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Types of Tablet Coating- Tablet Coating Techniques

Types of Tablet Coating- Tablet coating is a process in which a thin layer of material is applied to the surface of a tablet. This layer can serve various purposes, such as protecting the tablet from moisture or improving its appearance. Tablet coating is an important part of the manufacturing process for many types of tablets.

Types of Tablet Coating

Why Tablet Coating is Required?

The process of tablet coating is a surface modification technique that can be used to improve the appearance, stability, and/or patient acceptability of tablets. It involves the deposition of a thin layer of material onto the tablet surface.

The coating material may be a polymer, an inorganic compound, or a combination of both. Tablet coatings can provide numerous benefits including: -Improved aesthetics: A smooth, glossy finish can make tablets more visually appealing and easier to swallow.

-Improved stability: Coatings can protect active ingredients from degradation due to exposure to light, oxygen, or moisture.

-Reduced interactions with other drugs: Some coatings can reduce the likelihood of drug interactions by delaying or preventing the release of active ingredients into the gastrointestinal tract.

-Taste masking: Certain materials can be used to mask the taste of unpleasant-tasting drugs.

The Different Types of Tablet Coating

There are different types of tablet coating (Tablet coating defects) available which imparts various properties to the tablet. The type of coating and technique used depends on the desired purpose of the coating. Some common types of tablet coatings are:

Sugar Coating

Sugar coating is the most common type of tablet coating. It’s typically used for aesthetic reasons, as it gives tablets a shiny, attractive finish. Sugar coating also provides some level of protection against moisture and oxygen. Sugar coating applies a thin layer of a mixture of sugar and water onto the tablet surface.

The tablet (Tablet Defects) is dipped in that mixture, then dried. The type of sugar used for this process can vary depending on the application. Research has shown that glucose works well because it doesn’t cause irritation in the gastrointestinal tract. Maltose or sucrose are also common choices for sugar-coating tablets, but they aren’t as effective at forming a tough outer coating around the tablet.

Polymer Coating

Many pharmaceuticals use polymer coatings instead of sugar coatings because they provide better protection against moisture and oxygen. Polymer coatings also help to control how quickly medicine is released into the body when taken orally (i.e., absorbed by the digestive tract). This is useful for drugs that need to be released over a period of hours or days rather than all at once.

Polymer coatings are formed from a variety of different compounds, including acrylic resins and polymers like ethylcellulose and cellulose acetate phthalate (CAP). Ethylcellulose is often used because it’s easy to apply and can be dissolved in certain solvents without damaging medication. CAP is also used often because it provides good protection against moisture and oxygen. It can be applied in a variety of different ways, including spraying or rolling the tablet through a coating solution.

Enteric Coating

Enteric coating is designed to protect the stomach from the acidic environment of the digestive system. This type of coating is often used for medications that are designed to be released in the small intestine. Enteric coating is a type of barrier applied to pharmaceutical drugs or supplements that prevents them from being broken down or dissolved in the stomach. Enteric coatings are typically made from materials like cellulose, shellac, and other polymers. The coating allows the drug or supplement to pass through the stomach and be absorbed in the small intestine. This can improve the absorption of certain drugs and reduce side effects like stomach upset.

Other Coatings:

Film Coating

Film coating of oral solid dose forms is a process in which a thin layer of material is applied to the surface of the dosage form. The film coating material can be a natural or synthetic polymer, and the thickness of the coating is typically in the range of 0.1-10 microns. The purpose of film coating is to improve the appearance, taste, and/or stability of the dosage form. Film coatings are also used to mask unpleasant tastes, and to control release characteristics.

Extended-release Coating

An extended-release coating delays the release of medication into the body. The extended-release coating is designed to keep a constant level of medication in your body throughout the day. This type of coating is typically used on medications that are meant to be taken once or twice a day. The extended-release coating allows you to take the medication at a time that is convenient for you and still have the same level of medication in your system throughout the day.

Gelatin coated tablets

Gelatin coated tablets offer many advantages over uncoated tablets. They are easier to swallow, have a more pleasant taste, and dissolve more slowly in the stomach, which can be beneficial for those with sensitive stomachs. Gelatin coating also protects the tablet from moisture and oxygen, which can degradation.

The Various Tablet Coating Techniques

If you are looking to get your tablets coated, there are a few different techniques that you can choose from. Here is a brief overview of the various tablet coating techniques:

1. Spray coating: This is a popular tablet coating technique where the coating material is sprayed onto the surface of the tablet.

2. Brush coating: This technique involves using a brush to apply the coating material to the tablet.

3. Roll coating: This is a tablet coating technique where the coating material is applied to the surface of the tablet using a roller.

4. Dip coating: This is a tablet coating technique where the tablet is dipped into a vat of coating material.

5. Electrostatic spray coating: This is a tablet coating technique where the coating material is electrically charged and then sprayed onto the tablet.

Each of these tablet coating techniques has its own advantages and disadvantages, so it is important to choose the one that best suits your needs.

The Pros and Cons of Tablet Coating

When it comes to tablet coating, there are a few different methods that can be used. Each has its own set of pros and cons that you should consider before making a decision.

Here is a look at the most popular tablet coating techniques:

Spray coating: This is the most popular method of tablet coating. It is quick and efficient, and can be done on a large scale. However, it can be difficult to get an even coat with this method.

Dipping: This method is slower than spray coating, but it gives you more control over the thickness of the coat. It can be tricky to get the tablet evenly coated, however.

Roller coating: This is a newer method of tablet coating that is growing in popularity. It is similar to dipping, but uses rollers instead of immersion to apply the coat. This method is said to provide a more even coat than either spray or dipping.

Whatever tablet coating technique you choose, make sure you weigh the pros and cons carefully before making your decision.


There are many different types of tablet coating available, each with its own advantages and disadvantages. The type of tablet coating you choose will depend on your specific needs and requirements. Whether you need a quick-drying coat for a high-speed production line or a more durable coat for long-term storage, there is a tablet coating technique that can meet your needs. Contact a professional tablet coater to discuss your options and find the right solution for your business.

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