a brief description on transdermal drug delivery system of M. pharm first year VERY HELPFUL IN SEMINAR AND PRESENTATION

1. TRANSDERMAL
DRUG DILEVERY
SYSTEM
PRESENTED BY
SAKSHI SINGH

2. LEARNING OBJECTIVES
◦ TO UNDERSTAND THE STRUCTURE OF SKIN
◦ KNOW THE VARIOUS APPROACHES FOR FORMULATION OF
TDDS
◦ ACQUIRED THE KNOWLEDGE OF DRUG PENETRATION
ENHANCEMENT THROUGH SKIN BY DIFFERENT MEANS
◦ EXPLORE THE EVALUATION PARAMETERS FOR TDDS
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3. ◦ Transdermal therapeutic systems are defined as self-contained
,self-discrete dosage forms ,which when applied to the intact skin
deliver the drug at a controlled rate to the systemic circulation.
◦ A simple patch that you stick onto your skin like an adhesive
bandage, which utilize passive diffusion of drugs across the skin
as the delivery mechanism.
◦ Controlled absorption, more uniform plasma levels, improved
bioavailability, reduced side effects, painless and many more
INTRODUCTION
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4. ◦ STRUCTURE OF SKIN
◦ EPIDERMIS;-
I. STRATUMCORNEUM
II. STRATUM LUCIDUM
III. STRATUMGRANULOSUM
IV. STRATUMSPINOSUM
V. STRATUM BASALE
◦ DERMIS
◦ HYPODERMIS
(SUBCUTANEOUS)
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5. ◦ Percutaneous absorption
◦ Percutaneous absorption is
defined as penetration of
substances into various layers of
skin and permeation across the
skin into systemic circulation
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6. ROUTES FOR TRANSDERMAL DRUG
DILEVERY SYSTEM
TRANSEPIDERMAL
ROUTE
TRANSAPPENDAGEAL
ROUTE
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7. TRANSEPIDERMAL ROUTE TRANSAPPENDAGEAL ROUT
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9. ◦ ADVANTAGES
◦ Avoid GIT absorption problems for drugs
◦ Self-medication is possible
◦ Reduces dosing frequency
◦ Painless, non-invasive
◦ Controlled , steady delivery of medication over a long period of
time
◦ Advantage to patient who are nauseated or unconscious
◦ DISADVANTAGES
◦ Cannot achieve high drug level in bloods
◦ Cannot absorb large molecular drug
◦ Cannot deliver ionic drug
◦ Cannot be developed if formulation causes irritation to skin
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10. FACTORS
AFFECTING
TDDS
• Physiochemical factors:-
• Temperature and PH- Penetration varies if the temperature
varies. .whereas according to PH ionized molecules pass
readily across the membrane
• Partition coefficient- Drugs K should be between 0.1-0.4
• Molecular size and weight
• Diffusion coefficient: Penetration of drug depends on
diffusion coefficient of drug. At a constant temperature the
diffusion coefficient of drug depends on properties of drug,
diffusion medium and interaction between them.
• Biological factors:-
• Skin age
• Blood supply
• Regional skin site
• Species differences
• Skin metabolism
• Environmental factors
• Sunlight
• Cold season
• Heat
• Air pollution
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11. COMPONENTS
OF TDDS
Polymer matrix:
• Polymers are the backbone of transdermal drug delivery
system.
• System for transdermal delivery are fabricated as multi
layered polymeric laminates in Which a drug reservoir or a
drug polymer matrix is sandwiched between two polymeric
layers
• The polymer should be stable. should be nontoxic should
be easily of manufactured . should be inexpensive.
Molecular weight of the polymer should be such that the
specific drug diffuses properly and gets released through
it.
Drug substance:
• The drug should have a molecular weight less than 1000
Daltons.
• The drug should have affinity for both lipophilic and
hydrophilic phase
• Melting point = <200°C , Partition coefficient = 1 to 4
Aqueous Solubility = >1mg/mL
• Dose = Less than 20mg/day Halflife = < 10 hrs
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12. ◦ PENETRATION ENHANCERS/PERMEATION
ENHANCERS :
◦ Consist of 2 categories- 1) Physical enhancers
2) Chemical enhancers
◦ PHYSICAL ENHANCERS
◦
◦ Electroporation- It involves the application of short, high
voltage pulses to skin . Skin electroporation, also called electro
permeabilization, creates transient aqueous pores in the lipid by
application of high voltage of electrical pulses of
approximately 100–1000 V/Cm for short time (milliseconds)
◦ Iontophoresis- It is defined as permeation of ionized drug
through electrical impulses of 0.5 mA/cm by either galvanic or
voltaic cell . It contains cathode and anode which attracts
positively charged ion and negatively charged ions, respectively
(Garg & Goyal, 2012). Its mechanism strictly follows Faraday’s
law 12

