Transdermal drug delivery are defined as a self contained discrete dosage form which, when applied to the intact skin, will deliver the drug at a controlled rate to the systemic circulation. its also known popularly as “patches”

1. APPROACHES USED IN
DEVELOPMENT OF
TRANSDERMAL DRUG
DELIVARY SYSTEM
Submitted By:- Subhajit dutta
Roll no.-B15006
B.pharm,3rd Year

2. CONTENTS
INTRODUCTION
ADVANTAGE
DISADVANTAGE
STRUCTURE OF HUMAN SKIN
PROCESS OF TRANSDERMAL PERMEATION
BASIC COMPONENTS
APPROACHES AND DEVELOPMENT OF TDDS
REFERENCE

3. INTRODUCTION
• Definition:
• Transdermal drug delivery
are defined as a self
contained discrete dosage
form which, when applied to
the intact skin, will deliver
the drug at a controlled rate
to the systemic circulation.
 Also known popularly as
“patches”

4. ADVANTAGES
Avoid the stomach environment.
Avoid the first pass effect
Non invasive
Self administration is possible
Drug with narrow therapeutic indices can be safely
administered.
Allows effective use of drug with short biological half life.
Easy to prepare and easy to transport.

5. Only potent drugs are suitable candidate.
Unsuitable for drugs that irritate or sensitize the
skin.
Maintaining contact between device & skin can be
problem.
The barrier function of skin change from one site
to another on same person ,from person to person
& with age.
Some patients develop contact dermatitis at the
site of application.

6. STRUCTURE OF HUMAN SKIN
SKIN :
Skin is the largest organ of the
human body, providing around
10% of the body mass of an
average person , and it covers
an average area of 1.7 m2. Such
a large and easily accessible
organ apparently offers ideal &
multiple sites to administer
therapeutics agents for both
local and systemic actions.

7. PROCESS OF TRANSDERMAL PERMEATION
•Sorption by stratum corneum.
•Penetration of drug through viable epidermis.
•Uptake of the drug by a capillary network in the
dermal papillary layer.

8. BASIC COMPONENTS
 POLYMER MATRIX:
1. Natural polymer- Gelatin, Starch, Waxes, cellulose derivatives.
2. Synthetic Elastomers- Neoprene,silicon rubber,butyl rubber.
3. Synthetic polymer- polyethylene, PVC, polyacrylate, PVP,
polyamide.
 DRUG:
Selection parameter-
o Biological properties-1.therapeutic index 2.biological halflife
3.drug inactivation 4.skin toxicity
o Physicochemical properties-1.Mol. Wt 2.melting point 3.PH.

9.  PERMEATION ENHANCERS:
These are compound which are used to improve or alter
the permeability of skin by altering the barrier function of
the skin.
Ex. 1.Water 2.sulphoxide 3.Fatty acid &alcohols
4.surfactants-anions,cations and nonionic.
OTHERS EXCIPIENTS:
• Adhesives:-
1.Used for the fasting purpose.
Ex. Polyisobutylenes, acrylins,silicones.
• Backing Membrane:-
1.Hold and protect the drug reservoir from exposure to
atmosphere to avoid loss of drug.
2.Accept printing
Ex. Metallic plastic laminate, aluminium foli.

10. APPROACHES
AND
DEVELOPMENT

11. Drug reservoir is encapsulated in a shallow compartment moulded
from a drug- impermeable metallic plastic laminate and a rate
controlling ploymeric membrane which may be micro porous or
non-porous.
 The drug molecules are permitted to release only through the
rate- controlling polymeric membrane.
Eg.Transderm-scop(scopolamine)for motion sickness.

12. This is the simplified form of the membrane permeation –controlled
system.
The drug reservoir is formulated by directly dispensing the drug in
an adhesive ploymer. E.g. polyisobutylene.
Then spreading the mediated adhesive,by solvent casting or hot
melt, on to a flat sheet of drug impermeable metallic plastic backing to
form a thin drug reservoir layer.
Eg. Deponit system containing nitroglycerine for angina pectoris.

13.  The drug reservoir is formed by homogenously dispersing the drug
solids in a hydrophillic or lipophillic polymer matrix.
The medicated polymer is then molded into a medicated disc with a
defined surface area and controlled thickness.
Drug reservoir containing polymer dics is then pasted onto an
occlusive base plate in a compartment fabricated from a drug
impermeable plastic backing membrane
E.g. Nitro-Dur system for angina pectoris.

14. The micro reservoir type drug delivery system can be
considered a combination of the reservoir and matrix diffusion
type drug delivery system.
 This transfer is then produced by positioning the medicated
disc at the centre and surrounding it with an adhesive rim.
E.g. Nitrodisc system for angina pectoris.

15. REFERENCES:-
Lachman/lieberman’s ,Transdermal drug delivary system :A novel
drug delivery system,The Theory and Practice of Industrial
Pharmacy,CBS publication,4th edition:2013,(885-886).
N.K. Jain ,Transdermal drug delivery system :A Novel Drug
Delivery System, Controlled and Novel Drug Delivery, CBS
Publication, 1st edition:2001,(322-340).