Intra-luminal focused ultrasound for augmentation of gastrointestinal drug delivery
The recent article by Schoellhammer et al., “Ultrasound-mediated gastrointestinal drug delivery” primarily addresses practical limitations in drug delivery for medical management of inflammatory bowel disease (IBD), and presents pre-clinical data demonstrating that intra-luminal, sub-ablative focused ultrasound (FUS), delivered via a trans-rectal transducer, can overcome some of these limitations (1). The clinical application and benefit of such a device is clear. Currently, outpatient treatment of proctitis/proctosigmoiditis can involve patient self-administration of an anti-inflammatory drug enema (e.g., mesalamine, hydrocortisone) that is ideally retained overnight to maximize medication absorption (2,3). Compliance with this regimen can be highly challenging for patients with active colitis as symptoms include urgency and frequent bowel movements. Methods to improve the efficiency of drug transit/tissue penetration and thus decrease both the frequency of enema administration as well the required mucosal exposure time to the enema would likely be welcomed by patients. Improved compliance on this more rapid regimen could theoretically help to mitigate the long-term sequelae of under-treated disease. An important question raised and discussed in this article is how to expand upon this particularly well-suited clinical application to improve targeted drug delivery (TDD) to other areas of the gastrointestinal (GI) tract.