Diatomaceous Earth-Enabled Resveratrol Microemulsion for Enhanced Permeation and Stability

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Nanotechnology

Background:

• Resveratrol, a potent antioxidant, suffers from poor solubility and photostability, limiting its topical application.
• Microemulsions offer a promising vehicle for enhancing the delivery of lipophilic compounds.
• Diatomaceous earth (DE) is explored as a carrier for microemulsion systems in topical formulations.

Purpose of the Study:

• To develop and characterize a novel diatomaceous earth-based microemulsion system for enhanced topical delivery of resveratrol.
• To evaluate the impact of DE incorporation on microemulsion microstructure, rheology, and resveratrol stability.
• To assess the permeation, photostability, cellular uptake, and cytotoxicity of the developed DE:resveratrol microemulsion system.

Main Methods:

• Preparation of microemulsions using pseudo-ternary phase diagrams with varying ethanol:virgin coconut oil, Cremophor RH40, and water ratios.
• Incorporation of resveratrol into selected microemulsions (ME1, ME2) and subsequent combination with diatomaceous earth (DE:ME) at different ratios.
• Characterization using transmission electron microscopy (TEM), rheological analysis, differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR).
• Evaluation of resveratrol content, permeation studies, photostability testing, and in vitro cytotoxicity assays using human keratinocytes.

Main Results:

• Optimized microemulsion regions were identified, and DE was successfully incorporated into the microemulsions.
• DE incorporation altered microemulsion microstructure and rheological properties, with increased DE concentration affecting viscoelasticity.
• The DE:ME system demonstrated high resveratrol loading (near 100%) and significantly enhanced resveratrol permeation (3-fold increase).
• Formulations exhibited improved photostability, remained stable for 6 months at 40°C, maintained cellular uptake, preserved biological activity, and showed low cytotoxicity.

Conclusions:

• Diatomaceous earth serves as an effective carrier for resveratrol microemulsions, enhancing topical delivery.
• The developed DE:ME system offers improved resveratrol permeation, photostability, and biological efficacy.
• This DE-based system holds significant potential for topical applications of poorly soluble, photosensitive compounds.