Absorption and dosage of theophylline in the horse after single and repeated administration of a microencapsulated preparation.
The kinetics of 2 formulations of theophylline were studied in horses. In an initial cross-over study (Phase I) serum concentration-time curves were determined for granulated and microencapsulated theophylline after a single oral administration (5 mg/kg bwt). In Phase II microencapsulated theophylline was administered at 5 mg/kg bwt/12 h for 10 days at feeding time, as in normal clinical practice. Although no significant differences between the 2 preparations were found with respect to the main kinetic parameters, the microencapsulated form was more evenly and completely absorbed from the digestive tract; furthermore, after the repeated treatment, its trough-peak serum concentrations were always within the therapeutic window and no toxic effects were observed in treated animals.
Roncada
P
P
Istituto di Farmacologia, Farmacocinetica e Tossicologia, Facoltà di Medicina Veterinaria, Università degli Studi di Bologna, Ozzano Emilia (BO), Italy.
Tomasi
L
L
Montesissa
C
C
Grossi
G
G
Stracciari
G L
GL
Anfossi
P
P
D000704:Analysis of Variance; D000818:Animals; D002214:Capsules; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D005260:Female; D006736:Horses / Q000378:metabolism*; D007408:Intestinal Absorption; D008297:Male; D013806:Theophylline / Q000008:administration & dosage* / Q000493:pharmacokinetics*
D002214:Capsules; D003692:Delayed-Action Preparations; D013806:Theophylline