Soft Gel Capsules: The Complete Guide
Do you know soft gel capsules are a popular oral dosage form today?
Yes, but you can only benefit from soft gelatin capsules if you know everything they entail.
That is, from basic definition, benefits, properties, manufacturing process to application.
The best part?
Today’s guide covers every detail you need to know about soft gel capsules.
So, let me walk you through everything you need to know.
- What are Soft Gel Capsules?
- Disadvantages of Soft Gel Capsules
- Properties of Soft Gel Capsules You Should Know
- Soft Gel Capsules Manufacturing Process
- Applications of Soft Gel Capsules
Soft Gel Capsules
What are Soft Gel Capsules?
Medications come in many different forms. It could be a liquid injected intravenously, or transformed into a gas to be inhaled.
A more common form is solid medication, such as tablets and capsules.
A soft gel capsule is a form of medication in which the active ingredients are suspended within a liquid or semi-solid core, known as the inner fill.
This inner fill is wholly surrounded by a single solid capsule, the outer shell.
This outer shell has been traditionally made primarily from gelatin, hence the name.
Other materials composing the outer shell include water, plasticizer and opacifier.
The technology has been available since the 1930s.
- Soft gel Capsules Benefits
The key advantage of a soft gel capsule is how much it facilitates the intake of poorly bioavailable active pharmaceutical ingredients (API).
Swallowing Softgel Capsules
Bioavailability is the fraction of the actual amount of API that exerts a noticeable effect from the total amount introduced into circulation.
According to the Biopharmaceuticals Classification System, there are four main classes of APIs.
Class I are easiest to work with, while Class IV are most difficult.
Most modern drugs are Class II, which means they have a low solubility at certain doses but remain fairly permeable.
Because most drugs are given at fairly low doses, this would be a problem if there wasn’t an efficient delivery system.
Which is where soft gel capsules come in. They enhance bioavailability by delivering the drugs already suspended in solution, where absorption increasing compounds can also be added.
Another advantage of soft gel capsules is that they are easy to swallow.
They can either be designed tasteless, which is better than the bitterness of most tablets and hard capsule medication.
Further, they can also be flavored. This could include both the addition of an enticing color and the desired flavor. This makes drugs and supplements delivered by soft gel capsules quite desirable.
Soft gel capsules are good for high potency APIs. This requires only the smallest dosages, delivered in a highly controlled manner.
Disadvantages of Soft Gel Capsules
Probably the biggest challenge that comes with using the soft gel capsule is that gelatin is water soluble. This property renders it quite sensitive to water and heat.
In turn, this can adversely affect the shelf life of soft gel medications.
For the same reason, oil-based solutions must be used in the inner fill so that the drug doesn’t leach out.
Oblong and Suppository Softgel
The use of gelatin also means one can only use certain excipients in composing the medication, thus limiting one’s choices.
For instance, where aldehydes are involved, gelatin molecule can crosslink.
This chemical event irreversibly changes the structure of the gelatin shell.
Moreover, this reformed shell can result in little to no drugs being released as it should.
Beyond this, the fact that gelatin is derived from animals is problematic to some potential users.
Vegans and vegetarians, who both avoid using animal products wouldn’t wish to use medications so formulated.
If the gelatin is derived from pigs, it becomes unusable to both Jews and Muslims, who both are barred by their respective religions from using pig products.
With specialist technology required to make them, soft gel capsules can quickly become costlier, especially when compared to tablets.
Properties of Soft Gel Capsules You Should Know
As you think about soft gelatin capsules, you need to know some of the key factors that define them. Basically, these are what we call the properties of soft gel capsules.
So, what exactly should you look for?
· Bioavailability soft gel capsules
Bioavailability is a key indicator of a supplement or drug’s efficiency.
It is a descriptor of the rate at which the active ingredient is absorbed into the bloodstream and delivered to its intended target organ intact.
It must remain intact to exert its effect, whether this is reducing pain, or fighting an infection in the patient.
Thus, it is important to know the bioavailability of the substance within softgels because, once ingested, these substances are metabolized or simply not absorbed into blood.
When metabolized, the substances will be irreversibly transformed, often rendering them unhelpful.
The bioavailability of medication/supplement is usually determined by plotting a chart showing its levels in blood plasma over time.
Soft Gel Capsules
The three main factors that determine bioavailability are:
- Solubility – once released from the softgel, the ingredients must be dissolved in the stomach. If the ingredients cannot go into solution, then nothing will get into the bloodstream.
- Stability – Most of the active ingredient must withstand the conditions in the body. There are two main organs where stability is paramount.
One is the stomach, whose acidic environment should not destroy the ingredient.
