Biomaterial Database

Finite dose percutaneous drug absorption: theory and its application to in vitro timolol permeation. 1990

K Kubota, and T Yamada

Division of Clinical Pharmacology, National Medical Center, Tokyo, Japan.

The finite dose in vitro percutaneous absorption kinetics of timolol, a beta-blocker, was studied. The flux of timolol across excised human abdominal cadaver skin was measured over a period of 72 h following application of a 40-microns thickness patch containing 5, 10, or 20% (w/v) timolol free base. Amounts of timolol in the patch and skin were also determined at 6, 12, 24, 48, and 72 h after the application of the 20% (w/v) patch. The mean diffusion and partition parameters were estimated to be 0.018 h-1 and 125.9 microns, respectively, using a newly developed theory. Diffusion and partition parameters were estimated using the values for amounts of a drug eventually partitioning into the perfusing water, as well as two newly proposed conceptual parameter values, AUCAv and AUCAs which are the AUCs of drug amounts in vehicle and skin, respectively. The dose-dependent skin-timolol interaction is also discussed.

UI	MeSH Term	Description	Entries
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000287	Administration, Topical	The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.	Drug Administration, Topical,Administration, Topical Drug,Topical Administration,Topical Drug Administration,Administrations, Topical,Administrations, Topical Drug,Drug Administrations, Topical,Topical Administrations,Topical Drug Administrations
D012869	Skin Absorption	Uptake of substances through the SKIN.	Absorption, Skin,Intracutaneous Absorption,Intradermal Absorption,Percutaneous Absorption,Transcutaneous Absorption,Transdermal Absorption,Absorption, Intracutaneous,Absorption, Intradermal,Absorption, Percutaneous,Absorption, Transcutaneous,Absorption, Transdermal,Absorptions, Intracutaneous,Absorptions, Intradermal,Absorptions, Percutaneous,Absorptions, Skin,Absorptions, Transcutaneous,Absorptions, Transdermal,Intracutaneous Absorptions,Intradermal Absorptions,Percutaneous Absorptions,Skin Absorptions,Transcutaneous Absorptions,Transdermal Absorptions
D013999	Timolol	A beta-adrenergic antagonist that is similar in action to PROPRANOLOL; the levo-isomer is more active. Timolol has been proposed as an anti-hypertensive, anti-arrhythmic, anti-angina, and anti-glaucoma agent. It is also used in the treatment of MIGRAINE DISORDERS and tremor.	(S)-1-((1,1-Dimethylethyl)amino)-3-((4-(4-morpholinyl)-1,2,5-thiadazol-3-yl)oxy)-2-propanol,2-Propanol, 1-((1,1-dimethylethyl)amino)-3-((4-(4-morpholinyl)-1,2,5-thiadiazol-3-yl)oxy)-, (S)-,Blocadren,L-714,465,MK-950,Optimol,Timacar,Timolol Hemihydrate,Timolol Maleate,Timolol Maleate, (1:1) Salt,Timoptic,Timoptol,L 714,465,L714,465,MK 950,MK950
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In