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Opthalmic
Final Exam
53
Chemical Engineering
Graduate
11/04/2016

Additional Chemical Engineering Flashcards

 


 

Cards

Term
4 uses of topical opthalmics
Definition

glaucoma

 

infections

 

inflammation

 

dry eyes

Term
injections are________
Definition

faster more deeply distributed

(subconjunctival & intraocular)

Term
3 concentric eyeball layers
Definition

outermost [conjunctiva,sclera]

middle [uveal tract]

innermost [retina]

Term
inside eyeball divided by lens into
Definition
aqueaous (anterior) and vitreous(posterior) humor/segments
Term
____________divided by iris into anterior and posterior chambers
Definition
Aqueous humor
Term
this part of the eye is responsibel for tear production
Definition
LACRIMAL GLAND
Term
tears move from nasal cavity toward
Definition
NASOPHARYNX
Term
OPTHALMIC DRUG TARGETS
Definition

preocular structures

 

cornea

 

tissues in anterior and posterior seg

 

 

Term
Posterior segment is hot target for
Definition
topicals
Term

major pathways for topical opthalmics

thru _____ and _____

Definition
CORNEA(mostly) and SCLERA
Term
3 layers of tear film (*MLT like "melt" MNEUMONIC)
Definition

Mucoid layer [adhesion of aqueous tear fluiid]

 

Lipid Film [was/cholesterol adhere to tear fluid]

 

Tear Fluid [elec,proteins,glucose]

Term
This tear layer reduces evaporation of tear fluid
Definition
Lipid film
Term
Keeps cornea wettable
Definition
Mucoid layer
Term
CORNEAL MEMBRANES
Definition

-epithelium

-bowmans membrane

-stroma

- descemets membrane

- endothelium

Term
most important 3 layers for drug absorb in cornea (ESE)
Definition

-Epithilium

-Stroma

-Endothelium

Term

CONTINUOUS W/ CONJUNCTIVA

STRATIFIED EPITHELIUM

[5-6 LAYERS AT CENTER,8-10 IN PERIPHERY]

 

**MAIN BARRIER FOR DRUG PASSAGE THROUGH CORNEA

 

Definition
CORNEAL EPITHELIUM
Term
IN THE CORNEAL EPITHELIUM SQUAMOUS CELLS ARE SURROUNDED BY___________THAT HAVE MICROVILLI(TO INC SA)
Definition
TIGHT JUNCTIONS
Term
cORNEAL EPITHELIUM IS A _______BARRIER
Definition

LIPOPHILIC

[LIP RX PENETRATES BETTER RX IONIZATION STATE CAN BE IMPORTANT]

 

UNIONIZED DRUGS PASS THROUGH BETTER

Term
THIS CORNEAL LAYER COMPOSED OF COLLAGEN FIBERS IS MOSTLY WATER AND IS 200 TIMES MORE PERMABLE THAN EPITHELIUM
Definition
STROMA
Term

SINGLE CELL LAYER OF CORNEA PROVIDING METABOLIC EXCHANGE BETWEEN CORNEA AND AQ. HUMOR

MORE PERMEABLE THAN EPITHELIUM

Definition
ENDOTHELIUM
Term
BEST ABSORBED DRUGS HAVE ___ OCTANOL/WATER PARTITION AT PHYSIO PH
Definition
"MODERATE"
Term
Greater absorption occurs in ___
Definition
Damaged epithelium
Term

Less than ______% of dose instilled as drops will cross cornea

 

Peak aq. conc between ________mins

Definition

5%

 

 

20-60mins

Term

EYe drops are instilled in the _________

 

Drops range from___________

Definition

Lower cul de sac

 

 

25-56 uL [normal tear volume =7uL]

Term

Fates of applied eyedrop[BEFOREcross cornea] =

 

Spillage 

 

Removal by nasolacrimal Drainage

 

Enzymatic Degradation

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

Term
we blink our eye ________times per min
Definition

15-20

 

