title: Use of isosorbide dinitrate saliva concentrations for biopharmaceutical investigations.
abstract: The concentration of isosorbide dinitrate in paired samples of plasma and mixed saliva was monitored for up to 24 hr after oral administration of 60 mg of sustained-release isosorbide dinitrate to eight healthy volunteers. Measured isosorbide dinitrate plasma concentrations were mainly in the range of 0.1-10 ng/ml. Isosorbide dinitrate was excreted into saliva resulting in a mean (+/- SD) saliva-plasma concentration ratio of 0.68 +/- 0.37. A significant correlation between concentrations of isosorbide dinitrate in saliva and plasma was found (p less than 0.01). The sustained-release properties of the administered formulation were confirmed from the concentrations of isosorbide dinitrate found in both saliva and plasma. Saliva-plasma ratios were independent of the absolute concentrations of isosorbide dinitrate but showed a slight tendency to decrease with time. The principal factor relating saliva and plasma isosorbide dinitrate concentrations appeared to be the degree of plasma protein binding of the drug.
mesh_terms: D000293:Adolescent; D000328:Adult; D001702:Biopharmaceutics; D001798:Blood Proteins / Q000378:metabolism; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007548:Isosorbide Dinitrate / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood; D008297:Male; D011485:Protein Binding; D012463:Saliva / Q000032:analysis*; D013997:Time Factors
chemical_list: D001798:Blood Proteins; D003692:Delayed-Action Preparations; D007548:Isosorbide Dinitrate