How To Make Soft Gel Capsules?

Outer Shell 


The outer shell of a soft gel capsule requires the following ingredients:

Gelatin

Since the beginning, gelatin is the prime ingredient of gelatin capsules that comes in a variety of bloom or gelling strengths. Greater the bloom strength more resilient the gel. It is generally prepared by cooking/boiling animal skin, bone, ligaments & tendons as they are rich in collagen. This collagen is a pretty wonderful binding agent that gives a sticky and jelly texture.

The primary gelatin types used for making soft gel capsules are described below:

Sources of Gelatin

1.Animal-DerivedGelatin

Animal-derived gelatin is a partially hydrolyzed form of collagen from animal tissues. For instance: skin, tendon, and bones. The molecule of gelatin is made up of a long chain of amino acid by amid linkage.

Bovine Gelatin

Gelatin is obtained from a 100% pure bovine source. This form of gelatin is certified as halal which is a pure protein. Bovine collagen is very safe and flexible to incorporate into your diet as well.

Porcine Gelatin

This form of gelatin is extracted from pig sources. Porcine gelatin is characterized as a non-halal substance that is prohibited in some customs. It is safe for utilization in medicines under strict sterility, safety, and FDA norms.

Poultry Gelatin

Poultry gelatin is possibly a good alternative to mammalian gelatin. The poultry gelatin has promising rheological properties for industrial application.

Fish Gelatin

Fish Gelatin is a proteinous substance obtained from the collagen-rich skin of fish/scales with the help of boiled water.

2.Plant-DerivedGelatin

An ideal substitute for Vegan! Fortunately, there is plant-based gelatin commonly employed substitute for animal-based gelatin. This is the ideal source for vegans and most closely resembles gelatin.

Pectin

Pectin is non-animal; water-soluble polysaccharides are present in the cell walls of fruits as well as vegetables. It is also known as a gelling agent in terms of composition.

Agar Agar

Agar or agar-agar is a heterogeneous form of carbohydrate obtained from seaweed such as red sea algae. It has no flavor, no odor, and color good for culinary ingredients too.

Vegetable Gum

In soft gel capsules, vegetable gum such as xanthan, guar, and locust bean gum are also used.

Carrageenan (seaweed)

It is also known as Irish Moss, which is extracted from seaweed extract and is a good alternative to animal-derived gelatin. A carrageenan is a flavorless form of gelatin also used for various vegan products.

Plant-Derived Gelatin

For a perfect soft gel capsule you must require:

• A gel strength must be 150- 200 bloom
• Viscosity (60°C/6- 2/3 % w/w in water): 8–4 mPa s,
• Well-controlled viscosity breakdown
• Well-defined particle size
• A broad molecular weight distribution.

Plasticizer

The making of soft gel capsules needs the utilization of non-volatile plasticizers in water to improve the mechanical integrity of the shell, i.e. the elasticity of the shell before and after drying. The additional plasticizers lead to counterbalance the stresses which are induced by the shrinkage of the capsule shall as water molecules remove from it during drying.

The commonly used plasticizers are:

• Polyalcohol: approved by official pharmacopeias’ or local regulatory bodies.
• Glycerol:  Glycerol is a frequently used plasticizer due to its high efficiency and more compatibility and low volatility with gelatin.
• Sorbitol: Sorbitol is an indirect plasticizer majorly acting as a moisturizing agent with water being an effective plasticizer. For soft gel capsule, 85- 98%, special grade non-crystalline aqueous sorbitol, and sorbitol-sorbitan combination are used.
• Propylene Glycol (PEG): used as an inactive ingredient in pharmaceutical products such as solvent, surfactant, ointment, and plasticizers. This ingredient has the potency to retain water.
• PEG 200 (low molecular weight): derived from petroleum-based sources, similar uses as PEG.

For a perfect soft gel capsule you must require:

• The ratio by weight of dry plasticizer to dry gelatin is between 3:1.0for hard gelatin while for soft gelatin 1.8:1
• The choice of soft gelatin shell formula w.r.t the gelatin/plasticizer must be crucial to its physical stability and storage.

Water

The rate and extent of physical shell and inner fill strongly depend upon the qualitative and quantitative formulations. As a universal solvent, water is used to make a gelatin mass with a pouring viscosity at 60-70°C.

For a perfect soft gel capsule, you must follow its specification, such as:

The ratio by weight of water/solvent to dry gelatin (W/G) may between 0.7 to 1.3 which depends upon the viscosity of the gelatin. The water content is removed after drying; generally, it is recommended that finished moisture content must be at 4-10%.

Opacifier

Do You Know Why Using Opacifier in Soft gel capsules? This is because the opacity allows efficient masking of the capsule fill and protects the ingredient against photodegradation. Besides this, a distinctive brightness helps the brand owner to determine a distinct visual identity. Titanium dioxide is a suitable opacifier that offers various benefits for the manufacturer.

Coloring Agent

Consumers like colored capsules; side by side it is an important marketing tactic of various pharmaceutical manufacturers. According to the International Journal of Biotechnology, 75% of people preferred red- or pink-colored pills. The common coloring agent used are soluble dyes or insoluble pigments.

Preservatives

Perseverative is incorporated into the composition to protect the growth of microbes during storage. The common preservatives are potassium sorbate, methyl, propyl hydroxybenzoate.

Flavoring Agent

A flavoring agent is not a frequently used product. The purpose of using to enhance flavors while ingestion, patient compliance, and to protect the odor of the capsule. There are various flavoring agents available such as vanilla, apple, orange, etc.,

Composition Of Soft Gel Capsule- Inner Shell

There are primary three kinds of inner filling materials.

• Neat Substance/Transparent Substance such as oily fluids
• A solution such as the presence of an active in a carrier.

You must keep in mind that if the inner filling material is suspension, it can accommodate up to 30% solid particles. Furthermore, a suspending agent must be smaller than 80 mesh.