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Description  |
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FIELD OF THE INVENTION
The present invention relates to a cleaning apparatus for pharmaceutical
container components, in particular for pharmaceutical closures such as
for example aluminium caps, rubber or plastics stoppers, and rubber or
plastics seals.
DESCRIPTION OF PRIOR ART
Before pharmaceuticals containers are filled, the container components
generally have to be cleaned and sterilized.
Up to now, component washing, drying and sterilization has either been
performed in separate machines, which requires the operator to provide
means for sterile transfer of the components between the machines, or in
large, complex and expensive machines which are designed to process the
components in batches in a single processing chamber in which washing,
drying and sterilizing, and other optional handling operations such as
silicone treatment, are all performed. In general, these processing
chambers have been rotatable pressure vessels which are expensive to
construct and require complex mounting and drive mechanisms.
Typical among known pharmaceutical component cleaning and sterilizing
apparatus are the WTS and WPS machines produced by Anton Huber GmbH & Co.
KG of Freising, West Germany, the PHARMA-CLEAN SST-BSA machines produced
by Pharmatechnik SMEJA GmbH & Co. KG of Straelen-Herongen, West Germany,
and the LST machines produced by NICOMAC SRL of Milan, Italy.
As mentioned above, machines for washing pharmaceutical components for
subsequent drying and sterilization in separate apparatus are known. Thus,
for example, Paxall Schubert Machinery Co. A/S of Denmark produce a
washing machine capable of performing the washing operation in a chamber
having a single component inlet/outlet aperture; with this machine the
actual washing operation is effected by air agitation of a liquid
cleansing medium within the chamber. The washed components are then lifted
out of the chamber for subsequent sterilization in a separate apparatus.
I have now found that, by the use of a plurality of component processing
chambers selectively interconnectible by valve means capable of providing
a bacteriological barrier between the cleaning chamber and subsequent
chambers, disadvantages of the prior art apparatus may be avoided.
SUMMARY OF THE INVENTION
Viewed from one aspect the invention therefore provides a pharmaceutical
container component cleaning apparatus comprising a first chamber arranged
to receive pharmaceutical container components for cleaning and provided
with cleaning means, a second chamber arranged to sterilize pharmaceutical
container components cleaned in said first chamber and provided with
sterilizing means, and valve means operable to permit transfer of cleaned
components from said first chamber to said second chamber and closeable to
provide a bacteriological barrier between said first and second chambers.
Viewed from a further aspect, the invention also provides a process for
cleaning pharmaceutical container components comprising:
(i) loading pharmaceutical container components into a cleaning chamber
having a sealable valve means;
(ii) cleaning said components in a cleaning medium in said cleaning chamber
and thereafter draining said medium from said cleaning chamber;
(iii) passing said components through said sealable valve means and into a
sterilizing chamber;
(iv) sterilizing said components in said sterilizing chamber; and
(v) removing said components from said sterilizing chamber.
The valve means in the apparatus of the invention preferably comprises a
displaceable valve plate, a displaceable annular seal member, valve plate
displacing means operable to move the valve plate between an open position
permitting passage of components through the valve means and a closed
position preventing such passage, and seal member displacing means
operable to urge the seal member into sealing engagement with the valve
plate when the valve plate is in its closed position.
