Term
| Topical Opthalmic drugs can be used to treat |
|
Definition
| glaucoma, infection, dry eyes and inflammation |
|
|
Term
| An injection would be used in opthalmics when... |
|
Definition
| faster and higher ocular drug levels |
|
|
Term
| 3 concentric layers of the eye |
|
Definition
outermost: conjunctiva/sclera and cornea
middle: uveal tract(iris, choroid and ciliary body)
innermost: retina |
|
|
Term
| The lens divides the eye into: |
|
Definition
| The aqueous (anterior segement) and vitreous (posterior segment) humors |
|
|
Term
| The aqueous humor is divided into the |
|
Definition
| anterior and posterior CHAMBERS |
|
|
Term
| The aqueous humor is generated by what? |
|
Definition
|
|
Term
| The aqueous humor flows through where into the posterior chamber? |
|
Definition
|
|
Term
| where does the aqueous humor exit into systemic circulation? |
|
Definition
|
|
Term
| A thin transparent, vascularised mucous membrane the extends from the edge of the cornea across a portion of the sclera |
|
Definition
|
|
Term
| the gland responsible for tear production |
|
Definition
|
|
Term
| small openings into the lacrimal canaliculi |
|
Definition
|
|
Term
| the drainage system for lacrimal fluid |
|
Definition
|
|
Term
| the two major pathways for a topical opthalmic to reach intraocular tissues |
|
Definition
| cornea and sclera (cornea dominates) |
|
|
Term
|
Definition
|
|
Term
| three layers of the tear film |
|
Definition
mucoid layer- adhesion, keeps cornea wettable
tear fluid- inorganic electrolytes, proteins and glucose
lipid film- wax and cholesterol esters to reduce evaporation |
|
|
Term
| what produces the driving force for passive diffusion throgh the cornea? |
|
Definition
| the concentration of the drug |
|
|
Term
|
Definition
| epithelium-bowman's membrane-stroma-descemet's membrane-endothelium |
|
|
Term
| 3 most impt. layers of the cornea for drug absorption |
|
Definition
| epithelium-lipophilic, stroma-hydrophilic, endothelium- lipophilic |
|
|
Term
| stratified epithelium of the cornea |
|
Definition
| 3-5 layer at middle, 8-10 on the side |
|
|
Term
| T or F: the epithelium of the cornea contains enzymes for drug metabolism. |
|
Definition
|
|
Term
| 60 thin lamella, each composed of collagen fibers: made of mostly water |
|
Definition
|
|
Term
| the endothelium of the cornea is how much more permeable than the epithelium? |
|
Definition
|
|
Term
| Single cell layer that provides metabolic exchange b/w the cornea and the aqueous humor |
|
Definition
| endothelium of the cornea |
|
|
Term
| What type of drugs are best absorbed opthamlmically? |
|
Definition
| drugs with a moderate octanol/water partition at physiological pH |
|
|
Term
| how do you increase the rate drug penetration at the cornea? |
|
Definition
| increase the concentration |
|
|
Term
| T or F: greater absorption occurs through damaged epithelium |
|
Definition
|
|
Term
| what percent of the dose in eye drops will cross the cornea? |
|
Definition
|
|
Term
| most of the drug is removed from the surface of the eye through what two mechanisms? |
|
Definition
| spillage and nasolacrimal drainage |
|
|
Term
| the volume that can be accomodated int he lower cul-de-sac withough spillage |
|
Definition
| 30 ul (normal eye drop ~39ul) |
|
|
Term
| fates of drug after crossing the cornea |
|
Definition
penetration into deeper intraocular tissues
binding to proteins
elimination |
|
|
Term
| the concentration within the anterior chamber will be how much less than the applied product |
|
Definition
| 2 orders of magnitude (100x less) |
|
|
Term
| T or F: treatment of the posterior region is achievable with a topical product |
|
Definition
|
|
Term
| some lipophilic drugs bind to what protein in the iris? |
|
Definition
| melanin (dark irides-less drug effect) |
|
|
Term
| elimination of drug after penetrating the cornea is through: |
|
Definition
| the canal of schlemm and uveal blood vessels |
|
|
Term
| The lumen of the esophagus is lined with what? |
|
