Sucrose Acetate Isobutyrate (SAIB) as a Delivery Vehicle for Estradiol and Sulpiride: Evaluation of Endocrine Responses in Geldings and Ovarian Response in Seasonally Anovulatory Mares.

This research examines the use of Sucrose Acetate Isobutyrate (SAIB) as an alternative delivery vehicle for two drugs, sulpiride and estradiol, in horses. The study demonstrates that SAIB is effective in releasing these drugs and may serve as a better substitute for vegetable shortening.

Objective of the study

• The main goal of this research was to test the efficacy of Sucrose Acetate Isobutyrate (SAIB), a hydrophobic polymer, as a delivery medium for two drugs, Sulpiride and Estradiol in horses.
• The researchers conducted four in vivo experiments to compare the performance of SAIB with vegetable shortening as a delivery medium. Vegetable shortening was previously known to effectively release Sulpiride in horses for up to 10 days.

Research findings

• In the first part of the experiment, the researchers used geldings (male horses that have been castrated) to compare the impact of SAIB and vegetable shortening as delivery vehicles for Sulpiride. The results showed that both SAIB and vegetable shortening stimulated the release of prolactin hormone. This was the expected reaction, indicating that SAIB can effectively deliver Sulpiride.
• Sulpiride was combined with two forms of Estradiol for other experiments, namely Estradiol Cypionate (ECP) and Estradiol Benzoate (EB). The Estradiol-Sulpiride mixture was delivered in SAIB. The aim was to test if there were significant differences between ECP and EB on their stimulation of the luteinizing hormone (LH) concentrations. The study found that both ECP and EB alongside Sulpiride in SAIB stimulate the production of LH, with no significant differences between the two forms of Estradiol.
• In the third part of the experiment, the researchers administered simultaneous and nonsimultaneous injections of a combination of EB and Sulpiride and monitored their effects on the stimulation of prolactin. It was found that both treatment groups had a stimulated prolactin response. However, when the injections were administered separately, the response lasted two days longer than the simultaneous treatment.
• In the final phase, the research focused on the application of the two treatment methods (simultaneous and non-simultaneous injection) on seasonally anovulatory mares (female horses that do not ovulate seasonally). Both treatments stimulated prolactin and LH hormones similarly, but the non-simultaneously treated mares tended to have an ovarian response earlier.

Conclusion of the study

• Overall, the study concluded that Sucrose Acetate Isobutyrate (SAIB) was effective as a delivery vehicle for both Sulpiride and Estradiol drugs in horses. Therefore, SAIB could be considered a viable alternative to the earlier used method of vegetable shortening as a delivery system for these drugs.