title: [Biological availability of ophthalmic drugs. 1. Increasing drug permeability in the cornea].
abstract: Most eye diseases are treated by topical administration of ophthalmic preparations. Low ophthalmic bioavailability is due to a number of physiological and physicochemical factors. The main obstacle to the penetration of active ingredients to the eye is the layered character of the cornea. Formulation of ophthalmic preparations enabling easier penetration of this biological barrier thus ranks among the most effective ways of improving bioavailability. Penetrability of the cornea can be increased by the following methods: a) adjustment of the actual acidity in such a way that pH of the preparation makes it possible to produce the optimal portion of non-ionized particles; b) incorporation of absorption enhancers (non-ionic tensides, salts of bile acids, some antimicrobial substances, EDTA, cyclodextrins, etc.) into the composition of the preparation, and c) production of prodrugs or ionic pairs.
authors.affiliation: Ustav technologie léků Farmaceutické fakulty Veterinární a farmaceutické univerzity, Brno. masteikovar@vfu.cz
authors.forename: R
authors.initials: R
authors.lastname: Masteiková
authors.forename: Z
authors.initials: Z
authors.lastname: Chalupová
authors.forename: N
authors.initials: N
authors.lastname: Savickiene
mesh_terms: D000042:Absorption; D001682:Biological Availability; D003315:Cornea / Q000378:metabolism*; D006801:Humans; D009883:Ophthalmic Solutions / Q000737:chemistry / Q000493:pharmacokinetics*; D011355:Prodrugs / Q000493:pharmacokinetics
chemical_list: D009883:Ophthalmic Solutions; D011355:Prodrugs