pharma - routes of administration Flashcards
what creates the blood ocular barrier?
endothelium of capillaries
blood-aqueous
blood-retinal
is the epithelium hydrophobic or hydrophilic?
hydrophobic
is the stroma hydrophobic or hydrophilic?
hydrophilic
what type of drugs penetrate epithelium?
lipid soluble
what type of drugs penetrate stroma?
water soluble
what do topical drugs used in the eye require?
corneal penetration
what does drugs like chloramphenicol have that allows it to penetrate cornea easily?
lipophilic and hydrophilic properties
what can often reduce the hydrophobic nature of endothelium?
ocular surface inflammation
what may impede during drug penetration?
lipid layer of tear film
what do topical steroids need to work?
hydrophobic and hydrophilic capacities
does acetate/alcohol make steroids more hydrophobic or hydrophilic?
hydrophobic
does phosphate make steroids more hydrophobic or hydrophilic?
hydrophilic
what are the features of prednisolone acetate?
hydrophobic
good penetration in uninflamed cornea
used post-op
what are the features of prednisolone phosphate?
hydrophilic
poor penetration in uninflamed cornea
used for corneal disease or when low dose steroids required
what can aid in enhancing corneal permeability and how does it do this?
antiseptic concentrations benzalkonium chloride
disrupts lipid layer of tear film, aids penetration of drugs
where are tears pumped out of?
lacrimal sac
what do systemic absorption of topical drugs result in?
nasty taste in back of throat and excess gains systemic absorption at nasopharynx
when are intravitreal injections used?
administer antibiotics in endophthalmitis
intra-ocular steroids
