Effect of antioxidant properties of lecithin emulsifier on oxidative stability of encapsulated bioactive compounds

Yuanjie Pan, Rohan V. Tikekar, N. Nitin

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45 Scopus citations


Oxidation of encapsulated bioactive compounds in emulsions is one of the key challenges that limit shelf life of emulsion containing products. Oxidation in these emulsions is triggered by permeation of free radicals generated at the emulsion interface. The objective of this study was to evaluate the role of antioxidant properties of common emulsifiers (lecithin and Tween 20) in reducing permeation of free radicals across the emulsion interface. Radical permeation rates were correlated with oxidative stability of a model bioactive compound (curcumin) encapsulated in these emulsions. Rate of permeation of peroxyl radicals from the aqueous phase to the oil phase of emulsion was inversely proportional to the antioxidant properties of emulsifiers. The rate of radical permeation was significantly higher (p < 0.05) for emulsions stabilized using Tween 20 and oxidized lecithin compared to native lecithin that showed higher antioxidant activity. Free radical permeation rate correlated with stability of curcumin in emulsions and was significantly higher (p < 0.05) in lecithin stabilized emulsions as compared to Tween 20 emulsions. Overall, this study demonstrates that antioxidant activity of emulsifiers significantly influences permeation of free radicals across the emulsion interface and the rate of oxidation of bioactive encapsulant.

Original languageEnglish (US)
Pages (from-to)129-137
Number of pages9
JournalInternational Journal of Pharmaceutics
Issue number1-2
StatePublished - Jun 25 2013



  • Antioxidant properties
  • Emulsifier
  • Emulsions
  • Free radicals
  • Lecithin
  • Oxidation

ASJC Scopus subject areas

  • Pharmaceutical Science

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