Term
| 4 uses of topical opthalmics |
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Definition
glaucoma
infections
inflammation
dry eyes |
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Term
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Definition
faster more deeply distributed
(subconjunctival & intraocular) |
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Term
| 3 concentric eyeball layers |
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Definition
outermost [conjunctiva,sclera]
middle [uveal tract]
innermost [retina] |
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Term
| inside eyeball divided by lens into |
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Definition
| aqueaous (anterior) and vitreous(posterior) humor/segments |
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Term
| ____________divided by iris into anterior and posterior chambers |
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Definition
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Term
| this part of the eye is responsibel for tear production |
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Definition
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Term
| tears move from nasal cavity toward |
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Definition
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Term
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Definition
preocular structures
cornea
tissues in anterior and posterior seg
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Term
| Posterior segment is hot target for |
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Definition
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Term
major pathways for topical opthalmics
thru _____ and _____ |
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Definition
| CORNEA(mostly) and SCLERA |
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Term
| 3 layers of tear film (*MLT like "melt" MNEUMONIC) |
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Definition
Mucoid layer [adhesion of aqueous tear fluiid]
Lipid Film [was/cholesterol adhere to tear fluid]
Tear Fluid [elec,proteins,glucose] |
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Term
| This tear layer reduces evaporation of tear fluid |
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Definition
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Term
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Definition
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Term
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Definition
-epithelium
-bowmans membrane
-stroma
- descemets membrane
- endothelium |
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Term
| most important 3 layers for drug absorb in cornea (ESE) |
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Definition
-Epithilium
-Stroma
-Endothelium |
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Term
CONTINUOUS W/ CONJUNCTIVA
STRATIFIED EPITHELIUM
[5-6 LAYERS AT CENTER,8-10 IN PERIPHERY]
**MAIN BARRIER FOR DRUG PASSAGE THROUGH CORNEA
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Definition
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Term
| IN THE CORNEAL EPITHELIUM SQUAMOUS CELLS ARE SURROUNDED BY___________THAT HAVE MICROVILLI(TO INC SA) |
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Definition
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Term
| cORNEAL EPITHELIUM IS A _______BARRIER |
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Definition
LIPOPHILIC
[LIP RX PENETRATES BETTER RX IONIZATION STATE CAN BE IMPORTANT]
UNIONIZED DRUGS PASS THROUGH BETTER |
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Term
| THIS CORNEAL LAYER COMPOSED OF COLLAGEN FIBERS IS MOSTLY WATER AND IS 200 TIMES MORE PERMABLE THAN EPITHELIUM |
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Definition
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Term
SINGLE CELL LAYER OF CORNEA PROVIDING METABOLIC EXCHANGE BETWEEN CORNEA AND AQ. HUMOR
MORE PERMEABLE THAN EPITHELIUM |
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Definition
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Term
| BEST ABSORBED DRUGS HAVE ___ OCTANOL/WATER PARTITION AT PHYSIO PH |
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Definition
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Term
| Greater absorption occurs in ___ |
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Definition
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Term
Less than ______% of dose instilled as drops will cross cornea
Peak aq. conc between ________mins |
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Definition
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Term
EYe drops are instilled in the _________
Drops range from___________ |
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Definition
Lower cul de sac
25-56 uL [normal tear volume =7uL] |
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Term
Fates of applied eyedrop[BEFOREcross cornea] =
Spillage
Removal by nasolacrimal Drainage
Enzymatic Degradation |
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Definition
Spillage
[30uL can be accomodated w/out spillage in lower culdesac]
[blinking inc spill.10 uL lost in one blink]
Removal by nasolacrimal Drainage
[gravity&blink pumping mves rx through puncta to nasolacrimal apparatus]
Enzymatic Degradation |
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Term
| we blink our eye ________times per min |
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Definition
15-20
(one blink causes 10 uL loss) |
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Term
Fates of applied eyedrop[AFTERcross cornea] =
Penetrate deeper intraocular tissue
Binding proteins
Elimination |
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Definition
Penetrate deeper intraocular tissue
[conc w/ in anterior chamber 2 orders mag less than applied prod]
[amount getting to posterior signif less]
Binding proteins
[lipophilic rx can bind to melanin in iris***darker iris slow/reduce rx]
