Gelatin Capsules-The Ultimate Guide

Gelatin capsules are convenient alternatives to the bitter tasting, unpleasant, and hard to

swallow tablets.

They are common methods for taking blends of custom diet supplements, vitamins, and herbal

supplements among others.

In this guide, you are going to learn about every fact on gelatin capsules including how it works

among others.

Benefits of Using Gelatin Capsules

Some of the reasons why you should take gelatin capsules are:

Figure 1 Gelatin capsules

Affordable heap in comparison to vegetable capsules

In increases the bioavailability of poorly soluble nutrients

Easy to swallow because of the smooth texture

Helps in masking the bad taste and odor of other supplements such as tablets

Dissolves very easily after digestion

Available in different sizes such as 3,2,1,0,00 and 000

Has hermetical and tight seals making them tamper proof and protects the inner

materials from destruction by environmental factors.

Safe alternative to consume as it comes from healthy sources such as animal products.

Uses of Gelatin Capsules

You can use gelatin capsules for quite a number of functions including:

Figure 2 Types of gelatin capsules

Hard gelatin capsules are acid resistant and delay the release of the inner active

ingredients.

It serves as a great alternative for people who experience stomach irritation when they

consume Softgel capsules.

Improving the health of your skin and enhances the tone and evenness of the skin.

It enhances the production of collagen in the body thus reducing the formation of

wrinkles by tightening the skin.

Providing enough protein to the body resulting to healthy hair and better finger nails

among other protein functions.

Aiding in digestive functions and health by improving the ability of the body to digest

foods and beverages.

Ease of joint pains by improving muscle action through the amino acids in gelatin

Assist in controlling the blood sugar levels in your body

Maintain healthy bones by preventing the deterioration of cartilage that help in

maintaining the bones in place.

Aiding in weight loss due to high protein content and low calorie content.

Improving the quality of sleep by enhancing energy and supplementing the body with

enough gelatin that fights fatigue.

Improving the quality of your liver through the detoxification functions of the amino

acids glycine.

Ingestion of certain key materials such as dietary formula to assist in treatment of

different diseases such as phenylketonuria.

Limitations of Gelatin Capsules

Gelatin may not be an option for some people mainly because:

Figure 3 Soft gelatin capsules

Gelatin is a derivative of animal products such as bones, hides and skin.

It makes the gelatin capsules a total reject for vegetarians and people following a

religious diet restriction.

Apart from that, there is the fear that gelatin may contain contaminations from animal

tissues that may cause more diseases.

Although such risks are low many fear the use of gelatin capsules may lead to the

transmission of mad cow disease.

Gelatin may also cause allergic reactions in some people.

Other people complain about unpleasantness in taste, heavy sensations in the stomach,

heartburn, belching, and bloating.

During breastfeeding and pregnancy, it is important to stay on the safe side and avoid

gelatin capsules.

There is very little to no evidence on the medical effects of using gelatin capsules in

pregnancies.

Continuous consumption of gelatin capsules over a long period may become toxic to the

body.

Restricts the addition of certain components

Highly sensitive to moisture

Comparison Between Gelatin vs. Vegetarian Capsules

Capsules are available in two distinct categories which are the conventional gelatin capsules

and vegetarian counterparts.

Figure 4 Veg vs Gel Capsules

Both capsules serve the need of medication but they also have certain differences.

Similarities between Gelatin capsules and Vegetarian Capsules

Gelatin capsules and Vegetarian capsules are all available in different shapes, flavors, sizes and

color.

Both categories also allow you to come up with your own custom design of a capsule.

You can also store both of them for a long period without risking bacterial growth.

Both categories are fast reacting and react in the stomach except for the hard gelatin capsules

which are acid resistant.

Differences between Gelatin Capsules and Vegetarian Capsules

Gelatin capsules are derivatives of animal byproducts while vegetarian capsules are purely from

vegetable products.

You can easily obtain gelatin from animal byproducts such as skin, bones, and hives. On the

other hand, most vegetarian capsules are from specific plant products such as Tapioca.

Gelatin capsules have collagen as the main capsules base while vegetarian capsules rely on

cellulose as the main capsule base.

Vegetarian capsules are for the people who do not consume animal products or follow a strict

religious diet.

