Oil encapsulation in core-shell alginate capsules by inverse gelation. I: dripping methodology

J Microencapsul. 2017 Feb;34(1):82-90. doi: 10.1080/02652048.2017.1284278. Epub 2017 Jan 31.

Abstract

The production of capsules by inverse gelation consists of adding dropwise oil containing calcium dispersion into an alginate bath. A dripping technique to produce capsules from oil-in-water (O/W) emulsions was proposed by Abang. However, little is known about the oil encapsulation using water-in-oil (W/O) emulsions. This work aims to develop a new method of W/O emulsions encapsulation by inverse gelation. The success of the W/O emulsion encapsulation is due to three factors: 1) use of an emulsion with moderate stability (50 min); 2) production of an emulsion with at least 90 g/L of CaCl2 and 3) addition of ethanol (20% v/v) into the alginate bath. Both wet and dry capsules were obtained with a spherical shape with diameters of 7 and 3.6 mm, respectively. All volume of oil was encapsulated and the oil loading in the wet and dry capsules was of 23 and 68% v/v, respectively.

Keywords: Alginate; encapsulation; inverse gelation; oil; surfactants.

MeSH terms

  • Alginates / chemistry*
  • Capsules / chemistry
  • Drug Compounding / instrumentation
  • Drug Compounding / methods*
  • Emulsions / chemistry*
  • Equipment Design
  • Gels / chemistry*
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / chemistry
  • Oils / chemistry*
  • Surface-Active Agents / chemistry*
  • Water / chemistry

Substances

  • Alginates
  • Capsules
  • Emulsions
  • Gels
  • Hexuronic Acids
  • Oils
  • Surface-Active Agents
  • Water
  • Glucuronic Acid