high-frequency ultrasound facilitates drug penetration through the stratum corneum
a microchip embedded in the patch
Ex: salycylic acid for warts, lidocaine also, hydrocortisone
T/F: a patch is a rate-controlled system.
T/F: patches deliver a drug at a controlled rate to intact skin without buildup in the dermal layers.
T/F: patches release the drug promptly from the system into the s. corneum for penetration into the general circulation for systemic effects.
What is a therapeutic advantage of a patch that other dosage forms lack?
no drug is lost
they cause occlusion of the skin so there is only a 1-way flux of drug
Patches should cause no irritation or sensitization to the skin due to the _______, ______, or _________?
drug, vehicle, or adhesive used
Which dosage form is 'paradise for compliance' according to G?
What are some advantages of a patch?
avoid GI difficulties
substitute for oral administration
avoid first pass effect
substitute painful parenteral administration
provide multi-day therapy with a single application
drug's effect can be terminated by removing the patch
fast ID during an emergency (no medical record needed)
What are some disadvantages of a patch?
unsuitable for irritating or sensitizing drugs or highly sensitive people
can cause contact dermatitis
only relatively potent drugs can be made in a patch
technical difficulties during prep of a patch
can contaminate others if not disposed of properly
What are some examples of patches that are monolithic/matrix systems?
estradiol (Climara, Alora, VivelleDot)
What are some examples of patches that are membrane-controlled/reservoir systems?
T/F: Monolithic/Matrix system patches can be cut.
T/F: Membrane-controlled/reservoir system patches can be cut.
What patch is used once a day for the prophylaxis of angina pectoris?
NitroDur, Minitran, Transderm-Nitro
What patch is used to treat hypertension?
Which patch is used to treat urinary incontinence?
Which patch is used to treat Alzheimer's?
Which patch is used to treat Major Depressive Disorder?
Which patch system allows the skin to control the rate of absorption of the drug?
Which patch system usually has excess amounts of drug?
Which patch system delivers uniform quantities of drug to the skin over a period of time?
Which patch system contains drug (liquid or gel) that remains saturated and the release of the drug is constant?
Which patch system allows the patch itself to control the rate of delivery of drug with a rate-controlling membrane?
T/F: the adhesive layer (glue) of a membrane-controlled patch contains an initial priming dose.
Which patch system maintains a wide range of plasma concentration over which the drug is effective, but never toxic?
Which patch system has the drug blended or dissolved in a polymer matrix?
Which patch system is made of a release/film layer, an active drug plus adhesive layer, and a third layer of backing film?
Define a suspension.
a 2 phase system of finely divided drug particles (suspensoid) mixed into a vehicle (dispersion medium)
What is the study of flow?
What are some advantages of a suspension?
easy to swallow
range of doses can be given
can mask the bad taste of a drug
How can suspensions be administered (what are all the different ways)?
What are the ready to use commercial suspensions called?
What are the commercial suspensions that are in powder form and need to be reconstituted called?
"for oral suspension"
What are some features of suspensions?
T/F: thixotropy is desirable in a suspension for increasing physical stability.
T/F: the order of mixing the ingredients of a suspension is not important to its stability.
false; it is important
T/F: additives like flavoring, coloring, and preservatives should be added to the dispersed phase of a suspension.
false; to the dispersion medium
A ______ particle size equals slower sedimentation rate?
An _______in vicosity equals slower sedimentation rate?
Why do we not want too much of an increase in viscosity of a suspension?
will make it too hard to pour
A ____ density particle equals a faster sedimentation rate?
What is the most important consideration when referring to the dispersed phase of a suspension?
What are some ways to reduce the size of particles for a suspension?
fluid energy grinding (jet milling, micronizing)
What is the best range of particle size for a suspension?
Which method of reducing particle size makes particles which are 10-50 micrometer and are used for oral and topical suspensions?
Which method of reducing particle size makes particles that are less than 10 micrometers and are used for ophthalmics and parenterals?
fluid energy grinding (jet milling)
Particle ______ affects caking?