You will find the vegetarian capsule under the Halal or Kosher product classification. It is

considerably a better option for all masses including people who do not have strict adherence

to a diet.

Gelatin capsules are also most suitable for filling with powder supplements or medications.

Various materials such as liquids are usually not compatible with gelatin capsules. Vegetarian

capsules are, therefore, more suitable for filling gel and semi-solid materials.

Consumption of gelatin capsules over a long period may have considerable side effects on the

body. This is not the case in vegetarian capsules since they are absolutely natural and non-toxic.

Difference Between Soft Gelatin Capsules and Hard Gelatin Capsules

Despite the fact that, both hard and soft gelatin capsules come from animal byproducts, they

have their differences.

Figure 5 Hard gelatin capsules

Figure 6 Soft gelatin capsules

The main differences between the hard and the soft gelatin caps include:

i. Soft gelatin capsules have hermetical seals making them one piece capsules containing

liquid or semi-solid fill.

On the other hand, hard gelatin capsules have two parts namely cap and body.

ii. Hard gelatin caps receive a permanent seal after filling.

Implying that the making of the parts of the body are distinct processes from filling

them.

However, Softgel capsules combine both processes under the encapsulation of Softgel

capsules.

iii. Hard gelatin capsules have a rigid cylindrical shape due to its nature.

Soft gelatin capsules are flexible and can assume any shape depending on your

specifications.

iv. Soft gelatin capsules contain plasticizers, gelatin, sugars, preservatives, coloring and

flavoring agents, and opacifiers as the main ingredients.

Hard gelatin capsules on the other hand, have gelatin, opacifiers, coloring and flavoring

agents, and titanium dioxide as the ingredients.

It lacks plasticizers, hence the hardness of the capsule.

Apart from the structural differences, the hard and Softgel capsules also differ in terms of

functionality.

Also, some hard gelatin capsules are acid resistant and will not disintegrate in the acidic

stomach conditions.

It requires an environment with a higher pH such as the duodenum of the intestines before it

finally disintegrates.

Most soft gelatin capsules on the other hand are not resistant to acids prompting disintegration

in the acidic stomach environment.

How Long Gelatin Capsules take to Dissolve in Stomach

The time taken for a gelatin capsule to dissolve in the stomach depends on the following:

i. Type of gelatin capsule

ii. Content of the stomach

Figure 7 Capsule drug in stomach

Hard and soft gelatin capsules take different times to disintegrate in the stomach.

Soft gelatin capsules take a shorter period to dissolve in comparison to hard gelatin capsules.

For instance, soft gelatin capsules can take between 10 to 20 minutes to dissolve in the

stomach.

The Softgel capsules will dissolve much faster if the stomach contents are wet and warm.

Hard gelatin capsules take longer and you may wait for more than two hours before it dissolves.

Usually, the hard gelatin capsules do not dissolve in the stomach due to the low pH in the

stomach.

It will, however, dissolve in the upper part of the intestines where the pH is higher.

How Gelatin Acid Resistant Capsules Work

Gelatin Acid Resistant Capsules depend on the pH in the digestive track of the body to react.

Since it is resistant to acidic or low pH conditions, it will work best in higher pH conditions.

Figure 8 Acid resistant gelatin capsule

The resistance to acidic conditions are as a result of negative reactions in the stomach which

often lead to irritations.

To avoid irritations, the capsules usually have target release ingredients prompting them to

react as soon as they reach the target.

As soon as it reaches the stomach, the capsule usually stays intact until it moves and reaches

the right point.

Once in an environment with a higher pH, gelatin acid resistant capsules disintegrates and

releases the content resulting into pain relief.

What Gelatin Capsules are Made Of

Gelatin capsules are made of different ingredients such as:

Figure 9 Anatomy of hard gelatin capsule

Figure 10 Anatomy of soft gelatin capsule

Gelatin

It is a material that you can obtain through hydrolysis of collagen of animal products including

skin and bone.

Water in Gelatin

The quantity that you will use will depend on the viscosity of the gelatin that you need

averaging to 45% w/w.

Plasticizer such as Sorbitol and Glycerin

This is the ingredient that makes the soft gelatin to be soft.

Hard gelatin capsules do not have plasticizers to maintain their hardness.

