Transdermal Patches Flashcards
Define the transdermal patches
Is a medicated adhesive patch that is placed on yhe skin to deliver a specific dose of medication through the skin and into the bloodstream.
What are the types of patches?
1-single layer drug-in-adhesive(adhesive controlled)
2- Reservoir (membran controlled)
3-Multi-layered drug-in-adhesive(adhesive and membrane controlled)
4-Matrix controlled
What is the function of backing layer?
Prevent the drug to move in post direction and force the drug to move only in one direction towards the skin.
What are the functions of the drug-in-adhesive layer?
1_Affix the system to the skin.
2_As a carrier or vehicle or fundation containing drug and exciptients.
What are the single-layer drug-in adhesive characterized by?
Is characterized by inclusion of the drug directly within the skin contacting adhesive.
What are the rates of release of drug depend on in SINGLE-LAYER DRUG-IN ADHESIVE PATCHES?
Is dependent on the ability of the drug to diffuse across the skin
What are the reservoir transdermal system chracterized by ?
Is characterized by inclusion of a liquid compartment containing drug solution or suspension separated from the release liner by semi-permeable membrane and adhesive.
What are the rate of release of the drug from the patch of reservoir system depened on?
1-The type and the pore size of the membrane.
2-The ability od the drug to diffuse through the skin.
Why the multi-layerd drug-in adhesive is similar to singl-layer drug-in adhesive ?
Because that the drug are incorporated directly into adhesive.
The rate of release of the drug in multi-layer drug-in adhesive is dependent on …
1_The thickness of the patches.
2-The number of layer.
3-The ability of the drug to diffuse through the skin.
What are the matrix controlled patchs characterized by?
By the inclusion of semisolid matrix(hydrophilic or hydrophobic polymer containing drug solution or suspension) which is in direct contact with release liner.
What are the release rate of the drug from matrix controlled patches depened on?
1-Physicochemical interaction between the matrix and the drug.
2_The diffusion of the drug across the skin.
