A Chat with Biopharmaceutics Expert, Professor Jennifer Dressman

A Chat with Biopharmaceutics Expert, Professor Jennifer Dressman

Professor Jennifer Dressman is fearless—both in her science and her career. Born and raised in Australia, she holds degrees in pharmacy and a doctorate in pharmaceutics. Having held positions at Burroughs Wellcome and the University of Michigan, College of Pharmacy in the United States, she was offered her dream job as a professor at the Johann Wolfgang Goethe University in Frankfurt, Germany. The only catch? Having to become fluent in German.

I sat down with Prof. Dressman to ask about her research in biopharmaceutics, her vision for using modeling and simulation to enhance drug development, and how she learned to hold her own bantering in faculty meetings in German.

Suzanne Minton: Can you tell us about your path to serving on the faculty at Goethe University?

Jennifer Dressman: I had been serving as an associate professor at the University of Michigan in the College of Pharmacy. In 1992, I was on a sabbatical at the University of Paris, and I was invited to give a seminar at Goethe University in Frankfurt. After the seminar, the professors and I were chatting, and they asked me whether I’d be interested in a professorship in Frankfurt. And I thought that would be great, but there was a catch—I didn’t speak any German.

Then they said that they’d make me a deal: Spend the first year learning German; you won’t have to teach at all. But after that first year, you’ll need to teach all your classes in German!

SM: You’re a professor in pharmaceutics. How you would define this scientific field?

JD: Pharmaceutics embraces the design, manufacture, and quality testing of drug dosage forms both in a physical and biopharmaceutical sense. The dosage forms can include systemic dosage forms (tablets, capsules, intravenous injections, inhaled drugs, etc.) as well as local dosage forms (creams, plasters, implants, etc.).

SM: Can you describe your average day in five words?

JD: I can describe it in three words: Busy, busy, busy!

SM: Concise! [Laughing] I like that. What has been your biggest achievement?

JD: Pioneering the use of bio-relevant media and bio-relevant dissolution testing as a pharmaceutics tool that relates to the in vivo performance of the drug formulation.

SM: So, these tools are physiologically relevant because they can simulate the fed state, the fasted state, different parts of the gastrointestinal tract, etc.?

JD: Exactly. It’s not only about using dissolution media containing surfactants and bile salts. It’s also about the designing the dissolution test to account for factors like the hydrodynamics of the gut and the transit time through its different segments. These factors are not quite so important for rapidly disintegrating dosage forms that are absorbed in the upper small intestine. But if you are designing a dosage form that’s supposed to release a drug over 12-16 hours, then you’d better know what’s going on in the middle and lower part of the gut as well.

Other important parameters in dissolution testing include temperature, volume, pH, gastric emptying time, and the effects of fed/fasted state. We employed a multifaceted approach using in vitro tools, animal models, and clinical studies to optimize the design of bio-relevant dissolution testing.

SM: So you did a lot of work on animal models?

JD: We did. But, my aim was always to design an in vitro tool that could replace animal models because animals are overused in drug research. It’s also why I’m interested in physiologically-based pharmacokinetic and pharmacodynamic (PBPK/PD) modeling because it can help minimize animal testing.

SM: Reducing animal testing is an important goal.

JD: We should use animal models as a last resort to cover those aspects of in vivo drug behavior that we can’t explore using PBPK modeling, in vitro tools, or other in silico tools.

SM: I agree. That makes me think of the three R’s of animal research: replace, reduce, and refine.

JD: Definitely refine. And we can get to reduction. I’m not sure if we can get to complete replacement.

SM: In your development of in vitro tools, do you use in vivo-in vitro correlation (IVIVC) to use in vitro data to make predictions about in vivo drug behavior?

JD: We do. We use PBPK modeling to examine the relationships between in vitro testing and the in vivo performance for various types of drug products. We started by using homegrown PBPK models. But in the last years, we switched to commercial models [like the Simcyp Simulator] because we know that the interest level in the pharmaceutical industry of having to build your own model is quite limited. Also, homegrown models aren’t sophisticated enough to describe all of the situations that we want to cover. It became apparent that it would be wise to switch to the more sophisticated commercial PBPK models. So we’ve been working with those for the last years.

SM: What would you say is your worst trait?

JD: It’s the flipside of one of my best traits, which is persistence. If you’re not careful, persistence can quickly turn into being stubborn.

SM: What do you love most about your job?

