advanced transdermal drug delivery system

1. TOPIC:ADVANCED TRANSDERMAL
DRUG DELIVERY TECHNIQUES
Seminar submitted to
Department of Pharmaceutics
Submitted by
Juhi Priya (160617015)
First Year MPharm (I.P)
Under the guidance of
Dr . Srinivas Mutalik
MANIPAL COLLEGE OF
PHARMACEUTICAL SCIENCES 1

2. CONTENTS
 Introduction :
 Types of transdermal applications
 Recent techniques for enhancing transdermal drug delivery
 Microneedles
 Electrokinesis : Iontophoresis
Electro-osmosis
 Electroporation
 Sonophoresis
 Thermal methods
 Conclusion
 References
 Definition
 The structure of Human Skin
 Advantages of the transdermal route
 Disadvantages of transdermal route
2

3. DEFINITION
 Transdermal drug delivery systems (TDDS), also known as
“patches,” are dosage forms designed to deliver a therapeutically
effective amount of drug across a patient’s skin.
 It has been recognized as a promising drug delivery system for
systemic delivery of drugs and maintaining constant blood level for
longer period of time and decreased side effects.
 Advanced physical techniques are used for enhancing delivery of
drugs such as structure-based, electrically based, velocity based
and several other miscellaneous physical techniques for enhancing
the permeation of drugs.
3

4. THE STRUCTURE OF SKIN 4

5. THE STRUCTURE OF SKIN
 The stratum corneum is the outermost layer of the epidermis and is
composed mainly of dead cells that lack nuclei.
 It is the toughest barrier, which consists of 10-25 layers of
keratinized cells.
 The drug must traverse three layers, the stratum corneum, the
epidermis, and the dermis to the blood stream.
 Partition into skin requires:
 Prodrugs with low melting points.
 Penetration-enhancing substances.
5

6. ADVANTAGES OF TRANSDERMAL
DRUG DELIVERY SYSTEM
 Reasonably constant dosage can be maintained (as opposed to
peaks and valleys associated with oral dosage).
 The system avoids the chemically hostile GI environment.
 No GI distress as compared to oral route.
 Avoids first-pass effect.
 Drug input can be promptly interrupted when toxicity occurs.
 Allows effective use of drugs with short biological half-life.
 Increased patient compliance.
6

7. DISADVANTAGES OF
TRANSDERMAL DRUG DELIVERY
SYSTEM
 Skin structure poses a barrier on the mw of the drug (< 500 Da).
 Adhesive may not adhere well to all types of skin.
 Drug or drug formulation may cause skin irritation or
sensitization.
 Reserved for drugs which are extremely potent for example The
largest daily dose of a drug from a patch is the nicotine patch,
with delivers a daily dose of only 21 mg.
 It may be uncomfortable to wear.
 TDDS are more costly than the conventional dosage forms.
7

8. TYPES OF TRANSDERMAL
APPLICATIONS
 SINGLE-LAYER DRUG-IN-ADHESIVE
 In this type of patch the adhesive layer not only serves to adhere
the various layers together, along with the entire system to the
skin, but is also responsible for the releasing of the drug.
 The adhesive layer is surrounded by a temporary liner and a
backing.
 MULTI-LAYER DRUG-IN-ADHESIVE
 One of the layers is for immediate release of the drug and other
layer is for control release of drug from the reservoir. The drug
release from this depends on membrane permeability and diffusion
of drug molecules.
8

9. TYPES OF TRANSDERMAL
APPLICATIONS
 RESERVOIR
 The reservoir transdermal system has a separate drug layer. The
drug layer is a liquid compartment containing a drug solution or
suspension separated by the adhesive layer.
 The drug reservoir is totally encapsulated in a shallow
compartment moulded from a drug-impermeable metallic plastic
laminate, with a rate-controlling membrane made of a polymer on
one surface. This patch is also backed by the backing layer.
9