Opacifiers such as Titanium Dioxide

It produces an opaque shell that will prevent photo degradation of the capsule contents.

Hypromellose (Hydroxypropyl Methylcellulose) and Proprietary Polymers

It makes the hard gelatin capsules resistant to acidic conditions in the stomach.

Natural or Synthetic colors to improves the appearance of the gelatin capsules

Flavors to mask the bad taste of the active ingredients.

Inner fill materials

These are the components to enclose within the gelatin cover of the gelatin capsules.

Soft Gelatin Capsules Encapsulation Process

Making a Softgel capsule involves the following processes:

https://youtu.be/DrTWjYg8oXk

Step One: Preparation of the Ingredients

Gather all the primary ingredients for making the soft gelatin capsule.

Choose an appropriate gelatin mixing and heating tank.

Pour the ingredients in the mixing tank and then thoroughly mix the ingredients.

After that, pour ingredients in a gelatin melting tank and then heat for about 3 hours.

You will achieve a homogenous molten mixture liquid mass.

Maintain the temperatures of the molten gelatin to avoid solidification of the gelatin.

Step Two: Preparing the Fill Material

The fill materials can be in the forms of liquid, suspension, or semi-solid state.

Make sure that you have a homogenous mixture with all the active components in place.

To achieve a homogenous mixture, you may need the services of the following machines:

i. Hammer Mills

ii. Fluid Bed Processor

iii. Pharma Ovens

iv. Bins and Drums

Apart from the machines you have to ensure that the inner fill materials:

i. Guarantees overall stability of all the elements

ii. Increases bioavailability

iii. Guarantee efficient and safe filling process

iv. Guarantee stability of the Softgel capsule

Step Three: Actual Encapsulation Process

At this stage the fill material and the gelatin shell will come together and form a capsule.

With the right choice of machine, the process begins with the movement of the gelatin shell to

the tooling system.

Warm gelatin materials will flow from gelatin tank to spreader box.

It spreads over a revolving cooling drum to form a solid ribbon.

Since the machine has two sides, the same action happens on both sides of the machine.

The two ribbons will reach the tooling system at the same time.

At the same time, the fill material will flow from the hopper or product tank.

With the assistance of a positive displacement pump, fill materials will flow through tubes to

the heated injection wedge.

The injection wedge injects the fill materials into the die cavities as the ribbons move to the die

roller system.

It results into the filling of the ribbons as the die system cuts and seals the gelatin ribbons

hermetically.

Step Four: Drying the Soft Gelatin Capsules

The process of drying will depend on the number, size, as well as the moisture content of

capsules.

Also, the capsules will move on a conveyor belt to the tumble dryer which will remove about

25% of the moisture.

After that, you will load the capsules on to trays and move them to a drying tunnel or room.

Depending on the moisture content of the Softgel capsules, the drying process may last about

24 hours.

Step Five: Inspection of the Softgel Capsules

This is the point where you will determine the quality of the soft gelatin capsules.

You can use a Softgel sorting machine to eliminate possible errors on the soft gelatin capsules.

You should focus on:

i. Elimination of broken, misshaped and damaged Softgel capsules.

ii. Verifying the appearance, content uniformity, and weight of the capsule

iii. Conducting the microbiological testing of the Softgel capsules

iv. Determining the moisture content, weight, thickness, and sealing mechanisms.

Step Six: Polishing and Packaging

It involves the removal of any particle on the surface of the Softgel capsules.

Figure 11 CBD Softgel

The aim is to ensure that the soft gelatin capsules have the right texture and color.

You can use a Softgel polishing machine to assist in polishing the soft gelatin capsules.

After that, you can package the capsules for storage or transport to other places.

Hard Gelatin Capsules Manufacturing Process

Manufacturing a hard gelatin caps will go through the following processes:

Figure 12 Hard gelatin capsules manufacturing process - Photo courtesy: Clinical Gate

Step One: Preparing the Raw Materials

Prepare a concentrated gelatin solution of about 35 – 40% using demineralized water at 60 – 70

degrees centigrade.

Mix all the ingredients in jacketed pressure vessel and then stir to make a homogenous mixture

of gelatin.

After that, apply vacuum that will remove any entrapment of air within the mixture.

