The Parata Max by Parata Systems, Durham, NC (parta.com), holds and automatically dispenses up to 232 finished prescriptions, more than the 196 average prescription volume at U.S. pharmacists. Behind this improved preformance is a critical seal-coupler device design and manufactured by Minnesota Rubber and Plastic (MR&P), Minneapollis (mnrubber.com). It is used in chain, community, government, and institutional pharmacies to improve prescription-dispensing efficiency and capacity and reduce errors. The system automates 60 percent of an average pharmacy's total prescription volume with upkeep of less than an hour a day. The system does not make drug or dose errors, the source of 88% of medication errors, and delivers counting accuracy 10 times higher than the industry standard. The high capacity system is compact, occupying just 12 sq ft, so it replaces a single shelving unit in most pharmacies.

The Parata Mini is an entry-level automation solution that provides fast accurate counting, with a user experience that creates seamless scalability to the Parata Max as the pharmacy's volumes grow.

Key to pneumatic actuation

The seal-coupler is a critical intermediary device in the pneumatic motion high pressure system. Positive sealing is imperative in the system so no pressure changes occur that could affect compressor function, air flow rate, and ultimately pill count speed and accuracy.

When activated, regulated pneumatic pressure moves the pills from individual cells that have the dual purpose of both storage and dispensing. These are “smart cells” with an electronic circuit board that broadcasts the cell's location on the system, so the robot always selects the correct cell for dispensing.

The seal-coupler MR&P designed is a spring-loaded assembly with an upper and lower housing molded from a nylon material that is ultrasonically welded together. Within this housing, a spring is centered on a retainer at one end and a poppet core on the other end. This poppet core, under tension from the spring, locks into a special lip seal molded from a high-performance elastomer.

The lip seal design addressed the initial problem of seal alignment with a more precise-fitting lip configuration at the seal end, precision molded from an engineered elastomer. This material improved wear resistance with a leak-proof connection to the high-pressure system, 100 percent tested for quality.

Assemblies and related components

Parata challenged MR&P to address the components to which the seal-coupler was connected. First was the air manifold assembly. MR&P designers ensured that the overall manifold's profiles were designed and fabricated to strict specifications so that the manifold ports sealed and connected properly. Similar improvements and efficiencies were brought to other components including vial descrambler fingers and cradle assemblies.

Once these components and assemblies successfully passed prototype testing, large-volume production was initiated at MR&P's River Falls, WI, manufacturing facility. Testing was especially important to the success of this project with MR&P providing three stages of comprehensive testing during the design-manufacture cycle.

MR&P's contribution to improving the component and assembly designs and overall quality is evidenced by the fact that MR&P became an assignee of the patent application made on the system's cell calibration mechanism.