Transdermal Flashcards
Transdermal Delivery Systems are Designed to?
Support?
Support the passage of drug substances from the surface of the skin, through its various layers and into the systemic circulation
What you need to know
4 things
Two Types of Dermal Drug Delivery
How are these applied and what are thet for?
Functions of the Skin
4 functions
Structure of the skin draw it
how thick is each part?
What is the structure of the epidermis
5 layers
How thick is the stratum corneum? What are its features? What is it made up of?
Epidermis
What are the 5 layers
What is the most important for barrier to chemical penetration?
What type of vasculature?
Turnover of the epidermis is how many days?
Where is the highest turnover?
How much moisture to remain soft and supple?
Dermis
70% of it is made up of? What does this provide?
What is loosely arranged in all directions and provide the stretchyness to the skin
Contains cells that synthesize collagen, elastin and other connective tissued what is the cell?
Also contains three other cell types
What is increased here?
Dermis
Contains a supply of? What 3 things
How do drugs diffuse through this area? 70% of it is?
The dermis contains what 3 things
What are the 4 cells in the dermis
What is the subQ layer made of
What are sebaceous glands associated with?
This gland is dep on?
Increase of activity in?
What are the 3 functions of sebum
Eccrine gland what type of gland? What 2 types of stimulation does it respond to?
Apocrine gland known as what type of gland? Associated with? And doesnt appear until? What type of secretions? Development of? Largest number are found in?
Melonocytes
Frequency when are they found?
Synthesis and distribution of? This is capable of?
Landerhans cells?
Important aspects of the Stratum Corneum
- How thick?
- Blocks of? Embedded in?
- Shape of cells? These dont have a?
- Barrier in permeation of?
- Arranged?
Composition of Human Strat corn
Chart
Diffusivities of water through the stratum corneum and other membranes
What is the take away from this?
Mechanism od drug absorption though the skin
Ficks First law of diffusion for drug transport accross the stratum corneum
Matching
steady-state flux across stratum corneum
thickness of the stratum corneum
partition coefficient of drug between skin and formulation
diffusion coefficient or diffusivity of drug molecules
drug concentration gradient across the stratum corneum
Simple diffusion
Absorption of drug is affected by 5 things?
Pathways of Drug permeation through skin think of transport
Transappendageal
What is the route of penetration here?
Hair Folicles
Sebumand what not
General rules for diffusion through skin
7 rules
Factors Affecting Transdermal Bioavailability
6 Physiological and 6 formulation
Site of permeation
Normal vs. Acne
Effect of water hydration
SS Transdermal fluxes, permeability, and their physiochemical structure
Look at the data and compare them
Effects of Area
Biotransformation of Xenobiotics into the Skin
8
Topical Drug Delivery
Classifications of Semisolids according to action of drug or base on skin.
Types of Vehicles
6 types
What Transdermal vehicles? 2 kinds and what are the subtypes
WHat are the four types of ointments or creams?
How do you describe an ointment?
What are the ointment 4 types of ointment bases?
What are creams?
What are the two different types?
Compared to ointments? Is it easy to spread?
What type of lesions is it for?
Gels
_____ ____ network of inorganic molecules what two types?
Washable in?
How is the drug dispersed in these?
The rate of drug release compared to ointments and creams?
What are 3 examples of useful gels?
Pastes
Larger portion of _____ than ointment
These are usually less _____ than ointment
Doesnt get?
This shouldnt be applied where?
Washable in?
Thing of Kris when he was putting sunscreen on.
Vehicle Effects
Hydrophobic products directly affect?
- How is drug absorption enhanced? What is happening to the stratum corneum?
- What types of substances are these?
- What type of creams?
Relatively hydrophilic substance (What do they cause between drug and the vehicle?) What are the 3 examples?
Greasy Products (2 Examples)
- Who are they preferred for?
- What can they do to clothing?
- Good for the drug that wants to do?
Creams: Have what type of effect?
What do gels provide? Think of release, what is it useful for?
Lotions and creams are unstable to?
Charts Go through or dont
Chart
Chart
Charts
What is the principle barrier for transdermal drug delivery?
Permeability correlates with what properties of the drug? 3 things
Transdermal systems are usefule for drugs that need ____ ____ and have high what?
What are some benefits to using a transdermal drug system?
8 products that are transdermal
TEN NECs and?
Properties of transdermal drugs
WHich one has the lowest efficacous blood level and which one has the highesT?
General rules for a transdermal patch 4 with their values and there is no requirement for?
Advantages and Disadvantages of Transdermal
7 Pros
4 Cons
Disadvantages of TDDS
- You need a drug that can absorb properly and is ____ but it has to have a low?
- What does the dose have to be? So what type of activity does it have to have?
- The drugs have to have a?
- What is possible at the site of application?
- The time to reach steady state?
