Mucoadhesive in situ forming Gels: Bridging Formulation design and physiological Realities

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Biomedical Engineering

Background:

• Thermosensitive mucoadhesive in situ forming gels are promising for localized oral drug delivery.
• Conventional assessment methods may not accurately reflect in vivo performance due to overlooked physiological factors.

Purpose of the Study:

• To evaluate the impact of physiological factors on the performance of in situ forming oral gels.
• To compare traditional versus physiologically relevant evaluation methods for these drug delivery systems.

Main Methods:

• Formulation of in situ forming oral gels with different mucoadhesive polymers.
• Assessment of gelation temperature, mucoadhesion, rheology, and drug release under traditional and physiologically relevant conditions.
• Utilized Small Angle X-ray Spectroscopy (SAXS) and rheological oscillatory temperature sweeps.

Main Results:

• Physiologically relevant methods yielded higher gelation temperatures and reduced mucoadhesion.
• A hexagonal liquid crystalline micellar arrangement formed at 35°C, enabling sustained drug release (4-6h).
• Drug release was influenced by salivary amylase, pH, and polymer properties; chitosan gels showed faster release at low pH, while sodium alginate gels exhibited slower release.

Conclusions:

• Integrating physiological factors into early formulation evaluation is crucial for accurate performance prediction.
• This approach helps identify suboptimal candidates before clinical studies, optimizing oral drug delivery system design.
• Novel insights guide the development and evaluation of other oral mucoadhesive systems.