Transdermal drug delivery systems (TDDS) deliver medication through the skin and into the bloodstream. This summary discusses the key points about TDDS covered in the document: 1. TDDS were first approved in 1981 and over 35 products have been approved, with the US market reaching $1.2 billion. 2. TDDS offer advantages like avoiding first-pass metabolism, maintaining constant drug levels, and increased patient compliance. 3. The skin is a barrier to drug permeation, so penetration enhancers like chemicals, solvents, surfactants, and physical methods like iontophoresis and electroporation are used to promote drug flux across the skin. 4. Examples of

1. RAJARSHI SHAHU COLLEGE OF PHARMACY
TRANSDERMAL DRUG DELIVERY SYSTEM
Guide by: Dr. Prakash Kendre sir
Presented by: Priya Talekar
RAJARSHI SHAHU COLLEGE OF PHARMACY
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2. CONTENT
◼Introduction
◼History
◼Structure of skin
◼Adventages
◼Disadventages
◼Factors affecting TDD
◼Penetration enhancers
◼Marked products
◼Application
◼Reference 2
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3. INTRODUCTION
◼Transdermal system delivers medications through the skin direct into the
blood stream.
◼One long standing approach to increase the range of drugs that can
effectively delivered through this route has been to use penetration
enhancers: chemicals that interact with skin constituents to promote drug
flux.
◼Defination: TDDS is also known as patches , are dosage forms degined to
deliver to therapeutically effective amount of drug across the patient’s skin.
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4. HISTORY
◼The first Transdermal patch was approved in 1981 to prevent the nausea
and vomiting associated with motion sickness.
◼The FDA has approved, till 2003, more than 35 transdermal patch products,
spanning 13 molecules.
◼The US transdermal market approached $1.2 billion in 2001.
◼ Two new, recently approved Transdermal patch products (a contraceptive
patch containing ethinyl estradiol and nor-elgestromin, and a patch to treat
over active bladder containing oxybutynin.)
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6. ADVANTAGES
◼Avoids first pass hepatic metabolism.
◼Decrease unwanted/ side effects.
◼Maintains constant blood levels for longer period of
time.
◼Easy to discontinue in case of toxic effects.
◼Increased patient compliance (unconscious and
nauseated).
◼Provides an ability to modify the properties of
biological barriers to improve absorption.
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7. DISADVANTAGES
◼Drug must have some desirable physico-chemical
properties.
◼Drugs for daily dose less than 5 mg/day are preferred, If
drugdose is more than 10-25 mg/day the TDD will be
difficult.
◼Local irritation at the site of administration.
◼The barrier function of skin changes form one site to
another, from person to person and with age.
◼ TDD can not achieve high drug levels in Blood/ plasma.
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8. STRUCTURE OF SKIN
• Structure of skin contain 4 layers :
• Non epidermis (stratum
corneum)
• Viable epidermis
• Dermis
• Hypodermis. (Subcutaneous
layer)
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9. SKIN PERMEABILITY KINETIC’S
◼It express by Fick’s first law of Diffusion-Drug molecule diffuse
from a region of higher concentration to the lower concentration.
Until equilibrium is attained.
Fick’s First law of Diffusion, dm/dt = J = DAK/h ,Where,
dm / dt =J= study state flux through a unit area of skin per unit
time
◼ D = diffusion coefficient ,A = surface area, K= partial coefficient
between the Stratum corneum and the vehicle, H= diffusional
path length or membrane thickness
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10. TRANSPORT MECHANISM
◼ Transepidermal route:
◼ Intercellular penetration: Hydrophilic Drugs
are penetrate through the intercellular path or
between the cells. Ex. Gentamicin
◼ Intracellular penetration- Drug molecule
passes through the cells of the stratum corneum.
It is generally seen in case of lypophilic drugs.
Ex.Morphine
◼ Transappendegeal penetration:(shunt
pathway)the drug molecule may transverse
through the hair follicles and sweat glands.
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11. TRASPORT MECHANISM
Transdermal delivery pathway:1.transepidermal routh ( intra and intercellular), 2.The
sweat gland 3.Hair follicle 11
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12. FACTORS AFFECTING TRANSDERMAL DRUG DELIVERY
◼Physiological factors:
◼Skin age
◼Anatomical location
◼Skin hydration
◼Skin condition
◼Temperature
◼Skin metabolism
◼Race 12
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13. ◼Physico-chemical factors:
◼Solubility
◼Partition coefficient
◼Drug concentration
◼Surface area
◼Molecular mass
◼Melting point
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14. IDEAL PARAMETERS FOR THE SELECTION OF DRUG CANDIDATE
FOR TDDS
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15. PENETRATION ENHANCERS
◼Permeation enhancers are the substances added to
pharmaceutical formulation in order to increase the membrane
permeation or absorption rate of a co-administered drug.
◼These are used to increase the bioavailability of drugs which
have poor membrane permeation properties.
◼For permeation enhancers to be clinically acceptable they must
increase the bioavailability or increase membrane permeability
without damaging the membrane and causing toxicity.
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16. MECHANISM OF PENETRATION ENHANCERS
◼Causing disruptions in the highly organized structure of SC.
Interaction with proteins present intracellularly.
Improve the drug partitioning through SC with the help of co enhancer
i.e.solvent.
◼Ideal Penetration Enhancer :
◼Non-toxic, non-irritating, non-allergenic.
◼Immediate recovery of normal barrier properties upon removal
(reversible).
