1. Transdermal drug delivery systems (TDDS) deliver drugs systemically through intact skin at a controlled rate. They consist of a drug reservoir layered between a backing membrane and adhesive layer. 2. The key components of TDDS are the drug, rate-controlling polymer matrix, permeation enhancers, and adhesive. The polymer matrix controls drug release while permeation enhancers improve skin permeability. 3. There are four main approaches for TDDS - polymer membrane permeation, polymer matrix diffusion, drug reservoir gradient, and microreservoir dissolution systems. Polymer membrane and matrix diffusion systems release drugs by zero-order kinetics while gradient and microreservoir systems provide

1. SHREE CHANKYA EDUCATION SOCIETY,
INDIRA COLLEGE OF PHARMACY,PUNE
TRANSDERMAL DRUG DELIVERY SYSTEM
SEMINAR ON
Presented by : Vaishnavi S.
Jadhav
First Year M.Pharm
(Pharmaceutics)
Roll No.5
Guided by,
Mrs. Meghana Dabhadkar
Assistant Professor
Department :
Pharmaceutics
1

2. Contents :
2
1.Introduction
2.Basic Components
3.Approaches
4.References

3. Introduction:
3
• Transdermal Drug delivery System (TDDS) is self contained discrete dosage
form which delivers drug systemically by applying on to intact and healthy
skin, at a controlled rate
• Drug penetrates through Stratum Corneum, Passes through epidermis and
dermis then become available for systemic absorption
• Transdermal patches were developed in the 1970s and the first was approved
by the FDA in 1979 for treating motion sickness

4. 4
Basic Components
Drug Linear
Polymer Matrix
Permeation Enhancer
Adhesive
Backing membrane

5. Polymer Matrix (Rate controlling polymer)
• Responsible for control release of Drug
5
Natural
polymer
• Cellulose derivative
• Gelatin,Shellac,Gums
Synthetic
Elastomer
• Polysiloxane,Silicon rubber
• Butyl rubber,Acrylnitryle
Synthetic
Polymer
• Poly vinyl alcohol,Polyvinyl
• Polyvinyl carbonate

6. Criteria for selection of polymers
1. Molecular weight, glass transition temperature, chemical functionality polymer must
allow diffusion and release of the specific drug
2. Polymer should not react, physically or chemically with the drug
3. Polymer should be easily manufactured and fabricated into the desired product and in
expensive
4. The polymer must be stable and must not decompose in the presence of drug and other
excipient used in the formulation, at high humidity conditions, or at body temperature
5. Polymers and its degradation products must be non-toxic
6

7. Drug :
Dose Less than 20 mg/day
Half life < 10 hrs
Molecular weight < 400 Dalton
Melting point < 200oC
Partition Coefficient 1 to 4
Skin Reaction Non irritating and non sensitizing
Oral Bioavailability Low
7
Potential candidate for Transdermal drug delivery system should be follow below
criteria:

8. Permeation Enhancer:
• Promote skin permeation and are considered as an integral part of most
transdermal formulations
• Improve or alter the permeability of skin by altering the barrier function of the
skin
8
Permeation
Enhancer
Active
Delivery
Passive
Delivery

9. Active Delivery : Physical Penetration Enhancer
• Iontophoresis : Promotes the movement of ions across the membrane under the
influence of a small externally applied potential difference
• Sonophoresis : Ultrasonic waves with energy values between 20 kHz and 16
MHz. Ultrasound also increases the local temperature of the skin area and creates
a thermal effect, which further promotes drug penetration.
• Electroporation : High voltage electric pulses ranging from 5 to 500 V for
short exposure times (~ms) to the skin, which leads to the formation of small pores
in the SC that improve permeability and aid drug diffusion
9

10. 10
Passive delivery : Chemical Penetration Enhancer
Penetration enhancers can be used alone or in combination with chemical penetration
enhancers with proven superior skin penetration as compared to that of individual chemicals.
Class Example
Solvents Ethanol, Dimethyl formamides, Glycerol
Surfactant Na-lauryl sulfate, Dioctyl sulphosuccinate
Sodium Taurocholate, Sodium deoxycholate
Binary System Oleic acid, Propylene Glycol
Chelating agent EDTA

