Ensuring the Stability and Viability of Combination Products

Author: 
Bryan Wickson, Exova

Many of the testing procedures used to validate combination products are borrowed from the pharmaceutical industry. Since combination products are produced using CGMP-type manufacturing standards, manufacturers must employ such CGMP testing protocols as those used to test incoming raw materials. But in addition to incoming tests, developers of combination products must also often perform mechanical and physical testing on a sampling of manufactured devices.

A drug-dissolution apparatus at Exova can be employed to determine the API release rate from combination devices, a critical performance measurement used for performing product specifications.

Drugs administered to the body via combination products often begin as solid products. Hence, the rate at which such drugs dissolve into the body becomes a crucial issue. Therefore, manufacturers of combination medical devices must perform a range of drug-dissolution tests to measure the dissolution, or release, rate of the pharmaceutical agent from the device platform. And as in the case of standard pharmaceutical products, manufacturers must understand the degradation rates of the products they produce—both in terms of the pharmaceutical agents themselves and the material matrix, which is typically made from such polymer materials as PLGA.

When developing combination products, manufacturers must also perform a host of stability tests to determine the shelf life of the pharmaceutical agents used in their products. Such testing involves placing a sample into a chamber and then withdrawing small amounts of it at established time intervals—perhaps every three months. Then, the samples are subjected to a battery of tests to determine whether they have changed over the course of time.

As in the case of testing pharmaceutical agents, it is important for medical device manufacturers to test the stability of the material matrix itself. Assuming that a combination device’s material platform is a polymer-based material, manufacturers must analyze it to determine whether it contains residual monomers or extractables and leachables that might elute from the product into the body. The goal of such testing is to determine the toxicity effects such by-products may have. Does the polymer degrade over time? Does it need to be protected from light or from excess humidity or temperature? These questions must be answered during the process of developing and manufacturing combination products.

The procedures used by manufacturers to test existing product lines are also suitable for use in developing new products. Hence, when a manufacturer proceeds to develop new combination products, it is important to have all of the requisite analytical tools at hand because many of the design changes and optimizations that take place during the development phase can affect product stability or viability.