Mr. Sagar kadam

1. Presented By-
Sagar k. Kadam.
M.Pharm,FY Sem-I
Dept.Of Pharmaceutics
Appasaheb Birnale Collage Of Pharmacy,Sangli.

2.  DEFINITION
 ADVANTAGES
 DISADVANTAGES
 MECHANISM OF DRUG ABSORPTION THROUGH SKIN
 FUNDAMENTALS OF SKIN PERMEATION
 FACTORS AFFECTING TRANSDERMAL PERMEABILITY
 PERMEATION ENHANCERS
 TYPES
 CONCLUSION
 REFERENCES
2

3. Transdermal therapeutic are defined as self contained
discrete dosage form which when applied to the intact skin
deliver the drugs, through the skin, at a controlled rate to the
systemic circulation.
(or)
Transdermal drug delivery system (TDDS) are systems
that utilize skin as a site for continuous drug administration
into the systemic circulation.
3

4.  Avoidance of first-pass effect,
 Long duration of action,
 Comparable characteristics with IV infusion,
 Ease of termination of drug action, if necessary,
 No interference with gastric and intestinal fluids,
 Suitable for administered of drug having-
 Very short half-life, e.g. nitroglycerine.
 Narrow therapeutic window.
 Poor oral availability
ADVANTAGES

5. DISADVANTAGES
 Poor diffusion of large molecules,
 Skin irritation,
 Requires high drug load,
 Unsuitable –If drug dose is large,
 Absorption efficiency is vary with different sites of skin,

6. ANATOMY OF SKIN

7. Epidermis
a)Stratum corneum
b)Stratum lucidum
c)Stratum granulosum
d)Stratum spinosum
Dermis
Subcutaneous
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9. a) Transfollicular route
9
Transfollicular route is the shortest pathway that drug has to follow
to reach the systemic circulation that provides a large area for
diffusion of drugs.
b) Transcellular route
Drug delivering through this route passes from corneocytes which
has highly hydrated keratin creating hydrophilic pathway.
The drug passes through the corneocytes of stratum corneum.
c) Intercellular route
In intercellular pathway the drug diffuses through the
continuous lipid matrix present between the cells.

10. Rate of permeation, dQ/dt, across a skin can be expressed as
dQ/dt = Ps[ cd -cr ]
10
Where,
dQ/dt – Rate of permeation
Ps – Permeability coefficient
Cd – Concentration in donor compartment
Cr – Concentration in receptor compartment

11. The principle transport mechanism across mammalian skin
is by passive diffusion. The factors influencing and having
differences in transdermal permeability of the stratum
corneum.
LIPID SOLUBILITY:
At higher concentrations, the rate of penetration of the
alcohols is greatly increased, and does not follow the pattern
of absorption from weak solution.
But, high concentrations may damage the stratum corneum
impairing its 'barrier' properties.
11

12. PARTITION COEFFICIENT:
Drugs possessing both water andlipid Solubility are
favorably absorbed through the skin. Transdermal permeability
coefficient shows a linear dependency on partition coefficient. A
lipid/water partition of 1 or greater is generally required for
optimal transdermal permeability.
pH CONDITION:
The extent of dissociation in case of ionic drugs and their
transdermal permeability depends on pH condition of the skin
surface as well as the drug delivery system. Incase of ephedrine
and scopolamine, the transdermal flux of the drug increases with
increasing pH upto 1.2 approximately 1.2 higher than their
respective pKa values.
12

13. These are compounds which promote skin permeability
by altering the skin as a barrier to the flux of a desired
penetrant.
These may conveniently be classified below
i. Solvents
ii. Surfactants
iii. Miscellaneous chemicals
13

14. 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.
Ideal Penetration Enhancer
Non-toxic, non-irritating, non-allergenic.
Immediate onset of increased permeability.
Immediate recovery of normal barrier properties upon removal
(reversible).
Physically and Chemically compatible with a wide range of drugs.
CHEMICAL PERMEATION ENHANCERS

15. • Solvents - Ethanol, acetone, polyethylene glycol,
glycerol, propylene glycol, dimethyl sulfoxide
• Surfactants - Brij30, brij72, Pluronic, Sodium lauryl
sulphate, Span 20, Tween 80.
• Azones - N- Acyl hexahydro-2-oxo-1H-azepines,
N-Alkylmorpholine-2,3-diones.
• Terpenes - Limonene, Carvone
• Fatty alcohols - Lauryl alcohol, linolenyl alcohol, oleic and
fatty acids acid and lauric acid.

