The ____ of the tiger
List the order from most bioavailability to lowest bioavailability for solutions, ointments, gels, and suspensions
which type is the most common?
gel, ointment, suspension, solution
solution
what is a liposome and why would one be used?
small spherical vesicle made of phospholipids-- can have multiple bilayers
biocompatible to body
biodegradable in body
used for drug delivery-prolonged release-- protection against some side effects
surface can be modified
what type of containers are semi-solid preparations found in?
well closed or tight?
where should these containers be stored
Found in large mouth ointment jars or metal/plastic tubes
Well-closed containers
cool area
what is the target for TDDS systems
are side effects like nausea and gastritis expected?
skin-- no blood exposure
no-- should have no systemic side effects
what percent of ocular medicine is through the topical eye drop route
what is the percentage ocular bioavailability of aqueous ophthalmic solutions
90%
5%
what must a formulation contain for safe and effective ocular delivery (6)
what range of tonicity can the eye handle?
what is the pH of tears
what can be used to help viscosity?
preservatives, buffers, isotonicity, sterility, clarity, viscosity
0.6-1.8
7.4
Methylcellulose
Hydroxypropyl methylcellulose
Hydroxyethyl cellulose
Polyvinyl alcohol
what is liposome extrusion
what is used as a membrane for liposome extrusion
technique where lipososome suspension is passed through a membrane filter of defined pore size
polycarbonate
what are the advantages of creams
easier to spread and remove
consistency is is soft and spreadable
as the surface area of a patch increases, does the amount of drug released increase or decrease
increase
what size should particles be in ophthalmic suspensions be to not cause eye irritation
what is the drug release time period for ocular implants
< 10 mcm
5-6 months
Compare and contrast collagen shields and implants
longer term comparted to conventional-- go on the eye
Shields: shorter term compared to implants- like a bandage-- used for people with corneal surgery
implants-- last 5-6 months-- more invasive-- treats posterior eye problems
what are the four types of liposomes
stealth-sterically stabilized- polymer coating -- longer circulation time
immunoliposome-- antibody modified
cationic -- positive charge to deliver nucleic acids
conventional- neutral or negative charge
what percentage of pastes are made from powdered solids that are put into a hydrophobic base?
20-50%
iontophoresis, phonophoresis, and electrophoration are all examples of what type of enhancing method?
physical-- or electrically
what is the size of a liposome
what size must tumors reach for them to undergo angiogenesis
20 nm- 10 mcm
2-3mm
What are the four ways to sterilize something
steam autoclave 121 degrees Celsius 15 minutes
filtration 0.22 micrometers
Gas sterilization – ethylene oxide
Gamma radiation-- $$-- works for heat sensitive
what is the EPR effect
Molecules with smaller sizes accumulate in tumor tissue faster than normal tissue
tumor tissue/cells grow quickly
Blood vessels of tumors start forming and are abnormal
The shape is not normal- this leads to dilated, leaky, defective endothelial cells—not aligned- large gaps
This leads to the nanoparticles leaking into the tumor tissue
what are the four types of semi-solid preparations?
do all semi-solid preparations contain an API?
gel, ointment, cream, paste
no
what are the four types of microneedles
Solid-- no drug in needle just poke
Coated-- drug is coating needle
Dissolving--- drug dissolves through needle
Hollow--- drug goes down through bottom of needle
what percentage of finely powdered solids to pastes contain
what percentage of drugs are bases
20-50%
75%
Describe the physiological effects of the eye that must be considered for using drops
Cornea is primary route of topical drug absorption
Outer layers are lipophilic
Inner layers are hydrophilic
Drugs with Log P 2-3 and Low MW do the best
what is the difference between doxorubicin and doxil?
one is stealth and one isn't
Doxorubicin** no stealth —cancer drug half life is 20 min
Doxil—stealth and PEG—half life is 55 hours
What are the four types of ointment bases
which ones are more hydrophilic
which ones are more hydrophobic
hydrocarbon- phobic
absorption-- phobic
emulsion-- philic
water soluble -- philic
what can you do to the stratum corneum to modify it to help enhance transdermal drug delivery
chemically enhance-- damage/ pull apart
hydrate
ablasion- destroy
or bypass- through microneedles or follicular delivery
what is the temperature for long term testing
what is the relative humidity for an accelerated test
75%