The second is the liver, which breaks down all introduced chemicals.
As aforementioned, metabolism in the liver will render the ingredient useless, unless this was part of the design to get desired byproducts.
- Permeability – This is the ability of the ingredient, while in solution, to cross into cells and membranes.
Without this ability, the active ingredient cannot cross over from the stomach into the bloodstream. Similarly, it wouldn’t be possible for it to get into its target organ in the body.
Softgels enjoy high bioavailability because of their design. In tablets and 2-piece capsules, the drug is a solid (powder/pellet).
So when it reaches the stomach, it must first be dissolved. With softgels, the drug is already dissolved, allowing faster absorption times.
Also, because it is fully sealed, softgels improve the stability of the active ingredients when compared to tablets and 2-piece capsules.
Because softgels can be designed with a delayed release, it is easier to deliver targeted medication.
Softgels can be given a coating that allows them to pass through the stomach without being broken down. This is especially helpful when the drug is required further down the digestive system.
· Soft gel capsule dimensions
Softgels are available in five main shapes, further subdivided by their capacity. These shapes are:
A sixth category is the special shapes, in which the softgel is modeled into non-standard shapes such as fish, horse, crowns, trees and other items.
Soft Gel Dimensions
Within the five main shapes, the subcategories are identified by a numbering system for each different capacity within its main group.
Capacity is measured in either minims, or cubic centimeters.
A minim is a mostly deprecated unit of measure. It would measure about 61.61 microliters.
For example, within the Round softgels, there are 1,2,3,4,5,6,7,9,15,20,28,40, and 90.
This numbering may be shared across shapes, but do not represent the exact same capacities.
To give a specific example, Round No. 40 has 32-41 minims, while Oval No. 40 has 30-40 minims. The categories and subcategories are illustrated below.
· Soft gel capsule composition
As aforementioned, softgel capsules are composed of two parts, the outer shell and inner fill.
These are made from different materials.
In the outer shell, gelatin comes in different strengths.
This resilience of the gelatin to be used is measured in what is known as bloom strength.
Often, gelatin used in softgels has a bloom strength of 150.
Plasticizers are additives used to increase the capsule’s permeability and flexibility.
They include polyethylene glycol, glycerin, triethyl citrate, and sorbitol.
When polyethylene glycol is used as a plasticizer, gelatin of a bloom strength greater than 150 must be used.
According to some study, water another component, may account for some 40% of the wet gel formulation. In latter stages, the water is often dried out slowly, leaving only 5-8% w/w.
Titanium dioxide is a common opacifier in softgels. It creates an opaque shell that protects light-sensitive ingredients.
It is also common to find preservatives, though 0.2%, they form a tiny fraction of the whole. However, thy play a critical role, keeping microbes at bay.
Propyl paraben and methyl paraben have been the main preservatives.
Sugars such as sucrose, essential oils, and ethyl vanillin may also be found as flavoring compounds in softgel capsules.
Soft Gel Capsules Manufacturing Process
Probably you’re probably asking your self – How do we produce soft gel capsules.
Here, we will quickly go over the soft gel capsules manufacturing process.
But since this is a broad topic, I will give a brief summary plus all the useful links to every subject.
Already, we have extensively covered the subject in various guides.
But first, here is a quick summary in a picture:
Soft Gel Capsules Encapsulation Machine
Well some of the most common methods of manufacturing soft gel capsules include:
1. Rotary die
It’ probably the most used process. In this, a gel mass is pre
pared by heating and adding the other components, such as color and flavor.
This gel mass, now in a melting tank, is heated once again and moved as two separate ribbons to the encapsulation machine, air-heated rotating drums.
The ribbons go through rollers, and onwards towards a fill injector.
The two ribbons form the two halves of one softgel capsule.
They converge into a capsule as the fill injector pumps the inner fill.
These newly-formed softgel capsules are then dried in a drying tunnel.
2. Seamless gelatin
Drop formation is the principle technique in use here.
In this method, softgels are formed by two concentric tubes, as in one nestled in the center of the other. Also, in the inner tube flows the API/medicine, while the outer tube has the gelatin.
When these two form a droplet, the API ends up wholly encapsulated by the gelatin.
A rotary process, with the measuring roll directly above the die.
The pockets in these two rolls are aligned.
Of course, the fill material is held in the pockets of the measuring roll.
On the die roll, a plasticized sheet is held in place.
The measuring roll then transfers the fill material onto the plasticized sheet, and the two roll seal and cut out the formed capsules.
4. Plate process
In this, a sheet of gelatin is placed on a die with molds for the spaces where the inner fill will be. This sheet is then sucked into this mold, creating space for the inner fill as per the die.
