Nick Kristiansen reports on innovations in ultrasonic cleaning technology.
Product contamination is believed to be the second to third largest reason for pharmaceutical recalls in the EU. It is therefore not surprising that the EU commission recently published an update of chapters 3 (premises and equipment) and 5 (production) with a focus on minimising the risk of cross contamination.
When different pharmaceutical products are produced in shared facilities, the potential for cross contamination becomes an issue for concern. Residues of an active substance that remain after cleaning production equipment and other product contact surfaces may contaminate other medicinal products manufactured in the same facility.
The new EU requirements under the GMP guidelines for the use of multipurpose equipment and how to minimise the risk of cross contamination have drawn more attention to this subject. Tools for the manufacturing of tablets are often used for several different products, putting this segment in the risk zone for cross contamination.
Reasons for cross contamination can be many and caused by technical as well as organisational deficiencies. Insufficient cleaning of equipment is one of the most obvious and easiest to rectify.
Ultrasonic cleaning units provide consistent, thorough cleaning of all surfaces, which drastically reduces the risk of cross contamination.
Silent Sonic is a CE-compliant ultrasound cleaning unit that has been developed as a direct response to customers unable to find what they needed in existing cleaning solutions. They needed a cleaning solution that would incorporate a user-friendly interface with easy validation execution, worker health and safety compliance, and the ability for it to be used in the smallest of laboratories. Additionally, many organisations wished to incorporate more environmentally sustainable processes in their manufacturing.
Ultrasonic cleaning
When using an ultrasonic cleaner, the object to be cleaned is submerged in a chamber containing a cleaning solution. An ultrasound-generating transducer built into the chamber produces ultrasonic waves in the fluid by changing size in concert with an electrical signal oscillating at ultrasonic frequency, in the range from 21.5-60kHz.
The agitation produces high forces on contaminants adhering to substrates such as metals or plastics. This process is capable of removing impurities from the smallest holes or cavities in the subject. Cleaning normally lasts between three and ten minutes.
The Danish company behind the Silent Sonic, Anmasi, set out to meet the high-level sanitisation and validation requirements required by the pharmaceutical industry, and at the same time offer a cleaning solution that would fit the working environment in which personnel are present during the cleaning operation.
In the past, ultrasonic units on the market have exhibited a noise level that was disruptive to workers. This is one of the reasons why R&D departments haven’t used ultrasonic cleaning in the past.
Silent Sonic puts out 48 - 55 dB(A), which is below the decibel level of normal conversation. This reduction in noise, compared to standard ultrasonic units, is obtained through an innovative design and the use of a special insulation, PureSound. This significantly quieter unit makes the work environment more comfortable for personnel.
Fixtures – the key to success
Most standard ultrasonic cleaning units utilise a simple wire basket to hold the items to be cleaned while submerged in the chamber. This approach will work with many solid-shaped items, but if more complex equipment is to be cleaned, a specially designed fixture is needed. The fixture will guarantee that the equipment is always oriented in the most optimal position and ensure that every cleaning job is performed with identical conditions – thus making the validation process easier.
A prime example of this is the cleaning of tablet tooling for micro tablets (tablets <3mm.) These tools are often manufactured in a multiple tip configuration, with up to 50 fragile individual tips. Add to that the tip holders, key slots and rotating heads, and you are faced with a very time-consuming cleaning job. The alternative to taking the whole punch apart, is simply to place it in a dedicated fixture and submerge it in the Silent Sonic ultrasonic cleaner. This saves considerable time while providing a thorough cleaning.
As a tablet-tooling supplier, Natoli recommends ultrasonic cleaning, since this is the most effective and gentle way of cleaning. The Silent Sonic unit’s smart design has provided new opportunities for successfully minimising cross-contamination risk. This innovation in standard procedure is just one way to meet EU requirements.
For more information visit www.scientistlive.com/eurolab
Nick Kristiansen is technical director of Natoli Scandinavia.
