Colonic Delivery of Aqueous Suspensions Using 3D Printed Capsules

Abstract

The efficient oral delivery of aqueous suspensions to the distal intestine or the colon is a significant pharmaceutical challenge because few capsules are sufficiently stable to protect aqueous suspensions while enduring the conditions during gastrointestinal (GI) transit. Herein, a design is introduced for enteric capsules intended to transport aqueous media to the distal part of the intestine. These capsules consist of a water‐insoluble body and lid that encapsulate the solution and are held together by an enteric water‐soluble locking cap. The capsules are fabricated using a combination of 3D printing methods enabling design control and precision. Mechanical testing reveals that the capsules are soft, strong, and could withstand forces generally encountered during GI transit. The capsules also exhibit resistance to proton diffusion, which is important for protecting their content from gastric acidity. In vitro dissolution assessments and in vivo imaging studies demonstrate that the capsules release their content in the later stages of the GI tract. This unique design has potential applications in targeted delivery of aqueous suspensions of live bacterial suspensions to the colon, offering a promising platform for therapeutic interventions and research in gut health.