The effect of feeding on the pharmacokinetic variables of two commercially available formulations of omeprazole.

The study investigates the impact of different formulations of orally administrated omeprazole and feeding conditions on pharmacokinetic factors in racehorses. Though not statistically significant, hints of reduced drug bioavailability in fed animals were noted, suggesting the need for further study.

Objective of the Study

• The main aim of this research was to delve into the effects of formulation (specifically enteric coated and buffered versions) and feeding conditions on different pharmacokinetic variables. This was done in the context of oral administration of omeprazole in horses.

Study Design and Methodology

• The experiment included six thoroughbred racehorses and was carried out using a crossover design. This type of design is a type of longitudinal study in which subjects receive a sequence of different treatments. It’s often used to reduce confounding variables and improve the reliability of findings.
• Each horse received 2 grams of either an enteric-coated or buffered formulation. These two treatment regimes were introduced in both the fed and fasted state.
• The concentration of omeprazole in the horse’s plasma was determined utilising UHPLC-MS (ultra-high performance liquid chromatography-mass spectrometry), a method often used for drug detection and analysis.

Findings and Interpretations

• Upon analyzing the results, the researchers observed that the effects of feeding or the specific formulation of the drug on various pharmacokinetic parameters such as AUC0-inf_obs (the total drug exposure over time from zero to infinity), half-life, Tmax (the time it takes for a drug to reach its maximum concentration in the blood), or Cmax (the maximum or peak concentration of a drug after administration) were not statistically significant.
• Despite this, the study highlighted a wider-than-expected range of variation. This refers to the variability noticed in the drug absorption levels among the horses.
• Scrutinizing the raw data suggested that horse feeding could potentially affect the formulation, where the bioavailability (the degree to which a drug is absorbed into the bloodstream) of omeprazole may be reduced in the fed animal.
• While this possible effect of feeding was not statistically significant in their sample size, the researchers recognized that it may warrant investigation in a broader population of animals to identify the factors that contribute to the broad absorption range observed.

Future Research

• The researchers recommend further investigation in a larger animal population to understand the elements that contribute to the wide-ranging degree of absorption noticed. Additional research would further verify if the feeding does in fact have a noticeable impact on the absorption of the omeprazole.