Preventing the thermal degradation of astaxanthin through nanoencapsulation

Int J Pharm. 2009 Jun 5;374(1-2):119-24. doi: 10.1016/j.ijpharm.2009.03.001. Epub 2009 Mar 14.

Abstract

The encapsulation of astaxanthin into polymeric nanospheres by solvent displacement was compared for three chemically diverse polymers, namely; poly(ethylene oxide)-4-methoxycinnamoylphthaloylchitosan (PCPLC), poly(vinylalcohol-co-vinyl-4-methoxycinnamate) (PB4) and ethylcellulose (EC). Although capable of forming nanospheres themselves, EC could not encapsulate astaxanthin at all, whilst PB4 yielded a poor encapsulation efficiency. In contrast, PCPLC yielded reasonably good encapsulation efficiency (98%) at a loading of 40% (w/w). Moreover, the freeze-dried astaxanthin-encapsulated PCPLC nanospheres showed good dispersibility in water yielding stable aqueous suspensions of 300-320 nm nanoparticles. A steady release of astaxanthin from the nanospheres up to a maximum of approximately 85% payload over 60 min was also demonstrated, at least in acetone. NMR analysis indicated that after a two-hour-heating at 70 degrees C in an aqueous environment, PCPLC nanoencapsulated astaxanthin showed minimal heat degradation of olefinic functionality in contrast to that of the unencapsulated pigment molecules which were almost completely destroyed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cellulose / analogs & derivatives
  • Cellulose / chemistry
  • Chitosan / analogs & derivatives
  • Chitosan / chemistry
  • Cinnamates / chemistry
  • Delayed-Action Preparations
  • Drug Stability
  • Freeze Drying
  • Hot Temperature
  • Magnetic Resonance Spectroscopy
  • Nanospheres*
  • Pigments, Biological / chemistry
  • Polyethylene Glycols / chemistry
  • Polymers / chemistry*
  • Polyvinyls / chemistry
  • Solvents / chemistry
  • Time Factors
  • Xanthophylls / chemistry

Substances

  • Cinnamates
  • Delayed-Action Preparations
  • Pigments, Biological
  • Polymers
  • Polyvinyls
  • Solvents
  • Xanthophylls
  • poly(ethylene oxide)-4-methoxycinnamoylphthaloylchitosan
  • poly(vinylalcohol-co-vinyl-4-methoxycinnamate)
  • Polyethylene Glycols
  • ethyl cellulose
  • astaxanthine
  • Cellulose
  • Chitosan