Biomaterial Database

Comparative bioavailability of sustained-release and conventional tablets of hydroxyethyltheophylline in man. 1979

P L Sharma, and R M Sharma

The comparative bioavailability of sustained-release and conventional tablets of hydroxyethyltheophylline was studied in normal subjects. In a single dose study on 7 subjects, 3 conventional tablets or 2 sustained-release tablets were administered orally after a light breakfast and blood samples taken for 6 and 12 hours respectively. With conventional tablets the mean peak concentration (8.10 +/- 0.751 microgram/ml) was reached at 3 hours and concentrations less than 5 microgram/ml were observed in 4 out of 7 subjects at 6 hours. In contrast, with sustained-release tablets of theophylline and hydroxytheophylline complex the mean peak concentration (8.90 +/- 0.88 microgram/ml) was reached at 6 hours and levels above 5 microgram/ml were observed in 4 out of 7 cases at 12 hours. Administration of 2 sustained-release tablets twice a day produced trough plasma concentrations varying between 6.9-13.8 microgram/ml, i.e. within the therapeutic range in all the 5 subjects. It is concluded that this new oral sustained-release preparation provides therapeutic plasma theophylline concentration on a 12 hourly dosage schedule.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D003692	Delayed-Action Preparations	Dosage forms of a drug that act over a period of time by controlled-release processes or technology.	Controlled Release Formulation,Controlled-Release Formulation,Controlled-Release Preparation,Delayed-Action Preparation,Depot Preparation,Depot Preparations,Extended Release Formulation,Extended Release Preparation,Prolonged-Action Preparation,Prolonged-Action Preparations,Sustained Release Formulation,Sustained-Release Preparation,Sustained-Release Preparations,Timed-Release Preparation,Timed-Release Preparations,Controlled-Release Formulations,Controlled-Release Preparations,Extended Release Formulations,Extended Release Preparations,Slow Release Formulation,Sustained Release Formulations,Controlled Release Formulations,Controlled Release Preparation,Controlled Release Preparations,Delayed Action Preparation,Delayed Action Preparations,Formulation, Controlled Release,Formulations, Controlled Release,Prolonged Action Preparation,Release Formulation, Controlled,Release Formulations, Controlled,Sustained Release Preparation,Timed Release Preparation,Timed Release Preparations
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001682	Biological Availability	The extent to which the active ingredient of a drug dosage form becomes available at the site of drug action or in a biological medium believed to reflect accessibility to a site of action.	Availability Equivalency,Bioavailability,Physiologic Availability,Availability, Biologic,Availability, Biological,Availability, Physiologic,Biologic Availability,Availabilities, Biologic,Availabilities, Biological,Availabilities, Physiologic,Availability Equivalencies,Bioavailabilities,Biologic Availabilities,Biological Availabilities,Equivalencies, Availability,Equivalency, Availability,Physiologic Availabilities
D013607	Tablets	Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)	Tablet
D013806	Theophylline	A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Theophylline inhibits the 3',5'-CYCLIC NUCLEOTIDE PHOSPHODIESTERASE that degrades CYCLIC AMP thus potentiates the actions of agents that act through ADENYLYL CYCLASES and cyclic AMP.	1,3-Dimethylxanthine,3,7-Dihydro-1,3-dimethyl-1H-purine-2,6-dione,Accurbron,Aerobin,Aerolate,Afonilum Retard,Aquaphyllin,Armophylline,Bronchoparat,Bronkodyl,Constant-T,Elixophyllin,Euphylong,Glycine Theophyllinate,Lodrane,Monospan,Nuelin,Nuelin S.A.,Quibron T-SR,Slo-Phyllin,Somophyllin-T,Sustaire,Synophylate,Theo Von Ct,Theo-24,Theo-Dur,Theobid,Theocin,Theoconfin Continuous,Theodur,Theolair,Theolix,Theon,Theonite,Theopek,Theophylline Anhydrous,Theophylline Sodium Glycinate,Theospan,Theostat,Theovent,Uniphyl,Uniphyllin,Uniphylline,1,3 Dimethylxanthine,Anhydrous, Theophylline,Constant T,ConstantT,Ct, Theo Von,Glycinate, Theophylline Sodium,Quibron T SR,Quibron TSR,Slo Phyllin,SloPhyllin,Sodium Glycinate, Theophylline,Somophyllin T,SomophyllinT,Theo 24,Theo Dur,Theo24,Theophyllinate, Glycine,Von Ct, Theo
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor