PhD Thesis Defense Notification – Amy Wood-Yang – December 2

Title: Microneedle Patches and Self-Pressurizing Oral Capsules for Needle-Free Drug Delivery

Time and Date: 10 a.m. December 2

Location: ES&T L1120 and Zoom (https://gatech.zoom.us/j/91208504110)

Advisor: Mark Prausnitz

Committee:
Marcus Cicerone (Chemistry), Ravi Kane (ChBE), Hang Lu (ChBE), Krishnendu Roy (Vanderbilt University)

This thesis focuses on innovative drug delivery systems using microneedle (MN) patches and self-pressurizing capsules for needle-free administration. In the first part, core-shell MN patches were developed to enable self-boosting delivery of multiple vaccine doses, addressing challenges like vaccine storage and accessibility. Our manufacturing process improved upon existing technology to minimize vaccine exposure to heat and organic solvents, achieving a 4-week delayed release and preserving tetanus toxoid activity. The second part addresses rapid drug delivery needs, such as pain management, with a dissolvable MN patch designed for faster drug release. By incorporating sodium bicarbonate in the MN formulation, MN dissolution in skin increased by 60%, enabling a 10-second wear time for ~24 µg lidocaine delivery, above the analgesic threshold. This patch offers quick administration for acute conditions and can accommodate various drug solubilities. The third part focuses on overcoming gastrointestinal tract barriers to enable oral delivery of biologics. The design of an engineered self-pressurizing oral capsule was improved by adding enteric coating to enable its passage through gastric fluids. The enteric coating delayed drug delivery for at least 30 minutes in gastric fluids, followed by fast drug release upon transfer to intestinal fluid. Next, we reduced the water content of the capsules to prevent capsules from pre-reacting to enable longer shelf-life stability. Reducing water content of the excipients and air inside the capsule allowed for a prolonged shelf-life stability of 3 days (compared to < 1 day previously). The improvements made to the capsule design enable future translation to larger in vivo models and eventual clinical application.