Drug Absorption Flashcards
Pharmacodynamics
The mechanism of drug actions Pharmaological effect Clinical response (efficacy or toxicity)
Pharmacokinetics
Examines the movement of a drug over time though the body
Adminstration > concentration > site of action > distribution > metabolized/excreted
Bioavailability
Percent of the dose that gets into the body
Bioequivalence
Similarity between two formulas of the same drug
Speed of drug onset
How long it takes the drug to being working
Dosing Interval
How often the drug should be give
Site of action
Whether the drug stay local or acts systemically
What is drug administration?
Movement of drug molecules across biological barriers from the site of administration of the blood stream
What will the rate of drug absorption be affected by?
Rate of release of drug from pharmaceutical prep
Membrane permeability of drug
Surface area in contact with drug
Blow flow to site of absorption
Destruction of a drug near site of absorption
What is the dosage form?
The determinate of how much drug is released
If a drug comes in solution form and gets shot into your arm what is the response like?
Immediate
If you take some pills and capsules of vitamin D because you never go outside what is the release like?
Delayed dissolution and then rapid release
Rub that cream on your skin. So nice. What is the release like?
No delay but slow release
What type of additive (excipients) will decrease the rate of dissolution?
Binder
Lubricants
Coating agents
What type of additive (excipients) will increase the rate of dissolution?
Disintegrants
What type of additive (excipients) will have variable effects on the rate of dissolution?
Diluents
Coloring agents
Flavoring agents
Which type of tablet will dissolve slowly?
Hard tablet
Round tablets
Large tablet
What is the benefit of an enteric coating?
Will dissolve in intestine but not the in the stomach
What type of sustained release is reservoir diffusion?
Drug diffuses from pill to core through membrane shell
What type of sustained release is matrix diffusion?
Drug diffuses through matrix which is embedded
What type of sustained release is matrix dissolution?
Drug released as matrix dissolves
What type of sustained release is osmotic tablets?
Drug pumped out of tablet by osmotic forces
What type of sustained release is ion-exchange?
Drug bound to resin exchanges with endogenous ions
What is lipophilicity?
Increases the membrane permeability
Where would you find lipophilicity things happening?
In the presence of aliphatic and aromatic structures
Absence of polar groups
What is ionization for drug permeability?
Decreases membrane permeability
What happens to acid and base drugs and where are they ionized?
Weak acids in intestine
Weak bases in stomach
Screw the henderson-hasselback quation.
I hate it.
pH = pka + ([nonprotonated species]/[protonated species])
What are low surface areas for drug absorption?
Eyes, nasal cavity, buccal cavity, rectum, stomach, large intestine
What are high surface areas for drug absorption?
Small intestines and lungs
Where would there be low blood flow physiological for drug absorption?
Eyes, stomach, large intestine, rectum, subcutaneous tissue
Where would there be high blood flow physiological for drug absorption?
Small intestines, lungs, muscle, buccal cavity and nasal cavity
What are some factors that influence blood flow based on pharmcology?
Vasoconstrictors
Co-administration with vasoconstrictors
Vasodilators
What determines whether a drug is destroyed at or near site of administration?
The biochemistry of the drug
Liver - hepatic enzymes (“first pass”
Colon - intestinal microfolra
Stomach - digestive enzymes and acids
What are some direct, non-invasive way to take a drug?
Oral
Sublingual
Rectal
