Have you ever wondered why some capsules look shiny and smooth? Why don’t they stick together in a jar? That’s because of hard work, manufacturers do to coat the capsules. If you are an entrepreneur and want to start your own capsule manufacturing business, this guide is for you.
Let’s learn the basics of capsule coating in simple terms that can help you achieve stability, quality and better patient experience.
What is Capsule Coating?
Capsule coating is the process in which a thin layer is applied to the surface of capsules. It is commonly a hard gelatin shell. You will find two types of capsules in the market: coated and uncoated capsules.
Coated capsules are easy to swallow. Many patients find themselves unable to swallow a capsule due to its bitter taste and bad odor. As coating adds an extra layer to the capsules. So, it covers the bad taste of capsules.
Uncoated capsules can be produced easily and are also cheaper than the coated ones. But coated capsules provide a better experience for the patients. That is why coated capsules are now in demand in the markets.
Make sure you don’t miss the coating step because it protects your medicine from sticking together. The best thing is, coating protects the medicine inside and allows it to release in the body efficiently.
Advantages of Capsule Coating
Taste and Odor Masking
Have you ever faced difficulty while taking medicine? It’s because the taste was not pleasant. There are many active ingredients present in the capsules that affect their taste and odor.
That’s why coated capsules are in demand.
Moisture and Light Protection
The uncoated capsules need more protection from light and moisture. Direct sunlight can waste the impact of the medicines. A small amount of moisture in a capsule can waste the whole medicine. You can add an extra layer of protection to the capsules with the help of coating.
Improved Swallowability
Have you ever seen a patient struggling to swallow a medicine? It’s because the medicines are not coated. Capsule coating minimizes the friction, and it goes down easily due to its slippery surface. If you want your capsules to be loved by patients, do the coating step carefully.
Controlled and Delayed Release
If you have a medical background, you might know the factors that affect how well a medicine works. Yes, we are talking about control that how fast and where the medicine should release in the body. Capsule coating plays its role here. It protects active ingredients and they do not dissolve early when they enter the mouth or stomach.
You can learn how long capsules take to dissolve.
Branding and Aesthetic Enhancement
The coated capsules enhance the aesthetic of the brand as they give medicine a smooth finish. You can give your capsules a colorful and glossy look to make them more visually appealing.
You can also use your branding color on coating to differentiate the capsules from your competitors. Moreover, you can print your logo on the capsules directly. For this reason, coated capsules look very aesthetic and professional.
Types of Capsule Coating Techniques
Film Coating
This is the most popular method to coat capsules in pharmaceutical industries. In this technique, a thin film of polymer based solution is applied. One reason for its popularity is that it protects medicine in the capsule without increasing the size of the capsule.
Enteric Coating
This is another type of coating in which the polymer barrier is layered on the capsules. Mostly, fatty acids or plant fibers are used as enteric coatings. These coatings protect active ingredients from dissolving in stomach acids. If you want targeted drug delivery, you should go for enteric coating.
Sugar coating
As the name suggests, capsules are coated in sugar syrup to give them a sweet taste. Sugar-coated capsules are for those patients who can not eat bad tasting medicines. This type of coating is especially used for children. Because they cannot take bitter-tasting medicines.
Delayed/Extended Release Coating
Some medicines are made to dissolve when they reach the high pH area of the small intestine. Hence, these types of capsules are coated with a specific material. These specific materials protect the active ingredients of capsules from stomach acid. If the capsules are not coated, they can combine with stomach acid and disturb your digestive system.
Specialized Coating
The specialized coatings are usually done for specific functions. These coatings need advanced materials to meet the requirements that other capsules can not. It includes targeted delivery coating, time-release coating, or mucoadhesive coating.
Materials Used in Capsule Coating
If you are not in the pharmaceutical industry, you might know only the most common materials that are used for capsule coating. Yes, we are talking about polymers and plasticizers.
However, the colorants and opacifiers, solvents and anti-tacking agents are also used for this process. The basic purpose of these materials is to provide flexibility to the capsule coatings. Make sure your capsules are coated with colorants and opacifiers to give an aesthetic look to your medicines.
Capsule Coating Process
Do you know the capsule coating process is slightly different for different kinds of capsules? Let’s discuss in detail.
1. Preparation of Solution
In the first step, you have to prepare coating solution. If you want to manufacture hard gelatin capsules, you should opt for the dip coating process. You can create a viscous solution by dissolving gelatin in hot water. If you want to add flexibility, add some plasticizers. Coloring is also done at this stage but make sure you use approved colorants. Coating for soft capsules needs a thin film. You can prepare it with cellulose polymers.
2. Coating
There are two types of coating, dip coating and spray coating. You have to coat the metal pins in gelatin solution if you want to manufacture hard capsules.
As you know, soft capsules need a thin film of coating, so we only spray the solution on the surface of the capsule.
3. Drying
Different techniques are used for drying the coating of capsules. You can use perforated drums to dry softgels. These drums usually have less than 35 degrees temperature.
4. Quality Control
This is the last process where quality is checked. Here you will check mechanical strength, appearance and thickness of the coating.
Common Challenges in Capsule Coating
Capsule costing is more challenging than tablet coating. Here are a few problems that you might face in capsule coating.
Cracking and Chipping of the Coating
Have you ever seen cracked capsules? It mostly happens when the capsules are placed in an uneven environment. Another reason could be the improper plasticizer level. So, make sure you know the right balance of capsule coating materials.
Inconsistent Coating Thickness
Your product will not make you money if you compromise on its aesthetics. Inconsistent coatings can affect the quality and overall look of the capsules.
Capsule Sticking
Have you ever seen capsules sticking together? This is done due to the moisture present in it. Capsules also stick together due to the high temperature. And as a result, it affects the quality of the product.
Active Ingredients Stability
Your primary focus should be to cover capsules from humidity with its coating.
Stability issues happen when the coating failed to protect the capsule from a humid environment.
Conclusion
Capsule coating is necessary to protect the capsule from damage. It enhances the quality of the capsule and makes it easy to swallow. Coated capsules are far better than uncoated ones and can generate more revenue.
At Sainty Tec, we manufacture a wide range of pharmaceutical machines. If you want to start your capsule coating or capsule manufacturing business, contact us today for a free consultation.
