatus also includes an encoder coupled to the rotating shaft of a motor that rotates a tablet feeder. The encoder provides output signals that are used to regulate the timing of beam pulses so that the occurrence of beam pulses relative to tablet position, and hence the pattern generated, is synchronized.
U.S. Pat. No. 5,376,771 to Roy discloses a laser apparatus capable of simultaneously forming a plurality of holes on the semipermeable membrane of an osmotic device. The apparatus, marketed as the DIGIMARK™ system, includes a linear array of individual laser tubes directed at a tablet surface. The different laser tubes can be pulsed independently of one another to created an array of circular or slotted apertures on the surface of the tablet.
U.S. Pat. Nos. 5,658,474 and 5,698,119 to Geerke et al. disclose a single beam laser apparatus for drilling holes into a single side of a tablet. The apparatus employs a laser beam diverting system, which is a series of mirrors, to determine the presence of a tablet in the tablet slot of a tablet feeder prior to entry of the tablet into the firing zone of the apparatus. If a tablet is detected in the tablet slot, the laser fires a pulse into the respective slot as it passes through the firing zone. The beam can be pulsed or continuous and more than one hole can be drilled into the same side of a tablet. The hole can be a continuous channel, a single hole or a series of overlapping holes. The hole can be shaped as a slot, polygon or circle.
U.S. Pat. No. 4,806,728 to Salzer et al. discloses a laser apparatus for perforating the surface of solid dosage forms. The apparatus creates a laser beam that has an adjustable spot size at different locations while maintaining a constant path length for the beam. This apparatus requires a beam focusing means, beam shaping means and a dichroic mirror for reflecting the beam. The beam is programmable and is used to produce a pattern on the surface of a solid dosage form.
U.S. Pat. No. 4,903,813 to Gajdos discloses a laser apparatus for applying markings or break-notches on tablet surfaces. The laser operation of the apparatus is synchronized with the operation of a tablet press. The apparatus includes a mirror that deflects the laser beam through a mask to create the marking or break-notch on the tablet surface. The laser is intensity modulated and it can be made telescopic or swiveling so that the laser can mark the top or side surface of the tablet.
U.S. Pat. Nos. 5,399,828 and 5,294,770 disclose a laser apparatus that fires multiple pulses at a single site of a tablet as it passes under a laser beam. The laser is synchronized with movement of a tablet conveyor. The apparatus includes a controller responsive to movement of the conveyor and to operation of laser. A laser pulse only occurs when a “laser-ready” window in time coincides with a “tablet-ready” window in time. The apparatus can drill the top or bottom side of tablet. The laser beam is stationary and does not track the movement of the tablets. The apparatus can include a “side” detector to detect which side of tablet should be drilled. The apparatus can also include a pyroelectric detector off of the beam path to detect misfire of the beam and reject undrilled tablets. As with other systems, the apparatus can drill a series of holes on each side of the tablet. After passing through the firing zone all of the tablets enter a collection tube comprising an abort mechanism to separate drilled and undrilled tablets. The surfaces of the tablets are not examined and a determination that a tablet was not drilled is made by determining whether or not the laser fired a pulse at the tablet when the tablet passed through the firing zone. In order to synchronize the “laser-ready” window with the “tablet ready” window, the apparatus includes a rotary encoder to provide periodic synchronization counts to the controller to synchronize the position of the moving tablets on the carrier means relative to the firing zone. Since the laser only fires when the “laser-ready” and “tablet ready” windows are synchronized, a lead counter means responsive to the synchronization increment counts from the encoder is used to define the distance along the tablet path between the synchronization home count and the start of the treatment window corresponding to the leading edge of the treatment site on the moving tablet. Likewise, a window counter means responsive to the lead counter means and to the synchronization increment counts is used to define the distance along the tablet path between the start of the treatment window and the end of the treatment window corresponding to the trailing edge of the treatment site on the moving tablet. This system does not employ a sensor that actually detects the presence of a tablet in the slot of a conveyor, nor does it permit immediate return of undrilled tablets to the tablet reservoir. This system results in excess product loss due to the number of tablets that pass through the firing zone without being drilled. It also does not include process validation means or tablet inspection means subseque
Heinrich Samuel M.
Innovar L.L.C.
Matos Rick
Osmotica Corp.
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