Formulation of wax oxybenzone microparticles using a factorial approach

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Cosmetic Science

Background:

• Oxybenzone is a common UV filter used in sunscreens.
• Developing advanced delivery systems for UV filters is crucial for enhancing sunscreen efficacy and user experience.
• Microparticle technology offers potential for controlled release and improved formulation stability.

Purpose of the Study:

• To prepare and optimize oxybenzone-loaded wax microparticles (MPs) using a hydrophobic congealable disperse phase method.
• To investigate the influence of formulation parameters on the characteristics of oxybenzone MPs.
• To generate a range of sunscreen delivery systems with tunable properties.

Main Methods:

• Hydrophobic congealable disperse phase method for MP preparation.
• 2⁴ experimental design for formulation optimization.
• Factorial analysis to determine the impact of key parameters (drug loading, emulsification speed, emulsifier concentration, HLB).

Main Results:

• Optimized MPs were spherical with a size range of 50.5–88.1 μm.
• Drug content ranged from 17.8–38.9 mg/100 mg MPs.
• Oxybenzone release varied from 33.1–87.2% within 1 hour, indicating tunable release profiles.

Conclusions:

• The formulation of oxybenzone MPs can be effectively optimized using a systematic experimental design.
• Key formulation parameters significantly influence MP characteristics and drug release.
• The developed microparticle systems provide a versatile platform for advanced sunscreen formulations with potentially improved performance.