 

(one blink causes 10 uL loss) 

Term

Fates of applied eyedrop[AFTERcross cornea] =

 

Penetrate deeper intraocular tissue

 

Binding proteins

 

Elimination

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]

Term

Opthalmic metabolism occurs after crossing the cornea and is a form of elimination. (prodrugs)

EX:??[2]

Definition

Dipivefrin to Epinephrine 

 

Latanaprost to PGF2alpha

Term
contribute to tissue absorption of topical opthalmics
Definition

lacrimal sac

nasopharynx

cheecks

and GI tract

Term
Conjunctiva covers a greater surface areea than cornea and is more_______
Definition
permeable
Term

 

Conjunctiva covers a greater surface areea than cornea and is more_______

Definition

permeable

[highly vascularized]

Term
No hepatic first pass in absorption of topical opth except in _____ absorption
Definition

GI

 

[but over 50% of drug absorbed in eye is absorbed systemically anyway]

Term
consider for topical opth. design
Definition
pH, osmolarity, viscosity,sterility
Term

Sterility

 

organism: w/ ex Rx

 

other bacteria:

 

Definition

Org:Pseudomonas Aeruginosa

[Trypan Blue (recalled rx)]

 

staph aureis,candida albican,asperigillus niger,Escherichia coli

Term
EXCIPIENTS: Antimicrobial preservatives are required in_____
Definition

multidose eye drops

 

[benzalkonium chloride BAC 0.01% or less]

 

[polyquad(polyquaternium-1 doesnt penetrate cornea well]

 

 

Term
benzalkonium chloride BAC effective agnst_____
Definition
pseudomonas aeruginosa
Term
Oxidants
Definition

Sodium perborate

 

Purite (stabilized oxychloro complex)

Term

Tears pH 

 

 

[irritation,sensitivity and reflex tears, & blinking seen in pH]

Definition

7-7.4

 

 

[<6.6 & >9.0]--->>speeds drug elimination

Term
buffers used to stabilize or solbilize =
Definition

acetate

phosphate

citrate

borate

 

(strong acids[HCl,H2SO4]/bases[NaOH] added to adjust pH)

Term
Tear osmolarity
Definition
302-318 mOsm/kg
Term
Hypertonic products are 5% and treat corneal______
Definition
Edema
Term

High viscosity causes____

 

Modifiers include____

Definition

irritation (cause blurring and crust forming)

(reduce draining,inc retention rate)

 

[glycerin,cellulose derivs(hydroxyethylcellulose),polyvinyl alcohol, PEGs,carbomer]

 

 

Term
STerilize Solutions by
Definition

HEAT or  MEMBRANE FILTRATION

 

[add other sterilized excipients and bring to vol w/ sterile water ***if needed]

Term
Suspensions require particle size less than ______
Definition

10 micrometers(smaller than oral susp)

[reduces irritation and speeds dissolution]

Term
Opthalmic susp used for
Definition

to improve rx soluble

 

stay in cul de sac better/longer

Term

Antioxidant excipient:

 

 

Chelator:

 

Surfactant:

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]

Term
Droptainer/eyedrop packaging is dropper bottles.SIZE:___
Definition

5,10,15 and 30 mL 

sterilized before use

Term

semisolid eyedrops

 

ointments[base=white petrolatum]

Definition

prolong contact time[good]

[0.5% leaves per min cleared slowly]

 

 

blur vision

 

Term
sterilize ointment base _____
Definition

with heat then filter with molten

 

used frequently following surgery

 

[3.5 g is standrard tube]

Term
Gels use ____ for gel forming
Definition

cellulose derivatives(carbomers or gums) 

 

 

Akten prolong contact time

Term
Akten is a gel opth
Definition
high viscosity slowing removal
Term
Ciloxan
Definition

Ciprofloxacin HCl

 

used for Bacterial Keratitis,conjuctivitis

 

 

Term

thimerisol is

 

Definition
preservative
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