Some things to consider in determining the packaging material are that gamma sterilization can product elevated temperatures and you want to make sure that your materials can withstand these temperatures. They will also be nonporous in nature to maintain the moisture barrier you are requiring.  I would recommend the following article that was published in MD&DI in the February 2000 issue to assist in this decision entitled “Polymer Materials Selection for Radiation-Sterilized Products,” by Karl Hemmerich.

The ultimate solution to this problem is to monitor your distribution environment and come up with a test profile specific to your shipping environment.  Because this can be timely and expensive, many of our customers will default to the International Safe Transit Association (ISTA) 7D standard.

I would avoid direct contact with the dry ice. This could be done by creating a cavity that is surrounded by dry ice and placing your product in the cavity.

Another suggestion might be to design an interior package system (corrugated box) that is placed in the thermal container and then the dry ice could be packed around it.

To my knowledge, there are no standards that require a shelf life on individual packaging system components. This is only required on the entire package system, as you currently do. I believe there is no additional action required for you and your company in this regard.

If the vacuum leak test does not work because there is no air in the package for expansion (and internal pressurization), how about simply applying a compressive load to the package and allowing it to sit over time. The load would be small so as not to cause the seals to open over time (creep), but if there was a small leak, the fluid would be forced out and/or the package would begin to deflate. Many pouches could be set-up for testing using small plate weights. There is no ASTM method for this test, but you could validate it by making small holes in control packages and observing the results. This is how I would perform the test.

I would recommend utilizing a Haug vacuum leak tester. Visit www.haugquality.com.

Depending upon the packaging itself, I would propose ASTM D3078 “Standard Test Method for Determination of Leaks in Flexible Packaging by Bubble Emission” or ASTM D4991 “Standard Test Method for Leakage Testing of Empty Rigid Containers by Vacuum Method.”

The utilization of D3078 is for more flexible nonporous packages, while ASTM D4991 is used for rigid nonporous packaging.

There is wide debate over what are the typical vibrational frequencies encountered during the various global modes of shipping and handling. Additionally, there has been significant research into dynamic inputs encountered during the global distribution of packaged products.

Organizations such as ISTA, International Safe Transit Association(www.ista.org), in conjunction with testing and monitoring equipment manufacturer Lansmont Corp. (www.lansmont.com), have conducted extensive environmental monitoring of the distribution environment.

Standards-setting organizations such as ISTA sell testing standards which will provide you with all the details for frequency, amplitude, and GRMS. It is much too comprehensive to provide you with a snapshot. I would suggest going to their Web site and purchasing ISTA Project 2a test standard for a wealth of detail on the dynamic inputs. This focuses on the single parcel environment, not palletized loads.

Additionally, the standards setting organization ASTM (www.astm.org) has several test standards and recommended practices for environmental distribution simulation with similar specifications.

I recommend reviewing ASTM D 4169-05 and -08, Standard Practice for Performance Testing and Shipping Containers and Systems. This standard references specific test standards for the performance of loose load vibration and vehicle vibration.

The low-cost mechanical vibration table would be marketable in industry; these rotary motion “shake” tables currently exist and the specifics regarding the execution of this test is outlined in ASTM D 999, so there is both a current test method and equipment to accomplish the repetitive shock of a packaged product.

For terminally sterilized medical devices for compliance to ISO 11607, Packaging for Terminally Sterilized Medical Devices, it is required to evaluate any changes that may impact sterile barrier integrity and determine whether a revalidation is required. So your focus should be on continuously evaluating material, process, and device changes that could negatively impact sterile barrier integrity and establishing a revalidation plan if such changes can be rationalized as impacting sterile barrier integrity. If no changes have occurred in materials, processes, or device, then it may be prudent to consider a 5-year revalidation plan in conjunction with any major shifts in regulatory policy and testing methodologies.

Seal strength and burst strength values are performance-based requirements, that is, the minimum burst or seal strength should be whatever required to meet your real world experience and required performance standard. That said, in an analytical world you would have to quantify the maximum force you would expect to be placed on your seals during their life cycle—distribution, handling (bundling, dropping), shipping, point of use, etc.  I suspect that this is not practical for you.

I cannot comment if your current burst strength specification is reasonable or sufficient for your magazine application. As pouches or sachets typically have destructive or nonpeelable seals, my gut reaction is that these are reasonably sufficiently strong seals when placed in a dynamic environment.

For sterile medical packaging, where maintaining seal integrity throughout the product or package shelf life is imperative, there is a performance-based test within ASTM D 4169, “Performance Testing of Shipping Containers and Systems” (www.astm.org to buy standard) to simulate a high altitude, low pressure situation (air shipment) that could cause nonporous packages to experience a seal breach. That is when the pressure outside the package is lower than the atmospheric pressure inside (packages sealed at sea level or a few thousand feet above sea level, which then experience high altitudes during air travel), the package will blow or puff up, stressing the seals and film.

Again, this is not a specification-driven test, but rather, a performance-based test, which may provide some increased confidence on the seal strength of your pouch package during distribution and shipping.

Your thoughts around contacting suppliers for their experience with customers in a similar application makes sense, too.

I cannot comment if the 18 PSI line pressure is appropriate, per se, for your pouch integrity tests. I can, however, direct to several industry standard tests for whole package integrity evaluation.

The positive pressurization of packages for leak detection such as the testing performed per ASTM F 2096 “Detecting Gross Leaks in Medical Packaging by Internal Pressurization (Bubble Leak Test)” has as part of the procedure a calibration step, which is essentially conducted by making a known defect in the pouch with a calibrated wire of calibrated diameter and slowly increasing the pressure until the know defect begins to leak.  The pressure level at which the known defect begins to leak is the test pressure. It is different for every package of every different type of geometry and size, hence no pressurization standard. If your package fails or bursts at or about the required test pressure then the test method may be inappropriate for that package design (assuming that seal strength is sufficient for maintaining physical integrity, as determined by other means) and you need to select a different test method, possibly a vacuum leak test.

According to ASTM F2097 “Standard Guide for Design and Evaluation of Primary Flexible Packaging for Medical Products”  under Package Integrity (the ASTM test methods for Package Integrity), perhaps trying a vacuum leak test such as ASTM D 3078 “Determination of Leak in Flexible Packaging by Bubble Emission” may be a viable alternative to prevent bursting of the new pouch.

I hope this information is useful, essentially there is no absolute minimum pressurization standard, other than the necessary test pressure as determined through those test methods utilizing positive pressure and having a test pressure “calibration” step.