In addition to evaluating the risk of leachables from a medical device used to deliver a drug, the compatibility of the drug product with the medical device also needs to be demonstrated.     Analytical assay methods are needed to demonstrate the stability and compatibility of the drug product.  If available, the USP method for the drug product should be used.  If a USP method is not available for the drug product, an analytical assay method will need to be developed and validated.

Once the analytical methods are in place, the drug compatibility experiment can be described in the following steps:

1. Load drug product into each configuration of the medical device to be evaluated
2. Dispense drug product at a clinically relevant rate for a clinically relevant time (or store in device for a clinically relevant time) under ambient conditions
3. A control of the drug product that has not been exposed to the medical device is stored for the same time under the same conditions
4. Collect representative aliquots at end (and intermediate time points depending upon length of time dispensed).
5. Assay dispensed sample and control.   Calculate the difference between the two.
6. Determine if the results meet the acceptance criteria.

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