Drug delivery devices are a specialty area within the medical device industry. These are combination products that may require review and approval by either device or drug agencies, or both. The end use of the device generally determines which agency will take the lead. Typical products would be external or implanted pumps, implanted polymers with slow release or degradation properties, catheters with surface modifications, or materials such as bone cement. However, this device category can also include drug delivery patches and syringes. Thus, the approach to non-clinical evaluations may take a variety of directions.
The following scenarios regarding drug/device combinations are possible:
- The device and drug are approved and on the market individually
- The device is approved but the drug is not approved
- The device is not approved but the drug is approved
- Neither the device nor the drug are approved
In the first scenario (drug and device both approved), the biocompatibility of the device and the toxicology of the pharmaceutical are known. It must be shown that the stability and bioavailability of the drug have not been compromised by the new drug-device combination. Assays typically used to evaluate the drug product will be needed as well as functional studies as indicated below.
In the second scenario (device approved/drug not), the drug will need to go through extensive evaluations as typically done for a new drug product, plus those studies indicated in scenario 1 above.
In the fourth scenario (neither approved), significant device (IDE, PMA) and drug evaluations (IND, NDA) will be required. Discussion with NAMSA Scientists and the FDA or Notified Body should precede testing in order to design the optimum test protocol.
This test program summary will address scenario three, since most of these devices today fall into a category where a known drug is available but the delivery system needs enhancement to achieve improved therapy.
Depending upon the exact nature of the device, a range of biological effects may need evaluation per ISO 10993. Please also see our guidance documents for additional detail.
NAMSA Technical Specialists and Scientists are adept at developing non-clinical testing programs for these products. Veterinary surgeons on staff are experienced at implanting and/or evaluating the biocompatibility and functionality of such devices.
Standards and Regulation
First consideration should be given to vertical standards (an FDA guideline or ISO standard in use for a specific device). In the absence of such guidance, ISO 10993-1 should be consulted to determine areas of concern for these devices.
Each device should be examined on it's own merits. In some cases, prior data may be available from suppliers or in the literature, or there may be efficacy or functionality testing in progress that can be used to satisfy a portion of the safety requirements.
