Today’s guide will focus on how to make Softgel capsules.
It will take you through the Softgel capsules formulation, ingredients, equipment, and other processing procedures, among other critical aspects.
By the end of it all, you will not only know how to make Softgel capsules but also choose the right equipment for the process.
Without further ado, let us begin with the formulation as we proceed.
Before you start making a soft gelatin capsule, you need to know what a Softgel capsule really is.
In this section, you are going to learn about the ingredients that make up a soft gelatin capsule.
A soft gelatin capsule has two main sections which are:
i. Outer shell
ii. Fill matrix
Let us begin with the Softgel formulation of the outer shell.
What is Gelatin?
Gelatin is a product that comes from animal products such as bones, connective tissues, and skins.
You can obtain gelatin from the animal products through partial hydrolysis of collagen.
Remember, the process of sourcing for gelatin should meet the following criteria:
i. Gelatin strength should be between 150 to 200
ii. Gelatin viscosity should range between 25 to 40 milli poise.
iii. Gelatin particle size
iv. Broad molecular distribution of weight.
Implying that gelatin is one of the main products you will need in the making of a Softgel capsule.
What about vegan?
Let’s look at that briefly.
Gelatin Options for Vegans
Since gelatin comes from animal products, vegans or people following strict diets may not use it.
However, it does not mean that they will not use Softgel capsules.
Vegans can now use soft gel capsules with the main shell ingredient coming from vegetable products.
You use Tapioca which is a product that comes from cassava plants.
It will serve the same purpose as gelatin thus providing a better option for vegans.
Water in Gelatin
You need to have enough water or solvent for the process of preparing soft gelatin capsules.
The amount of water that you will need will depend on the viscosity of the soft gelatin capsule.
On average, you will use about 45% weight per weight of water.
Plasticizer in Gelatin
To make the soft gelatin capsule pliable and elastic, you need to add a plasticizer to the ingredients.
You can use the most common types of plasticizers such as glycerin and sorbitol.
As you mix the plasticizer the ratio will vary but often ranges between 0.3 and 1.8.
The variation will depend on the final capsule strength that you will need.
Other Ingredients of Soft Gelatin Shell
Apart from the main ingredients, there are other types of ingredients that you can use.
Among the other ingredients that you can use include:
You can either decide to use a synthetic or a natural color for your soft gelatin capsule.
Your choice of color will depend on the appearance that you desire for your soft gelatin capsule.
Color is important for the identification of the soft gelatin capsules.
As you decide on a color, you have to ensure that it will not result in darkening or fading in storage.
This might occur when the choice of color reacts negatively with the other soft gelatin ingredients.
You need to use an opacifier such as titanium dioxide.
An opacifier will produce an opaque shell to prevent the photodegradation of particular soft gelatin capsule content.
Note that you will only require an opacifier when you are dealing with suspension forms of the formulation.
You need to include preservatives to increase the shelf life of the soft gelatin capsules.
The shells are always tasteless and may have the inconsistent taste of the active ingredients.
You can use essential oils, sucrose, and vanillin as flavor for the soft gelatin capsules.
Now, the ingredients above are the main formulations for the outer shell of the capsule.
Let us have a look at the fill matrix.
Fill Matrix or Inner Fill Ingredients
You understand that the most significant function of making Softgel capsules is to dispense the active ingredients.
In a soft gelatin capsule, you will find the active ingredients in:
i. Liquid solutions
ii. Semi-solid solutions
You need to have a unique formulation that will take the following factors into account:
i. Guarantee of the stability of the active ingredients
ii. Enhancing bioavailability of active compounds
iii. Provision of an efficient filling process
iv. Achieving a physically sturdy capsule.
You can classify the fill matrix into solutions fills, oil mixtures, and suspension fills.
Let’s have a brief look at these classifications as we proceed.
You can refer to the oily mixtures as neat substances since they consist of pure oil liquids.
You can have the active ingredients in solution with the carrier solution.
As an example, you can have soybean oil and Myglyol 812.
You can also include non-volatile solvents which do not affect the gelatin shells such as diethylene glycol monoethyl ether.
Additionally, you may also include water, glycerin, and polyvinylpyrrolidone.
You can have suspension fills comprising of the active ingredient in a uniform dispersion in a carrier formulation.
It can comfortably accommodate around 30% of solids without destabilization of viscosity.
Some of the suspension fills that you can use include oily mixtures, polyethylene glycol, and glycerides.
In short, these are some of the main ingredients of soft gelatin capsules.
With that in mind, let us proceed to the main machines you will need for making soft gelatin capsules.
Softgel Encapsulation Technology
Whenever you think of how to make Softgel capsules, choosing the right machine is a priority.
In this section, you will learn about the machines that you can use in making a soft gelatin capsule.
Let us begin with the main machine which is the soft gelatin encapsulation machine.
