Encapsulation Release Mechanisms
Micro/Nano Encapsulation

image of mechanically ruptured microcapsules that are used to manufacture paper products such as scratch and sniff items and carbonless copy paper

Mechanically ruptured microcapsules are used to manufacture paper products such as scratch and sniff items and carbonless copy paper.  

 

Osmotic release is triggered by the absorption of water into the microcapsule core. Subsequent swelling ruptures the microcapsule shell.

Osmotic release is triggered by the absorption of water into the microcapsule core. Subsequent swelling ruptures the microcapsule shell.

 

image: Particle size is one of many parameters that may be adjusted to control release rates of encapsulated ingredients.

Click image for enlarged view 
Particle size is one of many parameters that may be adjusted to control release rates of encapsulated ingredients.

To achieve one or more release mechanisms to meet product performance requirements, Southwest Research Institute (SwRI) scientists develop particle and capsule formulations and routinely fine tunes these formulations and their particle properties to tailor release rate and/or release profile.

Common Controlled Release Profiles

  • Triggered release
    • Release occurs due to a change in environment, such as:
      • pH
      • Temperature
      • Moisture
      •  Pressure
      • Electromagnetic changes
    • This is used to achieve immediate, delayed or pulsatile release profiles.
  • Sustained release
    • Release occurs for an extended period of time.
    • This can be used to achieve constant active ingredient exposure for a fixed period.
  • Burst release
  • Combination release profiles

Release Mechanisms

  • Diffusion
  • Dissolution
  • Molecular trigger (such as pH)
  • Biodegradation
  • Thermal
  • Mechanical
  • Osmotic
  • Biochemical

Related Terminology

microencapsulation  •  nanoencapsulation  •  encapsulation  •  release mechanisms  •  controlled release  •  osmotic release  •  microcapsules  •  capsule formulations

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 11 technical divisions.
01/24/13