Researchers examine how changes in the gut – including those that result from posture – affect drug bioavailability
Stephanie Sutton | | 2 min read | News
Researchers at Johns Hopkins University and Johns Hopkins School of Medicine have been delving into the complicated workings of the stomach – specifically, trying to gain a better understanding of what happens after we swallow a pill (1).
“The stomach is a very complex chemical and biomechanical environment. The rate at which an orally ingested pill will dissolve within is a function of many factors, including what we have eaten, our posture, and whether we have some condition that impairs our stomach function,” explains Rajat Mittal, co-author of the study and a professor of mechanical engineering at Johns Hopkins University.
According to Mittal, current methods for testing oral pill dissolution employ a device that does not accurately mimic what happens in the stomach. To address that limitation, Mittal and colleagues spent three years developing an in-silico stomach simulator – aptly named StomachSim – that leans on earlier models of cardiovascular flow, as well as on the anatomy and morphology of the stomach.
“Using StomachSim, we realized that we could easily model the effect of posture on drug dissolution and gain some interesting results,” says Mittal. In fact, the research team discovered that changes in posture can affect the release of the API from the pill into the duodenum by 83 percent – one of the most surprising outcomes of the work. “Our results showed that the effect of posture may even be larger than that of gastroparesis – a condition in which the grinding movement of the stomach is impaired.”
The tool requires immense amounts of computing time; each simulation must be run in parallel on thousands of computer processors for over a week. Nevertheless, the team see promise in their work and are now exploring other applications for StomachSim; for example, understanding how the stomach processes different foods, researching stomach conditions associated with diabetes and enteric infections, or even adapting the model to guide gastric surgery.
With plenty of past experience working on the biomechanics and fluid dynamics associated with other organ systems, Mittal had come to recognize a dearth of bioengineering research into the stomach. “The work on drug dissolution was, in some sense, an easy entry point into this arena compared with modeling the digestion of food,” he explains.
- JH Lee et al., Physics of Fluid, 34 (2022). DOI: 10.1063/5.0096877.