◼Physically and Chemically compatible with a wide range of drugs
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17. Summary of the technologies utilised for enhancing TDD

18. TYPES OF PENETRATION ENHANCER
◼ Drug-vehicle interaction
This is a first method which can be used to improve skin absorption. In second-generation
strategy the Prodrug and ion pairing methods will be utilised.
◼ Prodrugs:
◼ The prodrug approach has been investigated to enhance transdermal delivery of drugs with
unfavourable partition coefficients.
◼ The prodrug design strategy generally involves addition of a pro-moiety to increase partition
coefficient and solubility to increase the transport of the drug in the stratum corneum.
◼ Upon reaching the viable epidermis, esterases release the active drug by hydrolysis there by
optimizing concentration in the epidermis.
◼ Ex.morphine,carbamate,etc
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19. ION PAIRS
◼Charged drug molecules do not readily partition into or permeate through
human skin. Formation of lipophilic ionpairs has been investigated to increase
stratum corneum penetration of charged species.
◼This strategy involves adding an oppositely charged species to the charged
drug, forming an ion-pair in which the charges are neutralized so that the
complex can partition into and permeate through the stratum corneum.
◼The ion-pair then dissociates in the aqueous viable epidermis releasing the
parent charged drug that can diffuse within the epidermal and dermal tissues.
◼Ex. Zaltoprofen and nicotine,etc.
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20. ◼ A substance that will increase the permeability of the epithelial barrier
by modifying its structure also termed as accelerants or sorption
promoters-can enhance drug flux.
◼Solvents-Ethanol, acetone, polyethylene glycol, dimethylsulfoxide, etc.
◼Surfactants-Span 20, Tween 80(polysorbate),etc.
◼Azones- N-Alkylmorpholine-2,3-diones ,etc
◼Terpenes- menthol and carvacrol,etc.
◼Fatty alcohols and fatty acids: Lauryl alcohol and oleic acid and
lauric acid.drug ex.propranolol
CHEMICAL INHANSER
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22. PHYSICAL INHANSER
◼ Sonophoreis, phonophoresis, iontophoresis, Electrophoresis, etc.
◼ Ultrasound (Phonophoresis / Sonophoresis)
Used originally in physiotherapy and sports medicine, applies a preparation topically and
massages the site with an ultrasound source.
◼ The ultrasonic energy (at low frequency) disturbs the lipid packing in stratum corneum by
cavitation.
◼ Sonicators operating at frequencies in the range of 20kHz to 3MHz are available commercially
and can be used for Sonophoresis.ex.ketoprofen,proteins
Therapeutic ultrasound (1–3MHz)- for massage,
Low-frequency ultrasound (23-40kHz) – in dentistry,
High-frequency ultrasound (3-10 MHz) – diagnostic purposes.
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23. ULTRASONIC ENHANCERS
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24. IONTOPHORESIS
◼Iontophoresis is defined as a method for increasing permeation of drugs
into the skin using small electrical currents.
◼The electrical current applied in iontophoresis varies from 0.5 to 20 mA.
◼The principle of this system is based on the different charges of the
electrodes used, namely the anode and cathode. Anionic drugs are placed
under a cathode, and the cationic or neutral drugs are placed ions under
the anode. Upon application of low electricity current at low voltage, ions
permeate into the skin.
◼Iontophoresis is mostly used for increasing skin absorption of ionisable
drugs. Like nonsteroidal anti-inflammatory drugs (ibuprofen, aspirin)
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25. IONTOPHORESIS
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26. ELECTROPORATION
◼It is a technique utilised to create micropores in the skin by
applying high voltage (10–1000 V) over a very short time period
(less than a few hundred milliseconds)
◼The principle of electroporation involves exposing a drug
solution, which has been placed on the skin, to pulse waves.
◼This pulse wave will create aqueous pores in the lipid bilayer of
the SC and allow drug penetration into the deeper skin layers via
the pores created.
◼Ex. tetracaine, insulin 26
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27. ELECTROPORATION
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28. ◼Mironeedles (MNs) are micron-sized needles, on a solid support, with
needle heights ranging between 25 and 2000 µm.
◼Hollow MN : The ability of MN to penetrate the skin, following which a
drug solution is injected through the hollow needles into the skin
◼Needle free Jet injection: Pain-free delivery because particles are too
small(20–100µm) to trigger pain receptors on the skin. Using a
supersonic shock wave of helium gas. The device avoids skin damage or
infection from needles or splash back of body fluids.
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30. MARKETAD PRODUCTS
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31. APPLICATION
◼For treatment of angina pectoris
◼Smoking Cessation(Nicotine Patch)
◼Antiemetic
◼Antimflammatory
◼Cosmatics
◼Contraceptive
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32. REFERENCE
◼ Original Article pulished: 20 January 2021
Enhancement strategies for transdermal drug delivery systems: current trends and applications
Delly Ramadon, Maeliosa T. C. McCrudden, Aaron J. Courtenay & Ryan F. Donnelly
Drug Delivery and Translational Research (2021)Cite this article
◼ https://link.springer.com/article/10.1007/s13346-021-00909-6
◼ Controlled drug delivery-concepts and advances – by S. P. Vyas R. K. Khar.
◼ Controlled and Novel drug delivery edited by N. K. Jain reprint 2007
◼ Transdermal drug delivery- penetration enhancement techniques- Heather A.E. Benson.
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33. Thank you
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