Egg Microneedle for Transdermal Delivery of Active Liraglutide

Liraglutide, a human glucagon-like peptide-1 (GLP-1) analog, is promising for safely treating type 2 diabetes mellitus (T2DM), compared to insulin, by significantly reducing the risk of glucose-dependent hypoglycemia. Concerns related to injection prevent T2DM patients from taking liraglutide regularly, even though once-a-day subcutaneous (SC) injections. Dissolving microneedles (DMNs) are promising substitutes for SC injection and for improving patient convenience. However, there are two fundamental limitations: the low drug delivery due to incomplete insertion and loss of drug activity during DMN fabrication. Here, it is shown that an egg microneedle (EMN) designed with three functional layered structures can maintain the maximum activity of the loaded compound during DMN fabrication and deliver it completely into the skin, with the base layer allowing the complete delivery of liraglutide, and the shell layer maintaining the drug activity by mimicking the role of albumin in eggs. In a diabetic mouse model, liraglutide administration via EMN exhibited similar effect when compared to that of injection. Therefore, EMN-mediated liraglutide administration is a good potential option for replacing liraglutide injections in T2DM treatment.