Automated Tablet Sorting: Raising Efficiency

Current US Food and Drug Administration (FDA) regulations mandate a strict adherence to standards of safety and quality before pharmaceuticals are allowed to be released to hospitals, clinics and the general public. Electronic document standards are also guided by 21 CFR Part 11 requirements, which pertain to the traceability of documents that encourage best practices.

Japan, known for its stringency, is moving to open its domestic market to more foreign pharmaceutical imports. Manufacturers wishing to supply pharmaceuticals to Japan, the US, Europe and other developed markets would do well to install processes that comply with or exceed the current markers in pharmaceutical regulatory standards.

During the manufacturing process, capsules and tablets sometimes suffer defects in terms of their shape, size, color, printing and other assorted faults. Laboratories perform sorting operations to eliminate the defective tablets, ensuring the integrity of the batch. There are three options to choose from:

• manual sorting, which is inspection by hand
• automated involving machines that are specially built for the task
• discarding the entire suspect batch

There are advantages and disadvantages for each option, and the automated route may not necessarily qualify as the best solution for all manufacturers.

Naked Eye Sorting
The manual inspection process is a relatively simple operation to set up, requiring the installation of a few inspection belts and the hiring of staff. There is no need for large capital expenditures, nor is there a requirement for technical training. To a certain extent, manual inspection is a scalable operation where output can be easily increased through the addition of inspection belts and man-hours.

Manual sorting relies solely on individual human judgement, giving rise to varying standards of quality control. This can often end in inconsistent sorting results between the operators. Furthermore, each individual operator may also lack uniformity in his/her own judgement of quality throughout the entire sorting process.

This means that the manufacturer can potentially be left with a bin of inconsistent output, and the decision of whether to put the drugs through a second round of sorting - this time with stricter (and more time consuming) criteria, or to discard the output altogether.

This sorting process is labor-intensive and is limited by the speed of its operators. A low throughput can result in weeks of delay. Should there be consecutive problem batches, production may bottleneck at the inspection stage, further slowing down the entire production process.

Since the process relies on human judgement, the results of an operation are not repeatable for subsequent batches. This produces a lack of validation and without the collection of data, determining the causes of defects can be difficult.

A manual inspection process therefore, does not allow meaningful documentation to be produced, which also means that international pharmaceutical regulations like 21 CFR Part 11, cannot be satisfied. This can create problems in getting specialty drugs to market, or worse, result in a product recall.

The Automatic Option
Given the inherent problems associated with manual sorting, automatic inspection could present a more efficient alternative.

Making an investment in the automation of the sorting process can be costly, both in terms of finances and time. Often, it requires a sizeable upfront capital investment. However, this has to be weighed against the fact that typically, automated sorting machines can post good returns-on-investment. With average utilization, turnaround times of two years or less are not uncommon.

Put into perspective, the technology may turn out to be a cost-effective investment, in the light of the astronomical cost of discarding batches or of products recalls. In addition, automated sorting machines utilizing artificial vision are becoming increasingly user-friendly and can be operated by non computer-literate staff.

Upon purchase, the automated inspection machine will require some time - up to a few weeks for the validation process to be fully completed and tested for Installation Qualification (IQ) and Operational Qualification (OQ). Most vendors offer validation packages together with the machine's set-up and start-up, to facilitate the handover process.

Automatic inspection offers other advantages. Using an array of sensors and dedicated lighting, automatic sorters carry out checks for more than just surface defects. Products with unusual characteristics (eg, bi- or tri-layer tablets, tablets with laser-drilled holes, embossed tablets, transparent and partially filled capsules) require critical inspection and should be examined with the precision that artificial vision machines offer. Typical optical systems are built to detect defects that have a size of 100 microns or less. Inspection machines can also act as real-time process tools, helping to maintain production standards, quality and consistency.

Automation offers the advantage of high volume, high speed, accurate and non laborintensive sorting. For example, a batch of one million tablets can be processed in a single sitting. In comparison, a manual process involving two operators working on a single conveyor belt could take up to four shifts to complete.

The technology for automated sorting has achieved such a level of usability that the average worker with no special training can comfortably operate the machine. Coupled with inbuilt, failsafe ejection systems, artificial vision inspection machines can help a laboratory achieve higher levels of productivity and efficiency.

The process of automatic sorting is accomplished according to pre-established parameters which can be repeated across batches, yielding verifiable results and allowing for validations and audit trails. Built-in software also provides a statistical analysis of defects. This allows the manufacturer to track and identify the root causes of problems and to resolve them for future production runs.

Perhaps most importantly, automated sorting machines produce records that satisfy 21 CFR Part 11 and other regulatory requirements, providing document chain consistency. By ensuring that documents are in line with existing standards, automatic sorting can bring a manufacturer one step closer to regulatory compliance and to international markets.

Manual vs Auto
Manual and automatic inspection methods both come with their own unique advantages and benefits, with each suited to different circumstances.

Manual inspection methods are labor intensive and can be prone to errors and Manual sorting is labor-intensive and is limited by the speed of its operators. (Source: Proditec) inconsistencies. They do not allow for an accurate analysis of problematic issues, nor do they provide verifiable documentation. However, manual sorting is easy to carry out, and may be one of the most cost-effective solutions for small amounts of tablets or drugs which are not targeted at regulated markets.

In contrast, inspection machines are more effective and consistent at spotting defects. Their high sorting capacity, precision and ability to track and analyze defects can translate into higher productivity and lower waste. By automating the sorting process, laboratories can also save on labor. Automatic artificial vision machines are also a suitable option for a manufacturer seeking to ensure compliance with FDA regulations.

Automated sorting technology based on standard-compliant machines allows companies to meet regulatory requirements, helping to open the doors to foreign markets.

The science of artificial intelligence in industrial vision pharmaceutical sorting machines is continually improving. For example, Near Infra-Red (NIR) technology for high-speed sorting machines provides a solution against batch contamination. With the accelerating pace of scientific advancement, it appears that artificial vision sorting technologies will be enhanced with additional capabilities in the near future.