1. TRANSDERMAL DRUG DELIVERY SYSTEM Ms.Wajiha Iffat M.Pharm
DEFINITION
TYPES OF TDDS
FACTORS AFFECTING TDDS
TDDS IN USE

2. Transdermal Drug Delivery System (TDDS)
A self-contained, discrete dosage form
It delivers a drug through intact skin at a controlled rate into the systemic circulation
Delivery rate is controlled by the skin or membrane in the delivery system

3. Transdermal Drug Delivery System
TDDS:
A sophisticated complex drug delivery system difficult to formulate. It requires specialized manufacturing process/equipment.
Formulated to meet specific biopharmaceutical and functional characteristics. The materials of construction, configuration and combination of the drug with the proper cosolvent, excipient, penetration enhancer, and membrane are carefully selected and matched to optimize adhesive properties and drug delivery requirements.
Formulated to deliver the drug at optimized rate into the systemic circulation
should adhere to the skin for the expected duration
should not cause any skin irritation and/or sensitization

4. Transdermal Drug Delivery System
Types of TDS
Liquid Reservoir Patch
Drug in solution or suspension between the backing layer and a rate controlling membrane. Active, gelling agent, solvent, penetration enhancer, adhesive, membrane, backing, release liner
Drug in Adhesive Patch
Drug dispersed in adhesive, in direct contact with skin.
Active, pressure sensitive adhesive, solvent, penetration enhancer, backing, release liner
Polymer Matrix Patch
Drug in solution or suspension dispersed within a polymer
Multi-laminate Matrix Patch
Drug dispersed in adhesive in multi-layers separated by membranes

6. Transdermal Drug Delivery System
TDDS IN USE:
GLYCERYL TRINITRATE & ISOSORBIDE DI NITRATE for treatment of angina , Congestive heart failure & myocardial infarction.
Designed to deliver drug for 24 hrs
Applied to chest area.
Free drug period necessary to prevent tolerance.

7. Transdermal Drug Delivery System
TRANDERMAL ESTRADIOL
Estradiol for alleviation of menopausal symptoms and prevention of osteoporosis.
Treat symptoms of menopausal or post menopausal such as flushing & vaginal atropy.
these patches are applied once or twice weekly to skin below the waist ( away from breast .
They can used alone or in combination with progestogens.

8. Transdermal Drug Delivery System
TRANDERMAL NICOTINE
Nicotine in the alleviation of with drawl symptoms in smoking cessation provides an alternative route of administration to the gum, sprays etc.
Patches are used for hrs period & are available in the range of strength – rate of delivery of nicotine.
They provide high plasma level obtained from smoking. they may other beneficial status in other disease states.
Applied to the trunk.

9. Transdermal Drug Delivery System
TRANDERMAL HYOSCINE:
to treat symptoms of travel sickness. For up to 24hrs.
Applied to behind of ear.
70% control of patch.
Dry mouth: instrumentalist in orchestra –decrease salivation
Decrease side effect of oral hyoscine: excitement,vertigo ,confusion & hallucination
Control emetic side effect of anti cancer drug
Inhibits sickness & control vertigo
Testestrone: applied to the trunk .used for hormone replacement.

10. Transdermal Drug Delivery System
Advantages:
Continual drug delivery
No drug deactivation by gastric juices
No first pass effect
Cessation of treatment by removal of patch.

11. Transdermal Drug Delivery System
Disadvantages:
Only potent drug to be incorporated.
Small quantity absorbed so lipid soluble drug are effective.
Durg with long half life …not suitable.
Localized reaction because of irritancy of drug.e.g, clonidine (new patch to be placed each time.
Steady state blood level have produced tolerence.16 hr patch .& 8 hr free time.

12. Method of use:
Applied to clear dry skin
Old patch to be removed first
Area of application to be different from previous location.( to maintain same level of absorption.
Patch to be disposed of care fully.
Patch should be folded together to avoid being stuck to other person.