Prof. Alessandra Maroni, PhD
Associate Professor at the School of Pharmacy, University of Milan. Her main research interests are in the area of oral delivery and formulation. She is a peer reviewer for the leading journals in the field, serves on the Editorial Advisory Board of Journal of Pharmaceutical Sciences and is a member of the scientific societies CRS Italy Chapter, AFI, ADRITELF and SCI. She has authored over 65 publications, including journal articles, patent applications and book chapters, and more than 100 conference presentations.
Time-Based Approaches to Oral Colon Delivery of Drugs
Alessandra Maroni, Andrea Gazzaniga
Oral colon delivery has been drawing interest for over three decades, particularly because of the need for improved pharmacological treatment of Inflammatory Bowel Disease (IBD). In addition, it still holds promise as a strategy for non-invasive administration of biological drug molecules having poor stability and permeability in the upper gastrointestinal tract. Colon delivery via the oral route has been sought by leveraging a range of inherent physiological variables, such as pH, microbiota and luminal pressure, to trigger release when the target site is reached.
Alternatively, approaches relying on small intestinal transit time have been pursued, where formulations incorporating a predetermined lag phase in their release patterns are used. While this lag phase is programmed so as to cover the entire time span the dosage form takes to move from the duodenum down to the caecum, an outer enteric coating is required to circumvent its highly variable residence in the stomach. The delay phase starting on gastric emptying has been attained through functional polymer coatings or plugs that control the onset of release based on differing mechanisms, such as primarily water swelling, dissolution/erosion, rupture on expansion or increased permeability.
In this presentation, the rationale and main design strategies behind time-dependent approaches to oral colon delivery are reviewed and discussed.