Automated tableting

Murtagh, R. (2002), Identifying Improvements to Current Industry Practice for the Validation of Automated Tablet Compression Machines, M.Sc. Dissertation, University of Manchester Institute of Science and Technology, Manchester, U.K. 

Some presses are equipped with strain gauges at key points in the overall feed—compress—eject cycle. Thus, these measure compression and ejection forces. Tight specifications for punch lengths and weU-designed and prepared granulations have led to better control of variations in tablet weight. In fiiUy automated presses, weight variations are adjusted by computer. 

Fig. 20 Automated high-output rotary tablet press. (Courtesy of Fette America.)...

There are as many variations in coating procedures as there are tablet coaters, and so the account given here is only a guide. Nevertheless, it illustrates the complexity and time-consuming nature of the process, and the reader will realize why efforts have been made to develop alternate coatings, equipment, and methods that permit at least some degree of automation. 

In a recent application, the appearance testing of tablets through measurement of color changes has been automated through the use of fiber optic probes... 

Most manufacturers of dissolution testing devices offer semi-automated systems that can perform sampling, filtration, and UV reading or data collection. These systems automate only a single test at a time. Fully automated systems typically automate entire processes including media preparation, media dispensing, tablet or capsule drop, sample removal, filtration, sample collection or analysis (via direct connection to spectrophotometers or HPLCs), and wash cycles. A fully automated system allows automatic performance of a series of tests to fully utilize unused night and weekend instrument availability. 

The prednisone tablets use deaerated water as the medium. There are numerous methods for deaeration of medium (14,22). As mentioned above, there are also automated methods available. The method described in <711> uses heat, filtration, and vacuum. Helium sparging is also a typical method... 

So far the discussion has revolved around completely automated dissolution. Meaning that media is prepared, dispensed into the vessels, tablets dropped, sampled, filtered, collected or read, and lines and vessels washed. This series of events must be reproduced multiple times without human intervention after it has been initiated (Fig. 3). 

For automated dissolution systems, OQ testing can include testing balance functionality, testing the functionality of individual components including bath communication, sample cannulae, waste cannulae, thermistor communication, tablet dispensers, sensors, valves, pumps, filter dispenser and holder, and testing fluid pathways. 

Motz SA, Klimundova J, Schaefer UF, Balbach S, Eichinger T, Solich P, Lehr C-M (2007) Automated measurement of permeation and dissolution of propranolol HC1 tablets using sequential injection analysis. Anal Chim Acta 581 174—180... 

Fully automated workstations can automatically fill vessels with dissolution medium, drop the tablets or capsules, collect multiple samples, and clean vessels. Zymark MultiDose Automated Dissolution Workstation (Zymark Corporation, Hopkinton, MA), Sotax AT70 Smart (Sotax Corporation, Horsham, PA), and AUTO DISS systems (Pharma Test GmbH, Hainburg, Germany) are several popular automated systems used within the pharmaceutical industry. 

Burns [27] described a fully automated approach for HPLC analysis of vitamin tablets. A sample valve provides the injection interface in this apphcation. Tablets direct from the production plant are dispensed into the sample cups on a Technicon Sohd Prep sampler, they are dissolved, and the fat-soluble vitamins are extracted. The solution is concentrated... 

In the pharmaceutical industry, it is important that aU products are properly tested and vahdated prior to release for sale. One of the most important tests is the determination of tablet dissolution rate. In this procedure tablets are immersed in a suitable medium to mimic the action of the stomach and the release of the active ingredients monitored over a period of time. Automation of these procedures is obviously important for various reasons including cost, accuracy of analysis and for validation of the results according to good laboratory practice. 

Final volume using the automated method will be 100 mL minus tablets volume displacement (refer to Section 5.3.1). 

Volume Displacement. This parameter is not a factor in dissolution testing but can prove to be a very important factor in automated assay, content uniformity, or degradation and impurities testing. It specifically addresses the volume displaced by the tablets in solution. Since manual sample preparations are often prepared utilizing volumetric flasks where the solution is diluted to the mark, the actual volume of solvent added to the flask is irrelevant. However, this actual volume... 

When attempting to convert a manual method into an automated method, there are certain elements, such as tablet size and solvent selection, which will have an impact on the ease of the conversion from manual to automated. For instance, some of the elements of an assay method that would make it easier to automate would be that the dosage form fits into a test tube the extraction uses neutral media or acid not more concentrated than 0.1 M makes use of nonvolatile, low-toxicity solvents does not use surfactants and uses premixed, room-temperature solvents. Some of the elements of a dissolution method that would make it easier to automate would be that the dosage form fits in the sample carousel, does not use media more concentrated than 0.1 M acid, does not use isopropanol or surfactant in large quantities, uses magnetic sinkers or no sinkers at all, and uses no or minimal reagent addition volumes for pH control. 

D. Complex configurable SCADA system Automated workstations for tablet assay... 

The system provides a new possibility for industrial manufacturing and galenical development of pharmaceutical solids specialties and has following purposes to make possible automated, unattended production, withdrawing from scale-up experiments, and thus a shorter development time for new specialties, with the aim of a shorter time to market. Manufacturing procedures can be simplified and validated faster, and the quality of granules, tablets, and kernels compared to conunon production is equal or better. Different solids specialties have been tested and validated. 

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