Validation of an RP-HPLC method for simultaneously quantifying three UV filters encapsulated into nanostructured...

Area of Science:

• Cosmeceutical science
• Analytical chemistry
• Nanotechnology

Background:

• Sunscreens increasingly use nanostructured lipid carriers (NLCs) for enhanced photoprotection.
• Accurate quantification of UV filters within NLCs is essential but analytically challenging.
• Existing methods often lack validation for nanoformulations, focusing on free filters.

Purpose of the Study:

• To develop and fully validate a robust RP-HPLC method for simultaneous UV filter quantification in NLCs.
• To assess the encapsulation efficiency of key UV filters within NLCs.
• To address the analytical gap for nanoformulated cosmeceuticals.

Main Methods:

• Optimization and validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) method.
• Simultaneous quantification of diethylamino hydroxybenzoyl hexyl benzoate (DHHB), bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), and ethylhexyl triazone (EHT).
• Method validation according to ICH guidelines, assessing sensitivity, robustness, accuracy, and precision.

Main Results:

• A highly sensitive RP-HPLC method with a limit of detection (LOD) as low as 0.6 µg mL⁻¹ was established.
• The method accurately determined extracted filter content and encapsulation efficiency (EE) for NLCs.
• Encapsulation efficiency for UV filters consistently exceeded 70%, meeting critical quality attributes.

Conclusions:

• The validated RP-HPLC method provides a reliable tool for analyzing UV filters in NLCs.
• This analytical advancement supports the optimization and industrial scalability of nano-based sunscreen formulations.
• The study successfully addresses a critical need for validated analytical methods in emerging nanoformulation technologies.