The gut in the beaker: Missing the surfactants?

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery
• Physical Chemistry

Background:

• Gastrointestinal (GI) drug administration is common but complex, influenced by physiology, diet, and disease.
• In vitro drug performance tests aim for consistency but face challenges due to GI tract variability.
• Surfactant excipients in formulations interact with natural bile salts, impacting drug absorption.

Purpose of the Study:

• To explore the complexities of drug dissolution and absorption in the GI tract.
• To investigate the role of surfactant excipients and their interaction with bile salts.
• To address challenges in translating in vitro drug performance to in vivo outcomes.

Main Methods:

• Exploration of drug, formulation, and surfactant interactions within the GI environment.
• Analysis of challenges including drug dissolution, solubility, supersaturation, and precipitation.
• Review of lipid-based formulations and the influence of surfactant excipients.

Main Results:

• Surfactant interactions begin early (mouth, swallowing) and pose significant challenges in the stomach and small intestine.
• Drug behavior is heavily influenced by formulation type, especially lipid-based systems, and excipient surfactants.
• Difficulties exist in correlating in vitro test results with actual in vivo drug performance.

Conclusions:

• The interplay between drug formulation, surfactants, and GI physiology is intricate and not fully understood.
• Further research using advanced methodologies is crucial to elucidate drug behavior and optimize GI drug delivery.
• Predicting in vivo drug performance from in vitro tests remains a significant hurdle in pharmaceutical development.