Prodrugs are “inactive” compounds that are metabolized – normally via enzymatic action - in the body to produce “active” therapeutic agents. Prodrugs are used to overcome specific limitations of the active therapeutic drug, such as poor solubility, limited bioavailability, undesirable side effects and/or to improve drug delivery, targeting, and overall efficacy.
However, testing and understanding prodrugs in vitro presents unique challenges. Traditional drug testing typically focuses on the end therapeutic compound: Does it behave as expected? How does it perform, release, and clear from the body? For prodrugs, there is an added layer of complexity. Researchers must also consider: How does the prodrug convert into its active form? When does this occur? And how does this transition impact the drug's release profile, behavior, speed, and overall efficacy?
Mimicking this enzymatic conversion in vitro in a functional and biorelevant way is essential to understanding a drug's release mechanisms, performance, and therapeutic effect.
Scientists need reliable methods to compare prodrug formulations in vitro, yet there are no established methods which effectively examine how a prodrug transitions from its inactive to its active form, and how this process influences the release profile in a dynamic, biorelevant setting.
In our recent application note, Conserving biorelevant enzymatic activity during in situ analysis of biotransformable drugs, we explored adding active enzymes to the artificial extracellular matrix we use in our SCISSOR platform to simulate subcutaneous injection conditions, in vitro. In this work, we were able to successfully incorporate active enzymes covering an experimental range on SCISSOR, allowing us to study specific subcutaneous prodrug formulations in vitro in a functional, bio-relevant assay, allowing more in depth understanding of the product and its behavior before reaching in vivo studies.
If you’re interested to learn more about testing prodrug formulations in vitro, download our app note or reach out to a member of the Pion team!
