The customer was looking for capsules to protect a mixture of 5 essential oils, which would be released only when the capsules were broken by rubbing with a hand. The essential oils were very expensive and highly volatile. The capsules also needed to be shelf-stable for 6 months in air without loss of the volatile essential oils.
AVEKA used PMU encapsulation to contain and protect the 5 essential oils. AVEKA also developed a method to preserve the cost of the high-value essential oils by diluting with vegetable oil to 50%. The two types of capsules (100% essential oil and 50% essential oil) were exposed to air and measured for weight loss over 9 months:
- Non-encapsulated essential oils lost 87 wt% over 9 months
- 100% essential oil capsules only lost 3.2 wt%
- 50% essential oil capsules only lost 1.2 wt%