This valve construction, since it allows the valve plate to be moved
between its open and closed positions without rubbing against other
elements of the valve assembly or housing, is not prone to leakage due to
abrasion and is thus generally applicable to pharmaceutical container
component cleansing apparatus. Thus viewed from a still further aspect the
invention also provides a pharmaceutical container component cleaning
apparatus comprising a first chamber arranged to receive pharmaceutical
container components for cleaning and provided with cleaning means, a
second chamber arranged to receive pharmaceutical container components
cleaned in said first chamber, and valve means operable to permit transfer
of cleaned components from said first chamber to said second chamber and
closeable to provide a bacteriological barrier between said first and said
second chambers, said valve means comprising a displaceable valve plate, a
displaceable annular seal member, valve plate displacing means operable to
move said valve plate between an open position permitting passage of
components through the valve means and a closed position preventing such
passage, and seal member displacing means operable to urge said seal
member into sealing engagement with said valve plate when said valve plate
is in its closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of one embodiment of a cleaning
and sterilizing apparatus according to the present invention;
FIG. 2 is a schematic cross-sectional view of a further embodiment of a
cleaning and sterilizing apparatus according to the present invention; and
FIG. 3 is a schematic cross-sectional view of one embodiment of a cleaning
apparatus according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In one preferred embodiment, the cleaning and sterilizing apparatus
according to the invention is provided with a conduit arranged between the
first and second chambers and with means for establishing a pressure
differential along the conduit whereby to urge components passing through
the valve means along the conduit towards the second chamber. By arranging
the conduit so that at least part of it is upwardly directed, it is
possible not only to arrange the first and second chambers in a
side-by-side fashion (thereby reducing the overall height of the
apparatus) but also to avoid the need for a separate drying chamber since
the tumbling action of the components as they are driven upwards in the
conduit throws excess liquid from their surfaces onto the inner surface of
the conduit along which inner surface the liquid is then driven by the gas
flow. Furthermore, by providing the conduit with heating means to heat its
inner wall, the evaporation of the liquid film thereon can be ensured and
the temperature of the components on their way to the sterilization
chamber can be maintained or even raised to or towards the sterilization
temperature.
In another preferred embodiment, the cleaning and sterilizing apparatus of
the invention comprises at least three selectively interconnectible
chambers with valve means provided between each mutually interconnectible
pair of chambers, these valve means being openable to permit components to
pass between adjacent chambers and closeable to provide a bacteriological
barrier between adjacent chambers. In this way, by suitably controlling
the operation of the valve means, a microbiological barrier can be
maintained at all times between the cleaning chamber and the sterilizing
chamber.
Where the apparatus contains three or more chambers, these may for example
be connected via conduits or, in one preferred arrangement, these may be
arranged to permit direct gravity feed of components from one chamber to
the next. In such a gravity fed arrangement however it will generally be
preferred to have a drying chamber interposed between the cleaning and
sterilizing chambers.
One or more of the valve means in the apparatus of the invention, and
particularly the valve means for component discharge from the cleaning
chamber, preferably comprises a displaceable valve plate, a displaceable
annular seal member, a valve plate displacing means and a seal member
displacing means as discussed above. In a preferred valve design, the
valve plate and the seal member are displaceable in mutually perpendicular
directions; thus for example the valve plate may be rotatable in the plane
of its major surface while the seal member, which may for example be an
inflatable seal or an O-ring seated in a pressurizable channel, may be
caused to move into contact with the valve plate in a direction
perpendicular to that plane.
Where a such valve means is situated at the base of a chamber, it is also
preferably provided with a drainage port by means of which liquid in the
chamber may be drained away from the chamber and the valve.
In this manner, even with a non-rotating cleaning chamber, it is possible
to ensure that the cleaned components discharged from the cleaning chamber
do not contact any surfaces which have not been cleaned to the same degree
as have the components themselves. For this reason, such a valve assembly
is useful even in the case of cleaning apparatus which is not equipped for
subsequent component sterilization.
Preferred embodiments of the invention will now be described further with
reference to the accompanying drawings.
Referring to FIG. 1, there is shown a cleaning and sterilizing apparatus 1
comprising a cleaning chamber 2, valve means 3, conduit 4 and sterilizing
chamber 5.
The cleaning chamber 2 is double walled having an inner sleeve 6 with
apertures 7 about its upper and lower peripheries through which cleaning
or rinsing medium 8 may pass in the circulation of the cleaning medium in
the chamber. Excess liquid and particulate waste may be carried over
weir-like upper rim of sleeve 6 to be voided through duct 9. The chamber
has an openable lid 10 covering an upper aperture through which components
11 may be introduced for cleaning. The lower end of the cleaning chamber 2
communicates with hopper 12 via valve means 3. The cleaning chamber is
provided near its base with steam, air and water inlet ducts 64, 13 and 14
and also with detergent and silicone dosing duct(s) 15. The chamber is
further provided with clean water supply duct 67 which protrudes into the
upper part of the chamber and terminates with a spray nozzle 68. Within
inner sleeve 6, there is disposed a displaceable component support 16, for
example a rotatable apertured plate or grid, which is itself provided with
drive means 17 capable of moving the support 16 between a position in
which it prevents components falling to the base of the cleaning chamber
and a position in which it permits the components to pass to the base of
the chamber.
