Arriving at Appropriate Climatic Conditions
Ensuring that sterile barrier systems (SBS) charged with protecting medical devices can withstand climatic stress is an important part of medical device package development. But concerns that current testing may be too rigorous has prompted ASTM International Committee F02 to development a Standard Practice for Climatic Stressing of Packaging Systems. The goal is to develop a guideline that reflects the distribution environments commonly used by medical device manufacturers.
Curt Larsen and John Spitzley, principals of Spartan Design Group, are working on such a guideline. They shared their progress at the ASTM International’s October 2009 workshop in Prague. A draft standard has just been revised; Larsen and Spitzley hope balloting of the revision will be completed in time to introduce a revised version of a draft standard by Committee F02’s meetings in April 2010.
“Severe climatic stress exposures may be subjecting medical devices and packaging materials to stresses they were not designed to withstand,” Larsen and Spitzley explained during the workshop. “Those stresses may not reflect real conditions in the current distribution environment.”
During development of the draft guideline, ASTM F02 and D10 member companies and individual members were surveyed about their current programs for conducting climatic stressing. Larsen and Spitzley found that some respondents were using ASTM or ISTA methods and practices, but others were using methods of unknown origins.
“Climatic stressing is just like a ‘distribution test.’ It is really ‘sample stressing’ to duplicate what the package system may be exposed to during distribution, handling, and storage,” Larsen explains. “The engineer must prove that the design is adequate for use and can withstand the extremes in temperatures and humidities it is likely to see.”
When asked whether organizations have gathered field data from environmental mapping, survey respondents did not provide much data.
The pending ASTM standard aims to guide climatic stressing practice using exposure levels based on available information on shipping, handling, and storage environments. Users would identify various modes and durations of transportation. Three conditions are outlined: Freeze, Desert, and Tropical. Environmental conditions included in the standard are based on industry experience, global climate, typical distribution duration, and guidance from ASTM D4332, ISO 2233, and ISTA test procedures.
After climatic stressing is completed, users would expose test samples to simulated distribution stresses as specified in ASTM D4169, Standard Practice for Performance Testing of Shipping Containers and Systems, Distribution Cycle 13; ASTM D7386, Standard Practice for Performance Testing of Packages for Single Parcel Delivery Systems; one of the ISTA procedures; or ISO 4180, Packaging—Complete, Filled Transport Packages—General Rules for the Compilation of Performance Test Schedules–Part 1: General principles. Samples would be evaluated based on pass/fail criteria established in the test plan.
For more details, contact Larsen, also a PMP News Editorial Advisory Board member, at firstname.lastname@example.org. Medical device manufacturers are encouraged to attend ASTM International’s Committee Week, April 18–23, in St. Louis. For details, visit www.astm.org.