Presentation Transcript
COATED MICRONEEDLES FOR TRANSDERMAL DELIVERY :COATED MICRONEEDLES FOR TRANSDERMAL DELIVERY H.S. Gill, M.R. Prausnitz., Journal of
Controlled Release,
Vol. 117; 227–237; 2007
Mohana Marimuthu
200840090
PRESENTATION OVERVIEW :PRESENTATION OVERVIEW INTRODUCTION
DISCUSSION OF THE RESULTS
MICRONEEDLE FABRICATION METHODS
MICRONEEDLE COATING METHODS
DELIVERY FROM COATED MICRONEEDLES
CONCLUSION
PERSPECTIVE ON THIS ARTICLE
INTRODUCTION :INTRODUCTION Biopharmaceuticals - pharmaceutical therapies
Parenteral delivery - patient complaince due to needle phobic
Hypodermic needles
Microneedles
Transdermal patches
INTRODUCTION :INTRODUCTION 4 modes of delivery
1. Piercing microneedle +
application of drug patches
2. Coated microneedle
3. Encapsulated biodegradable
microneedle
4. Injecting drug through hollow
microneedles
molecular weight drugs
Solid state-long term stability
Vaccine delivery into skin
INTRODUCTION :INTRODUCTION Essential characters of coating process:
Uniform coating
Limit deposition onto microneedle
Avoid temperature
High drug loading
Good adhesion of coating solution
aqueous coating solution
Rapid or controlled – dissolution kinetics
INTRODUCTION :INTRODUCTION Coating processes
-dip coating – micron
scale-used
-roll coating
not used
-spray coating
INTRODUCTION :INTRODUCTION
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS 1. Microneedle fabrication methods
Laser-cutting – stainless steel
Diferent geometrics
“pocketed” microneedles – 20 µm
Forms of barbes and serrated edges
Bench-scale apparatus – cut & polished – two 50 needle arrays/hr.
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS 2. Microneedle coating methods
Coat by dipping into aqueous Drug solution – no surface coverage
1% carboxymethylcellulose - viscosity enhancer, 0.5% Lutrol F-68 NF - surfactant
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS Simple dipping process
Contamination of microneedles substrate due to capillary force
Capillary effect – bridging of coating solution between adjacent microneedles
Dip coating device – dip holes with dimension similar to individual microneedles
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS Single, in-plane and out-of-plane Microneedle
Requires – less volumes of coating solution – 10 µl to 100 µl
Vent holes – prevent air bubbles
Evaporation of coating solution – solid deposits – block dip-coating holes – avoid by syringe.
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS 3. Delivery from coated microneedles
No residue on skin surface -
bioavailability
Vitamin B – upto 2.6µg / Microneedle
Vaccine delivery – potent immune response
Storage - antigen stability
Eliminate cold-chain storage
DISCUSSION OF THE RESULTS :DISCUSSION OF THE RESULTS
CONCLUSION :CONCLUSION Coating methods
Pressure sensitive adhesive patches
Dip-coating approaches – control surface tension
First time – organic and inorganic microparticles, viruses were coated
In vitro study – cadaver skin
In vivo study – uncoated microneedle in human subjects
CONCLUSION :CONCLUSION
PERSPECTIVE ON THIS ARTICLE :PERSPECTIVE ON THIS ARTICLE Simple versatile, controllable method to coat microneedles with protein, DNA, viruses and microparticles for rapid delivery into the skin
be smaller, cheaper, pain-free and more convenient with a wide range of biomedical and other applications.
Future of drug delivery-influenced by microfabrication technologies.
Slide 20:animation microneedle
QUESTIONS? :QUESTIONS?