Microneedle arrays formed from polymer films
The present invention provides for transdermal delivery devices having microneedle arrays, as well as methods for their manufacture and use. In one embodiment, a transdermal delivery device is provided. The transdermal delivery device includes a polymer layer which has microneedles projecting from one of its surfaces. The microneedles are compositionally homogenous with the polymer base layer.
1. A method of manufacturing a transdermal drug delivery device having a microneedle array, comprising:
providing a substrate;
applying a polymer solution to the substrate to form a base layer;
disposing an exposed surface of the base layer with a textured surface having elevated points protruding therefrom such that the elevated points contact the exposed surface of the base layer;
distancing the textured surface from the exposed surface of the base layer such that the elevated points draw out tube-like projections from the exposed surface of the base layer, wherein the textured surface is distanced from the exposed surface of the base layer at a rate of about 0.1 mm/s to about 100 mm/s;
drying the base layer having the tube-like projections to form microneedles, wherein drying includes exposing the base layer to reduced pressure; and
trimming the microneedles to a predetermined length and tip-bevel to form the transdermal drug delivery device.
2. The method of claim 1 , wherein the microneedles are hollow.
3. The method of claim 1 , wherein the microneedles are regularly spaced on the exposed surface of the base layer.
4. The method of claim 1 , wherein the step of drying is concurrent with the step of distancing.
5. The method of claim 1 , wherein the step of drying can include one of blowing, baking, or combinations thereof.
6. The method of claim 1 , wherein the substrate is not incorporated into the transdermal drug delivery device.
7. The method of claim 1 , wherein the substrate is a backing layer.
8. The method of claim 1 , wherein an active agent is included in the polymer solution.
9. The method of claim 8 , wherein the composition containing the active agent includes a polymer which is different than the polymer in the base layer.
10. The method of claim 1 , further comprising loading the microneedles with a composition containing an active agent.
11. The method of claim 10 , wherein the polymer included in the active agent composition has solubility characteristics that differ from the polymer composing the micro needles.
12. The method of claim 1 , wherein the microneedles are dried or baked subsequent to the loading thereof with an active agent composition.
13. The method of claim 1 , further comprising cutting the base layer to form the transdermal drug delivery device.
14. The method of claim 1 , wherein the microneedles are solid.