Many drugs, especially those that are poorly absorbed in the stomach and small intestine, require delivery to the distal intestine or colon in order to achieve the desired therapeutic effect. However, the acidic environment of the stomach and the enzymatic degradation in the small intestine can cause instability and low bioavailability of the drug.
One approach to overcome this challenge is the use of enteric-coated capsules, which can protect the drug from the harsh conditions of the upper GI tract and ensure delivery to the lower intestines. These capsules have a pH-sensitive coating that dissolves in the alkaline environment of the small intestine, releasing the drug in the distal intestine or colon where it can be absorbed.
The development of stable and efficient oral delivery systems for aqueous suspensions to the distal intestine or colon is essential for improving the bioavailability and therapeutic efficacy of drugs that require targeted delivery to these regions of the GI tract.
In a recent paper, Colonic Delivery of Aqueous Suspensions Using 3D Printed Capsules, the researchers took a novel approach to colonic delivery of an aqueous suspension. They designed a capsule with a unique water-insoluble body and lid combined with a water-soluble locking cap. They combined mechanical, in vitro dissolution testing with in vivo imaging to demonstrate that the capsules released their content in the later stages of the GI tract.
Mechanical, in vitro dissolution testing was accomplished by Pion’s novel Surface Dissolution Imaging (SDI2) instrument which takes real-time UV images and video of an immobilized capsule in a field of flow, allowing the researchers to study the integrity and dissolution of the capsules over time and in different pH and solvent conditions to establish a release profile. “The results demonstrated the potential of the capsule to transport and protect an aqueous solution across the early GI and release its encapsulated content at the late intestine/colon.”
Contact us today to learn more about our novel SDI2 surface dissolution imaging system.
