Pharmacokinetics of ascorbic acid in horses

Area of Science:

• Veterinary Pharmacology
• Equine Metabolism
• Nutritional Science

Background:

• Ascorbic acid (vitamin C) is essential for various physiological functions.
• Understanding its pharmacokinetics in horses is crucial for effective supplementation.
• Previous studies on equine ascorbic acid pharmacokinetics are limited.

Purpose of the Study:

• To determine the pharmacokinetics of ascorbic acid in horses.
• To compare bioavailability and safety across different administration routes (IV, SC, IM, oral).
• To identify the optimal route for ascorbic acid supplementation in horses.

Main Methods:

• Pharmacokinetic study in 29 horses.
• Administration of ascorbic acid via intravenous (IV), subcutaneous (SC), intramuscular (IM), and oral routes.
• Serum ascorbic acid levels were measured over time to determine pharmacokinetic parameters.

Main Results:

• IV administration followed a two-compartment open model, with distribution and elimination dose-dependent.
• SC and IM routes showed good bioavailability (82% and 61%, respectively) but caused local irritation.
• Oral administration resulted in very poor systemic availability, with minimal increase in serum levels.

Conclusions:

• Intravenous injection is the most effective route for ascorbic acid administration in horses.
• Subcutaneous and intramuscular routes are viable but associated with local irritation.
• Oral supplementation with ascorbic acid is largely ineffective in horses.