Effect of camphor/cyclodextrin complexation on the stability of O/W/O multiple emulsions

Int J Pharm. 2003 Aug 11;261(1-2):1-8. doi: 10.1016/s0378-5173(03)00261-8.

Abstract

Camphor (CA) encapsulation in oil/water/oil multiple emulsions prepared with cyclodextrin disturbs the emulsifier potential of alpha- and beta-natural cyclodextrins (CD). It was suggested that the size and geometrical fit between the CD cavity and CA could induce CD/CA complex formation in place of emulsifier formation leading to perturbation of emulsion stability. The complexation between CA and alpha-, beta- or gamma-CD in solution in the presence of oil phase are confirmed by phase-solubility diagrams, circular dichroism and 1H NMR. Furthermore, in order to mimic the emulsion system, CD/CA/soybean oil ternary dispersions were prepared to observe the complexation behavior of alpha-, beta- or gamma-CD/CA by circular dichroism. X-ray diffraction on emulsion samples prepared with alpha- and beta-CD confirms that the precipitates observed in emulsions are probably composed of crystals of CD/CA complexes. A preliminary study of the interaction between drug and CD before the formulation seems indispensable to prevent the risk of incompatibility.

MeSH terms

  • Camphor / chemistry*
  • Chemistry, Pharmaceutical
  • Circular Dichroism
  • Crystallization
  • Cyclodextrins / chemistry*
  • Drug Stability
  • Emulsions / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Weight
  • Solubility
  • Soybean Oil
  • Surface-Active Agents
  • Water
  • X-Ray Diffraction
  • alpha-Cyclodextrins*
  • beta-Cyclodextrins*
  • gamma-Cyclodextrins*

Substances

  • Cyclodextrins
  • Emulsions
  • Surface-Active Agents
  • alpha-Cyclodextrins
  • beta-Cyclodextrins
  • gamma-Cyclodextrins
  • Water
  • Camphor
  • Soybean Oil
  • betadex
  • gamma-cyclodextrin
  • alpha-cyclodextrin