Published on

  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1.  Introduction, advantages & disadvantages . Skin : site of drug delivery. Skin Anatomy , transport mechanisms. Components of transdermal patches. Generations of TDDS. Recent Methods for enhancing permeation of TDDS
  2. 2.  Transdermal drug delivery offers an attractivealternative to the oral administration and injection. Today about 74% of drugs are taken orally andare found not to be as effective as desired.Drug delivery through the skin(for systemic effect ) is commonlyknown as TDD and differs fromtraditional topical drug delivery.
  3. 3. also known popularly as ‘patches’.Transdermal patches: are dosage forms designedto deliver a therapeutically effective amount ofdrug from the outside of the skin through itslayers into the blood stream.
  4. 4. 1. avoids the stomach environment;2. no GI distress or other physiologicalcontraindications of the oral route exist;3. easy to use, patches can compliance &medical costs;4. avoids the first-pass effect;5. If a transdermal delivery system is used inplace of a needle, then medical waste canalso be , again, healthcare costs.
  5. 5. 6. allows for the effective use of drugs with shortbiological half-lives;7. allows for the administration of drugs withnarrow therapeutic windows;8. provides steady plasma levels of highly potentdrugs;9. TDDS, especially simple patches, are easyto use and noninvasive and patients likenoninvasive therapies.
  6. 6. 1. drugs that require high blood levels cannot beadministered;2. The adhesive used may not adhere well to alltypes of skin;3. drug or drug formulation may cause skinirritation or sensitization;4. the patches can be uncomfortable to wear;5. and this system may not be economical forsome patients.
  7. 7.  FDA (2005) announced that fentanyl td patches causenarcotic overdose and deathsCause: manufacturing defect that allowed the gelcontaining the medication to leak out of its pouch tooquickly, which could result in overdose and death.Improvement : use a matrix/adhesivesuspension (where the medication isblended with the adhesive instead ofheld in a separate pouch with a porousmembrane)
  8. 8. oThe human skin is a readily accessible surface fordrug delivery.oSkin of an average adult bodycovers a surface of ~ 2 m² andreceives about 1/3 of theblood circulating throughthe body.oHuman skin comprises of threedistinct but mutually dependentlayers :
  9. 9. Microscopically skin is a multilayered organ broadly composed ofthree tissue layers : The Epidermis The Dermis Subcutaneous fatty tissue.
  10. 10. Hairy skin develops hairfollicles and sebaceous glandsThe most important layer is thestratum corneum, or horny layer,which usually provides the rate-limiting or slowest step in thepenetration process.
  11. 11. Principle mechanism is passive diffusion of drugthrough the skin. macro-routes may comprise:a.Transepidermal pathway b. Transfollicular pathwayHair follicleSebaceousgland Sweat gland
  12. 12. 1- Backing,2- Drug,3- Membrane,4- Adhesive,5- Liner.
  13. 13. 1. Liquid reservoir system where the patch consists of a backing materialthat is both protective and adhesive,a liquid drug reservoir, a releasemembrane.2. Adhesive matrix system where the adhesive and the drug arecombined in the same layer leaving only three layers to the patch;the backing layer, the drug and adhesive layer, and the protective layer.1st Generation
  14. 14. Estraderm®Androderm®use the liquid-reservoirdesignMost currently available patches are theadhesive matrix design.1st Generation
  15. 15.  delivery of organic molecules by disrupting st.cor. barrier function by providing a driving force forthe movement of molecules through the epidermis. This disruption should be reversible and avoidinjury to the skin.Enhancement techniques are limited tosmall, lipophilic molecules and still have little effecton larger or hydrophilic molecules.2nd Generation
  16. 16. Enhancement techniques include:1.chemical penetration enhancers,2. gentle heating,3. iontophoresis.2nd Generation
  17. 17. 1. Chemical Penetration Enhancers
  18. 18. 2. Heat as a penetration enhancer The use of heat to increase the permeability of theskin.One safe use of heat as a penetration enhancer is theControlled Heat-Assisted Drug Delivery(CHADD)system.The lidocaine/tetracaine patch system.
  19. 19. lidocaine/tetracaine patch
  20. 20. The use of tiny electric current to promote flowof the drug (usually charged) through the skin.3. Iontophoresis as a 2nd G.penetration enhancerIontophoresis is a powered drugdelivery system that is indicated forthe local administration of ionicdrug solutions into the body formedical purposes and can be usedas an alternative to injections.
  21. 21. 3. Iontophoresis as a 2nd G.penetration enhancer
  22. 22.  Self-contained, ultra-thin battery technology. Prepared by the clinician and applied to the patient in theclinic. With no external batteries or wires, patients areable to return to their daily activities whilereceiving time-released iontophoresis.A chargeddrug deliveryelectrode(negative)repels thedrug ionsinto theunderlyingtissue.
  23. 23. 3rd Generation3rd generationTDDS aim toseverely disrupt thestratum corneum toallow largemolecules to passinto the circulation.
  24. 24. Human GnRHGnRH is not a small, organic compound but a somewhatlarger oligopeptide.1. Iontophoresis as a 3rd G.penetration enhancer
  25. 25. GnRH Smart Patch® iontophoretic technologyQuich, non-invasive, 10min. Application to skin.
  26. 26. 2. Thermal ablation as a 3rd G.penetration enhancerThermal ablation technique seeks to severely disrupt thestratum corneum.100s of degrees for very short periods of time (micro- tomilliseconds) and forms painless, reversible microchannels inthe stratum corneum without damaging the underlying tissue(2008).
  27. 27. 3. Ultrasound as a penetration enhancer
  28. 28. 3. Ultrasound as a penetration enhancerUltrasound to Enhance Skin Permeability
  29. 29.  Microneedle array consists of chips. Used for adminstration of therapeutic proteins andvaccines.4. Microneedle as a penetration enhancer200-750 microns in length150-650 microneedles/cm2
  30. 30. 4. Microneedle as a penetration enhancerPoke and patch Method
  31. 31. 4. Microneedle as a penetration enhancerHollow micro needle array
  32. 32. Intanza® is a seasonal fluvaccine that has beenapproved in Europe since2009.4. Microneedle as a penetration enhancer
  33. 33. Transdermal drug delivery technologies arebecoming one of the fastest growing sectors withinthe pharmaceutical industry.Despite some disadvantages, transdermaldrug delivery offers many advantages capableof improving patient health and quality of life. 1st and 2nd generation TDDSoffer these advantages but arelimited in the scope of moleculesdelivered through the skin.