Intestinal absorption of strontium chloride in healthy volunteers: pharmacokinetics and reproducibility.
1. The absorption kinetics of orally administered strontium chloride and its reproducibility were investigated in healthy volunteers after administering strontium either under fasting conditions (study I, n = 8) or in combination with a standardized meal (study II, n = 8). Each subject received strontium orally at day 0, 14, and 28 and intravenously at day 42. The study was performed as part of a project in which a simple clinical test for measuring intestinal calcium absorption is being developed, based on the use of stable strontium as a marker. 2. Plasma strontium concentration-time curves were analysed by noncompartment analysis and a four compartment disposition model. Within a volunteer each oral curve was fitted simultaneously with the intravenous curve, by which means a two segment model for absorption was revealed. 3. Mean absolute bioavailability of strontium was 25% without a meal and 19% with a meal, whereas the intraindividual variation was 24% and 20%, respectively. 4. Various limited sampling absorption parameters were determined in order to select a potential test parameter for measuring intestinal calcium absorption using strontium as a marker. Fractional absorption at 4 h (Fc240), obtained after co-ingestion of strontium with a meal, appeared to be the best test parameter, because it represented bioavailability well (r = 0.90).
Sips
A J
AJ
Department of Endocrinology, Free University Hospital, Amsterdam, The Netherlands.
van der Vijgh
W J
WJ
Barto
R
R
Netelenbos
J C
JC
D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D015415:Biomarkers / Q000097:blood; D005215:Fasting; D005502:Food; D006801:Humans; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D008297:Male; D015203:Reproducibility of Results; D013324:Strontium / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
D015415:Biomarkers; C025700:strontium chloride; D013324:Strontium