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Phase-transition Microneedle Patch Technology

Microneedles offer a promising solution for transdermal drug delivery. Tiny needles can penetrate the most difficult to penetrate skin layers, creating diffusion channels for lipid-sparing molecules without causing skin damage or pain. Phase-change microneedle patches consist of an array of microneedles loaded with biologically active agents such as drugs and a drug-free support plate. The microneedle array loaded with a bioactive agent may include a thin layer of the same polymeric material containing the same drug between the microneedle and the drug-free plate.

Images of PTM patches.Fig. 1 Images of PTM patches. (Yang et al., 2017)

About Phase-transition Microneedle Patches

Phase change microneedle patches utilize a solvation-activated release mechanism and non-reactive microcrystalline cross-linking to overcome, once and for all, the difficulty that the micropore created by the needle tip cannot be sealed immediately after peeling off the microneedle patch, enabling efficient, accurate and safe transdermal delivery of proteins and peptides. Phase change microneedle patches can be completely removed from the application site after administration without leaving the needle tip material in the skin.

Potting Procedure and Mold Design

The casting preparation procedure for phase-conversion microneedle patches must meet two requirements: the polymer solution can be infused into the micropores of the mold; and the needle shape of the microneedle must not be damaged after drying.

In order for the polymer solution to enter the micropores smoothly, certain forces must be applied to the solution, commonly centrifugal force and liquid hydrostatic pressure. In order to keep the needle shape intact, the drying process must allow the water to evaporate from the needle body part rather than the back, otherwise it will make the needle body shrink and deform.

Phase-transition Microneedle Patches Service

The process of manufacturing microneedle patches consists of several steps, including:

a) Casting (applying and pasting) of an aqueous solution of the drug-carrying polymer onto a micro-hole array mold made of porous material;

b) Drawing the viscous polymer solution into the micropores by applying a vacuum to the back of the mold;

c) Freezing and thawing the cast polymer solution to induce gelation;

d) Drying the cast microneedle sheet.

For pilot production, our team moved from the already successful large-format molding to more efficient rapid 3D printing. At room temperature or lower, hundreds of microneedle patches can be printed in less than 1 minute without physical or reactive hazards. In addition, microneedle tips can be made in a variety of shapes to meet the appropriate application and improve bioavailability.

Applications for Phase-transition Microneedles

Phase-transformed microneedle patches can be used for transdermal delivery of a wide range of therapeutic agents, including proteins, peptides, genes and RNA, subunit vaccines, and cosmetic substances. Proteins and peptides with molecular weight less than 200,000 can also be delivered transdermally using this microneedle system, such as insulin, calcitonin, erythropoietin, etanercept, GLP-1, GM-CSF, interferon, factor VIII, interleukin, HSF, PEG-IFNα2b, IFN, PTH1-84, CD154, BMP, IL-15 LIF, IL-2, rHGH, EGF, FGF, TGF-β1, VEGF, PDGF, ECGF, NGF, BDGF, BDGF-A, TPA, antibodies, agglutination factor VIII, genetic factor IX, immunoglobulins, SDFs, activator protein C.

If you are interested in our technology and would like to communicate and consult with us more, please feel free to contact us and we will customize our technical support for you.


  1. Yang, S., et al. (2017). Phase-transition microneedle patch for efficient transdermal delivery of bio-medicines. Journal of Controlled Release, 259, e127-e128.
Please note: Our products and services are not intended to be used directly in diagnostic or therapeutic procedures.
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