Method of manufacturing solid solution perforator patches and uses thereof
Methods for fabricating and manufacturing solid solution perforators (SSPs) using sharp metal or glass needles and/or subsequent molding and use are described. The methods entail making microneedles by various precision machining techniques and micromold structures from curable materials. Various designs of patch, cartridge and applicator are described. Also described are methods for adjusting the microneedle mechanical strength using formulation and/or post-drying processes.
1. A method of manufacturing a microneedle array, the method comprising:
(a) preparing a positive master mold comprising a plurality of microneedles penetrating through a defining plate to extend from a bottom surface thereof, wherein the plurality of microneedles are spaced from one another at a predetermined distance;
(b) individually adjusting at least some of the plurality of microneedles by an actuator array individually moving the at least some microneedles through the defining plate to extend different distances from the bottom surface thereof, thereby providing a desired surface contour to the master mold;
(c) preparing a negative mold having a negative surface contour that is the reverse of the desired surface contour of the positive master mold by shaping a curable gel or thermoplastic material against the bottom surface of the defining plate having the adjusted microneedles;
(d) preparing a microneedle array having a surface contour that is the reverse of the negative surface contour of the negative mold by shaping a dissolvable polymer against the negative mold; and
(e) drying the microneedle array.
2. The method of claim 1 , wherein the curable gel or thermoplastic material is uncured silicone.
3. The method of claim 1 , wherein the curable gel or thermoplastic material is polydimethylsilozane (PDMS).
4. The method of claim 1 , wherein the dissolvable polymer is a hydrogel.
5. The method of claim 4 , wherein the hydrogel comprises sodium carboxymethyl cellulose (SCMC).
6. The method of claim 1 , wherein the dissolvable polymer holds a selected drug.
7. The method of claim 1 , further comprising applying a vacuum, centrifugal, or compressive force to the negative mold to fill the negative mold with the dissolvable polymer and/or with a selected drug.
8. The method of claim 1 , further comprising separating the dried microneedle array from the negative mold.
9. The method of claim 1 , wherein the method further comprises casting an adhesive layer between microneedles of the microneedle array.
10. The method of claim 1 , wherein the method further comprises incorporating vitamin C into the dissolvable polymer.
11. The method of claim 1 , wherein the method further comprises creating a micro-hole at a location through the negative mold.
12. The method of claim 1 , wherein said shaping of the curable gel or thermoplastic material is conducted either by casting or by dipping.
13. A method of manufacturing a microneedle array system, the method comprising:
(a) manufacturing a microneedle array according to the method of claim 1 ; and
(b) mounting the microneedle array in a cartridge for delivery to skin.
14. The method of claim 13 , wherein the cartridge is in association with an injector.