The valve means 3 at the base of the cleaning chamber comprises a valve
housing 18 containing a valve plate 19 which is rotatable about pivot 20
under the action of drive means 21, and an O-ring 65 seated in an annular
groove 22 and displaceable in the vertical direction under the action of
gas pressure applied within groove 22 by means of gas supply line 23. The
supply line 23 leads to a pressurized gas source 24 and is provided with a
3-way valve 25 whereby groove 22 may be connected to gas supply 24 or to
duct 26 (which vents to the atmosphere or is connected to a vacuum pump)
to raise or lower O-ring 65 respectively. Valve means 3 is also provided
with a drainage duct 27 which itself is provided with a valve 28.
Components leaving the cleaning chamber 2 enter hopper 12 and are fed by
motorized feed regulator 66 into conduit 4 which is provided with steam
heating jacket 29 and valve 30. Jacket 29 is heated by steam entering at
valve 31, the condensate being removed by trap 32. Any excess liquid
entering hopper 12 may be drained therefrom by suction line 33. The
components are caused to move along conduit 4 through valve 30 and into
sterilizing chamber 5 under the action of a pressure differential created
by vacuum pump 34 which is connected to the sterilizing chamber by duct 35
and valve 36.
The sterilizing chamber 5 is provided at its base with a valve means 37 and
is also provided with a displaceable component support 38. Valve means 37
and support 38 are substantially similar in construction to the valve
means 3 and support 16 described above. The sterilizing chamber is also
provided with a steam inlet duct 39, temperature sensing probes 40, and
air inlet duct 41. The air and steam inlet ducts are provided with valves
42 and 43, and the air inlet duct is also provided with a filter 44 and a
heater 45.
The component discharge valve for the sterilizing chamber is valve means 37
and when this is opened sterilized components may pass into a delivery
hopper 46.
To perform a cleaning operation in the cleaning chamber 2, steam (e.g. at
an inlet pressure of 1-3.5bar, preferably about 2 bar) is first admitted
into the steam jackets of the apparatus until they stabilize to the
desired temperature (for example about 121.degree. C.), the support 16 is
set to its horizontal position, valve means 3 is closed, lid 10 is opened,
the chamber 2 is charged with components for cleaning, for example rubber
stoppers or aluminium caps, and the wash cycle is begun.
The washing process may consist of water fill through duct 14 (e.g. at a
water inlet pressure of 1-3 bar) followed by heating, for example by steam
injection through duct 64, and then agitation by compressed air introduced
through duct 13 (e.g. at a supply pressure of 4-6 bar) with or without the
introduction of detergent through duct 15. This is followed by rinsing. In
the washing and rinsing operations, clean water is introduced either
continuously or at intervals with soiled cleaning medium being discharged
through ducts 9 and 27. On completion of the washing or rinsing cycles,
valve 28 is opened and the liquid is drained away through the drainage
duct 27.
After the washing, heating, rinsing, draining and optional other treatments
(e.g. silicone treatment) of the components in cleaning chamber 2, the
3-way valve 25 is operated to vent groove 22 to lower O-ring 65 and valve
plate 19 is rotated to its open position and support 16 is rotated to
allow the cleaned components to fall into hopper 12. To prevent the
components from sticking to the sides of the cleaning chamber, valve 69 is
opened and a fine spray of clean water, e.g. demineralized water, is
directed through nozzle 68 onto the contents of the chamber.
If desired, before and/or after the components are cleaned, the valve means
3 may itself be subjected to a further cleaning and rinsing operation in
which the water level within the chamber is not allowed to rise up to the
support 16.
For the delivery of components from hopper 12 to the sterilizing chamber 5,
the valve means 37 is closed, support 38 is set to its horizontal
position, valves 42 and 43 are closed, feed regulator 66 and pump 34 are
actuated and valves 30 and 36 are opened.
When the transfer of components into the sterilizing chamber is complete,
valve 30 and valve means 3 are closed and the cleaning chamber can be
loaded with a fresh charge of components and the cleaning of these new
components can begin.
For the sterilization of the components in the sterilization chamber 5,
valve 36 is kept open until the desired vacuum in the chamber is reached.
