Abstract
Microneedles have been extensively studied for the transdermal delivery of drugs over the last number of decades. They are an attractive means for drug delivery as they are painless and can facilitate the delivery of drugs which would not ordinarily penetrate the skin.
In recent times, additive manufacturing techniques such as stereolithography have been used to fabricate microneedles. However, research to date is limited to solid, hollow and coated microneedles 1, 2 . Stereolithography methods do not lend themselves well to dissolving microneedle fabrication. The traditional method of fabricating dissolving microneedles by micro-moulding techniques has its drawbacks such as variability in the administered dose, non reproducibility, needle breakage upon removing from moulds and long curing times.
Aerosol Jet Printing is an additive manufacturing technique which may overcome these issues due to its high reproducibility and precision. Structures are formed as the instrument creates an aerosol mist and deposits the ink dropwise in a controlled manner onto a substrate, thus building up layers to form a microneedle array. The instrument gives freedom of design, in terms of needle shape and spacing, allows for increased drug loading capacity as no backing layer is present and can print formulations with a wide range of viscosities.
Here we report the manufacture of the first dissolving microneedle array fabricated by Aerosol Jet Printing. The formulation is a mixture containing PVP, trehalose, glycerol and water. The formulation characteristics include a measured viscosity of 3.82 ± 0.22 cP and surface tension of 63.76 ± 0.25 mN/m. The formulation was deposited onto a double sided polished silicon wafer via ultrasonic atomisation. The printed microneedle array consisted of 64 needles which was made up of 75 layers of the deposited formulation. Print times for a full array is less than 150 min. The fabricated needles are printed at temperatures below 50° C, therefore, the technique is suitable for many thermolabile active ingredients.
The potential for the fabricated microneedle arrays to penetrate porcine skin is currently being evaluated. Future work will focus on the inclusion of therapeutic peptide molecules into the microneedle array and the study of the release properties from the array using Franz diffusion cells.
In recent times, additive manufacturing techniques such as stereolithography have been used to fabricate microneedles. However, research to date is limited to solid, hollow and coated microneedles 1, 2 . Stereolithography methods do not lend themselves well to dissolving microneedle fabrication. The traditional method of fabricating dissolving microneedles by micro-moulding techniques has its drawbacks such as variability in the administered dose, non reproducibility, needle breakage upon removing from moulds and long curing times.
Aerosol Jet Printing is an additive manufacturing technique which may overcome these issues due to its high reproducibility and precision. Structures are formed as the instrument creates an aerosol mist and deposits the ink dropwise in a controlled manner onto a substrate, thus building up layers to form a microneedle array. The instrument gives freedom of design, in terms of needle shape and spacing, allows for increased drug loading capacity as no backing layer is present and can print formulations with a wide range of viscosities.
Here we report the manufacture of the first dissolving microneedle array fabricated by Aerosol Jet Printing. The formulation is a mixture containing PVP, trehalose, glycerol and water. The formulation characteristics include a measured viscosity of 3.82 ± 0.22 cP and surface tension of 63.76 ± 0.25 mN/m. The formulation was deposited onto a double sided polished silicon wafer via ultrasonic atomisation. The printed microneedle array consisted of 64 needles which was made up of 75 layers of the deposited formulation. Print times for a full array is less than 150 min. The fabricated needles are printed at temperatures below 50° C, therefore, the technique is suitable for many thermolabile active ingredients.
The potential for the fabricated microneedle arrays to penetrate porcine skin is currently being evaluated. Future work will focus on the inclusion of therapeutic peptide molecules into the microneedle array and the study of the release properties from the array using Franz diffusion cells.
| Original language | English (Ireland) |
|---|---|
| Pages | 50 |
| Number of pages | 1 |
| Publication status | Published - 20 Apr 2022 |
| Event | Perspective in Percutaneous Penetration - La Grande Motte, Montpellier, France Duration: 20 Apr 2022 → 22 Apr 2022 Conference number: 17 https://pppconference.org/ |
Conference
| Conference | Perspective in Percutaneous Penetration |
|---|---|
| Abbreviated title | PPP |
| Country/Territory | France |
| City | Montpellier |
| Period | 20/04/2022 → 22/04/2022 |
| Internet address |