Gabe Gamboa

How much?

When launching a product, the product’s packaging often gets short shrift. Ignore packaging at your peril, as it can be quite costly and time consuming if not approached correctly. Perhaps the most common question we get is: What is the cost?

Packaging validations are not one size fits all; they vary from company to company. They have one thing in common, though: they must adhere to ISO 11607 “Packaging for Terminally Sterilized Medical Devices”.  Depending on the procedure and sample size, costs will vary. As with most standards, ISO 11607 provides guidelines, not an exact procedure. However, all packaging validations must address three different categories: conditioning, aging, and integrity testing.

Conditioning:

Conditioning is intended to create test samples that have undergone simulations associated with sterilization, distribution, and environmental hazards. All samples must undergo conditioning prior to any aging or integrity studies, and conditioning is based on the design specifications of the product.

Aging:

Accelerated and real time aging ensure that the packaging can maintain a sterile barrier throughout the product’s shelf life. Shelf life is determined by the product’s design specification for expiration. Accelerated and real time aging is done after the simulated conditioning of the packaging system. Accelerated aging is conducted by simulating the period claimed for product expiration. Simulation is achieved by varying temperature, exposing the packaged product to a designated shelf life. The identified expiration date through accelerated aging is tentative until receipt of the real time aging results. Real time aging must be initiated at the same time as accelerated aging. In addition to simulated aging, baseline data must be collected in order to determine the effects of non-aged samples versus aged samples.

Integrity:

Integrity testing ensures that the package seal and barrier characteristics are still intact after all simulation hazards (conditioning and aging) have been carried out. The integrity of the package is typically tested by seal strength and bubble leak testing.

The cost of the testing is broken down between these three categories.

Conditioning and aging require testing chambers that are adjusted to temperature/humidity. Costs associated with this testing come down to the space the product occupies in the testing chamber, duration in the chamber, and number of simulation distribution cycles. Conditioning profiles are determined by the specifications of the product and are typically taken from standards like ISTA 2A and ASTM 4169. Aging typically follows ASTM 1980-07 and aging profiles are determined by the manufacturing design specifications. Prices typically seen for temperature/humidity conditioning cycles alone can range from $1.2k-$5k with another $3k-$6k for the distribution simulation. Accelerated aging and real time aging are more difficult to estimate, as aging can be as short as 1 month and as long as 5 years. Averages for accelerated aging can be anywhere from $1.5k-$6k and are similar for real time aging. These prices may vary due to the dimensions of the packaging and the sample size; prices can be higher but typically are not lower than this range.

The cost of integrity testing, consisting of seal strength and bubble leak testing, varies greatly based on the procedure. Some companies prefer to test packaging integrity at the conditioning and aging stages to ensure that there is not one element of testing affecting the packaging more than the other. However, some test packaging for integrity solely after conditioning and aging, requiring less samples and bringing costs down. Another element is the number of peels performed for peel strength. Some prefer to do all sides of the package and others prefer to do only their seal and one side of the pouch’s manufacturers seal. This testing varies so much that it is difficult to approximate a price range; the procedure must be nailed down first.

In summary, plan for packaging design and validation, as they take time and money. For a rough estimate of costs, just taking testing fees into account, don’t expect to pay anything less than $8k for bare minimum testing, a low shelf life, and minimal requirements on distribution.

To know which sterilization method to choose, it depends on your bioburden, desired SAL and the dose your product can handle. The number of test samples will greatly impact your decision. Since products are required to undergo a sterilization audit every three (3) months, you may want to choose a method that requires less samples to cut down on scrapping product and testing costs.

If your product can withstand at least 15 kGy, VDmax method is your best bet since it requires the lowest number of samples. Dosing at this range is also the most cost effective when sourcing sterilization vendors. Here are some suggestions for samples sizes.

1. VDmax15-35 (≈ 46 samples total)
   1. Typical for a bioburden of 1.5 CFU or higher. Options are for 15-35 kGy in increments of 2.5 kGy. Refer to AAMI TIR33:2005, another guidance document that has tables for additional VDmax testing other than 15 and 25 kGy, shown in ISO 11137-2.
2. Method 1 (≈ 120 samples total)
   1. Used if you’re trying to achieve a low sterilization dose (≤15 kGy).
      • B/F = 6 samples
      • Bioburden = 10 samples
      • Sterilization Validation = 100 samples sterilized at verification dose.
   2. Used to achieve a SAL lower than 10^-6 (i.e., 10^-5, 10^-4, 10^-3, etc.)
      • B/F = 6 samples
      • Bioburden = 10 samples
      • Sterilization Validation = 30 samples (10 samples from 3 lots) sterilized at verification dose.
3. Method 2a or b (≈ 540 samples)
   1. Used for product with very low sterilization dose and a low bioburden during initial processing.
   2. Used to determine lowest dose possible and is ideal for radiation-sensitive product.
   3. Rarest method of testing.
      • 9 doses at 60 samples/dose.
      • Doses are between 2-18 kGy
      • 540 samples tested!

A dose audit consists of the same number of samples minus the B/F samples.

In short, avoid Methods 1 & 2 unless you have a valid justification for using them. Also keep in mind that the tightest tolerance a sterilizer can achieve is ±10%, typically achieved at costly R&D facilities.

Validating sterility is one of the most important steps in the validation process. It ensures that your product is free from viable organisms. Any compromise in sterility can result in infection or even death. In most situations a sterility assurance level (SAL) of 10^-6 is preferred (i.e. a 1 in a million chance of a non-sterile unit). This SAL is not absolutely necessary, though, depending on your requirements and product capabilities.

So what standards must you follow? ANSI/AAMI/ISO 11137 is the main guidance for the sterilization of health products. Like most standards, it is broken into two parts: 11137-1 & 11137-2.

ANSI/AAMI/ISO 11137-1 describes the overall requirements needed for the development of the sterilization process. Think of it as a general overview of the processes involved, including establishing dose, equipment validations, sterilization audits, and maintenance of equipment.

ANSI/AAMI/ISO 11137-2 describes the different types of validation methods, including VDmax 25, VDmax 15, Method 1, and Method 2. Each of these methods consists of three steps:

1. Bacteriostasis/Fungistasis (5 day test)
   1. Determines if the product contains inhibitory properties (e.g. antibiotics) or chemicals that can inhibit or mask the growth of microorganisms in the sample.
      • Refer to USP <71> for methods.
2. Bioburden (12 day test)
   1. Determines population of viable organisms in the product in the form of colony forming units (CFU).
      • Test methods are detailed per ANSI/AAMI/ISO 11737-1
   2. Includes all components labeled sterile NOT just the product.
   3. Establishes the verification dose to achieve 10^-2 SAL, based on tables provided in the standard.
3. Sterilization Validation (14 day test)
   1. Samples are dosed at the verification dose and samples are tested for bioburden.
      • Test methods are detailed per ANSI/AAMI/ISO 11737-2
   2. Depending on the method, zero (0) samples or two (2) samples can test positive for the product to pass the validation.