16. ELECTRICALLY ASSISTED METHODS
1.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 lipidpacking in stratum
corneum by cavitation.
Sonicators operating at frequencies in the range of 20kHz to3MHz are
available commercially and can be used for Sonophoresis.
Therapeutic ultrasound (1–3MHz) - for massage,
Low-frequency ultrasound (23-40kHz) - in dentistry,
High-frequency ultrasound (3–10 MHz) - diagnostic
purposes.

18. 2.IONTOPHORESIS
The electrical driving of charged molecules into tissue, passes a
small direct current (approximately 0.5 mA/cm2) through a drug
containing electrode in contact with the skin. The most popular
electrodes are based on the silver/silver chloride redox couple.
Three main mechanisms enhance molecular transport:
Charged species are driven primarily by electrical repulsion
from the driving electrode.
Flow of electric current may increase the permeability of skin
and
Electroosmosis may affect uncharged molecules and large polar
peptides.
Limitations: Hair follicle damage is possible

20. There are four main types of TDDS
1) Single-layer Drug-in-Adhesive
2) Multi-layer Drug-in-Adhesive
3) Drug Reservoir-in-Adhesive
4) Drug Matrix-in-Adhesive
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21. The Single-layer Drug-in-Adhesive system is characterized by
the inclusion of the drug directly within the skin-contacting
adhesive.
In this transdermal system design, the adhesive not only serves
to affix the system to the skin, but also serves as the
formulation foundation, containing the drug and all the
excipients under a single backing film.
The rate of release of drug from this type of system is
dependent on the diffusion across the skin.
21

22. 22

23. The Multi-layer Drug-in-Adhesive is similar to the Single-
layer Drug-in-Adhesive in that the drug is incorporated
directly into the adhesive.
However, the multi-layer encompasses either the addition of a
membrane between two distinct drug-in-adhesive layers or the
addition of multiple drug-in-adhesive layers under a single
backing film.
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24. 24

25. The Reservoir transdermal system design is characterized
by the inclusion of a liquid compartment containing a
drug solution or suspension separated from the release
liner by a semi-permeable membrane and adhesive.
The adhesive component of the product responsible for
skin adhesion can either be incorporated as a continuous
layer between the membrane and the release liner or in a
concentric configuration around the membrane.
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26. 26

27. The Matrix system design is characterized by the inclusion of a
semisolid matrix containing a drug solution or suspension
which is in direct contact with the release liner.
The component responsible for skin adhesion is incorporated
in an overlay and forms a concentric configuration around the
semisolid matrix.
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CONCLUSION
Transdermal drug delivery technologies are becoming one
of the fastest growing sectors within the pharmaceutical
industry.
Advances in drug delivery systems have increasingly
brought about rate controlled delivery with fewer side effects
as well as increased efficacy and constant drug delivery.
The market value for transdermal delivery was $12.7billion
in2005, and is expected to increase to $21.5 billion in the
year2010 and $31.5 billion in the year 2015 – suggesting a
significant growth potential over the next 10 years.

29. 29
 Controlled drug delivery –concepts and advances – by
S.P.Vyas R.K.Khar.
 Encyclopedia of pharmaceutical technology -third
edition
edited by James Swarbrick volume-4 Microsphere
Technology
and Applications by Diane J. Burgess and Anthony J.
Hickey.
 Controlled and Novel drug delivery edited by N.K.Jain
reprint 2007
 Encyclopedia of controlled drug delivery volume 2
encyclopedia of controlled drug delivery
 Asian Journal of Pharmaceutical and Clinical Research
transdermal drug delivery system: a review p. k.gaur,s.
mishra,

30. Ramteke K.H., Dhole S.N., Patil S.V. Journal of Advanced
Scientific Research, 2012, vol:3(1), Pg no:22-35.
Richard.H.Guy, Jonathan Hardgraft.Transdermal Drug
Delivery, second edition, Revised and expanded. India Special
edition,2012,vol123,page no: 1-143,361-367.
Dipen Patel, Sunita A. Chaudhary, Bhavesh Parmar, Nikunj
Bhura, Vol. 1 No. 4, 2012 ,Pg no:78-87.

31. Thank
You…