Single crystal structure, solid state characterization and dissolution rate of terbinafine hydrochloride

Area of Science:

• Pharmaceutical Sciences
• Solid-State Chemistry
• Materials Science

Background:

• Terbinafine hydrochloride (TH) is a crucial antifungal medication.
• Understanding TH's solid-state properties is vital for optimizing drug delivery and efficacy.
• Poor water solubility of TH presents formulation challenges.

Purpose of the Study:

• To comprehensively characterize Terbinafine hydrochloride (TH) using various solid-state techniques.
• To investigate the structural and morphological properties of newly obtained TH crystal habits.
• To evaluate the impact of crystal habit on the intrinsic dissolution rate (IDR) of TH.

Main Methods:

• Solid-state characterization: Differential scanning calorimetry (DSC), thermogravimetry (TGA), X-ray powder diffraction (XRPD).
• Spectroscopic analysis: Fourier transform infrared (FTIR), Raman, solid-state nuclear magnetic resonance (ssNMR).
• Crystallography: Single-crystal X-ray diffraction for structure determination; solvent evaporation for new crystal habit formation; intrinsic dissolution rate (IDR) testing.

Main Results:

• Multiple solid-state techniques confirmed the physicochemical properties of TH.
• A new needle-like crystal habit of TH was successfully synthesized.
• The needle-like TH crystal habit exhibited a lower intrinsic dissolution rate compared to the raw material, likely due to crystal orientation.

Conclusions:

• The study provides a detailed solid-state characterization of Terbinafine hydrochloride.
• The formation of a new needle-like crystal habit impacts TH's dissolution behavior.
• These findings are crucial for developing improved formulations of Terbinafine hydrochloride with enhanced bioavailability.