This document discusses topical and transdermal drug delivery systems. It defines a topical drug delivery system as applying medication onto the skin to treat ailments. Topical systems are classified by physical state as solid, liquid, or semisolid and can be applied externally or internally. Transdermal drug delivery involves a medicated adhesive patch that delivers medication through the skin and into the bloodstream. Both systems avoid first-pass metabolism and provide convenient dosing but can cause skin irritation and have limitations on drug permeability and the types of drugs that can be delivered.

1. Topic: Topical & Transdermal Drug Delivery
System
Name: Muhammad Haider Ali
Roll No: 43

2. 1- Topical Drug Delivery System:
DEFINITION:
A topical drug delivery system is a way to deliver
medication that is applied onto a particular part of the
body, typically the skin, to treat various ailments e.g.
(acne).

3. Types of topical drug delivery system:
 Includes two types of topical drug delivery system.
 External: spread or dispersed on the cutaneous surface
 Internal: applied to mucous membranes e.g. eye(conjunctiva),
ear, nasal cavity.
 Classification based on physical state.
 Solid: Powder, aerosol, plasters.
 Liquid: lotion, liniment, solution, emulsion, suspension.
 Semisolid: ointment, cream, paste, gel, suppository.

4. Advantages:
 Avoidance of first pass metabolism.
 Easy application.
 Avoidance of the risks and inconveniences of administration.
 Achievement of efficacy with lower total daily dosage of drug
by continuous drug input.
 Avoids fluctuation in drug levels.
 Easy termination of medications when needed.
 Relatively large area of application.
 Drug can be delivered more selectively to a specific site.

5. Continued:
 Avoidance of gastro-intestinal incompatibility.
 Provide utilization of drugs with short biological half life.
 Improve patient compliance.
 Suitable for self medication.

6. Disadvantages:
 Skin irritation.
 Poor permeability of some drugs through the skin.
 Possibility of allergic reactions.
 Enzymes in epidermis may denature the drug.
 Drugs with larger particle size are difficult to get absorb
through the skin.

7. 2- Transdermal drug delivery system:
DEFINITION:
 Transdermal drug delivery is 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 defined as medicated adhesive patch that is placed on
the skin to deliver a specific dose of medication through the
skin and into the blood stream.

8. Examples:

9. Advantages:
 Easy to use.
 Avoid GIT absorption problems for drugs.
 Avoids first pass metabolism of drugs.
 More improved and convenient patient compliance.
 Rapid termination in case of toxicity is possible.
 Self medication is possible.
 Reduces the frequency of dosing.

10. Disadvantages:
 Daily dose of more than 10 mg is not possible.
 Local irritation is a major problem.
 Drug requiring high blood levels are unsuitable.
 Drug with long half life cannot be formulated in TDDS.
 Uncomfortable to wear.
 Barrier function changes from person to person and within
the same person.

11. Thank You