Sugaring the regulatory pill

Suppliers to the pharma sector are under constant scrutiny to adhere to ever-more stringent standards. Tom Dennis, of Coating Systems International (CSI), explains how sophisticated technology can benefit those in the firing line.

Coating Systems International (CSI), based in East Anglia in the UK, is a leading manufacturer and supplier of tablet coating and spray systems within the pharmaceutical and related industries worldwide.Working closely with customers, the CSI team provides a complete solution, consisting of design, manufacture, installation and basic validation of tablet coating plants. Where necessary, developments in specialist product testing processes are provided.

One of the key factors in the performance of CSI tablet coating plants is the stability of the inlet air temperature control; the optimum performance is ±1°C or better.

The first step in achieving this is a clean steam supply at a steady pressure and the effective removal of the condensate to prevent the backup of condensate in the heat exchange coils. The innovative design of the steam skid at CSI helps to achieve optimum performance every time.

The company's plant at Thompson & Capper in Runcorn has been running between 16 and 20 hours per day, maintaining a straight-line temperature control throughout, for more than two months.

The Technicota machines incorporate CSI's latest spray nozzle design with anti-bearding air cap technology, and are said to offer improved efficiency and convenience of set-up. The facility for continual spraying during the coating process eliminates downtime that is usually incurred when stopping to clean the caps. This, in turn, improves the GMP capability of the machine as it reduces the need to open the machine to withdraw the spray boom to clean the nozzles.

The Technicota 200 and 400 control system has been designed to comply with GAMP 4 guidelines. The standard CoTech control system can be supplied fully compliant to 21CFR part 11 using a paperless chart recorder system.

Another benefit is an instant improvement in the working environment for many, thanks to rapid set-up times, the user-friendly operating screens on the HMI control panel, and the use of inverter motor speed controls that have reduced operating noise levels.

To improve process efficiency further, the spray manifold has been carefully researched and developed to enhance its aerodynamic effect. The spray nozzle manifold has been shaped to minimise air turbulence within the drum during the coating process, leading to the air atomised spray velocity being co-current to the airflow through the drum, maximising the drum cleanliness throughout the coating process. This ensures a rapid and efficient process resulting in the best quality finish.

simultaneous adjustment

Both atomising air and spray width are remotely controlled and easy to adjust. The simultaneous adjustment of all spray nozzles ensures optimisation of the spray pattern. This feature minimises the risk of over-wetting while maintaining the optimum nozzle distance from the tablets. CSI worked with Malvern Instruments, utilising the latter's laser spectrometer droplet analysis kit to ensure the optimum atomisation of spray products is achieved. Nozzle maintenance is kept to a minimum with the aerodynamics of the manifold designed to reduce the build up of coating material during production.

The drums come complete with four mixing baffles that provide gentle yet effective mixing for both film and sugar coating processes. Homogeneous mixing is assured providing the rapid colour and weight consistency essential for obtaining high quality results. The baffles also provide minimum disturbance to the tablet bed during the coating process, minimising the risk of over wetting the tablets.

reverse rotation

Unloading the drum is quick and easy - using the simple reverse rotation command, the tablets can be safely unloaded into small containers or intermediate bulk container systems. The stainless steel finish allows easy manual or clean-in-place options.

The user-friendly control screen defines the process details and displays critical safety and process alarms. These are timed, logged and displayed on a dedicated alarm page. FilmTech provides a pump unit that enables accurate control of the delivery of the coating solution to the individual spray nozzles. The FilmTech also controls the atomising air pressure, spray width pressure and the speed of the solution vessel mixer; which can be supplied from a range of CSI solution vessels. All vessels come complete with hygienic fittings with contact parts manufactured in 316L stainless steel.

The CIP system incorporates a hygienic pump to supply strategically placed rotating wash nozzles, providing the coater with an effective means of cleaning.