Method of molding for microneedle arrays

A method of manufacturing a molded microneedle array comprising:

• providing a negative mold insert characterized by a negative image of microneedle topography wherein at least one negative image of a microneedle is characterized by an aspect ratio of between about 2 to 1 and about 5 to 1;
• transferring the negative mold insert into an injection molding apparatus, wherein the negative mold insert is exposed and defines a structured surface of a negative mold cavity;
• heating the negative mold cavity to a temperature of more than about 10 degrees centigrade above the softening temperature of a moldable plastic material;
• heating the moldable plastic material to at least the molten temperature of the moldable plastic material in a chamber separate from the negative mold cavity;
• injecting the molten plastic material into the heated negative mold cavity,
• allowing the molten plastic material to fill at least about 90 percent of the volume of the negative indentations defined by the negative mold insert;
• cooling the molten plastic material to a temperature at least below the softening temperature of the moldable plastic material;
• and
• detaching the molded microneedle array from the negative mold insert.

A method of manufacturing a negative mold insert used for preparing molded microneedle arrays comprising:

• providing a positive mold master member characterized by microneedle topography wherein at least one microneedle is characterized by an aspect ratio of between about 2 to 1 and about 5 to 1;
• electroforming a negative mold insert around the positive mold master;
• and
• detaching the negative mold insert from the positive mold master member.