Absorption and dosage of theophylline in the horse after single and repeated administration of a microencapsulated preparation.

The research study was focused on analyzing the absorption rates and dosage measurement of two forms of a drug called theophylline in horses. Despite similar kinetic parameters, microencapsulated theophylline was more uniformly absorbed and sustained within the therapeutic range without any toxic effects observed.

Study Design and Research Phases

• The study was divided into two separate phases, both involving the administration of theophylline to horses.
• In Phase I, the researchers conducted a cross-over study to determine the serum concentration-time curves for granulated and microencapsulated forms of theophylline. The horses received a one-time oral dose of the drug (5 mg/kg bwt).
• In Phase II, only microencapsulated theophylline was given to the horses. The dosage was 5 mg/kg bwt/12 h, consistently administered over a period of 10 days during feeding time to emulate regular clinical practice.

Comparison between the Two Formulations

• The researchers did not find significant differences in the main kinetic parameters between the granulated and microencapsulated drug forms.
• The primary distinction was noticed in the absorption process from the digestive tract. The microencapsulated form of theophylline was more evenly and fully absorbed by the horses’ digestive systems as compared to its granulated counterpart.
• Besides, another crucial observation was related to the trough-peak serum concentrations post-repeated administration of the microencapsulated form. The concentrations consistently remained within the therapeutic window, suggesting controlled and beneficial dosage levels.

Safety of Microencapsulated Theophylline

• Another important contribution of the research was related to the safety level of the microencapsulated form of theophylline.
• Despite its repeated administration over a relatively long period (10 days), the animals didn’t exhibit any signs of toxic effects.
• This finding indicates that microencapsulated theophylline can be considered safe, at least in the context of this experiment’s conditions and dosage levels, for administration in horses.

In conclusion, the study results support the utility of microencapsulated theophylline for efficient and safe administration to horses, showing its potential as a preferable option over its granulated form in veterinary medicine.