13. ◦ Ultrasound-
It is also termed as phonophoresis or sonophoresis. It is defined as the transport
of drugs across the skin by application of ultrasound peturbation at frequencies
of 20KHz-16MHz which has sufficient intensity to reduce the resistance of
skin. Mechanism involves either of the two ways:
(a) application of sound waves to the skin increases to fluidity of
lipids and increases permeation via transcellular pathway
(b) formation of bubbles which generates pores which even
allows large molecular weight drugs such as protein or vaccine
◦ Thermal approaches- Which include
◦ Laser thermal ablation – selective removal of the stratum corneum without
damaging deeper tissues thus, enhancing the delivery of lipophilic and
hydrophilic drugs.
◦ Radiofrequency – Involves the placement of thin , needle like electrode
directly into the skin and application of high frequency alternating current
(100KHz) which produces microscopic pathways in stratum corneum.
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14. ◦ Microneedle (MN) Arrays -
Microneedles are devices which act as both hypodermic needles and
transdermal patch. It consists of drug pool and some protrusion termed as
microneedles which helps in drug permeation across without reaching nerve
. These needles are 200–750 microns in length and are composed of groups
called arrays which contains 150–650 microneedles/ cm2 and have diameter of
tip 25 mm
◦ There are 4 strategies of TDD using MN
a) Poke and Patch
b) Coat and Poke
c) Poke and Release
d) Poke and Flow
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15. CHEMICAL ENHANCERS :-
Chemical enhancers help in permeation across the skin by disruption of the highly ordered structure of
stratum corneum lipid, interaction with intercellular protein or improve partition of the drug into stratum
corneum
PROPERTIES:-
• It should be non-toxic and non-allergen.
• It should have rapid working activity and the duration should be predictable .
• It should be unidirectional.
• Its compatibility with both excipients and drugs.
• Its properties according to drugs and cosmetic act
Some of the chemical enhancers are as follows
• Sulphoxides - eg : Dimethyl sulphoxide (DMSO)
• Pyrolidones- eg : N-methyl-2-pyrolidone
• Fatty acids- Eg, oleic acid
• Others- Essential oils, terpenes, surfactants, glycols, alcohols
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16. • is a material that helps in maintaining an intimate contact between transdermal system and the skin surface.
• It should adhere with not more than applied finger pressure, be aggressively and permanently tacky, exert a strong holding force.
• Additionally, it should be removable from the smooth surface without leaving a residue
• e.g.: polyacrylamides, polyacrylates, polyisobutylene, silicone based adhesive.
ADHESIVES:-
• Backing layer protects the patch from outer environment. While designing the backing membrane following points must be taken
into consideration
• Must be flexible
• Should have low water vapor transmission so as to promote skin hydration and thus greater skin permeability of drug
• Should be compatible
• Should have good tensile strength
• Examples; Polyethylene film, Polyester film
Backing membrane:-
• During storage the patch is covered by a protective liner that is removed and discharged immediately before the application of
the patch to skin. It is therefore regarded as a part of the primary packaging material rather than a part of dosage form for
delivering the drug
• the linear is in intimate contact with the delivery system, it should comply with specific requirements regarding chemical inertness
a
release liner:-
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17. METHODS OF
PREPERATION O
F TDDS:
Polymer matrix
controlled TDDS
Membrane
permeation
controlled TDDS
Adhesive
diffusion type
TDDS
Micro-reservoir
dissolution
controlled TDDS
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18. Micro-reservoir distribution controlled TDDS
Adhesive diffusion controlled TDDS
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19. EVALUATION
METHODS OF
TDDS
◦ PHYSIOCHEMICAL METHODS
◦ Thickness of the patch
◦ Weight uniformity
◦ Folding endurance
◦ Percentage moisture content
o Percentage moisture uptake
◦ Drug content
◦ Content uniformity test
◦ Shear Adhesion test
◦ Peel Adhesion test
◦ Rolling ball tack test
◦ IN VITRO EVALUATION TEST FOR TDDS
◦ In vitro drug release studies
◦ In vitro skin permeation studies
◦ IN VIVVO EVALUATION TEST FOR TDDS
◦ Animal model
◦ Human models 19

20. CONCLUSION
◦ Due to the recent advances in technology and the incorporation of
the drug to the site of action without rupturing the skin membrane
transdermal route is becoming the most widely accepted route of
drug administration. This article provides valuable information
regarding the formulation and evaluation aspects of transdermal
drug delivery systems as a ready reference for the research
scientists who are involved in TDDS. The foregoing shows that
TDDS have great potentials, being able to use for both
hydrophobic and hydrophilic active substance into promising
deliverable drugs. To optimize this drug delivery system, greater
understanding of the different mechanisms of biological
interactions, and polymer are required. TDDS a realistic practical
application as the next generation of drug delivery system.
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21. REFERENCE
◦ Tanwar H and Sachdeva R: Transdermal Drug Delivery System: A Review. Int J Pharm Sci
Res 2016; 7(6): 2274-90.doi: 10.13040/IJPSR.0975-8232.7(6).2274-90
◦ Volume 6, Issue 2, January – February 2011; Article-016 ISSN 0976 – 044X
◦ ISSN: 1071-7544 (Print) 1521-0464 (Online) Journal homepage:
https://www.tandfonline.com/loi/idrd20
◦ Kumar JA, Pulla Andam N, Prabu SL, Gopal V. Transdermal drug delivery system: An
overview. International Journal of Pharmaceutical Sciences Review and Research. 2010;
3(2): 49-53
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