Exploring Microstructural Changes in Structural Analogues of Ibuprofen-Hosted In Situ Gelling System and Its...

Area of Science:

• Physical Chemistry
• Materials Science
• Pharmaceutical Sciences

Background:

• In situ gelling systems offer advantages for drug delivery, but their performance is linked to complex microstructural behavior.
• Understanding the internal structure of glyceryl monooleate (GMO) and oleic acid (OA) based systems is crucial for optimizing pharmaceutical formulations.

Purpose of the Study:

• To investigate the inner structuration and mesophasic transformations of a glyceryl monooleate (GMO) and oleic acid (OA) in situ gelling system.
• To elucidate the impact of ibuprofen structural analogues on the system's microstructure and pharmaceutical performance.

Main Methods:

• Small-angle X-ray scattering (SAXS) was employed to probe microstructural changes.
• Differential scanning calorimetry (DSC), rheology, and plane polarized light (PPL) microscopy were used for complementary analysis.
• Sol-gel transformation and drug release kinetics were evaluated.

Main Results:

• The blank system transformed from a water-in-oil (W/O) emulsion to a reverse hexagonal structure upon the addition of ibuprofen analogues.
• SAXS analysis indicated that increased hydrophobic volume within the system drives these structural transformations.
• An inverse relationship was observed between the log P value of ibuprofen analogues and water molecule binding to surfactant chains, affecting sol-gel transitions.

Conclusions:

• The addition of ibuprofen analogues induces significant microstructural changes in GMO/OA gelling systems, impacting their pharmaceutical performance.
• The observed transformations and their relationship with drug properties provide insights into designing effective in situ gelling formulations.
• The developed in situ gelling system demonstrated sustained drug release, adhering to the Higuchi model, indicating its potential for controlled drug delivery applications.