What is the Difference Between Microcapsule and Microsphere

The key difference between microcapsule and microsphere is that microcapsule is a solid spherical particle with a core, while a microsphere is a strict-sense, spherical particle that is hollow.

Microparticles are particles between the sizes 1 and 1000 μm. Microcapsules and microspheres are two types of spherical microparticles. They are commercially available, and there is a wide variety of materials. Microparticles show therapeutic use in diseases.

CONTENTS

1. Overview and Key Difference
2. What is a Microcapsule
3. What is a Microsphere
4. Similarities – Microcapsule and Microsphere
5. Microcapsule vs Microsphere in Tabular Form
6. Summary – Microcapsule vs Microsphere

What is a Microcapsule?

A microcapsule is a small spherical particle with a size varying between 50 nm to 2 mm. It consists of a core. Therefore, it is a membrane-enclosed particle with a core and shell-like coating. A variety of coating materials are present for microencapsulation. They include inert polymers and pH-sensitive substances such as carboxylate and amino derivatives. The core material is in the form of a solid or liquid. The observation of scanning electron microscopes has shown complex and varying structural features of microcapsules.

The structure of a microcapsule is observed as a walled, mononuclear prototype or with multiple core structures with multiple concentric coatings. Microcapsules that are aggregated vary considerably in size and shape and consist of external walls. Perfect microcapsules are usually obtained using liquid cores or liquid dispersed phases before solidification. Even though the membrane and interior structure of the microcapsule is observed through the scanning electron microscope, the physical quality, porosity, crystallinity, and tortuosity are hardly characterized quantitatively. Therefore, features such as permeability and porosity are calculated through data such as dimensions, densities, and core-to-wall ratios when needed. Microcapsules vary in dosage forms, such as hard gelatinous capsules and soft gelatinous capsules. Hard gelatinous capsules are enteric-coated, and soft gelatinous capsules are suspensions in liquids.

What is Microsphere?

A microsphere is a small spherical particle with a diameter of 1μm to 1mm. They are composed of a solid, hollow structure and do not contain fluid inside. Microspheres are made of various materials that are natural and synthetic. Commercially available microspheres are polymer microspheres, glass microspheres, ceramic microspheres, and metal microspheres. These microspheres vary in density since they are hollow and solid and are therefore used for different applications. Hollow microspheres are used as additives to lower the density of certain materials.

The application of solid microspheres depends on the size and material from which they are constructed. A type of microsphere that is widely used is a polymer microsphere. Its common types are polyethylene, polystyrene, and expandable microspheres. Polystyrene microspheres are typically used in the biomedical industry since they have the ability to facilitate cell sorting and immunoprecipitation. Protein and ligand are adsorbed onto polystyrene effectively, thus, making it easier for medical research and laboratory experiments.

What are the Similarities Between Microcapsule and Microsphere?

• Microcapsules and microspheres are drug delivery methods.
• Both are spherical particles.
• They act as drugs or bioactive molecules.
• They are generally 1–1000 µm.
• They are available as commercially available material.

What is the Difference Between Microcapsule and Microsphere?

A microcapsule is a solid spherical particle with a core, while a microsphere is a strict sense, spherical particle which is hollow. Thus, this is the key difference between microcapsule and microsphere. A microcapsule is a particle that varies between the sizes 50nm to 2mm, while a microsphere is a particle that varies with a diameter of 1μm to 1mm. Microcapsule contains a liquid inside, while microsphere does not contain any liquid inside.

The following table summarizes the difference between microcapsule and microsphere.

Summary – Microcapsule vs Microsphere

Both microparticles and microspheres are microparticles. A microcapsule is a solid spherical particle with a core, while a microsphere is a strict sense, a spherical particle that is hollow. So, this is the key difference between microcapsule and microsphere. Moreover, a microcapsule is a small spherical particle with a size varying between 50nm to 2mm. Its core consists of either a solid or liquid. A microsphere is a small spherical particle with a diameter of 1μm to 1mm. It is composed of a solid, hollow structure and does not contain fluid inside. Hence, this summarizes the difference between microcapsule and microsphere.

Reference:

1. Komal Bharat and Prof. Indrakumar -. “Microencapsulation: A Promising Technique for Controlling Drug Delivery.” International Journal For Multidisciplinary Research, vol. 4, no. 6, 2022.
2. “Microspheres.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “AP microcapsule integrity, GI simulated transit” By Christopher Martoni, Jasmine Bhathena, Mitchell Lawrence Jones, Aleksandra Malgorzata Urbanska, Hongmei Chen, and Satya Prakash – (CC BY 3.0) via Commons Wikimedia
2. “Glass microsphere in concrete” By Lylegordon at en.Wikipedia (CC BY 2.5) via Commons Wikimedia