Elimination
[Sys circ-->thru canal of SCHLEMM]
[thru uveal blood vessels] |
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Term
Opthalmic metabolism occurs after crossing the cornea and is a form of elimination. (prodrugs)
EX:??[2] |
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Definition
Dipivefrin to Epinephrine
Latanaprost to PGF2alpha |
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Term
| contribute to tissue absorption of topical opthalmics |
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Definition
lacrimal sac
nasopharynx
cheecks
and GI tract |
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Term
| Conjunctiva covers a greater surface areea than cornea and is more_______ |
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Definition
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Term
Conjunctiva covers a greater surface areea than cornea and is more_______ |
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Definition
permeable
[highly vascularized] |
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Term
| No hepatic first pass in absorption of topical opth except in _____ absorption |
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Definition
GI
[but over 50% of drug absorbed in eye is absorbed systemically anyway] |
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Term
| consider for topical opth. design |
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Definition
| pH, osmolarity, viscosity,sterility |
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Term
Sterility
organism: w/ ex Rx
other bacteria:
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Definition
Org:Pseudomonas Aeruginosa
[Trypan Blue (recalled rx)]
staph aureis,candida albican,asperigillus niger,Escherichia coli |
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Term
| EXCIPIENTS: Antimicrobial preservatives are required in_____ |
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Definition
multidose eye drops
[benzalkonium chloride BAC 0.01% or less]
[polyquad(polyquaternium-1 doesnt penetrate cornea well]
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Term
| benzalkonium chloride BAC effective agnst_____ |
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Definition
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Term
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Definition
Sodium perborate
Purite (stabilized oxychloro complex) |
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Term
Tears pH
[irritation,sensitivity and reflex tears, & blinking seen in pH] |
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Definition
7-7.4
[<6.6 & >9.0]--->>speeds drug elimination |
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Term
| buffers used to stabilize or solbilize = |
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Definition
acetate
phosphate
citrate
borate
(strong acids[HCl,H2SO4]/bases[NaOH] added to adjust pH) |
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Term
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Definition
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Term
| Hypertonic products are 5% and treat corneal______ |
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Definition
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Term
High viscosity causes____
Modifiers include____ |
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Definition
irritation (cause blurring and crust forming)
(reduce draining,inc retention rate)
[glycerin,cellulose derivs(hydroxyethylcellulose),polyvinyl alcohol, PEGs,carbomer]
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Term
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Definition
HEAT or MEMBRANE FILTRATION
[add other sterilized excipients and bring to vol w/ sterile water ***if needed] |
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Term
| Suspensions require particle size less than ______ |
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Definition
10 micrometers(smaller than oral susp)
[reduces irritation and speeds dissolution] |
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Term
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Definition
to improve rx soluble
stay in cul de sac better/longer |
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Term
Antioxidant excipient:
Chelator:
Surfactant: |
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Definition
Antioxidant excipient:Sodium metabisulfites
Chelator: EDTA disodium (inc act of BAC against P. aeruginosa)
Surfactant: Polysorbate(tween 80) 80 & tyloxapol
[used as wetting agents for susp/red surf tension] |
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Term
| Droptainer/eyedrop packaging is dropper bottles.SIZE:___ |
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Definition
5,10,15 and 30 mL
sterilized before use |
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Term
semisolid eyedrops
ointments[base=white petrolatum] |
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Definition
prolong contact time[good]
[0.5% leaves per min cleared slowly]
blur vision
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Term
| sterilize ointment base _____ |
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Definition
with heat then filter with molten
used frequently following surgery
[3.5 g is standrard tube] |
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Term
| Gels use ____ for gel forming |
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Definition
cellulose derivatives(carbomers or gums)
Akten prolong contact time |
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Term
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Definition
| high viscosity slowing removal |
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Term
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Definition
Ciprofloxacin HCl
used for Bacterial Keratitis,conjuctivitis
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Term
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Definition
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