Definition
|
|
Term
| prepared and formulated like hard candy, dissolve slowly for local effect |
|
Definition
|
|
Term
| compressed into a hard disc, intended to dissolve slowly in the mouth |
|
Definition
|
|
Term
|
Definition
| yeast infection in the mouth, treated with lozenges or troches |
|
|
Term
| prepared by wet granulation, sometimes without a disintegrant and often have high mannitol or xylitol |
|
Definition
|
|
Term
| what excipients are used in effervescent tablets? |
|
Definition
| sodium bicarbonate and citric acid |
|
|
Term
| claims of fast dissolving tablets |
|
Definition
| easier to take or swallow, possible faster onset of action |
|
|
Term
| methods of formulation of fast dissolving tablets |
|
Definition
| lyophilization (porous product) and direct compression (with effervescent exipients: problem-makes hygroscopic) and molding |
|
|
Term
|
Definition
|
|
Term
| ventral surface of the tongue and the floor of the mouth |
|
Definition
|
|
Term
| epithelium of the mouth is... |
|
Definition
|
|
Term
| T or F: Buccal and sublingual membranes are keratinized |
|
Definition
|
|
Term
| which membrane is thicker? more permeable? |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| drainage of drugs via the sublingual route occurs through what vein? |
|
Definition
|
|
Term
|
Definition
| relatively low permeability for most drugs, drug can be washed away by saliva, unpredictable bioavailabity (mucosal variations) |
|
|
Term
| why should drugs and exipients of subllingual/buccal dosage forms be bland? |
|
Definition
| so you dont stimulate saliva flow |
|
|
Term
|
Definition
| compressed tablets-lightly (to facilitate disintegration) |
|
|
Term
| what is lactose used for in nitroglycerin tablets? |
|
Definition
| adsops to NO to reduce volatility and explosive risk |
|
|
Term
| which tend to be softer; molded or compressed tablets? |
|
Definition
|
|
Term
| why are tablets dried under ambient conditions? |
|
Definition
|
|
Term
| What is polyethylene glycol used in NTG tablets? |
|
Definition
| lowers vapor pressure: more stable |
|
|
Term
| T or F: NTG interacts with plastic |
|
Definition
| True (should be stored in glass) |
|
|
Term
|
Definition
|
|
Term
|
Definition
| nicotine is bound to a cation exchange resin and is formulated to a pH of 8.5 to increase the unionized form |
|
|
Term
|
Definition
| rapid absorption followed by prolonged: mouth and GI |
|
|
Term
| mucoadhesive tablets have what type of excipient? |
|
Definition
| cellulose derivative to make them stick |
|
|
Term
| examples of mucoadhesive tablets |
|
Definition
| striant-testosterone, nitroguard |
|
|
Term
|
Definition
| for parkinsons disease, orally disintegrating tablet, absorption is buccal |
|
|
Term
| most widely used antimicrobial excipient, can increase corneal penetration |
|
Definition
| BAC, effective against p. aeruginosa |
|
|
Term
| what is an alternative to BAC but does not penetrate the corneal wall |
|
Definition
|
|
Term
| and organic mercurial antimicrobial preservative |
|
Definition
|
|
Term
| examples of important buffers |
|
Definition
| acetate, phosphate, citrate, borate |
|
|
Term
| use drugs in this pH range to avoid irritation |
|
Definition
|
|
Term
| the normal osmolarity of tears |
|
Definition
|
|
Term
|
Definition
| increase retention time/bioavailability although can irritate if too high |
|
|
Term
|
Definition
| glycerin, cellulose, polyvinyl alcohol, PEGs (can be lubricating) |
|
|
Term
|
Definition
|
|
Term
| suspensions are used for what type of drugs? |
|
Definition
|
|
Term
| T or F: you can filter sterilize suspensions of eye drops. |
|
Definition
|
|
Term
|
Definition
| chelator, and increase the activity of BAC ag. P. aeruginosa |
|
|
Term
|
Definition
| wetting agent, surfactant, facilitate spreading |
|
|
Term
| eyedrops are packaged in? |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| if the drug is in an aqueous vehicle |
|
Definition
| Partition coefficient increases with molecular weight |
|
|