What shape of particles are more stable in a suspension?
symmetrical barrel shaped = more stable than asymmetrical needle shaped
_______ cake upon standing and cannot be redistributed in a suspension?
needles (needle shaped particles)
How can we avoid caking in a suspension?
using a flocculating agent
What is a floc or floccule?
a loose aggregate of particles held together by weak particle-particle bonds
less prone to caking
settle faster than fine particles
break up easily and can be redistributed readily with agitation
What are some common flocculating agents?
clays (bentonite magma)
electrolytes like KCl and NaCl
change the pH of the dispersed phase
T/F: viscosity is inversely related to sedimentation in a suspension.
The ________ ______ supports the suspensoid in a suspension?
_______/________ agents help to suspend the suspensoid and provide structure in a suspension?
What are some common suspending agents?
bentonite (also a flocculator)
How do you make a sustained release suspension?
the drug is complexed with ion exchange resins
this complex is then coated with ethyl cellulose
What is a Pennkinetic system?
when a drug is complexed with ion exchange resins
ex: Tussionex extended release suspension
T/F: you can make an extended release suspension by crushing an ER tablet and adding it to other ingredients.
When formulating a suspension for a newborn, what should not be included? (4 different things)
preservatives (benzyl alcohol, propylene glycol)
alcohol (includes Aromatic Elixir, NF)
What can benzyl alcohol do to a neonate if it is used in a prep?
cause Gasping syndrome- multiple organ dysfunction and death
What can propylene glycol do to a neonate if it is used in a prep?
cause seizures or stupor
What can alcohol do to a neonate if it is used in a prep?
cause CNS depression
alter liver function
What 3 things should be considered when packaging a suspension?
wide mouth container
air tight, light resistant container
adequate head space for thorough mixing
What 3 things should be considered when talking about storage of a suspension?
keep at room temp or refrigerated
protect from freezing
protect from excessive heat
When labeling a suspension, what should absolutely go on the labels?
shake well before use
how to store (room temp, fridge)
external or internal use
When telling your patient about the suspension, what 2 things do you need to make sure you mention?
give them the correct measuring tool, show them how to use it
tell them to watch for color/consistency changes in the suspension during use
_____ are semisolid systems consisting of dispersions of small inorganic particles or large organic molecules interpenetrated by a liquid?
______ are semirigid systems in which the movement of the dispersed medium is restricted by an interlacing 3-D network of particles or solvated macromolecules of the dispersed phase? (second definition by USP)
_____ are excellent drug delivery systems for oral, topical, nasal, vaginal, rectal use and are compatible with many different drugs?
T/F: gels are relatively easy to prepare and are very efficacious.
What are some examples of alcohol penetration enhancers?
What are some examples of fatty acid penetration enhancers?
What are some examples of fatty alcohols for penetration enhancers?
What are some examples of some fatty acid esters for penetration enhancers?
What is an anionic surfactant that is used for a penetration enhancer?
What are some polyols that are used as penetration enhancers?
What are some cationic surfactants used for penetration enhancers?
What is an amphoteric surfactant used as a penetration enhancer?
What are some nonionic surfactants used as penetration enhancers?
What is imbibition (gels)?
taking up of a liquid with no increase in volume
T/F: some gels may be clear as water, while others might be turbid.
T/F: most gels are water-washable, water-solublem, water-absorbing and greaseless, but some have continuous phase alcohol or oleaginous.
What are some common preservatives used in gels?
benzalkonium chloride (also a cationic sufactant/penetration enhancer)
What is the normal concentration of gelling agent in a prep?
What is a single-phase gel system?
a gel that contains linear or branched polymer macromolecules that dissolve in water and have no apparent boundary with the dispersing medium
What is a two-phase gel system?
a gel that contains small, discrete particles
these gels are thixotropic
if the particles are larger, it is called a magma
What is a magma or milk?
a two-phase system with large particles or floccules of small, distinct particles
ex: Bentonite Magma, NF
what are some gelling agents?
alginic acid (seaweed)
animal/vegetable fat: lard, cocoa butter
petrolatum, mineral oil, plastibase
What is a neutralizer (for gels)?
it thickens the gel after the gelling agent is dispersed