1. EMAC 276 Brian Cheung, Connie Chien, Corinne Nelson, Michelle Song, Xiaoxin (Shawn) Zhu

2. First approved in 1979 3-day patch for motion sickness in astronauts Became popular in 1990s with nicotine patch Currently used for birth control, glucose monitoring, local anesthesia, etc

4. - only a couple hundred Daltons - heavily favor lipids and require doses of milligrams per day or less - hard for hydrophilic drugs to pass through

5. Matrix-formers Permeation enhancers Rate-controlling membrane Pressure-sensitive adhesives (PSAs) Backing laminate Release liner

6. 1.Biocompatible 2.Highly dependent on the solubility of drug 3.Easy control of composition and thickness

7. Ethylene-Vinyl Acetate (EVA) Permeability can be altered by adjusting vinyl-acetate content VA group leads to better solubility and diffusivity of polar groups Cost of Material: $1.6-1.7 per kilogram

8. Silicone Rubber: Good Biocompatibility, ease of fabrication Free rotation around silicone rubber backbone induce high permeability Cost of Material: $4.8-5.5 per kilogram http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18600/ar ticle.pdf http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18600/ar ticle.pdf

9. Polyurethanes: Condensation of polyisocyanates and polyols PU is suitable for hydrophilic polar compounds Cost of Material: $2.2-2.5 per kilogram http://upload.wikimedia.org/wikipedia/commons/c/ca/Polyurethane.png

10. Natural polymers can potentially reduce the skin irritation or allergic reactions induced by synthetic polymers Formed by deacetylation of chitin Thacharodi, D., and K. P. Rao. "Development and in Vitro Evaluation of Chitosan-based Transdermal Drug Delivery Systems for the Controlled Delivery of Propranolol Hydrochloride." Biomaterials 16 (1995): 145-48. Web. 8 Apr. 2012..

11. 1. Adhere easily 2. Permanently tacky 3. Does not cause instability of the a. drug b. enhancer, and c. adhesive 4. Does not leave residue when peeled off

12. Polyisobutylene: Mix of low and high molecular weights Fillers are used for reinforcement, reducing viscosity and cost Cost of Material: $1-100 per kilogram http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18600/ar ticle.pdf http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18600/ar ticle.pdf

13. Polyacrylates: Amorphous and water-clear color in solution Stability toward aging Great resistance to acidic and alkaline hydrolysis and UV degradation Cost of Material: $3.2-4.5 per kilogram http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18 600/article.pdf http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18 600/article.pdf

14. Silicones: Stable adhesive in throughout a wide range of temperature (-73 to 250C) Outstanding combination of bicompatibility and ease of fabrication for hydrophilic drugs Poor solubility, permeability and releasing property Cost of Material: $6.2-8.3 per kilogram http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18600/a rticle.pdf http://www.pharmtech.com/pharmtech/data/articlestandard/pharmtech/192002/18600/a rticle.pdf

15. Layer of protective material Chemical Resistance is the most important factor It keeps the medication from seeping out of the patch Good chemical resistance: Low modulus High flexibility Good oxygen transmission High moisture vapor transmission rate

16. Relatively Inert Increase hydration of the skin Make sure that any polymers used do not irritate the skin

17. Polyethylene Vinyl Polyester

18. Protects the skin contacting adhesive It is removed immediately before being placed on the skin More a part of the packaging material than the actual patch itself Made of Polyethylene or PVC and Silicone or Teflon Cross linking may occur Increase force to remove liner from patch

19. Silicone Teflon PVC

20. Only small-sized molecules delivery (very thick stratum corneum) Difficult balancing the degree of damage and penetration

21. Electroporation Cavitational ultrasound Thermal ablation Microdermabrasion Biochemical enhancer Chemical enhancer combination Microneedles http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2700785/

22. SLS + phenyl piperazine + http://en.wikipedia.org/

23. S. H. Bariya, M. C. Gohel, T. A. Mehta, and O. P. Sharma, "Microneedles: An Emerging Transdermal Drug Delivery System," Journal of Pharmacy and Pharmacology, 64(1), 11-29 (2012).

24. Questions?