10. TYPES OF TRANSDERMAL
APPLICATIONS
 MATRIX
 The matrix system has a drug layer of a semisolid matrix
containing a drug solution or suspension. The adhesive layer in
this patch surrounds the drug layer, partially overlaying it.
 Also known as a monolithic device.
 VAPOUR PATCH
 In a vapour patch, the adhesive layer not only serves to adhere the
various layers together but also to release vapour.
 Vapour patches release essential oils for up to 6 hours and are
mainly used for decongestion.
10

11. RECENT TECHNIQUES FOR
ENHANCING TRANSDERMAL DRUG
DELIVERY
Structure- Based
• Microneedles
• Macroflux
• Metered-dose
Transdermal Spray
Electrically -
Based
• Iontophoresis
• Ultrasound
• Photomechanical
• Waves
• Electroporation
• Electro Osmosis
Velocity -Based
• Power Jet
• Needle Free
Injections
Others
• Transfersomes
• Medicated Tattoos
• Skin Abrasion
• Heat
• Laser Radiation
• Magnetophoresis
11

12. MICRONEEDLES
 It delivers drug without reaching the nerves in the underlying
tissues
 Length 50–110 µm of needles will penetrate the SC and epidermis
to deliver the drug from the reservoir
 These are made from many different materials including silicon,
metal, glass and plastic. Ex:MicronJet 600 ( Nano Pass
Technologies Ltd.)
12

13. TYPES OF MICRONEEDLES
Solid Microneedle System (sMTS):
 For highly potent proteins or vaccines.
 375-1300 solid microneedles per cm2, 150-700μm tall, each
coated with drug or vaccine.
 Wear time ranges from 2 to 20 minutes
 0.3 mg capacity
13

14. TYPES OF MICRONEEDLES
Hollow Microneedle System (hMTS):
 Delivery of liquid formulations.
 18 hollow microneedles per cm2, approximately 950μm tall
 Wear time is short, ranging from 30 seconds to 10 minutes
 2 ml capacity
14

15. CONTINUED...
Dissolving patchless microneedles(DMNs):
 Dissolving microneedles (DMNs) are polymeric, microscopic
needles that encapsulate pharmaceuticals within their matrix
 Insertion of DMNs into the skin catalyzes the degradation of the
polymeric compound, thereby releasing the drug for systemic or
local delivery
 DMN application method used is to superimpose an array of
microneedles onto patches that facilitates the insertion and
maintenance of the microneedles.
 “Microlancer”, a novel micropillar based system by which
patients can self-administer DMNs and which would also be
capable of achieving 97 ± 2% delivery
 Humalog insulin (Eli Lilly and Company)
15

16. 16

17. ELECTROKINESIS
 Electrokinetic drug delivery is the sum of two processes:
 Iontophoresis
 Electro-osmosis
 Iontophoresis is the delivery of ions of a drug into the skin by
means of an electric field.
 Electro-osmosis is the bulk fluid flow associated with cation
transport by an electric field. Neutral drug molecules are
transported passively by electro-osmosis.
17

18. SoloVir™ (Transdermal Pharmaceutical)Electrokinetic
Transdermal System (ETS) Combination Product for
Herpes labialis.
18

19. IONTOPHORESIS
 Involves permeation of ionic drug molecules across the biological
membrane under the influence of electrical current.
 In iontophoresis, cationic drug are placed under an anode(+vely
charged chamber) or anionic drug under a cathode(-vely charged
chamber).
 Low voltage and low current density (< 0.5 mA ) application
provides an external force to the drug ions for passage across
Stratum Corneum.
19

20. MECHANISM 20

21. IONTOPHORESIS 21

22. EXAMPLES 22

23. ELECTROPORATION
 High voltages in the form of direct current [DC (100 volts)] are
applied on skin for a very short period of time (milliseconds)
which induce formations of transient pores.
 Short pulses of high voltage current are applied to the skin
producing hydrophilic pores in the intercellular bilayers via
momentary realignment of lipids.
 These pores allow the passage of macromolecules from the
outside of the cell to the intracellular space via a combination of
possible processes such as diffusion and local electrophoresis.
23