At this point you can transfer small amounts of the solution into suitable containers before

adding the coloring agents.

Test the viscosity of the gelatin solution and adjust it by adding hot water as it will determine

the capsule thickness.

Transfer the gelatin solution to a heated hopper and then add a gelling agent such as

carrageenan.

You should also add a co-gelling agent such as potassium chloride to convert hypromellose

solution into a gelling system.

Step Two: Dipping Mould into Gelatin Solution

Transfer the homogenous mixture to the dip pan at the front end of the machine.

The dip pan will hold the gelatin solution at a fixed temperature between 45 and 55 degrees

centigrade.

A feed from the gelatin hopper will always maintain the level of gelatin mixture in the dip pan.

The machine will automatically dip sets of mould at room temperature into the dip pan.

A film forms by gelling around the surface of every mould.

Step Three: Rotation

After that, the machine removes the pins from the solution as it rotates them slowly to the

upper decker.

Rotation helps in the uniform distribution of the gelatin around the pins to avoid bead

formation.

Step Four: Drying

Pass the moulds through drying kilns where air will blow over them and solidify the gelatin.

Ensure that the drying parameters are right to avoid over drying or melting of the film.

Step Five: Stripping

The machine will then remove the dry gelatin from the pin moulds and then cut them

accordingly.

Using a series of bronze jaws, strip the cap and body portion form the pins.

Step Six: Trimming

Trimming ensures that the capsules are if the right length and size.

Rotations of the machine trims the capsules to the right length.

Step Seven: Fusing the Cap and the Body

With the help of the machine, fuse the cap and the body together.

This seal is not permanent as the capsules await filling.

In most cases, the cap and the body are of different colors for easy identification.

Step Eight: Quality Control and Labeling

After drying the capsule to a certain moisture content level, you can pass it through a sorting

machine.

The machine will eliminate any capsule with a defect and allow the good capsules to proceed.

After that you can pass the capsules through a labeling machine for the unique codes before

packaging them.

In most cases, the capsules are often empty and the filling occurs at a totally different stage.

Step Nine: Filling Hard Gelatin Capsules

https://youtu.be/QIN6Z3X840Q

This process involves:

i. Rectification of the hard gelatin capsules so that they face the same direction

ii. Separation of the body from the cap

iii. Dosing the fill material or filling the capsules

iv. Replacement of the cap and ejecting the full capsules.

Gelatin Capsules Sizes

The size of capsules ranges between 000 all the way to 5.

Figure 13 Sizes of capsules

In this case, 000 is often the biggest in size and 5 is often the smallest capsule size.

The larger the size of the capsule the higher the volume of medication inside.

For instance, capsule size 000 contains 1000 mg of aspirin while capsule size 5 contains 60 mg

of aspirin.

The factors that you need to consider when choosing the right capsule size include:

Maximum diameter and length of the capsule

Intended dosage

Density of the fill materials

Type of capsule

Volume of the capsule

Defects in Gelatin Capsules (& How to Solve)

Some of the most common defects include:

Defects in Hard Gelatin Capsules (Two-piece Gelatin Capsules)

Figure 14 Defects in hard gelatin capsules

The main defects in hard gelatin capsules include:

I. Misshapen or Lumpy Capsules Are as a Result of the Storage Conditions

Make sure that the temperatures in the storage area are between 15 and 30 degrees

centigrade.

The relative humidity should be between 40 and 65%.

Do not expose the capsules to direct sunlight or heat.

II. Improper Rectification

Do not use plastic containers and scoops to transport and load the capsule fillers.

Plastic causes an electrostatic charge that may hider proper rectification of the gelatin capsules.

You should also adjust the machine properly to align the capsules well for the filling process.

III. Failure to Separate

Check the gauge of the machine in case the cap and body fail to separate properly.

Adjust the parameters of the machine accordingly and ensure that it operates perfectly.

Check the timing on the filling process and properly align it to the right specifications.

Check and clean the filter bags periodically.

IV. Dented Capsules

Dents can occur on the capsule due the application of excess pressure or over filling the

capsules.

You should do a proper calculation of the parameters and adjust the parameters accordingly.

V. Telescoping

Occurs when the body and the cap misalign resulting into a split of the capsule body that covers

the cap.

