Biodegradable Mouth Patch Delivers Peptide Drugs Without Needles

Most peptide-based drugs — including widely used medications like semaglutide for weight management and diabetes — must be injected because the gut rapidly degrades them and their large molecular size limits absorption through biological barriers. Finding needle-free alternatives that work reliably remains a major challenge in drug delivery science.

Researchers at ETH Zurich built on a prior concept of a bioinspired suction patch that physically adheres to the inner cheek (buccal mucosa) to deliver peptides transbuccally. The innovation here was replacing non-degradable silicone materials with biodegradable copolyesters, addressing sustainability concerns around medical device disposal. A scalable mold-casting process was used to thermally crosslink the new polymers into functional patches.

Key results were promising. In ex vivo porcine buccal tissue experiments, the biodegradable patch combined with a chemical permeation enhancer significantly increased permeation of a poorly permeable dye — confirming drug delivery functionality. In live beagle dog studies, semaglutide (4.11 kDa) showed substantially improved bioavailability compared to a commercial oral tablet, with only 10 minutes of patch application needed. Bremelanotide (1.03 kDa) reached 26% relative bioavailability versus subcutaneous injection.

The implications for longevity-relevant therapeutics are notable. Peptide drugs targeting metabolic health, hormone regulation, and body composition could become more accessible and patient-friendly if needle-free delivery achieves comparable efficacy. Semaglutide in particular has garnered significant interest for its metabolic and potentially longevity-related effects.

Caveats include the early-stage nature of the research, animal model limitations, and the fact that 26% bioavailability relative to injection still represents a meaningful gap. Commercial translation will require further safety, tolerability, and human clinical data.