PRESENTATION OUTLINE 1.Introduction 2.Evaluation Of Transdermal Drug Delivery System 2.1 Physicochemical Evaluation 2.2 In Vitro Release Studies 2.3 In Vivo Evaluation 2.4 Cutaneous Toxicological Evaluation 3. Recent Techniques For Enhancing TDDS 3.1 Structure Based Enhancemnet Techniques 3.2 Electrically Based Enhancement Techniques 3.3 Velocity Based Enhancement Techniques 3.4 Other Enhancement Techniques 4. Conclusion 5. References 1.Introduction :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. 2.Evaluation of Transdermal Drug Delivery System: 2.1Physicochemical Evaluation: Physicochemical Evaluation In Vitro Release Studies In Vivo Evaluation Cutaneous Toxicological Evaluation 2.2. In Vitro Release Studies ●The Paddle over Disc: The transdermal system is attached to a disc or cell resting at the bottom of the vessel which contains medium at 32 ±5°C. ●The Cylinder modified USP Basket: The system is attached to the surface of a hollow cylinder immersed in medium at 32 ±5°C. ●Franz diffusion cell: The cell is composed of two compartments: donor and receptor. The receptor compartment has a volume of 5-12ml and effective surface area of 1-5 cm.The diffusion buffer is continuously stirred at 600rpm by a magnetic bar. 2.3. In Vivo Evaluation ●Animal models: The most common animal species used for evaluating transdermal drug delivery system are mouse, hairless rat, hairless dog, hairless rhesus monkey, rabbit,guinea pig etc. ●Evaporative water loss management: Content irritation also disrupts the stratum corenum barrier and causes and excessive water loss from the damaged surface that can be measured means of evaporimetry. 3. Recent Techniques for Enhancing TDDS 3.1. Structure-Based Enhancement Techniques ●Macroflux: This technology offers a needle-free and painless transdermal drug delivery of large-molecular-weight compounds such as insulin,several peptidic hormones, and vaccines. ●Microfabricated Microneedles: A transdermal patch or skin adhesive patch is that device which is loaded with drug candidate and usually applied on the skin to transport a specific dose of medication across the skin and into the blood circulation. 3.2.Electrically-Based Enhancement Techniques ●Ultrasound: In this technique, there is a mixing of drug substance with a coupling agent (usually with gel, cream or ointment) that causes ultrasonic energy transfer from the system to the skin. ●Iontophoresis: 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 3.3. Velocity Based Enhancement Techniques: ●Needle-Free Injections: The liquid or solid particles are fired at supersonic speeds through the outer layers of the skin using a reliable energy source for delivering the drug.

1. “EVALUATION AND RECENT TECHNIQUES
OF TRANSDERMAL DRUG DELIVERY SYSTEM”
Project of PracticeSchool on
MERULING SHIKASHAN SANSTHA’S
COLLEGE OF PHARMACY, MEDHA, SATARA.
MAHARASHTRA (INDIA),
YEAR 2021-2022
PRESENTED BY
Mr. Rahul B. Gole
PRN No. 51639020181382310034
UNDER THE GUIDANCE
Asst. Prof. Mr. Junghare S. L.
(M. Pharm in Pharmaceutics)
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2. PRESENTATION
OUTLINE
1.INTRODUCTION
2.EVALUATION OF TRANSDERMAL DRUG DELIVERY SYSTEM
2.1 PHYSICOCHEMICAL EVALUATION
2.2 IN VITRO RELEASE STUDIES
2.3 IN VIVO EVALUATION
2.4 CUTANEOUS TOXICOLOGICAL EVALUATION
3. RECENT TECHNIQUES FOR ENHANCING TDDS
3.1 STRUCTURE BASED ENHANCEMNET TECHNIQUES
3.2 ELECTRICALLY BASED ENHANCEMENT TECHNIQUES
3.3 VELOCITY BASED ENHANCEMENT TECHNIQUES
3.4 OTHER ENHANCEMENT TECHNIQUES
4. CONCLUSION
5. REFERENCES
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3. Introduction
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. The patch contains substances that can pass
through the skin and into the bloodstream. Drugs that are applied to the skin as patches scopolamine, nicotine,
oestrogen, nitroglycerin, and others as well as Lidocaine.