To solve this defect, ensure that the capsules are properly round and check the alignment of

the cap and body.

Make sure that the environmental conditions of the factory are also right.

You can stop the machine for some time to ensure that the environmental conditions are

conducive.

VI. Popping

This involves the opening or elongation of the capsules after filling due to over filling or excess

locking pressure.

Adjust the machines accordingly to avoid popping of the capsules.

VII. Brittleness

Occurs when the capsule lose moisture due to the storage conditions.

The threshold is often at 12.5% and anything below that cause brittleness of the capsule.

The use of HPMC as an ingredient often reduces the brittleness of the capsule.

Defects in Soft Gelatin Capsules (Single Piece Capsule)

Some of the defects you might experience in a Softgel capsule include:

Figure 15 Defects in Softgel capsules - Photo courtesy: SENSUM

I. Weight Variation

The Softgel capsules may vary in terms of weight due to excess filling in other capsules.

Also, the remedy is to adjust the machines accordingly and ensure that you fill the capsules

uniformly.

II. Content Uniformity

The content may not be uniform due to the improper preparation of the inner fill materials.

In this case, ensure that you properly mix the ingredients of the inner fill materials to form a

homogenous mixture.

III. Dissolution Failure

The capsule may fail to dissolve properly or in time during the dissolution test.

This occurs due to improper measuring and mixing of the ingredients.

Remember to conduct proper calculations and measure the ingredients properly to avoid

dissolution problems.

IV. Disintegration Failure

Disintegration may also be as a result of improper measurements and omission of certain

ingredients.

Be careful with the ingredients you add to the mixture and ensure they are of the right

quantity.

How to Store Empty Gelatin Capsules

A complete empty capsule usually requires specific storage conditions to maintain its integrity.

The capsule usually has an equilibrium moisture between 13 and 16%.

Ensure that the storage area is clean enough and maintains a humidity of 40 – 60%.

The temperature in the room should range between 15 and 30 degrees centigrade.

Keep the empty capsules away from direct sunlight as that may raise the surface temperature

of the cartons.

Store the capsules on pallets away from the ground.

Make sure that the room is free of a potential source of water that might interfere with the

moisture content.

Gelatin Capsules Filling Machines

Some of the filling machines that you may use include:

Tamping Capsule Filling Machine

This is a high speed filling machine that depends on dosing disk and tamping technology to fill

the empty capsules.

Figure 16 Tamping pin capsule filling machine

Dosator Capsule Filling Machine

The machine depends on the dosator technology to fill low fill weight capsules that often tends

to vary.

Figure 17 Dosator capsule filling machine

Manual Capsule Filling Machine

With the help of the machine, you will do most of the work such as filling the capsules.

Figure 18 Manual capsule filling machine

Softgel Encapsulation Machine

The machine automatically fills and hermetically seals the soft gelatin capsules at the same

time.

Figure 19 Softgel encapsulation machine

Common Problems in Gelatin Capsules Filling Process

The most common problems of gelatin capsule filling process include:

1. Capsule May Not Enter the Magazine

Set the baffle plate accordingly to allow free and proper flow of the capsule from hopper to

reservoir.

Smoothen the magazine in case of any damages.

Set the right speed of the machine to avoid entry of excess filling materials.

In case of damages on the capsule, remove the capsules with damages.

2. Capsule May Not Enter the Rectifier Block

Adjust the storage conditions in the storage areas accordingly to avoid such problems.

Align the magazine properly to fit with the rectifier block.

3. Capsule Damage during Loading

Align the rectifier block and ensure that the cap and the body are in the right position.

4. Loss of Cap During Transfer

Adjust the vacuum accordingly and avoid using excess vacuum which results into loss of caps.

5. Capsule Non-separation

The capacity pump should be in proper working conditions with proper alignment of the cap

and body.

Replace the bushes with new ones and adjust the spring tension of the machine.

6. Weigh Variation

Select proper dosing discs and maintain the dosing at proper specifications

Conclusion

Soft and hard gelatin capsules are considerably different in a number of factors.

The differences are in accordance to their target application. Therefore, you should know your

target requirements before choosing the right type of gelatin capsule.

With this guide, you will can definitely choose a suitable gelatin capsule.