11. Adhesive:
Pressure sensitive adhesive : Used to maintaining an intimate contact
between transdermal system and the skin surface
Example:
• Polyacrylamates
• Polyacrylates
• Polyisobutylene
• Silicone based adhesive
11

12. Backing membrane:
• flexible
• provide a good bond to the drug reservoir
• prevent drug from leaving the dosage form through the top
• accept printing
Examples :
• Aluminium Vapour coated layer,
• Plastic film and heat real layer.
12

13. Release Liner :
During storage release linear prevents the loss of drug that has migrated into the
adhesive layer and contamination. However, as the linear is in intimate contact with
the delivery system, it should comply with specific requirements
• regarding chemical inertness
• permeation to the drug
• penetration enhancer
• water.
13

14. 14
Transdermal permeation of drug for systemic delivery :

15. 15
Approaches
1.Polymer Membrane Permeation – Controlled TDD System
2.Polymer Matrix Diffusion – Controlled TDD System
3.Drug Reservoir Gradient – Controlled TDD System
4.Microreservoir Dissolution Controlled TDD System

16. Polymer Membrane Permeation – Controlled
TDD System
16

17. 17
• Drug Reservoir is sandwiched between a drug –impermeable backing laminate and a rate
controlling polymeric membrane
• Drug reservoir is encapsulated in shallow compartment
• A thin layer of drug compatible, microporous, hypoallergic adhesive polymer e.g. Ethylene vinyl
acetate copolymer
• External Surface of polymer membrane there is a thin layer of pressure sensitive adhesive such
as polyisobutylene; Suspended in a unleachable, viscous liquid medium e.g silicone fluid
• Drug release takes place by zero order kinetics
• Drug release is controlled by controlling partition coefficient of drug, diffusivity & thickness of
polymer membrane
• Example : Nitro-glycerine releasing TDDS – Once a day – Angina Pectoris

18. Polymer Matrix Diffusion - Controlled TDD
System
18

19. 19
• Drug reservoir is obtained by homogenous dispersion of drug in Hydrophillic or
lipophilic rate controlling polymer
• Followed by Cross linking of polymer chains
• Drug and polymer is dissolved in common solvent followed by evaporation of solvent in
the mould under vaccum or at elevated temperature
• A medicated disc is obtained is glued onto an occlusive base plate in a shallow
compartment which is drug impermeable backing layer
• No dose dumping
• Drug release will not be zero order
• Example :Verapamil TDDS

20. Drug Reservoir Gradient – Controlled TDD
System
• Overcome the non – zero order drug release profiles
• Forming a gradient of drug reservoir along the diffusional path across the
multilaminate adhesive layer
Drug Reservoir
20
Dispersed in multi laminate adhesive polymer
Medicated Disc
( Solvent Casting or Hot melt )
Impermeable metallic plastic backing

21. Microreservoir Dissolution Controlled system
21

22. 22
• Hybrid of the reservoir and matrix dispersion – type drug deliver system
• Drug reservoir is formed by first suspending the drug solids in an aqueous solution of a
water miscible drug solubilizer e.g. polyethylene glycol
• Thermodynamically unstable dispersion is quickly stabilized by immediately cross –
linking the polymer chains in situ which produce a medicated polymer disk with a
constant surface area and a fixed thickness
• Example: Nitroglycerin Releasing TDDS ( Nitrodisc , Searle USA)

23. 23
Marketed transdermal Patches :

24. References :
1. Yie W.Chien “ Novel Drug Delivery System", published by Marcel Dekker
,Volume 50 , Second edition 2007 Page no.306-364
2. Vyas S.P,Khar R.K. (2012), Controlled drug delivery : Concept and advances,
Page no.611-615
3. Woo Yeup Jeong, Mina kwon, Hye Eun Choi, “Recent advances in transdermal
drug delivery system : a review , Biomaterials Reaserch ,2021
4. https://www.pharmatutor.org/articles/transdermal-drug-delivery-system-a-
review-article
5. Himanshi Tanwar and Ruchika Sachdeva, “ Transdermal Drug Delivery System
: A review”, International journel of Pharmaceutical Sciences and Research ,
IJPSR(2016), Vol 7
6. https://www.slideshare.net/ArshadKhan63/transdermal-drug-delivery-system-
119177012
24

25. 25