Biomaterial Database

What is bioavailability? Philosophy of bioavailability testing. 1984

W A Ritschel

Bioavailability is viewed by many as a criterion of clinical effectiveness. FDA regulations recognize measurements of pharmacologic responses and clinical effectiveness as sufficing bioavailability. However, most or practically all bioavailability studies are based on blood level or urinary excretion data. Unless explicitly correlated, blood level and urinary excretion data do not per se reflect clinical effectiveness. Clinical effectiveness is so complex (disease states, nutritional status) and the factors influencing absorption so numerous (food intake, circadian rhythm, age, etc.) that a test in a small sample size can only be regarded as a biologic quality control test under specified conditions. The problem of evaluation of raw data by various pharmacokinetic methods is also addressed in this paper.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D004194	Disease	A definite pathologic process with a characteristic set of signs and symptoms. It may affect the whole body or any of its parts, and its etiology, pathology, and prognosis may be known or unknown.	Diseases
D004341	Drug Evaluation	Any process by which toxicity, metabolism, absorption, elimination, preferred route of administration, safe dosage range, etc., for a drug or group of drugs is determined through clinical assessment in humans or veterinary animals.	Evaluation Studies, Drug,Drug Evaluation Studies,Drug Evaluation Study,Drug Evaluations,Evaluation Study, Drug,Evaluation, Drug,Evaluations, Drug,Studies, Drug Evaluation,Study, Drug Evaluation
D004364	Pharmaceutical Preparations	Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.	Drug,Drugs,Pharmaceutical,Pharmaceutical Preparation,Pharmaceutical Product,Pharmaceutic Preparations,Pharmaceutical Products,Pharmaceuticals,Preparations, Pharmaceutical,Preparation, Pharmaceutical,Preparations, Pharmaceutic,Product, Pharmaceutical,Products, Pharmaceutical
D005502	Food	Substances taken in by the body to provide nourishment.	Foods
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000042	Absorption	The physical or physiological processes by which substances, tissue, cells, etc. take up or take in other substances or energy.