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4. Evaluation of
Transdermal Drug
Delivery System
 Physicochemical Evaluation
 In Vitro Release Studies
 In Vivo Evaluation
 Cutaneous Toxicological Evaluation
The evaluation methods for transdermal dosage form can be
classified into following types:
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5. Physicochemical
Evaluation
 Thickness
The thickness of transdermal film is determined by travelling
microscope, dial gauge, screw gauge or micrometer at different points
of the film.
 Uniformity of weight:
Weight variation is studied by individually weighing 10 randomly
selected patches and calculating the average weight.
 Drug content determination
An accurately weighed portion of film (about 100 mg) is dissolved in
100 mL of suitable solvent in which drug is soluble and then the
solution is shaken continuously for 24 h in shaker incubator. Then the
whole solution is sonicated. After sonication and subsequent filtration,
drug in solution is estimated spectrophotometrically by appropriate
dilution.
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6. Physicochemical
Evaluation
 Moisture Uptake
The prepared films are weighed individually and kept in a desiccators
containing calcium chloride at room temperature for 24 h. The films are
weighed again after a specified interval until they show a constant
weight.
The percent moisture content is calculated using following formula.
% Moisture content = Initial weight – Final weight X 100
 Flatness
One strip is cut from the center and two from each side of patches. The
length of each strip is measured and variation in length is measured by
determining percent constriction. Zero percent constriction is equivalent
to 100 percent flatness.
% constriction = I1 – I2 X 100
I2 = Final length of each strip I1 = Initial length of each strip
 Folding Endurance
Repeatedly folding the film at the same place until it break. The number
of times the films could be folded at the same place without breaking is
folding endurance value.
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7. Physicochemical
Evaluation
 Tack properties
To determine tensile strength, polymeric films are sandwiched
separately by corked linear iron plates.
Tensile strength= F/a.b (1+L/l)
F is the force required to break; a is width of film;
b is thickness of film; L is length of film;
l is elongation of film at break point.
a. Thumb tack test
b. Rolling ball test
c. Quick stick (Peel tack) test
d. Probe tack test
It is the ability of the polymer to adhere to substrate with little contact
pressure. Tack is dependent on molecular weight and composition of
polymer as well as on the use of tackifying resins in polymer.
 Tensile Strength
Rolling Ball Test Apparatus
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8. In Vitro Release
Studies
 The Paddle over Disc
 The Cylinder modified USP Basket
The transdermal system is attached to a disc or cell resting at the
bottom of the vessel which contains medium at 32 ±5°C.
The system is attached to the surface of a hollow cylinder immersed in
medium at 32 ±5°C.
 The reciprocating disc
In this method patches attached to holders are oscillated in small
volumes of medium, allowing the apparatus to be useful for systems
delivering low concentration of drug. In addition paddle over
extraction cell method may be used.
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9. In Vitro Release
Studies
 Franz diffusion cell
The cell is composed of two compartments: donor and receptor. The
receptor compartment has a volume of 5-12ml and effective surface area
of 1-5 cm.The diffusion buffer is continuously stirred at 600rpm by a
magnetic bar. The temperature in the bulk of the is maintained by
circulating thermostated water through a water jacket that surrounds the
receptor compartment.
Franz diffusion cell
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10. In Vivo Evaluation
 Animal models
The most common animal species used for evaluating transdermal drug
delivery system are mouse, hairless rat, hairless dog, hairless rhesus
monkey, rabbit,guinea pig etc.
 Human models
Clinical trials have been conducted to assess the efficacy, risk involved,
side effects, patient compliance etc.
a. Phase I clinical trials are conducted to determine mainly safety in
volunteers
b. Phase II clinical trials determine short term safety and mainly
effectiveness in patients.
c. Phase III trials indicate the safety and effectiveness in large number of
patient population
d. Phase IV trials at post marketing surveillance are done for marketed
patches to detect adverse drug reactions.
