Drug-Delivery Pumps: An EKG Labs Case Study

Drug-Delivery Pumps: An EKG Labs Case Study

Last month, we shared how EKG Labs is leading the way in analytical testing of drug delivery pumps. EKG leverages our knowledge of material compatibilityextractables & leachables, and ISO 10993-18 chemical characterization to help clients submit drug-device products for regulatory approval. This month we wanted highlight a specific infusion pump study EKG has been working on for the past couple years.


pacemakerOur client is a relatively small private company looking to develop and market drug/device combination products for chronic neurological disease. Their unique strategy seeks to bypass the blood-brain barrier by delivering drug product directly to the brain. We’ve had the honor of partnering with this team since the early days of their product development, providing regulatory guidance from our years of experience in the field. As our client doesn’t specifically have a lab of their own, we operate as their eyes and ears. With weekly conference calls and a steady stream of daily emails, ours is a close partnership.

Drug Product Work

Some of the early work we performed, and continue to perform as strategies change and develop, revolves around the characterization of a wide variety of formulations of the client’s proprietary drug product–across different concentrations, pHs, and with or without different parenteral excipients. Characterization has included assessment of titration curves, solubility, viscosity, and other physicochemical properties. Longer drug characterization studies have included stability/degradation studies and freeze/thaw studies. We’ve also assessed equivalence to similar drug products currently on the market. After consistently observing one significant unidentified impurity, we worked to successfully identify and characterize the impurity. As a part of our drug product characterization work, we also validated an assay and impurities HPLC method.

Material Compatibility

A number of our studies for this client have looked at various aspects of material compatibility. We’ve evaluated some individual material components of the drug delivery systems: notably, compatibility with the flow path materials in the infusion pumps along with a variety of potential catheters and specific delivery components. We have also looked at the stability/compatibility of the long term storage of drug product in different plastics and in glass vials.

Pump Work

Across our journey with this client, we’ve analyzed six different brands/styles of implantable pumps, each with unique features and challenges: ranging from small 2 mL osmotic animal pumps to established and FDA-approved variable flow rate pumps to constant flow rate pumps with a delivery design new to the United States. With all of our many pump studies, we have primarily focused on assessing the compatibility of the drug product and the effect of the drug product concentration, pH, viscosity, temperature, etc. on flow and performance of the pumps.

While some of these studies have been short, many have been year-long (and beyond) studies. Some of the pump studies have been for research and development purposes, while others are intended for IND submission and run per EKG Lab’s full quality system.

Extractables and Leachables

Of course, a key element in regulatory submissions for medical devices is the performance of extractable and leachable studies. For the client’s primary implantable pump and infusion system, we performed an exhaustive extraction study on the patient-contacting surfaces and an exaggerated extraction on the drug-contacting surfaces. These studies were run following ISO 10993-18 chemical characterization. This was followed up with a leachable study. Across the studies, we analyzed 7 different solvent systems.

We’ve also run several dozen full delivery setups, with myriad configurations of pumps, drug products, catheters, and proprietary delivery components, followed by both assay/impurity assessment and elements of leachable assessment. This testing has included running ICPMS on eluents to assess the drug product’s elemental impurity extraction potential in the pump and throughout the flow path.

For more on drug delivery pumps and analytical services at EKG Labs, visit our drug delivery pump webpage.

About EKG Labs

EKG Labs is an analytical service provider for the pharmaceutical and medical device industries. Our wide variety of analytical services support product development, regulatory filings, and analytical chemistry investigations. You can contact EKG Labs at or at 810-354-5229.