Hard Gelatin Capsule Formulation and Manufacturing Process

The pharmaceutical industry cannot be imagined without hard gelatin capsules. These capsules are majorly used for filling the medicine in the form of dry powder or small pellets. If you wish to know hard gelatin capsule formulation and manufacturing process and the considerations you need to bear in mind, this article is certainly for you.

What is a hard gelatin capsule?

Hard gelatin capsules are also referred to as hard shell gelatin capsules or two piece capsules. A hard gelatin capsule comprises of two fabricated cylindrical shaped sections named as the body and the cap. Hard gelatin capsules are supplied by shell manufacturing companies and they are filled later on in a separate process or operation altogether. During the process, the body is filled with the necessary drug substances and the shell is closed by bringing together the body and the cap.

Components of a hard gelatin capsule

As the name suggests a hard gelatin capsule is mainly composed of gelatin. It may contain other materials as well though. These materials could be colorants, plasticizer, preservatives and opacifying agents depending upon the need. Hard gelatin capsules also contain about 12 to 16 percent of water. Again the quantity depends on various aspects such as storage conditions.

Shapes and Sizes

Another crucial consideration is the shape and size while manufacturing hard gelatin capsules. Empty capsule size might vary between 000 to 5. Here 5 is the smallest and 000 is the largest size available. The size is determined by the formulation requirements. This includes dose of the active ingredients and drug’s compaction characteristics as well. If you wish to estimate the exact or necessary capsule size, you must determine the density of the formulation by utilizing tapped density for powders and bulk density for granules, minitablets and pellets. Target fill weight, capsule volume and measured density of the formulation are some of the key attributes to be taken into consideration. Know that some specific needs may require elongated sized capsules. These capsules typically have 10 percent extra fill volume as compared to regular hard gelatin capsules.

Manufacturing of Hard Gelatin Capsules

Empty hard gelatin capsules are manufactured using the dip-coating method. There are a number of stages involved. Let’s take a look at some of the stages.

Stage 1- Preparation of the gelatin solution

Stage 2- Dip coating the prepared gelatin solution on the metal pins

Stage 3- Dip coated pins are rotated

Stage 4- Gelatin coated pins drying stage

Stage 5- This stage involves drying and trimming

Stage 6- Trimmed capsule shells are joined

Stage 7- The printing process takes place at this stage

Hard Gelatin Capsules Filling Process

It goes without saying that the hard gelatin or hard shell gelatin capsule filling process is not possible without a machine. There is a wide array of equipment available ranging from small scale manual filling to intermediate level, semi-automatic and fully automatic large scale machines. They can also be hand-filled and compounding pharmacy is an example of that.

Steps of hard gelatin capsule filling

  • Place empty gelatin capsules on the removable plate and make sure that bodies are facing downward.
  • Separate the cap from bodies.
  • Now, the body must be filled with the formulation utilizing a plastic spatula. Any excess powder should be removed.
  • Now, the capsule shells are closed and filled capsules are ejected.

Powder Formulation Filling in Hard Gelatin Capsules

Hard gelatin capsules can also be filled manually using hands for research purposes. Place the powder on a clean paper or porcelain plate and press the open end of the capsule downward till the time it is filled. Now place the cap to close the capsule.

In any small scale manufacturing unit, hard gelatin capsules are filled manually using a hand operated machine. Hand operated capsule filling machines come in a variety of capacities ranging from 24 to 300 capsules. You can also produce about 200 to 2000 capsules per hour by focusing a bit more on efficiency.

Large scale manufacturing units have a number of machines at their disposal. These machines are semi-automatic as well as automatic and you can expect huge production capacities ranging between 3000 to 1,50,000 per hour. You must know that in large scale units the filling process depends on one of these two dosing devices- dosing disk/tamping device or dosator device.
Hope you found the post useful. For more information related to Adinath’s International’s wide array of pharmacy manufacturing machine range, feel free to get in touch with us.