Designing Drug-Device Products for Predictable Elution Rates

Predictable medication delivery is one of the most critical aspects of patient-focused care and precision medicine. Drug-device combination products give manufacturers a platform for engineering more consistent, predictable elution rates. However, this requires novel design choices and engineering insights into how to control drug elution.

Once perfected, targeted therapies at more accessible prices could become more common, delivering higher-efficacy care with greater success rates. Following these steps is essential for creating compliant pharmaceuticals that leverage materials science to address industry pain points.

The Foundations of Material Science and Polymer Selection

The market for drug-device combination products will be worth an estimated $379.17 billion by 2030, driven by the urgency to combat chronic diseases and stabilize aging populations, among other factors. Many types of medical devices need a reliable drug elution rate, from implantable stents to topical patches. Because these delivery methods vary so widely in scale and design, perfecting the release timing is complex.

In the worst-case scenarios, the medicine could be too concentrated and lead to toxicity if eluted too quickly, or it could fail to treat an ailment in time if it’s not fast enough. The most influential considerations engineers and material scientists must consider include:

• Porosity
• Glass transition temperature
• Tortuosity
• Propensity for adverse effects, like inflammation
• Degradation rates

This makes polymer selection and its biodegradability among the most foundational decisions, as it’s the medium through which the active drug ingredients move in the body. It’s one of the most significant factors in the elution profile. Durable and biodegradable options are available, and both are similarly effective for cardiogenic shock and acute myocardial infarction patients.

Some options include silicone and polyesters. Silicone is a popular option thanks to its chemical inertness and hypoallergenic properties. However, researchers are considering the impacts of eliminating polymers, though further studies are necessary to determine whether there are notably different health outcomes.

The Importance of Drug Formulation and Integration

The active pharmaceutical ingredient (API) is another crucial component in elution determinations. This is because the body may handle the ingredients differently depending on individual biomarkers and the API’s characteristics. Its molecular structure, weight, and state in the polymer all influence its elution times, especially the initial release.

Burst effects can be an issue, especially when a topical delivery method has poor absorption. This could lead to infection, irritation, and longer treatment durations. This is why the formulation matters so much—it determines stability and dissolution times.

Solubility is another important material property. One study affirmed which quality-testing methods were most viable for a topical cream prescribed for skin conditions. Extracting information about the API was the first step, but the testing procedure needed to ensure it didn’t affect elution rates. The research determined the API’s solubility based on its interaction with the solvent and micellar solution, which correlated with its elution strength.

Researchers strive for a zero-order release, which means elution is steady and predictable. However, it relies on the starting concentration and accurate dosing predictions, meaning the formulation must be repeatable and safe.

From product launches to M&A and manufacturing trends, the MPO Source delivers the medtech news you need twice a week. Subscribe here!

The Manufacturing and Sterilization Process

Developing the formulation is the beginning of the engineering and materials science process, but manufacturing greatly impacts how well the medicine is processed. For example, a 2015 study observed the impact of manufacturing parameters of the stent-coating process, including flow rates, nozzle-to-stent spray droplet travel distance, temperature, and shroud pressure. Even small variances could be detrimental to consistency and quality.

Additionally, pharmaceutical manufacturing could influence elution by altering environmental conditions. Metrics like humidity, air quality, and temperature may change how solvents evaporate or how polymers morph. Experts must know the most detrimental circumstances and how much time they have to rectify the conditions before irreversible changes to elution occur.

When the drug-device combination products are complete, they undergo sterilization. The technique used is important for sensitive precision drugs. Sterilization methods can affect material properties, including elution behavior, so designers should account for methods such as gamma irradiation or ethylene oxide (EtO) early in development. Designers need to select the sterilization strategy early in the process to ensure the formulation and manufacturing environments are suited to it.

The Proof of Regulatory Compliance and Quality by Design (QbD)

Every step in this process influences decision-making, but none are more influential than regulatory standards and industry compliance. Agencies have guidelines for pharmaceutical engineers and manufacturers that outline best practices for QbD. Every stakeholder in the process must respect these principles, as they set expectations and ethical standards for the medicine’s development.

These principles enforce a systematic approach to medical device design rather than relying entirely on final product testing for adherence. The U.S. Food and Drug Administration’s (FDA) 21 Code of Federal Regulations Part 4 outlines current good manufacturing practice requirements for combination products, including expectations for managing their drug, device, and biologic constituent parts.

To apply these ideas, industry experts need to define several criteria. A target product profile is the first. This creates the goal framework for the medicine, outlining the maker’s ideal elution rates, dose, duration, and burst, among other qualities. These critical attributes consider the ingredients’ physical and chemical properties, as well as known interactions with biological factors. These understandings yield further insights, such as which coatings are needed to mitigate adverse reactions and how thick they should be.

Then, materials scientists can communicate with manufacturers to clarify the production expectations and necessities. This may include spray rates or processing temperatures. Without using QbD as a guiding influence in planning, the pharmaceutical development process would omit essential communication channels and transparency that are necessary for creating lifesaving products.

How Drug-Device Combination Products Enhance Predictable Drug Delivery

Consistent elution rates could unlock the future of precision medicine and more advanced therapies. However, the delivery technologies pharmaceutical experts use need more refinement from an engineering and materials science perspective. There are too many influences on these release windows that require a big-picture analysis before the drug begins forming. Researchers who use these guidelines to formulate new drugs could see more reliable elution rates and a brighter future for patient-focused care.

More from this author: 6 Ways Automated Workholding Accelerates Medical Device Machining

Emily Newton is a technology and industrial journalist and the editor-in-chief of Revolutionized. She manages the site’s publishing schedule, SEO optimization, and content strategy. Newton enjoys writing and researching articles about how technology is changing every industry. When she isn’t working, Newton enjoys playing video games or curling up with a good book.