Silk fibroin hollow microneedle system for sustained transdermal administration of liraglutide: development and characterization

Liraglutide demonstrates a glucose-dependent hypoglycemic mechanism with significant therapeutic potential for type 2 diabetes mellitus. This study developed a hollow microneedle system featuring dual drug loading mechanisms cavity encapsulated and matrix embedded to achieve sustained release of liraglutide. The cavity structure avoids direct contact between the drug and the silk fibroin shell, as well as the binding state transition caused by hydrophobic interactions. The shell has piercing mechanical properties and provides swelling diffusion channels. The pharmacokinetic data in SD rats showed that the release time of hollow microneedles was 25 h, the peak concentration time was 10 h, and the relative bioavailability exceeded 80 %. The peak concentration is 19.83 ± 1.85 μg/mL, indicating a smaller diffusion flux. It helps to achieve controlled long-term release and reduce the frequency of administration. The release amount of a single microneedle is 0.3 mg, and two patches per day can meet the demand. This hollow microneedle design establishes a promising platform for transdermal delivery of biopharmaceuticals, potentially enabling non-invasive glucose regulation in diabetes management.