Encapsulation of Active Molecules and Their Delivery System

Shirish Sonawane, Bharat A. Bhanvase, Manickam Sivakumar, Sivakumar Manickam, Shirish Hari Sonawane, Shirish H. Sonawane

• Publisher: Elsevier
• Year: 2020
• Print ISBN:
  9780128193631
• eBook ISBN:
  9780128193648
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

Encapsulation of Active Molecules and Their Delivery System covers the key methods of preparation of encapsulation, as well as release mechanisms and their applications in food, biotechnology, metal protection, drug delivery, and micronutrients delivery in agriculture. The book also provides real-life examples of applications in food and other industries. Sections encompasses (i) Synthesis and characterization methods of micro- and nanocarriers as the delivery systems, (ii) Up-to-date encapsulation techniques in the areas of pharmaceuticals, nutraceuticals and corrosion, (iii) The release methods of the encapsulated materials, and (iv) Industry perspectives, including scale up of the processes. - Focuses on encapsulation processes in chemical and materials engineering and biotechnology - Provides a relevant resource for the pharmaceutical and food industries - Presents wide coverage on the entrapment of molecules that scales-up to industrial sized needs

1

Current overview of encapsulation

Shirish H. Sonawane¹, Bharat A. Bhanvase², Manickam Sivakumar³ and Shital B. Potdar⁴, ¹Chemical Engineering Department, National Institute of Technology, Warangal, India, ²Chemical Engineering Department, Laxminarayan Institute of Technology, RTM Nagpur University, Nagpur, India, ³Chemical and Environmental Engineering Department, University of Nottingham, Jalan Broga, Malaysia, ⁴Department of Chemical Engineering, National Institute of Technology, Warangal, India

Abstract

Encapsulation is the process of stabilization of active compounds through the structuring of systems capable of preserving their chemical, physical, and biological properties, x their release or delivery under established or desired conditions In the process of encapsulation, either one or the mixture of bioactive material is coated with another single material or combination of materials. In encapsulation, two main terminologies are frequently used. One is the material that is being coated is termed active material or core material, and the other is the shell material that is also termed carrier material (shell). The shell material can be in solid, liquid droplets, and gas bubbles to encapsulate liquid or gas inside as a core. The core and shell structure can be in various shapes such as the sphere, microcapsules, microbeads, monocore, multicore, matrix, and multishell.

Keywords

Encapsulation; bioactive molecules; core; shell; applications

Chapter Outline

Outline

• 1.1 Introduction to encapsulation 1
• 1.2 Current trends in the encapsulation processes 4
• 1.3 Encapsulation of active substrate and their target applications 6
• References 7
• Further reading 8

1.1 Introduction to encapsulation

Encapsulation dates back to the 19th century. In the year 1963, Harvard Business School prepared a report on encapsulation and underlying phenomena of encapsulation. Fanger published an article in 1974 in the history of encapsulation. Encapsulation is the process of stabilization of active compounds through the structuring of systems capable of preserving their chemical, physical, and biological properties, as well as their release or delivery under established or desired conditions [1]. It is very well known that natural plants, herbs, and food materials have valuable compounds and possess the potential to utilized for various applications, such as in the treatment of diseases like cancer. As an alternative to synthetic preservative and flavouring agents it has been used since the dawn of medicine to treat various illnesses in Ayurveda or food-processing industries as an alternative to synthetic preservatives and flavoring agents. However, these bioactive compounds are subjected to degradation with environmental conditions such as temperature and moisture. So, it is essential to extract and store these valuable compounds. Encapsulation is a promising way to preserve these active compounds.

In the process of encapsulation, either one or the mixture of bioactive material is coated with another single or combination of materials. In encapsulation, two main terminologies are frequently used the material that is being coated is termed as the active material or core material, and another one is the shell material that is also termed carrier material (shell). The shell material can be in the form of solid, liquid droplets, and gas bubbles to encapsulate liquid or gas inside as a core. The core and shell structure can be in various shapes such as the sphere, microcapsules, microbeads, monocore, multicore, matrix, and multishell. The core and shell material of the encapsulation vary depending on the applications and possess specific characteristics, for example, core materials used in food are essential oils (acting as a preservative and flavoring agent) and shell materials are whey protein, gum arabic, maltodextrin, etc. In the medical field the used, core materials are drugs such as the influenza virus, stem cells, DNA, and insulin and shell materials are polymethylmethacrylate, and the encapsulation methods are copolymerization, solvent displacement, gelation, etc.

Encapsulation is used in various areas for different purposes. In biology, it is useful in the encapsulation of living tissue, individual cells, hormones, enzymes or antibodies, and other biological materials. In the food industry, encapsulation is carried out to add flavor to products that are reduced in various food-processing steps. The extraction of a drug molecule and its encapsulation in the pharmaceutical field give natural drug delivery and also help to reduce the side effects of synthetic drugs. Encapsulation technique is also used in the agricultural field to encapsulate pesticides, fertilizers, and other agrochemicals that allow growers to precisely control the conditions under which the active ingredient is released. Encapsulation can also help to minimize the use of pesticides and reduce their environmental impact. Nanocontainer preparation for corrosion inhibition is also an attractive area gaining the attention of many researchers to use nanoparticles such as titania, zinc molybdate as core material and encapsulate them with different polymers either through layer-by-layer approach or by in situ polymerization [2].