Valve 43 is then opened to admit steam through duct 39 and after a period
when any remaining air is purged through pump 34, valve 36 is closed and
the temperature in the chamber is allowed to rise to the desired
sterilizing temperature, for example 121.degree. C.
The sterilizing chamber is provided with a jacket 47 to minimize
condensation but any condensate may be drawn off through trap 70. Any
residual air or other condensibles can also be removed by trap 49. Jacket
47 is itself provided with a trap 48 for the removal of condensates.
When the temperature in the sterilizing chamber reaches the sterilizing
temperature, a timed period commences during which probes 40 may provide
data regarding treatment conditions to an indicator or recorder as
required. At the end of the sterilizing period, pump 34 is actuated and
valve 36 is opened. When the pressure in the sterilizing chamber reaches
ambient pressure, valve 42 is opened to admit filtered and heated air into
the chamber. During this period, it is advantageous to close valve 42 from
time to time to reduce the pressure in the sterilizing chamber since the
rush of air through the chamber when valve 42 is reopened tends to
re-locate the components and to ensure their even drying. At the end of
the drying period, valve 36 is closed and pump 34 stopped and the pressure
in the sterilizing chamber is allowed to return to ambient via valve 42.
Valve means 37 is then actuated to move the valve plate to the open
position and support 38 is rotated to deposit the sterilized components
into the delivery hopper 46. Valve
In practice, it is desirable that the surfaces contacted by the components
are smooth and durable and thus it is particularly preferred that these
surfaces be of stainless steel. It is also preferred that the valves and
the other moving parts be operated in the desired sequence and at the
desired times by remote actuators under the control of a control means 50
which is capable of automatic operation.
Turning to FIG. 2, there is there shown a further cleaning and sterilizing
apparatus according to the present invention. In FIG. 2, elements
equivalent to elements illustrated in FIG. 1 are similarly numbered. In
the apparatus of FIG. 2, the components are fed from the cleaning chamber
2 into a sterilizing chamber 5 via an intermediately positioned drying
chamber 51 with component feed between the adjacent chambers being through
valve means 3 and 52 and under the action of gravity. The drying chamber
51 is provided with valve means 52 and support 53 which are substantially
equivalent in construction and operation to valve means 3 and support 16
described above. The drying chamber is also provided with a steam jacket
54 supplied with steam through valve 55 and itself provided with a trap 56
for the removal of condensates. Preferably, the same steam pressure is
used as in the sterilizing chamber so that the components leave the drying
chamber at or near the sterilization temperature. Air is circulated
through the drying chamber by means of circulatory duct 57, which is
provided with a fan 58, an air heater 59 and a condenser 60. Any liquid
falling to the base of the drying chamber is drawn off through the
drainage duct 61 in valve means 52.
In this second embodiment of the apparatus of the invention, control means
50 (representative connections for which are shown schematically in FIG.
2) operates to ensure that valve means 3 and 52 are not simultaneously
open thereby maintaining a bacteriological barrier between the cleaning
and the sterilizing chambers. The three chambers can if desired be
operated simultaneously. However, before transfer of a charge of
components from the cleaning or drying chambers, the subsequent chambers,
i.e. the drying and sterilizing chambers respectively, must of course
first be discharged.
FIG. 3 illustrates an embodiment of a cleaning apparatus according to the
invention. Again, elements similar to those illustrated in the earlier
figures are similarly numbered. It will be seen therefore that the
apparatus of FIG. 3 comprises a cleaning chamber essentially similar to
the cleaning chambers of the apparatus of FIGS. 1 and 2 but which
discharges via valve means 3 directly into a receiving chamber 62. The
receiving chamber preferably comprises a removable bin 63 with an
apertured inner base to allow for drainage of the cleaned components. The
bin may be removed to take the cleaned components to separate apparatus
for further processing, for example sterilization. Alternatively, valve
means 3 may discharge directly into the component receiving compartment of
a further piece of component processing apparatus or onto a feed
mechanism, for example a conveyor, leading to such further apparatus.
Typically the apparatus of the invention might have an hourly throughput
for conventionally sized containers closures of the order of 5000 to 20000
pieces.
It will be appreciated that while the present invention has been described
in terms of apparatus for cleaning pharmaceutical container components it
might also be used for the cleaning of other items for use in the medical,
veterinary, dental or pharmaceutical industries.
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