Tip-loaded microneedle arrays for transdermal insertion

Abstract

A method of forming a microneedle array can include forming a microneedle array that has one or more bioactive component. The microneedle array can include a base portion and plurality of microneedles extending from the base portion, and the one or more bioactive components are present in a higher concentration in the plurality of microneedles than in the base portion.

We claim: 
     
         1 . A method of delivering one or more bioactive materials via transdermal insertion into a patient comprising applying a dissolvable microneedle array for transdermal insertion into a patient comprising:
 one or more bioactive materials;   a base portion;   a plurality of microneedles extending from the base portion, wherein the one or more bioactive materials are present in a higher concentration in the plurality of microneedles than in the base portion,   wherein the one or more bioactive materials comprise at least one viral vector or doxorubicin.   
     
     
         2 . The method of  claim 1  wherein the patient has a cutaneous tumor or a tumor metastatic to the skin, or any combination thereof. 
     
     
         3 . The method of  claim 2 , wherein the cutaneous tumor is basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, melanoma, or a combination thereof. 
     
     
         4 . The method of  claim 2 , wherein the tumor metastatic to skin is breast cancer, melanoma, or any combination thereof. 
     
     
         5 . The method of  claim 1 , wherein substantially all of the one or more bioactive materials are located in the plurality of microneedles so that the base portion is substantially formed without any bioactive materials contained therein. 
     
     
         6 . The method of  claim 5 , wherein the one or more bioactive materials are locally concentrated in the plurality of microneedles so that the one or more bioactive materials are generally present only in an upper half of respective microneedles in the microneedle array. 
     
     
         7 . The method of  claim 5 , wherein the plurality of microneedles are pre-formed to have a shape that comprises a first cross-sectional dimension at a top portion, a second cross-sectional dimension at a bottom portion, and a third cross-sectional dimension at an intermediate portion, wherein the intermediate portion is located between the top portion and the bottom portion, and the third cross-sectional dimension is greater than the first and second cross-sectional dimensions. 
     
     
         8 . The method of  claim 7 , wherein the one or more bioactive materials are substantially concentrated in the area at or above the intermediate portion. 
     
     
         9 . The method of  claim 8 , wherein each microneedle generally tapers to a point above the intermediate portion and each microneedle generally tapers to a smaller cross-sectional dimension below the intermediate portion. 
     
     
         10 . The method of  claim 3 , wherein each microneedle comprises a plurality of layers of dissoluble biocompatible material. 
     
     
         11 . The method of  claim 10 , wherein the dissoluble biocompatible material is carboxymethylcellulose. 
     
     
         12 . The method of  claim 3 , wherein the one or more bioactive component comprises at least two different bioactive material. 
     
     
         13 . The method of  claim 1 , wherein the at least one viral vector comprises an adenovector.