With time the domain of encapsulation received enormous attention, while various methods of extraction and encapsulation have been developed depending upon the application and the characteristics of materials. Various methods of extraction can be listed as hot water bath extraction, Soxhlet extraction [3], microwave-assisted extraction [4], extraction using the maceration [5], supercritical carbon dioxide extraction [6], and ultrasound-assisted extraction. Once the bioactive core material is extracted from a natural source, it is desired to encapsulate using various techniques. The encapsulation techniques can be broadly divided into two main categories, that is, chemical and physical encapsulations. There are three different methods of chemical encapsulation, namely, coacervation, molecular inclusion [7], and cocrystallization [8]. Physical encapsulation is also known as mechanical encapsulation. Spray-drying [9,10], extrusion [11], freeze-drying and vacuum drying, spray-cooling or chilling, and fluidized bed coating are the methods of physical encapsulation. New age techniques of encapsulation include high- and low-energy emulsification techniques [12]. Two types of emulsion are formed, namely, microemulsion and nanoemulsion. The fundamental difference between these two types is the droplet size of emulsion. The size for microemulsion is one to several microns, and it is in the range of few nanometers for nanoemulsion. The nanoemulsion technology is becoming attractive because of its advantages over microemulsion such as higher encapsulation efficiency and increased product yield (Fig. 1–1).

Figure 1–1 Encapsulation techniques and the release mechanisms.

Ultrasound-assisted miniemulsion is one of the advanced methods of encapsulation. In this method, miniemulsion polymerization is carried out using the ultrasound-assisted technique. The prepared emulsion using ultrasound is shown in Fig. 1–2. Using ultrasound the cavitation technique, it is possible to prepare the inorganic core surrounded by polymeric shell dispersed in the continuous matrix such as water. Using the ultrasound-assisted method, it is possible to encapsulate active material in a tiny size may be in the range of 20–50 nm. The encapsulated material could be used as a photoanode, drug delivery system, etc.

Figure 1–2 Ultrasound-assisted miniemulsion encapsulation process. Reprinted with permission from Sonawane, et al., J. Phys. Chem. C 114 (2010) 5148–5153.

The release of encapsulated core material can occur by two mechanisms: controlled release and uncontrolled (a triggered mechanism) release. The controlled release of the encapsulated core material is the critical step in the process. As shown in Fig. 1–3, the liquid core is encapsulated using a polymeric shell. Based on the crack propagation, the release of active agents occurs from the core. The liberated molecules react with the polymer matrix, and healing occurs. This type of release mechanism is based on mechanical stimulation.

Figure 1–3 Encapsulation of active molecules and the release mechanism.

The release of the encapsulated drug in a controlled manner gives the maximum therapeutic efficiency by delivering the drug at the targeted tissue at an optimal amount and in an optimal period. The controlled release of food flavor is desirable as sometimes if an uncontrolled release occurs, the flavor is lost within a short period before reaching the consumer for consumption. The benefits of encapsulation are shown in Fig. 1–4.

Figure 1–4 Applications of encapsulation.

The efficiency and benefits of encapsulation attract the researchers and scientists to study encapsulation to overcome limitations such as uncontrolled release in its practical use in ma...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of contributors
• 1. Current overview of encapsulation
• 2. Physicochemical characterization techniques in the encapsulation of active molecules
• 3. Ultrasonic cavitation assisted synthesis of multilayer emulsions as encapsulating and delivery systems for bioactive compounds
• 4. Encapsulation of active molecules in pharmaceutical sector: the role of ceramic nanocarriers
• 5. Sonochemical encapsulation of taxifolin into cyclodextrine for improving its bioavailability and bioactivity for food
• 6. Controlled release of functional bioactive compounds from plants
• 7. Bioactive molecule and/or cell encapsulation for controlled delivery in bone or cartilage tissue engineering
• 8. A review on application of encapsulation in agricultural processes
• 9. Nanofluids-based delivery system, encapsulation of nanoparticles for stability to make stable nanofluids
• 10. Corrosion and nanocontainer-based delivery system
• 11. Encapsulation and delivery of active compounds using nanocontainers for industrial applications
• 12. Virus-like particles: nano-carriers in targeted therapeutics
• 13. Formulation development and in vitro multimedia drug release study of solid self-microemulsifying drug delivery system of ketoconazole for enhanced solubility and pH-independent dissolution profile
• 14. Molecular recognition, selective targeting, and overcoming gastrointestinal digestion by folic acid–functionalized oral delivery systems in colon cancer
• 15. Mathematical modeling and simulation of the release of active agents from nanocontainers/microspheres
• 16. Flavor encapsulation and release studies in food
• 17. Encapsulation and delivery of antiparasitic drugs: a review
• Index