March/April 2018 • www.cemag.us 5
• Operating equipment under negative pressure
inside the processing chamber helps ensure that
no API escapes. Here, continuous negative pressure monitoring by a sensor inside the process
chamber is used to automatically close valves
should any internal positive pressure be detected. For additional safety, the split valves on a
deduster’s air inlet ports can be supplemented by
a two-way HEPA filter.
• A Wash In Place (WIP) system with all connections for cleaning media already piped in
and connected helps run a complete wash cycle
at the push of a button at a batch’s conclusion.
Even if the wash does not remove 100 percent
of the residual API inside the tablet press or
deduster, any residual material will be wet and
can therefore be safely cleaned away by the operator without having to wear PPI.
Following a WIP cycle, the equipment still
needs to opened, wiped down with alcohol in
some areas, and then air dried before it can be
swabbed. Clean In Place cycles have received
attention in the pharma industry, but have never
been truly achieved on a tablet presses and
dedusters due to an inherent limitation; namely,
this type of process would restrict drying as the
equipment would never be opened.
• Isolators allow placement of a complete piece of
process equipment inside an airtight box, which
starting to be installed more frequently on pro-
cess equipment. In addition to being signifi-
cantly lighter, the polymer solutions eliminate
the need for cleaning and are substantially less
• Automated pinch valves are used on inlet
and outlet ports that, typically, do not require
frequent disconnection. They contain the API
inside the equipment’s contaminated area,
and can only be disconnected after a Wash In
Place (WIP) cycle has been performed on the
machine. This sort of solution often is supplemented by Interlocked pressure decay tests,
which create a vacuum inside the machine for
a specified duration of time prior to startup to
check all valves and connections are correctly
attached and positioned. This helps make sure
there will be no leak from the process equipment prior to introducing the API onto it and
starting the manufacturing process.
• Closed tight-fitting silicone connections
between tablet presses and ancillary dedusters,
metal detectors, or diverters help ensure securely contained transfer of tablets also the production line, and must be cleaned via WIP system
prior to opening to prevent operator exposure.
Usually, they are secured at either end by retaining clips.
• For metal detectors specifically, closed round
silicone chutes help ensure contained transfer
throughout the inspection process. Most metal
detectors come with two-part Perspex chutes
that cannot be closed easily for containment
purposes. By contrast, a one-piece closed chute
connected in a containment manner at both
ends helps facilitate containment without resorting to tri-clover clamp connections and additional seals.
• Airtight seals on a metal detector’s reject assembly window also help ensure containment. These
seals are generally compressed into grooves in
the stainless steel portion of the reject assembly,
and are glued in place inside a groove on the
window. This is so they cannot be lost and do
not require refitting with each assembly.
• Rejected or sampled tablets are then collected
into a continuous liner instead of a bottle. The
liner is coiled onto a polymer stump underneath
the metal detector reject assembly, where a collection bottle would normally be placed. The
liner can be pulled down to a suitable length
and is either clipped or heat sealed before starting production, providing an airtight bag that
securely collects rejected tablets. At the end of a
batch, the liner gets clipped or heat sealed again,
creating a contained bag with tablets inside.
In tablet testing
operations, a strict
separation of dust or
tablet fragments from
the production stream
manufacturing for days
rather than mere hours.