Softgel Encapsulation Machine
You will need Softgel encapsulation machine whenever you want to make Softgel capsules.
Softgel encapsulation machine
It has different parts that will assist in the making of the outer shell and the fill matrix.
At some point of the machine, it will fill the inner ingredients into the outer shell and seal it completely.
It also has a tooling system that allows you to determine the shape of the soft gelatin capsule that you need.
You should note that most of the functions of the machine are automatic.
The machines are available in different types and sizes depending on your production preferences.
Despite the nature of the machine, you might need other equipment which you will learn about shortly.
As you choose a good encapsulation machine, make sure that it has the following:
i. Conforming to the CE and cGMP quality standards
ii. Meets the right criteria of production since there are low, medium and high production machines.
iii. Has the right specifications and features.
iv. Easy to maintain, operate, and change tooling system
v. Has robust control panels and automation systems.
Auxiliary Softgel Encapsulation Equipment
As you produce soft gelatin capsules, you will need to pass them through different equipment.
Softgel encapsulation support equipment will serve you in different capacities and support the process of soft gelatin encapsulation.
Here are some of the equipment that you will need:
i. Chilling System
ii. Gelatin Melting System
iii. Drying Trays
iv. Tumble Dryers
v. Softgel Polisher
vi. Softgel Pulverizer
ix. Gelatin Service and Medicine Tank
x. Vacuum Homogenizing Mixer
xi. Colloid Mill
Now, you have all the basic requirements for making a soft gelatin capsule.
Let us proceed to the first step of making a soft gelatin capsule.
Step One: Preparing Gelatin
Gelatin melting tank
Choosing a Suitable Melting Tank
You need to choose the best reactors that will produce shells that are reliable and of very high quality.
In this case, you need to choose a suitable melting tank to heat, melt and mix all the suitable ingredients.
You need to look at the following technical specifications when you are choosing a suitable melting tank:
i. Power consumption
ii. Tank capacity
iii. Temperature of the tank
iv. Mixing speed
v. Dimensions such as weight among other key factors.
vi. Thermal jackets to prevent the loss of heat
After that, the next step is to heat and melt the ingredients.
Let us have a brief look at this process.
Melt and Heat Gelatin Ingredients
You need to heat and melt all the gelatin ingredients for about 3 hours.
Note that this may vary according to the type of machine that you are using.
All the ingredients will mix uniformly and form a molten mass of liquid.
Once you have the gelatin ready, you can now proceed with the process of encapsulation.
As you prepare for encapsulation, you should make sure that the gelatin remains hot in a liquid state.
In the liquid state, you will allow the gelatin to flow to the spreader box.
At the spreader box, the gelatin will spread to the levels that you require then proceed to the cooling drum.
It results in the formation of a thin gelatin ribbon.
You are now done with the first step and now you need to prepare the fill material.
Here is how you will take care of the preparation of the fill material.
Step Two: Preparing Fill Material
You know that the fill matrix is the material that you will be enclosed in the gelatin.
You also understand that the fill material can either be liquid, semi-solid or in a suspension.
In the preparation process, you need to make sure that the final product is homogenous.
Homogeneity ensures that every significant component is in the capsule.
Depending on the type of fill materials you are preparing, you may need the following equipment:
i. Hammer mills
ii. Fluid bed Processors
iii. Bins and drums
iv. Pharma ovens
You should remember that the preparation process of the fill material will vary according to the ingredients.
For instance, making pastes are harder and will require more attention than making oil mixtures.
You will mix all the fill ingredients accordingly and make the fill material that you desire.
With the fill material in place, let us proceed to the main process of making the soft gelatin capsules.
Step Three: Beginning the Encapsulation Process
This is the stage where the gelatin materials and the fill matrix come together and form a soft gelatin capsule.
The process begins with:
Movement of Gelatin Shell to the Tooling System
Warm gelatin materials flow to the spreader box and the uniformly to the cooling drums.
It will form a solid gelatin ribbon.
Most of the soft gelatin encapsulation use air as the main cooling system.
Air has the following key parameters:
i. Cubic foot per minute
ii. Relative humidity
In the Softgel encapsulation machine, you will have all the components on the right and on the left.
The gelatin ribbons from the right and the left will reach the tooling at the same time.
Movement of Fill Materials to the Tooling System
After preparation of the fill materials, you will fill it in the product tank or the hopper.
With assistance from a displacement pump, you will allow the fill material to move to the injection wedge.
It will follow some tubes as it flows to the hot injection wedge.
You will find the injection wedge between the two die rollers.
Actual Manufacturing of Softgel Capsules
The injection wedge will, therefore, inject fill materials through to the die cavities.
Remember that the right and the left ribbons are also moving to the die roller system.
Softgel encapsulation process
The die roller system will cut and seal hermetically the two ribbons together.