24. MECHANISM 24

25. SONOPHORESIS
 Technique for increasing the skin permeation of drugs using
ultrasonic energy (20 KHz to 20 MHz) as a physical force.
 Drug mixed in a solvent (may be a gel, cream or ointment) placed
on the skin beneath the ultrasonic probe after applying coupling
agent to skin.
 Waves are generated by applying AC electric signal (using
sonicator) to a crystal(quartz or silicone dioxide) (transducer)
 The crystal undergoes rhythmic deformation thus producing
ultrasonic vibrations/ pressure waves which are transferred
through a coupling medium to skin surface to maximize the energy
transmission.
25

26. MECHANISM
 Ultrasound produces cavitation which leads to the disordering of
the lipid bilayers and formation of aqueous channels in the skin
through which drugs can permeate.
a) Cavitation inside skin- cavitation bubbles near the keratinocytes–
lipid bilayers interfaces cause oscillations in the lipid bilayers,
thereby causing structural disorder of the SC lipids.
b) Cavitation outside skin- cavitation bubbles can cause skin erosion,
due to generation of shock waves, thereby enhancing transdermal
transport .
26

27. Basic principle of sonophoresis. Ultrasound pulses are passed
through the probe into the skin fluidizing the lipid bilayer by the
formation of bubbles caused by cavitation.
27

28. EXAMPLES
 Echo Therapeutics, Inc. (Formerly Sontra Medical)
(www.echotx.com)
 Generation 1.5 Generation 2.0
28

29. THERMAL METHODS
 The use of controlled heat allows drugs to permeate the skin more
effectively and efficiently than traditional methods.
 Controlled heat initiates several physiological responses that
facilitate drug penetration through the skin, including:
 An increase in skin permeability
 An increase in local blood circulation
 Dilation of blood vessels, thus improving permeability through
the blood vessel wall
 An improvement in the solubility of most drugs
 An increase in the release rate of the drug, from local skin tissue
into systemic circulation
29

30. MECHANISM
 Zars Pharma [Controlled Heat-Assisted Drug Delivery
(CHADD™)]. lidocaine
 Consists of a powder-filled pouch laminated between a top cover
film with oxygen-regulating holes and a bottom film with a
pressure-sensitive adhesive layer.
 Upon contact with oxygen in ambient air, a chemical reaction
occurs in the heat-generating medium.
30

31. 31

32. CONCLUSION
 Transdermal drug delivery is hardly an old technology, and the
technology no longer is just adhesive patches.
 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.
 It promises to eliminate needles for administration of a wide
variety of drugs in the future.
 TDDS have great potentials, being able to use for both
hydrophobic and hydrophilic active substance into promising
deliverable drugs.
 TDDS realistic practical application as the next generation of
drug delivery system.
32

33. REFERENCES
 Abdul Hafeez et.al; Recent Advances in Transdermal Drug
Delivery System (TDDS); Journal of Scientific and Innovative
Research 2013; vol 2 (3); pp733-744.
 J.D Yadav; Microneedles: Promising Technique For Transdermal
Drug Delivery; International Journal of Pharma and Bio
Sciences.2011;2(1); pp:685-708.
 Peng HM et.al; Ultrason Sonochem. 2016 Nov 2; pii: S1350-
4177(16)30366-2.
 Shayan F. Lahiji et.al; Scientific Reports 5; Article number: 7914
(2015).
 Yeu-Chun-Kim et.al; Advance Drug Delivery Review.; 2012 Nov;
64(14); pp1547–1568.
33

34. REFERENCES
 http://www.fda.gov/downloads/advisorycommittees/committe
esmeetingmaterials/drugs/advisorycommitteeforpharmaceutic
alscienceandclinicalpharmacology/ucm178989.pdf. (accessed
on 18/11/2016).
 http://www.ijddr.in/drug-development/a-review-transdermal-
drug-delivery-system-a-tool-for-novel-drug-delivery-
system.php?aid=5627 (accessed on 22/11/2016).
34

35. 35