Advanced Formulation Design for Topical Creams Assisted with Vibrational Spectroscopic Imaging

Area of Science:

• Pharmaceutical Sciences
• Analytical Chemistry
• Materials Science

Background:

• Vibrational spectroscopic imaging is crucial for pharmaceutical quality control.
• Semi-solid drug products require detailed understanding of their microscopic structure for effective formulation.
• Developing robust analytical methods is key for ensuring drug product quality and performance.

Purpose of the Study:

• To apply microscopic attenuated total reflection (ATR)-IR and confocal Raman microscopy for analyzing semi-solid drug formulations.
• To elucidate the microscopic structure of creams and guide formulation design.
• To assess the compatibility of various oily solvents within semi-solid drug delivery systems.

Main Methods:

• Microscopic Attenuated Total Reflection (ATR)-Infrared (IR) imaging.
• Confocal Raman microscopy for in-depth and 2D component distribution analysis.
• Preparation of model creams with active pharmaceutical ingredients (prednisolone, fluconazole) and oily solvents.

Main Results:

• ATR-IR imaging identified oily internal phase domains and benzyl alcohol distribution, indicating an oil-in-water cream type.
• Quantitative analysis of prednisolone and benzyl alcohol distribution correlated well with imaging data.
• Confocal Raman imaging visualized component distribution in depth and confirmed the co-localization of fluconazole and benzyl alcohol in the oily phase.

Conclusions:

• Spectroscopic imaging techniques are feasible and powerful tools for the formulation design of semi-solid dosage forms.
• The study demonstrated the utility of ATR-IR and Raman microscopy in characterizing cream microstructure and solvent compatibility.
• These methods provide valuable insights for developing and optimizing semi-solid drug products.