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11. Cutaneous
Toxicological
Evaluations
 Content irritant dermatitis
Content irritant dermatitis result form direct toxic injury to cell
membrance, cytoplasms or nuclei. This is generally manifested by
information, cutaneous erythema and itching and can occur from the
drug, vehical, adsorption enhancers and form of the adhesive use to
secure the system. Screening of new systems for contact irritant
dermatitis involves use of animals like rabbit guinea pigs.
 Evaporative water loss management
Content irritation also disrupts the stratum corenum barrier and causes
and excessive water loss from the damaged surface that can be measured
means of evaporimetry.
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12. Recent Techniques for
Enhancing TDDS
 Structure-Based Enhancement Techniques.
 Electrically-Based Enhancement Techniques.
 Velocity Based Enhancement Techniques
 Other Enhancement Techniques
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13. Structure-Based
Enhancement
Techniques
 Transdermal Patches
A transdermal patch or skin adhesive patch is that device which is loaded
with drug candidate and usually applied on the skin to transport a specific
dose of medication across the skin and into the blood circulation.
 Microfabricated Microneedles
The systems consists of a drug reservoir and a some projections
(microneedles) extending from the reservoir, these helps in penetrating
the stratum cornea and epidermis to deliver the drug.
 Macroflux
This technology offers a needle-free and painless transdermal drug
delivery of large-molecular-weight compounds such as insulin,several
peptidic hormones, and vaccines. With this new system; patients can
receive drugs for 12 weeks
Macroflux
13

14. Electrically-Based
Enhancement
Techniques
 Iontophoresis
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
 Ultrasound
In this technique, there is a mixing of drug substance with a coupling
agent (usually with gel, cream or ointment) that causes ultrasonic
energy transfer from the system to the skin.
 Electroporation
This application involves short electrical pulses of DC voltage 4100 V
for milliseconds .This technique works in either of the two ways: first is
pore formation in lipid bilayers,corneocytes but small-charged molecules
cannot pass via this route and the second is applying high voltage.
Iontophoresis
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15. Velocity Based
Enhancement
Techniques
 Needle-Free Injections
The liquid or solid particles are fired at supersonic speeds through
the outer layers of the skin using a reliable energy source for
delivering the drug.
 Powderject Device
The solid drug particles are propelled across the skin with the aid of
high-speed gas flow.
Needle-Free Injections
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16. Other Enhancement
Techniques  Skin Abrasion
 Laser Radiation
This involves the exposure of the skin to the laser beam that results in
the ablation of the stratum cornea without damaging the epidermis
which remains in contact with it.
 Medicated Tattoos
Is a modification of temporary tattoo which contains an active drug
substance for trandermal delivery. useful in the administration of drug
in those children who are not able to take traditional dosage forms.
This involve direct removal or disruption of the upper layers of the skin to
provide better permeation of topically applied drug substance.
Skin Abrasion
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17. Conclusion
Transdermal drug delivery is a painless, convenient, and potentially effective way to deliver
regular doses of many medications. Wide range of drugs can be delivered improved drug
uptake Minimal complications and side effects low cost and easy to use. Example Ten years
ago, the nicotine patch had revolutionized smoking cessation; patients were being treated with
nitroglycerin for angina, clonidine for hypertension, scopolamine for motion sickness and
estradiol for estrogen deficiency, all through patches used by over a million patients per year.
Reference
1. Panchagnula R., Transdermal delivery of drugs. Indian journal of pharmacology, 1997; 29:140-156.
2. Wilkosz W., Transdermal Drug Delivery: Part I. U.S. Pharmacist. Jobson publication, 2003: 04.
3. Jayaswal S., Sood R., Transdermal drug delivery system A Review The Eastern Pharmacist., 1987;
30(357): 47-50.
4. Prausnitz M., Langer R., “Transdermal Drug Delivery.” Nature Biotechnology, 2008; 26(11): 1261-1268.
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