Intradermal delivery of substances

Abstract

A method for administration of a substance into the dermis of a mammal is disclosed. The method involves administration into the dermis by injection which results in improved systemic absorption relative to that obtained upon subcutaneous administration of the substance. The substance administered may be a growth hormone, a low molecular weight heparin or a dopamine receptor agonist.

What is claimed is:  
     
         1 . A method for directly delivering a substance into an intradermal space within mammalian skin comprising administering the substance through at least one small gauge hollow needle having an outlet with an exposed height between 0 and 1 mm, said outlet being inserted into the skin to a depth of between 0.3 mm and 2 mm, such that delivery of the substance occurs at a depth between 0.3 mm and 2 mm.  
     
     
         2 . The method according to  claim 1  wherein the delivered substance has improved pharmacokinetics compared to pharmacokinetics after subcutaneous injection.  
     
     
         3 . The method of  claim 1  wherein the injecting is through at least one small gauge hollow needle.  
     
     
         4 . The method of  claim 1  wherein the needle has an outlet with an exposed height between 0 and 1 mm.  
     
     
         5 . The method of  claim 1  wherein injecting comprises inserting the needle to a depth which delivers the substance at least about 0.3 mm below the surface to no more than about 2 mm below the surface.  
     
     
         6 . The method of  claim 1  wherein administering comprises inserting the needle into the skin to a depth of at least about 0.3 mm and no more than about 2 mm.  
     
     
         7 . The method of  claim 2  wherein the improved pharmacokinetics is increased bioavailability of the substance.  
     
     
         8 . The method of  claim 2  wherein the improved pharmacokinetics is a decrease in T max .  
     
     
         9 . The method of  claim 2  wherein the improved pharmacokinetics is an increase in C max .  
     
     
         10 . The method of  claim 2  wherein the improved pharmacokinetics is a decrease in T lag .  
     
     
         11 . The method of  claim 2  wherein the improved pharmacokinetics is enhanced absorption rate.  
     
     
         12 . The method of  claim 1  wherein the substance is administered over a time period of not more than ten minutes.  
     
     
         13 . The method of  claim 1  wherein the substance is administered over a time period of greater than ten minutes.  
     
     
         14 . The method of  claim 1  wherein the substance is a protein.  
     
     
         15 . The method of  claim 1  wherein the substance is administered at a rate between 1 nL/min. and 200 mL/ min.  
     
     
         16 . The method of  claim 1  wherein said substance is a hormone.  
     
     
         17 . The method of  claim 16  wherein said hormone is selected from the group consisting of insulin and PTH.  
     
     
         18 . The method of  claim 1  wherein said substance is a nucleic acid.  
     
     
         19 . The method of  claim 1  wherein the substance has a molecular weight of less than 1000 daltons.  
     
     
         20 . The method of  claim 1  wherein the substance has a molecular weight greater than 1000 daltons.  
     
     
         21 . The method of  claim 1  wherein said substance is hydrophobic.  
     
     
         22 . The method of  claim 1  wherein said substance is hydrophilic.  
     
     
         23 . The method of  claim 1  wherein the needle(s) are inserted perpendicularly to the skin.  
     
     
         24 . A method of administering a pharmaceutical substance comprising injecting the substance intradermally through one or more microneedles having a length and outlet suitable for selectively delivering the substance into the dermis to obtain absorption of the substance in the dermis.  
     
     
         25 . The method of  claim 24  wherein absorption of the substance in the dermis produces improved systemic pharmacokinetics compared to subcutaneous administration.  
     
     
         26 . The method of  claim 25  wherein the improved pharmacokinetics is increased bioavailability.  
     
     
         27 . The method of  claim 25  wherein the improved pharmacokinetics is decreased T max .  
     
     
         28 . The method of  claim 25  wherein the improved pharmacokinetics is an increase in C max .  
     
     
         29 . The method of  claim 25  wherein the improved pharmacokinetics is a decrease in T lag .  
     
     
         30 . The method of  claim 25  wherein the improved pharmacokinetics is an enhanced absorption rate.  
     
     
         31 . The method of  claim 24  wherein the length of the microneedle is from about 0.5 mm to about 1.7 mm.  
     
