Physicochemical attributes and dissolution testing of ophthalmic ointments.

Area of Science:

• Pharmaceutical Sciences
• Ophthalmology
• Materials Science

Background:

• Semisolid ophthalmic ointments present formulation challenges due to complex physicochemical properties and ocular anatomy.
• Loteprednol etabonate is a key corticosteroid used in ophthalmic preparations.

Purpose of the Study:

• To investigate the influence of manufacturing processes and excipient sources on the physicochemical properties and in vitro drug release of loteprednol etabonate ophthalmic ointments.
• To establish correlations between rheological parameters and drug release for quality control.

Main Methods:

• Loteprednol etabonate ointments were prepared using three manufacturing processes and two excipient sources (OWP and NWP).
• Physicochemical properties (drug content, particle size, rheology) and in vitro drug release (USP apparatus 2) were evaluated.
• Logarithmic linear regression was used to analyze correlations.

Main Results:

• Both manufacturing methods and excipient sources significantly affected ointment properties and drug release.
• Hot melt processes resulted in higher rheological parameters and slower drug release compared to non-hot melt methods.
• OWP excipients led to higher rheology and reduced in vitro drug release compared to NWP excipients.

Conclusions:

• Manufacturing processes and excipient selection are critical quality attributes for ophthalmic ointments.
• A strong correlation exists between rheological parameters and in vitro drug release, aiding in formulation development and prediction.
• These findings can guide the development of stable and effective ophthalmic ointment formulations.