JD: My job combines teaching, research, writing papers, and some consulting. This mix helps make me a better all-around scientist. And I teach all aspects of pharmaceutics—that keeps me on my toes! My research focuses on oral dosage forms, but I also teach the sterile techniques, inhalations, creams and ointments, etc.

I love working with colleagues and graduate students who are striving for research excellence. And it’s a pleasure to watch the graduate students develop and become excellent scientists themselves.

SM: What would you change about your job, if anything?

JD: Definitely the pharmacy oral exams. Pharmacy students take oral exams after studying for eight semesters. They get three tries to pass. It’s a pleasure when the students are really good, and they can answer the questions with no problem. But it’s heartbreaking to fail students who really aren’t up to it, even though they’ve been studying pharmacy for 8, 10, or even 12 semesters. But we have a commitment to the public to only graduate competent pharmacists.

SM: If you weren’t in academia, what job would you like to do?

JD: This is a tough question because being in academia in Germany is a great job. We have freedom to choose what research we pursue because of our good technical support, and because we have a certain budget at our disposal.

If I wasn’t an academic in Germany, I wouldn’t mind trying my hand at scientific journalism. Trying to distill a scientific area into something that’s easy to understand for the lay public is an interesting area.

SM: It’s a challenge I enjoy.

JD: It’s a huge challenge. I sometimes have trouble trying to explain complicated biopharmacy principles to undergraduates. So doing it for the lay public would be the next level of challenge I could take.

SM: What challenges in pharmaceutical sciences do you see being important over the next decade?

JD: The number one challenge will be to develop new antibiotics and to establish better methods of avoiding development of antibiotic resistance. It also would be great to find injection-free ways to deliver biologicals.

SM: That’s a good one.

JD: Yeah, that’s really a tough nut to crack. Another no-brainer is trying to improve efficiency in new drug development. Selecting better compounds and having fewer failures in a clinic is always the goal. That’s been a challenge for the last 20 years, and it will continue to be a challenge going forward.

Another one is to maintain effective drug supply at an affordable cost on a global basis. So that means having effective generics and biosimilars, and making drugs affordable for everybody. The affordability of medicine and healthcare is an issue in every country.

And we need to do a better job with patient education, so that they are able to adhere to their dosing regimens. That’s also a huge problem. In fact, the number one problem is to get the patient to actually use their drugs. The number two problem is to get patients to consistently use them as they’re supposed to. I think many therapeutic failures are due to patients not realizing the importance of adhering to the dosing regimen.

SM: So the drug itself might be safe and effective, but it “fails” because of medication non-adherence?

JD: Yes. We don’t adequately communicate to the patient that how and when you take a drug is just as important as whether you take it.

SM: So these are some of the challenges that the field faces over the next decade. In your opinion, what’s going to offer the biggest opportunities in the future?

JD: Well, part of the reason I joined the Simcyp SAB [scientific advisory board] is because I believe the integration of PBPK/PD modeling across the board in both development and regulatory applications is the key to future success. If we do this, it will lead to safer use of medicines in all sub-populations: males and females, patients from different ethnicities, old and young patients, fast and slow metabolizers, and for oral drugs, the fed and fasted states.

Since you can’t perform all of those clinical studies before the new drug application is approved, it’s a great idea to use PBPK/PD modeling to explore what would happen in the different patient groups to see who should be taking the drug at what dosage level and how often. This information will help doctors prescribe the drug correctly for any and every patient that they treat. That’s a really important thing.

I’m also interested to serving on the SAB because it’s a chance to work with leaders in the [PBPK] field. I’ve had a “narrow slice” of working with the Simcyp Simulator. I understand the global picture in broad brushstrokes, but I’ve mostly worked with oral dosage forms.

Now I have this opportunity to communicate with the Simcyp Simulator experts more often and on a variety of issues. I want to learn more about it. It’s like I’ve been tapping the toe of the elephant, but there’s a whole animal out there! I want to be better versed in the whole Simulator so that I can better understand and utilize it.

SM: We are grateful for your support! Thank you for talking with me.

More information about Professor Dressman’s research can be found at her university website.

To learn more about leveraging modeling and simulation technology to enhance all phases of the drug development process, please read this article in Contract Pharma.

Suzanne Minton

About the Author

Suzanne Minton

Scientific Communications Manager, Certara

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Dr. Suzanne Minton is the scientific communications manager at Certara. She helps develop the science-focused, value-oriented content that our customers go wild for. When she's not writing about the hottest problems in drug development, Suzanne enjoys spending time with her husband and two young children.