Mussel-inspired biphasic microneedle patch for long-acting hypothyroidism treatment

Area of Science:

• Biomaterials Science
• Endocrinology
• Drug Delivery Systems

Background:

• Hypothyroidism requires lifelong levothyroxine sodium (LT4) therapy, typically via oral administration.
• Oral LT4 faces challenges including variable absorption and poor patient adherence.
• Existing treatments necessitate daily dosing, impacting quality of life.

Purpose of the Study:

• To develop and evaluate a novel microneedle (MN) patch for sustained and patient-friendly hypothyroidism management.
• To assess the release kinetics and in vivo efficacy of LT4 delivered via MN patches.
• To investigate the feasibility of extended-interval LT4 delivery.

Main Methods:

• Fabrication of biphasic MN patches with LT4 microcrystals and a bioadhesive hydrogel backing.
• In vitro drug release studies over 9 days.
• In vivo pharmacokinetic evaluation in hypothyroid rat models.
• Preliminary tolerability and acceptability assessment in healthy volunteers.

Main Results:

• The MN patches demonstrated sustained, first-order LT4 release in vitro for 9 days.
• A single MN patch application in rats maintained therapeutic LT4 levels for approximately 6 days with high bioavailability.
• Placebo MN patches showed high insertion efficiency, good tolerability, and user acceptability in humans.

Conclusions:

• Mussel-inspired microneedle patches offer a promising strategy for sustained intradermal delivery of levothyroxine sodium.
• This approach addresses limitations of oral LT4 therapy, potentially improving patient adherence and convenience.
• Further clinical studies are warranted to confirm long-term safety and efficacy in hypothyroid patients.