     
         32 . The method of  claim 24  wherein the microneedle is a 30 to 34 gauge needle  
     
     
         33 . The method of  claim 24  wherein the microneedle has an outlet of from 0 to 1 mm.  
     
     
         34 . The method of  claim 24  wherein the microneedle is configured in a delivery device which positions the microneedle perpendicular to skin surface.  
     
     
         35 . The method of  claim 24  wherein the microneedle needle is contained in an array of microneedles needles.  
     
     
         36 . The method of  claim 35  wherein the array comprises 3 microneedles.  
     
     
         37 . The method of  claim 35  wherein the array comprises 6 microneedles.  
     
     
         38 . A microneedle for intradermal injection of a pharmaceutical substance, wherein the microneedle has a length and outlet selected for its suitability for specifically delivering the substance into the dermis.  
     
     
         39 . The microneedle according to  claim 38  wherein the length of the microneedle is from about 0.5 mm to about 1.7 mm.  
     
     
         40 . The microneedle of  claim 38  which is a 30 to 34 gauge needle  
     
     
         41 . The microneedle of  claim 38  which has an outlet of from 0 to 1 mm  
     
     
         42 . The microneedle of  claim 38  which is configured in a delivery device which positions the microneedle perpendicular to skin surface.  
     
     
         43 . The microneedle of  claim 42  which is in an array of microneedles needles.  
     
     
         44 . The microneedle of  claim 43  wherein the array comprises 3 microneedles.  
     
     
         45 . The microneedle of  claim 43  wherein the array comprises 6 microneedles.  
     
     
         46 . A method for delivering a bioactive substance to a subject comprising: contacting the skin of the subject with a device having a dermal-access means for accurately targeting the dermal space of the subject with an efficacious amount of the bioactive substance.  
     
     
         47 . The method of  claim 46  wherein the pharmacokinetics of the bioactive substance is improved relative to the pharmacokinetics of the substance when administered subcutaneously.  
     
     
         48 . The method of  claim 47  wherein the improved pharnacokinetics is an increase in bioavailability.  
     
     
         49 . The method of  claim 47  wherein the improved pharmacokinetics is a decrease  
     
     
         50 . The method of  claim 47  wherein the improved pharmacokinetics comprises an increase in C max  of the substance compared to subcutaneous injection.  
     
     
         51 . The method of  claim 47  wherein the improved pharmacokinetics is a decrease in T lag .  
     
     
         52 . The method of  claim 47  wherein the improved pharmacokinetics is an enhanced absorption rate.  
     
     
         53 . The method of  claim 46  wherein the device has a fluid driving means including a syringe, infusion pump, piezoelectric pump, electromotive pump, electromagnetic pump, or Belleville spring.  
     
     
         53 . The method of  claim 46  wherein the dermal access means comprises one or more hollow microcannula having a length of from about 0.5 to about 1.7 mm-mm.  
     
     
         54 . The method of  claim 46  wherein said dermal access means comprises one or more hollow microcannula having an outlet with an exposed height between 0 and 1 mm.  
     
     
         55 . A method for delivering a bioactive substance to a subject comprising: contacting the skin of a subject with a device having a dermal-access means for accurately targeting the dermal space of the subject with an efficacious amount of the bioactive substance at a rate of 1 nL/min. to 200 mL/min.  
     
     
         56 . The method of  claim 55  wherein the rapid onset pharmacokinetics of the bioactive substance is substantially improved relative to subcutaneous injection.  
     
     
         57 . The method of  claim 56  wherein the bioavailability is increased.  
     
     
         58 . The method of  claim 56  wherein the pharmokinetics is a decreased T max .  
     
     
         59 . The method of  claim 56  wherein the pharmokinetics is an increased C max .  
     
     
         60 . The method of  claim 56  wherein the pharmokinetics is a decreased T lag .  
     
     
         61 . The method of  claim 56  wherein the pharmokinetics is an enhanced absorption rate.  
     
     
         62 . The method of  claim 55  wherein the dermal access means has one or more hollow microcannula that inserts into the skin of said subject to a depth of from about 0.5 to about −2.0 mm.  
     
     
         63 . The method of  claim 55  wherein the dermal access means has one or more hollow microcannula having an outlet with an exposed height between 0 and 1 mm.