Release of lonapalene from two-phase emulsion-type ointment systems

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Dermatology

Background:

• Psoriasis treatment requires effective topical agents.
• Lonapalene is a novel nonsteroidal antipsoriatic agent.
• Understanding drug release from topical formulations is crucial for efficacy.

Purpose of the Study:

• To investigate the in vitro release kinetics of lonapalene from two-phase emulsion ointments.
• To evaluate the impact of formulation variables on lonapalene release rates.

Main Methods:

• In vitro release studies of lonapalene from emulsion ointments into propylene carbonate.
• Systematic variation of lonapalene concentration, saturation level, and internal phase volume fraction.
• Analysis of release profiles, including initial and diffusion-controlled rates.

Main Results:

• Lonapalene release exhibited an initial burst followed by diffusion-controlled release.
• Higher initial lonapalene concentration increased both release rates.
• Increasing internal phase volume fraction to 25% enhanced initial release rate.
• Reduced saturation level decreased both initial and diffusion-controlled release rates.

Conclusions:

• Formulation composition significantly affects lonapalene release from emulsion ointments.
• Optimizing drug concentration and internal phase characteristics is key for controlled topical delivery.
• The diffusion coefficient of lonapalene in the external phase was determined.