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August 17, 2017

Distek VIP 4400 Washer Performance Verification Guidelines


To supply Distek End Users with some suggested guidelines for verifying the performance of their Distek VIP 4400 washer.


This guideline is intended to assist the End User with a method to prove cleaning effectiveness of the Distek VIP 4400.

Proposed Procedure

Make an adequate amount of caffeine solution to cover the testing desired. The solution should be about 0.1mg/ml in water. This concentration should yield a response of about 1 AU on a typical UV spectrometer using a 0.2cm path length cell at 273nm. Be sure to blank the spectrometer with the water used to make the caffeine solution. It is best if the water in the rinse tank of the VIP 4400 is also from the same source.

Fill up the vessels with 1000ml each of the above caffeine solution. The 1000ml would simulate worst case scenario as it pertains to volumes in the vessel. Test a sample from each of the vessels to establish the response on the 100% sample.

Run a LIGHT wash cycle on each vessel. There should be 3ml to 10ml of water residue left in the vessels after the cycles in each vessel is complete. Take a sample from each vessel and read the solution in the spectrometer. Divide this response by the response gotten on the 100% sample from the same vessel and multiply the result by 100%. This represents the amount of caffeine solution left behind or %carryover.

The above steps can be repeated as deemed necessary for the longer washing cycles of MEDIUM and HEAVY.

The tests above should come out with negligible carryover. Less than 1% carryover should be expected.

The above test can be repeated with adjustments for the customer’s “worst case scenario” product. Things to consider for the worst case product might include the type of medium (heavy buffers, surfactants, etc.). The type of dosage may also be considered. Gel caps may make a tougher product to remove from the glass vessel than a normal tablet. The coating on a tablet may be another thing to consider. The amount of time between the end of the dissolution run and the removal of the remnants may need to be considered.

Any test would need to incorporate analysis procedures that can test for this type of carryover for the product selected.

For further guidance or suggestions, contact Distek’s Validation and Analytical Support Manager.

Related products

VIP 4400

The VIP 4400 automates one of the most time consuming and least productive aspects of dissolution testing: Post-test clean-up. The VIP 4400 is not only compatible with Distek baths, but almost every other bath on the market.

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