Biomaterial Database

Polymeric inhibitors of platelet aggregation. II. Copolymers of dipyridamole and related drugs with N-vinylpyrrolidone. 1987

C H Bamford, and I P Middleton, and K G Al-Lamee

A study has been made of the behaviour of the drugs dipyridamole and mopidamol (RA 233) attached to poly(N-vinylpyrrolidone). The inhibitory activities towards platelet aggregation induced by ADP or platelet activation factor (PAF) in sheep plasma have been examined and found to exceed the activities of the parent drugs, by factors up to 20. At the same time the abilities of the polymer-bound drugs in potentiating prostaglandin-type anti-aggregatory activities are much lower than those of the unattached drugs. The observations are explained in terms of polymer adsorption on to the platelet membranes, producing a high surface concentration of the drugs with consequent high inhibitory action. Intracellular action, such as the inhibition of phosphodiesterase, is reduced by the difficulty experienced by the polymeric drug in passing through the membrane, so that potentiation of prostaglandin activity, particularly against PAF, becomes small. A terpolymer containing units of dipyridamole and the prostaglandin analogue 5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl)hydantoin (245C) shows a degree of 'self-potentiation'.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009012	Mopidamol	A phosphodiesterase inhibitor which inhibits platelet aggregation. Formerly used as an antineoplastic.	RA-233,Rapenton
D010972	Platelet Activating Factor	A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.	AGEPC,Acetyl Glyceryl Ether Phosphorylcholine,PAF-Acether,Phosphorylcholine, Acetyl Glyceryl Ether,1-Alkyl-2-acetyl-sn-glycerophosphocholine,Platelet Aggregating Factor,Platelet Aggregation Enhancing Factor,Platelet-Activating Substance,Thrombocyte Aggregating Activity,1 Alkyl 2 acetyl sn glycerophosphocholine,Aggregating Factor, Platelet,Factor, Platelet Activating,PAF Acether,Platelet Activating Substance
D010974	Platelet Aggregation	The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.	Aggregation, Platelet
D011108	Polymers	Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).	Polymer
D011205	Povidone	A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.	Polvidone,Polyvidon,Polyvinylpyrrolidone,Arufil,Bolinan,Bolinan 40,Crospovidone,Dulcilarmes,Duratears Free,Enterodes,Enterodez,Hypotears,Kollidon,Lacophtal,Lacri-Stulln,Lagrifilm,Liquifilm Lagrimas,Nutrivisc,Oculotect,PVP 40,Periston,Plasdone,Polyplasdone XL,Povidone, Unspecified,Protagens,Protagent,Unifluid,Vidirakt S mit PVP,Vidisic PVP Ophtiole,Wet-Comod,Dulcilarme,Enterode,Hypotear,Polyvidons,Protagen,Unspecified Povidone
D004176	Dipyridamole	A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)	Antistenocardin,Apo-Dipyridamole,Cerebrovase,Cléridium,Curantil,Curantyl,Dipyramidole,Kurantil,Miosen,Novo-Dipiradol,Persantin,Persantine,Apo Dipyridamole,Novo Dipiradol
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine
D013058	Mass Spectrometry	An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.	Mass Spectroscopy,Spectrometry, Mass,Spectroscopy, Mass,Spectrum Analysis, Mass,Analysis, Mass Spectrum,Mass Spectrum Analysis,Analyses, Mass Spectrum,Mass Spectrum Analyses,Spectrum Analyses, Mass