Hard gelatin capsules can be referred to as solid dosage forms which are used to enclose one or more than one drug substance in a small shell. Hard gelatin capsules vary in size and are the most popular In the market. The size of a two piece hard gelatin capsule depends on the requirement. The capacity ranges between 0.13 mils and 28 mils.
Hard gelatin capsules offer a number of benefits which are as under:
- Easy to fill
- Easy to digest
- Minimum maintenance
- Longer shelf life
In this post, we will take a look at the step by step manufacturing process of hard gelatin capsules, but first things first! Let’s first take a look at the raw materials utilized in the manufacturing process.
Hard gelatin capsule shell is one of the major ingredients, which is mainly composed of gelatin. Besides, colorants, plasticizer, preservatives and opacifying agents are used to facilitate capsule formation and performance enhancement purposes. Hard gelatin capsules also contain about 12 to 16 percent of water. The quantity of water varies and depends on the storage conditions. Hard gelatin capsules are manufactured using a method called ‘dip-coating’. Let’s take a look at various stages of hard gelatin capsule manufacturing.
Step 1: Gelatin Solution Preparation
Gelatin is dissolved in demineralized water heated to about 60 to 70 degree Celsius to prepare a concentrated gelatin solution. This highly viscous solution comprises about 30 to 40 percent w/w gelatin. Vacuum is also applied in the solution to curb air bubbles which would otherwise problems during the filling stage and upon storage. Colourants and pigments are also utilized to achieve the final appearance of the capsule. One of the critical aspects to keep in mind is the viscosity of the gelatin solution. It has a direct impact on the downstream manufacturing process and hence it is quite critical.
Step 2: Dip-coat the gelatin solution on to moulds
Capsule shells are manufactured in an extremely controlled environment. Once the targeted level of viscosity is attained, proceed to the dipping process. The processed gelatin solution is required to be moved to the capsule manufacturing machine at this stage. This can be easily done by using gravity or a pumping mechanism. You have to make sure that the pins on the plate are completely submerged in the solution.
Step 3: Drying process
Coated pins are made to pass through the furnace for setting and drying purposes. It is important to control the temperature and humidity in the process to successfully remove the moisture from the capsule.
Step 4: Stripping and trimming process
The pin plate now enters the table section of the machine. Capsules are divided into 2 equal or roughly equal sizes. Later these are stripped off the pins. Once the stripping process comes to an end, shell trimming takes place. The machine automatically joins the two halves for you. These blocks are now moved to the conveyor belt and later on to the container.
Step 5: Printing
Printing stage involves putting on all crucial information such as dosage instructions, promotion and capsule identification.
Step 6: Testing
Testing takes place once the printing bit is over. The capsule has to undergo a series of rigorous quality checks to make sure they are of the desired quality and have a good shelf life.
Step 7: Packaging
The last stage of capsule manufacturing is packaging. Capsules are now packed in conventional manner. Conventional packaging method is used at this stage as it makes the capsule easy to handle.
Hope you found the post useful. In the next post, we will discuss the capsule manufacturing process. For more information related to capsule manufacturing, feel free to write in to us.