These spaces are then filled with the API and excipients. Thereafter, a second sheet is placed over the first, and pressure applied.
This holds the inner fill between the two sheets. Softgel capsules are then sealed, cut, and shaped into the desired final form.
5. Reciprocating die
It bears similarity to the rotary die, with a difference in how the API is encapsulated.
The gelatin ribbons in this case come from vertical dies that close and open at intervals to form spaces in which the medication will be placed.
These are then cut and shaped further down.
In case you want to learn more about these processes, here are some important guides you can review:
- Soft Gelatin Capsules Manufacturing Process: The Ultimate Guide
- Soft Gel Drying Step by Step Guide
- Gelatin Melting Tank: the Ultimate Guide
- Soft Gel Encapsulation Machine – Your Ultimate Guide
As you can see, those guides have been carefully designed to help you throughout the encapsulation process. It does matter whether you’re a newbie or a professional in the soft gel capsules making process.
They will walk you through the formulation process, Softgel encapsulation machine, Softgel encapsulation support equipment to post-processing procedures.
Having said that, let move to yet another important aspect,
Soft gel vs. 2-Piece Capsules – What’s the Difference & Similarity
While it may not seem like it, soft gel and 2-piece capsule are often both made from gelatin.
However, as you are by now aware, a soft gel capsule is one wholly intact capsule enclosing medication suspended in an aqueous form.
Soft Gel Capsules
2-piece capsules on the other hand are two rigid, fitting pieces.
Within these two pieces is the medication, often in powder form, or pellets in some cases.
Soft gel capsules are far better at masking the bitter taste of the medication, and their considerable efficiency means patients have to take smaller-sized medication.
Two-piece capsules on the other hand tend to be large, and thus difficult to swallow.
When using softgels, it may be easier to observe defects or tampering, when compared to capsules. Since the inner fill of a softgel is liquid, if the medication is punctured, it will leak.
Odd discolorations may also hint to tampering, or some other issue.
With capsules, someone may detach the two pieces, add an undesired compound, and the consumer may never know.
Additionally, it is possible, through rough handling, for some of the powder/pellets to be lost when the two pieces come apart.
An unscrupulous person may choose to simply reattach the capsules all the same, even if the dosage has now certainly become too little to be effective.
Applications of Soft Gel Capsules
Softgels are being used in various ways, including as an ophthalmic capsule, chewable medicine, and suckable medicine. Below are specific applications of softgels.
· CBD soft gel capsules
Many exist in the market including, PlusCBD Gold Formula, Bluebird Botanical CBD Oil, Charlotte’s Web Full Strength CBD capsule, Elixinol CBD Hemp oil, Ananda Hemp Spectrum Gels, Everyday Optimal Pure CBD Oil, Phytologia Full Spectrum Hemp softgels, Lazarus Naturals CBD Capsules, cbdMD CBD oil capsule, MedTerra CBD and NutraCanna CBD Dissolvable tablet.
CBD Soft Gel Capsules
· Vitamin and multivitamins supplement
Some of the most common types of vitamin supplements include: Vitaminum A 2500, Vitamin E synthetic, etc.
Hematogen contains iron, Vit. C, Folic Acid, and Vit. B12. Reno Caps (with z622) imprinted, are also multivitamin softgels.
Omega 3 Supplements
Of course we have soft gel capsules drugs such as:
- Diuretics – e.g. Pamabrom.
- Lecithin soft gel
- Benzoate soft gel
- Ct 10 MG softgel – used in the treatment of allergies such as urticaria and rhinitis
- Taytulla – claims to be the only oral contraceptive available as a softgel. Contains norethindrone acetate and ethinyl estradiol and ferrous fumarate.
- Ovol softgel – This is an antacid.
- Lycomost – a multivitamin softgel. It Contains, chromium picolinate, copper sulphate, lycopene, manganese sulfate, sodium selenite, Vit. C, Vit. E and zinc oxide.
- CVS stool softener – used to relieve a case of constipation. Contains docusate sodium
- Norvir (Ritonavir) – a protease inhibitor used to manage HIV
- Medicol Advance 400 (Ibuprofen)
As you can see, soft gel capsules play an integral role in medical and other related fields.
The good news is, you can buy a low or high-capacity Softgel encapsulation machine, which you can use for your production needs.
At this point, am sure you have known why soft gel capsules are becoming popular. Besides, the guide has given resourceful information on the manufacturing process, alongside other critical features.
Now, it’s your turn.
Do you want to start a Softgel capsules encapsulation plant, be it small or large scale?
Or what problems are you experiencing you’re your Softgel encapsulation machine.
Talk to us today, we’d love to hear from you too.