Acta Pharm. 51 (2001) 211-217

Comparison of bioavailability of calcium salts in rabbits

BEATA SZULC,¹ HALINA WOJDAK^1* and  WITOLD J. KOWALSKI²

¹Department of Applied Pharmacy and Drug Design Technology, Medical Academy of Silesia, 41-200 Sosnowiec, Poland
²Institute of Chemistry, University of Silesia, 40-006 Katowice, Poland

The dynamics of calcium concentration changes in the sera of rabbits after a single intragastric administration of calcium in the form of fumarate, gluconate or carbonate was evaluated. The bioavailability parameters for calcium gluconate and calcium fumarate (i.e., the maximal calcium concentration and the area under the concentration vs. time curve) were higher than in the case of administration of the reference, calcium carbonate.
Consideration of molecular structures of the organic calcium salts obtained by molecular modelling with the aid of molecular mechanics computational methods gave rise to the assumption that calcium ions in organic salts are better protected from exterior influences than in the case of calcium carbonate. Better availability of calcium from organic salts may be explained by the formation of a complex between calcium ions and organic ligands.

Keywords: calcium fumarate, calcium gluconate, calcium carbonate, molecular modelling, bioavailability parameters, rabbits