A Novel Desloratadine-Benzoic Acid Co-Amorphous Solid: Preparation, Characterization, and Stability Evaluation

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Amorphous drugs face limitations in physical stability, hindering widespread use.
• Co-amorphous systems offer a promising strategy for creating stable amorphous drug forms.
• Desloratadine (DES) solubility and stability can be improved using excipient co-formation.

Purpose of the Study:

• To investigate the formation and properties of desloratadine-benzoic acid (DES-BA) co-amorphous systems.
• To enhance the physical stability, dissolution, and solubility of desloratadine.
• To explore the potential of DES-BA co-amorphous systems for oral formulations.

Main Methods:

• Co-amorphous DES-BA systems were prepared using the melt-quenching method.
• Characterization involved differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and polarized light microscopy (PLM).
• Dissolution, solubility, and physical stability were assessed under various conditions.

Main Results:

• Solid-state analysis confirmed the amorphous and homogeneous nature of the DES-BA (1:1) co-amorphous system.
• DSC indicated a higher single glass transition temperature (Tg) for DES-BA compared to amorphous DES.
• FTIR revealed strong molecular interactions, including salt formation, between DES and BA. Dissolution and solubility of DES-BA were significantly higher than crystalline DES.
• PXRD analysis demonstrated improved physical stability of DES-BA over amorphous DES after three months at 40°C/75% RH.

Conclusions:

• The DES-BA co-amorphous system effectively improves the physical stability, solubility, and dissolution rate of desloratadine.
• Co-amorphous salt formation between DES and BA is key to these improvements.
• DES-BA co-amorphous systems show significant potential for developing improved oral formulations of desloratadine, enhancing bioavailability.