Nanoencapsulation: Techniques, Terms and Applications

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Nanoencapsulation is defined as the process of encapsulating substances with various coating materials at the nanoscale range. This technique is primarily used within the pharmaceutical, food and cosmetic industries

Encapsulation

Encapsulation refers to any technological process that allows one or more active compounds to be enclosed within an inert material. Encapsulated substances are therefore protected against harsh environments, such as hydrochloric acid within the stomach, and can also offer a controlled release of drugs. The substance being encapsulated can be referred to as the internal phase, core material, filler or fill, whereas the encapsulation material is known as the external phase, shell, coating or membrane.

Microencapsulation

Microencapsulation is a similar process to nanoencapsulation that only differs in the size of the particles, which typically range from 1 micrometer (µm) to 1 millimeter (mm), and the fact that it has been utilized for a longer period of time. Microencapsulation has been applied in almost all industrial sectors ranging from agriculture and environment to home and personal care.  

Nanocapsule Uniformity

The efficacy of many nanoencapsulated and microencapsulated processes often relies on uniformity in particle size and distribution. The use of supercritical carbon dioxide (CO₂) has shown promising benefits to ensure the optimal design of particle size in both microencapsulated and nanoencapsulated drugs, as well as the ability to control drug loading processes at various temperature, pressure and flow ratio ranges.  

Advantages of Nanoencapsulation

As previously stated, one of the most attractive advantages associated with nanoencapsulation is attributed to its ability to protect active pharmaceutical ingredients (API) from degradation. Nanoencapsulation has also improved the precision of drug delivery targets by utilizing surface coating or conjugating that ensures adequate cell entry. Furthermore, nanoencapsulated drugs can be labeled with fluorescent probes for imaging purposes, which is particularly useful for evaluating drug efficiency during preclinical and clinical studies.

Nanoencapsulation Techniques

A multitude of techniques are used in nanoencapsulation and as the field is an emerging one, new techniques are constantly being developed. Nanoencapsulation techniques can be categorized as either top-down or bottom-up approaches. When the top-down approach is utilized, precise tools are used to accurately reduce the size and structure of the material, whereas the bottom-up approach involves the use of materials derived from either self-assembly and/or self-organization molecular processes.

Some of the most recent technologies utilized for nanoencapsulation purposes include:

• Nanoemulsification
• Nanoliposomes
• Electrospray
• Nanostructure formation through the use of cyclodextrins
• Solid lipid nanoparticles
• Nanostructure lipid carriers

Applications

The main reason nanoencapsulation is so widely used is its efficiency in protecting the core material and ultimately releasing the API when required. Some of the most common applications of nanoencapsulation therefore can be found in:

• Targeted drug delivery systems that will only release drug upon its arrival at the correct location within the body
• Timed release drug delivery systems, in which slow degradation of the external phase allows for controlled release in the body. One example of this type of drug delivery system can be found in nasal drug delivery devices.
• Embedded fragrances for perfumed garments
• Food additions and enhancements
• Increased shelf life and stability of over the counter pharmaceutical products, such as vitamins

​References

1. “Encapsulation technologies: A general overview” – Capsulae
2. Suganya, V., & Anuradha, V. (2017). Microencapsulation and Nanoencapsulation: A Review. International Journal of Pharmaceutical and Clinical Research 9(3); 233-239. DOI: 10.25258/ijpcr.v9i3.8324.
3. Soh, S. H., Lee, L. Y. (2019). Microencapsulation and Nanoencapsulation Using Supercritical Fluid (SCF) Techniques. Pharmaceutics 11(21). DOI: 10.3390/pharmaceutics11010021.
4. “Nanoencapsulation Techniques” – Microfluidics
5. Jafari, S. M. (2017). An overview of nanoencapsulation techniques and their classification. Nanoencapsulation Technologies for the Food and Nutraceutical Industries. DOI: 10.1016/B978-0-12-809436-5.00001-X.

This article was updated on 29^th April, 2019.