You should know that the die rolls will determine the size and the shape of the soft gelatin capsules.
In other words, the processes are happening at the same time.
The process of producing the soft gelatin capsule vary according to the machine.
Here are some of the soft gelatin encapsulation processes to consider:
i. Rotary Die Process
ii. Plate Process
iii. Reciprocating Die
iv. Accogel machine
You can choose from any of the processes above depending on your production needs and machine availability.
In this guide, we are using the rotary die process which is the most common process of making Softgel capsules.
Apart from that, you can also use the plate technique which involves the following steps:
i. You will place gelatin sheets on die plate that have numerous die pockets
ii. A vacuum will draw the gelatin sheets into the die pockets
iii. After that, you can fill the die pockets with the fill materials.
iv. Finally, you will place another gelatin sheet above the die plate to sandwich it using a die press process.
At this stage, the formation of soft gelatin capsules occur and you can cut them.
After sealing the soft gelatin capsules, you will allow it to move via the discharge chute to the conveyor belt.
The conveyor belt will transport the capsules for further processing.
Step Four: Further Processing of Softgel Capsules
Why do you need to process the soft gelatin capsules further?
You need to process them further to make them stronger.
As the soft gelatin capsules leave the encapsulation machine on a conveyor belt, it is often too soft and moist.
In that condition, the soft gelatin capsules cannot withstand certain environmental conditions and are susceptible to damage.
Additionally, you need to inspect soft gelatin capsules to ensure that every capsule has the right quantity of fill materials.
So, let us see how you will go about these processes.
Drying of Softgel Capsules
You need to dry the soft gelatin capsules to remove excess moisture from the soft gelatin capsules.
The size and the number of capsules will determine the time it takes for you to dry the capsules.
You will take the capsules through two main stages including:
Using a Tumble Dryer
The soft gelatin encapsulation machine has a direct link to the tumble dryer.
You will see the soft gelatin capsules on the conveyor belt moving directly to the tumble dryer.
Tumble dryer for processing Softgel capsules
Tumble dryers remove almost a quarter of the moisture in the soft gelatin capsules.
Using Stackable Trays to Dry Soft Gelatin Capsules
You will remove the soft gelatin capsules from the tumble dryer and place them on stackable trays.
After that, you will take the stackable trays to the drying rooms or drying tunnels.
The drying tunnel allows air with the right humidity and temperature to flow and cause the drying effect.
The time it takes for the drying process to complete is usually 24 hours or more.
It will depend on the capsule moisture content.
The drying process can significantly increase the cost of making a soft gelatin capsule.
It is the main reason why you should opt for a modern encapsulation machine with refrigeration and dehumidifiers.
After a successful drying process, you are now in a position of inspecting the soft gelatin capsules.
Let us look at how you will go about sorting the capsules.
Sorting of Softgel Capsules
Sorting is a process of controlling the quality of the soft gelatin capsules
Softgel capsules sorting machine
At this point, you will inspect all the soft gelatin capsules and remove any of the capsules with defects.
You can employ the services of a soft gelatin sorting machine that will eliminate all the errors.
During the process of controlling the quality of the soft gelatin capsules, focus on the following:
i. Elimination of soft gelatin capsules with damages, different shapes and breakages.
ii. Verifying the appearance, content uniformity, and weight of the capsules.
iii. Conduct a microbiological test
iv. Determine the moisture level, weight, sealing mechanism and thickness of the shell
After ensuring that the soft gelatin capsules meet certain requirements, it is time to proceed to the final stages.
Polishing of Softgel Capsules
Polishing involves cleaning the soft gelatin capsules.
You will clean all the soft gelatin capsules and remove any possible impurity.
Polishing will make sure that the soft gelatin capsule has the right texture and color.
You might involve tumbling or the use of a solvent to clean the surface.
You should note that the polishing will depend on the type and design of soft gelatin polishing machine.
After polishing the capsules, you may need to have a label on the soft gelatin capsule.
Well, here is you can go about it.
Labeling a Soft Gelatin Capsule
You will need to have a soft gelatin printing machine.
The machine will assist you in printing and labeling unique marks on any shape of a soft gelatin capsule.
After that, your final process will be packaging.
Packaging of Softgel Capsules
In this case, you will use any form of technology in packaging the soft gelatin capsules.
The packaging should protect the soft gelatin capsules from any form of damage.
You should also ensure that it ensures that the active ingredients in the soft gelatin capsules are stable.
Well, you are now ready to transport your soft gelatin capsules to different places.
You should make sure that you store the capsules in a cool and dry environment to reduce any damages.
At this stage, you can claim to be a soft gelatin manufacturing expert.
All you need to do is ensure that the level of accuracy in every step is top notch.
Soft gelatin capsules are very sensitive as they help in curing and enhancing the health of human beings.
With all that under consideration, you are set to go.