prednisolone-hemisuccinate and prednisolone-acetate

Pharmacokinetic parameters of prednisolone after intramuscular administration of prednisolone acetate as a solution were determined in cattle. Analysis of absorption revealed that a first fraction of the dose (about 20%) was rapidly absorbed with an half time of absorption of 1.76 +/- 0.725 h; the second fraction (about 80% of the dose) was absorbed more slowly with an half time of absorption of 12.3 +/- 3.16 h. Such a process of absorption was different of that described for prednisolone acetate suspension for which rate of absorption was slower. Therapeutic consequences of these kinetic differences were discussed for the use of fixed combination of antibiotics and corticosteroid.

Topics: Animals; Anti-Bacterial Agents; Cattle; Dimethyl Sulfoxide; Drug Combinations; Female; Injections, Intramuscular; Injections, Intravenous; Prednisolone

The pharmacokinetics of prednisolone were studied in a group of 6 cows given prednisolone 21-sodium succinate IV and IM (600 micrograms/kg of body weight expressed as prednisolone alcohol) and prednisolone acetate IM (600 micrograms/kg of body weight expressed as prednisolone alcohol). After IV administration of prednisolone 21-sodium succinate, the half-life of elimination was 3.6 +/- 1.177 hours. After IM administration of prednisolone 21-sodium succinate, absorption was rapid and complete. After IM administration of prednisolone acetate, absorption was very slow with an absorption half-life of 48 hours, but was still complete. Basal plasma hydrocortisone was about 7.5 ng/ml. After IV and IM administration of prednisolone 21-sodium succinate, plasma hydrocortisone returned to normal values within 48 hours. In contrast, after IM administration of prednisolone acetate, a long adrenal suppression lasting from 4 to 6 weeks was observed.

Topics: Adrenal Glands; Animals; Cattle; Chromatography, High Pressure Liquid; Female; Half-Life; Hydrocortisone; Injections, Intramuscular; Injections, Intravenous; Prednisolone

Pharmacokinetics of dexamethasone and prednisolone were studied in 6 horses given dexamethasone alcohol (IV or IM) or dexamethasone 21-isonicotinate as a solution IV or IM (50 micrograms/kg of body weight), prednisolone 21-sodium succinate IV or IM (0.6 mg/kg of body weight), or prednisolone acetate IM (0.6 mg/kg of body weight). Plasma concentrations were determined using a high-performance liquid chromatographic method. After dexamethasone alcohol (IV) or dexamethasone 21-isonicotinate (IV), the half-life of elimination was similar (53 minutes) for both formulations. After dexamethasone (alcohol and isonicotinate, IM), concentrations were low or nondetected. After prednisolone 21-sodium succinate (IV), the half-life of elimination (99.5 minutes) was significantly (P less than 0.01) longer than that for dexamethasone. After prednisolone 21-sodium succinate (IM), absorption was rapid and bioavailability was high. After prednisolone acetate (IM), absorption was slow and prednisolone was present in plasma for about 7 days. Due to the nonlinearity of prednisolone kinetics, a bioavailability higher than 100% was obtained. The basal plasma hydrocortisone concentration was approximately 70 ng/ml. After dexamethasone (IV or IM), plasma hydrocortisone values decreased after a 2-hour delay and returned to base line after a 3 to 4 day delay. After prednisolone 21-sodium succinate (IV or IM), plasma hydrocortisone decreased immediately (IV) or rapidly (IM) and returned to base line after a 24-hour delay. After prednisolone acetate (IM), plasma hydrocortisone decreased for up to 21 days.

Topics: Absorption; Adrenal Glands; Animals; Biological Availability; Dexamethasone; Dexamethasone Isonicotinate; Female; Half-Life; Horses; Hydrocortisone; Kinetics; Male; Prednisolone