Robots test pharmaceutical inhalers

Citation

(1999), "Robots test pharmaceutical inhalers", Industrial Robot, Vol. 26 No. 6. https://doi.org/10.1108/ir.1999.04926faf.001

Robots test pharmaceutical inhalers

Robots test pharmaceutical inhalers

Keywords: Robots, Pharmaceutical

An Epson robot supplied by System Devices is at the heart of a new automated system which is revolutionising the testing of inhalers in the pharmaceutical industry (see Plate 1).

The system, called the Automated Andersen, is the result of seven years of development by Maidstone-based Novi Systems Limited. The company originally attempted to design a new impactor, but with the help of pharmaceutical companies Fisons and later Astra decided to automate the Andersen impactor instead.

Plate 1Complete view of Andersen stack showing the robot manoeuvring stage of the Andersen

Used throughout the world, the Andersen impactor measures particle size distribution for dry powder inhalers (DPIs) and metered dose inhalers (MDIs).

Inhalers contain valuable and often toxic active ingredients, so accurate particle size distribution is crucial to ensure that a patient receives the correct dose. It is also crucial to product registration, with regulatory authorities such as the FDA demanding ever-more stringent safeguards against any possible errors at all stages of inhaler manufacture.

However, when carried out manually, this is a time-consuming and labour-intensive process. It begins with weighing up to 30 MDI or DPI units and then putting them into a loading rack. Next each unit is shaken to mix the contents and then fired in an impactor. Each impactor then has to be dismantled, the contents removed, and any deposited material recovered by washing and rinsing with a particular solvent. The collected washings and rinsings then have to be analysed for quality control purposes and stability testing.

"It's a very boring job which can be both physically and mentally wearing for the people involved," said Novi Systems Managing Director Malcolm Smith. "A good analyst can do 3-4 inhaler tests in an eight-hour day. The Automated Andersen can do over 30 in a 24-hour period and it only takes ten minutes to reload between batches," he added.

The automated process begins with the MDIs or DPIs being placed in a rack. Then the Epson robot takes over. To begin with, it weighs the first selected unit. If this is an MDI, it is placed in a programmed shaker for the specified shaking and firing operation. The MDI is then primed to waste, reweighed and fired into the Andersen. In the case of a DPI, the unit is transferred directly into the preparation/firing station. Once a shot has been fired into the Automated Andersen, the robot moves the impactor to the demount station for disassembly.

To satisfy the regulatory authorities, this automation has to be absolutely accurate. "Robots are key to automation and the most important point here is repeatability. The Epson can repeatedly go to a position within about ten microns - such precision is essential for this project because the parts we are handling must be placed to incredibly tight tolerances - a bit like threading a small needle ready to do some sewing - the Epson robot operates well within the Fad's requirements," said Smith.

The automated system then goes on to wash and rinse the units, taking samples for analysis by HPLC. Later, a new filter is fitted to the disassembled Andersen stages which are then put back together. All the data generated along the way are stored in the database and are available for read-out and calculations.

Smith's reasons for using Epson robots on the Automated Andersens go well beyond their purely technical ability. "We also get great back-up and support from System Devices, which is so very important when at a business like Novi Systems we deal with a wide range of technologies and need quick and expert help when we get stuck" he said. "Which is one of the reasons why another of the company's products - the Opto I/O - has also found its way into the Automated Andersens.

System Devices is the sole UK supplier of Opto 22 products and Novi Systems uses Opto I/O to control all the Automated Andersen's on/off devices. "We have been using Opto I/O for a couple of years now. In the past we used PLCs, but they are not readily accessible from a computer which is a problem because we do our remote support over a phone line using modems," added Smith.

"The Epson link with System Devices eventually led to us using Opto I/O. And it's doing everything we ask of it," he concluded.

Companies already using Novi Systems products include Whatman, Astra, Kodak, Luicas and Verity.

Contact Roger Williams, System Devices Ltd, Ascot Industrial Estate, Icknield Way, Letchworth, Herts SG6 1TD. Tel: +44 (0)1462 670633; Fax: +44 (0)1462 480046; E-mail: roger@systemdevices.co.uk