Dissolving microneedles for transdermal drug delivery.

Area of Science:

• Biomaterials Engineering
• Drug Delivery Systems
• Nanotechnology

Background:

• Hypodermic injections pose risks like needle-stick injuries and biohazardous waste.
• Microneedle technology offers a potentially safer and less painful alternative for drug administration.

Purpose of the Study:

• To develop and characterize dissolving microneedles for encapsulation and controlled release of therapeutic molecules.
• To demonstrate both bolus and sustained drug delivery capabilities using this novel microneedle system.

Main Methods:

• Fabrication of microneedles using a centrifugation-based casting process with biocompatible polymers (carboxymethylcellulose, amylopectin).
• Encapsulation of model molecules (sulforhodamine B, bovine serum albumin, lysozyme) within the microneedle structures.
• Evaluation of microneedle insertion into cadaver skin, dissolution rates, and drug retention and activity (lysozyme enzymatic activity).

Main Results:

• Microneedles successfully encapsulated various molecules, with lysozyme retaining 96% activity after 2 months at room temperature.
• The fabricated microneedles were robust enough for skin insertion and dissolved within minutes.
• Achieved bolus delivery via shaft encapsulation and novel sustained delivery over hours to days via reservoir backing.

Conclusions:

• Dissolving microneedles provide a versatile platform for painless drug delivery, suitable for protein biotherapeutics and vaccines.
• The technology enables controlled release kinetics, including sustained delivery, addressing limitations of conventional injection methods.
• This approach eliminates sharp biohazardous waste, enhancing safety and patient compliance in drug administration.