Premium
Pharmacokinetics of ascorbic acid in horses
Author(s) -
LÖSCHER W.,
JAESCHKE G.,
KELLER H.
Publication year - 1984
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1984.tb01855.x
Subject(s) - ascorbic acid , bioavailability , pharmacokinetics , volume of distribution , chemistry , vitamin c , vitamin , oral administration , route of administration , subcutaneous injection , pharmacology , volunteer , distribution (mathematics) , medicine , biochemistry , biology , food science , mathematical analysis , mathematics , agronomy
Summary The pharmacokinetics of ascorbic acid were studied in 29 horses after intravenous (iv), subcutaneous, intramuscular (im) and oral administration. Following iv injection of 5 and 10 g ascorbic acid, respectively, a biphasic decline of ascorbic acid serum levels was found, indicating that the vitamin distributes in the body according to a two‐compartment open model. The apparent volume of distribution (average value for V d(ss) = 0.6 litre/kg) was approximately equivalent to the volume of total body water. The terminal half‐life of the biexponential serum level‐time curve (t 1/2β ) varied between 5 and 17 h. Both distribution and elimination were found to be positively correlated with the iv dose administered. Following subcutaneous and im injection, the average bioavailability of ascorbic acid amounted to 82 and 61 per cent, respectively. However, both routes of administration gave rise to marked local irritation. Following oral administration, the systemic availability of ascorbic acid was very poor. Serum levels in most experiments were not increased above the endogenous pre‐administration values of the vitamin. Thus, in horses iv injection appears to be the only satisfactory route of administration of ascorbic acid if supplementation is required.