Introduction, Type, Advantage and Disadvantage of Hard Gelatin Capsule and Soft Gelatin Capsule in Pharmacy

By Ankita Rai | Last Updated: July 17, 2018 Previous       Next

Gelatin capsule is first prepared in France by Mothes and Dublanc in 1834. It covers a method for producing olive-shaped and single-piece of a gelatin capsule.
Gelatin capsule is easy to take, slippery, easily swallowed and test less shell drug. It also has an unpleasant test or odor.

Gelatin capsules are not usually used for administration of extremely soluble material, for example, Potassium Chloride(KCl) and Potassium Bromide(KBr) because it causes the irritation in the stomach. Capsules should not be used for highly efflorescent or deliquescent material because it may because the capsules soften and deliquescent powders may dry the Capsule shell and cause excessive brittleness.

Capsules are the unit dosage form of the medicament. It is of two types…

1. Hard Gelatin Capsules- It is used for filling the solid substance.
2. Soft Gelatin Capsules- It used for filling liquid and semi-solid material.

Gelatin

It is the substance of material origin but does not occur in nature.
Gelatins are prepared by the hydrolysis of collagen (bone and skin) and it never occurs naturally.

Types of Gelatin

There are mainly two types of Gelatin.

Type A Gelatin:

It is derived from acid hydrolysis and it exhibits an isoletric point in the region of pH 9.

Type B Gelatin:

Type B Gelatin is produced by alkali hydrolysis, it exhibits an isoletric point in the region of pH 4.7.

Advantage of Gelatin Capsules

There are following importance of gelatin capsules-

• It is teast less, odorless and easy to administration.
• They are attractive to appearance.
• Easy to handle and carry.
• Drug having an unpleasant odor and placed in the closed shell.

Disadvantage of Gelatin Capsules

It has the following disadvantage-

• Hydroscopic drug is not suitable for filling into the capsule. Because the will absorb water present in the capsule shell and cause brittle shell and also altimetry breakdown in two pieces.
• Extremely soluble materials like potassium chloride, potassium bromide or ammonium chloride are sudden release such compound in the stomach cause irritation.
• Efflorescent substance may cause to capsule too soft.
• Deliquescent material may dry to the capsule shell to excessive.

Material used for Hard Gelatin Capsules

Hard gelatin capsule is referred to the Dry Filled Capsule(DFC).
Hard gelatin capsule is made by the mixture of Gelatin, Sugar, and water with or without coloring agent.

Gelatin is the most important and major compound use for the preparation of the capsules because gelatin posses the following essential basic properties-

1. It is non-toxic.
2. It is readily soluble in the biological fluid at body temperature.
3. It is used as a good forming material.
4. Acceptable for use.

Filling Equipment

At present, there is following capsule filling equipment are available.

1. Eli Lilly and company, Indiannpolis, IN
2. Formatic SNC, Bologna, Italy
3. Hofliger and Karg, waiblingen, Germany
4. Macofar SAS , Bologna, Italy
5. mG2 S.p.A., Bologna, Italy
6. Osaka, Osaka, Japan
7. Parke-Davis and company, Detroit, MI
8. Perry Industry, Green Bay, WI
9. Zanasi Nigris, S.p.A., , Bologna, Italy

Finishing

The filled and sealed capsule goes for finishing operation before inspection.
The following steps are involved in the finishing process.

1. Salt Polishing- Such polishing removes adhering material from the surface.
2. Cloth Dusting- In this process individual capsule clean with the cloth.
3. Brushing- There are remove all the remaining dust.

Inspection

Inspection is the process in which is desirable to pick up imperfect and damage capsules. ROTOSORT is a new filled capsule sorting machine sold by Eli Lilly and Company.
The Erweka KEA dedusting and polishing machine for hard gelatin capsule is sold by the United State of Key Industries, Englishtown, NJ

Soft Gelatin

Soft gelatin capsule is also known as “Soluble elastic” or “Soft elastic”. They consist of a gelatin-based shell surrounding a liquid fill. Softgel shells are a combination of gelatin, water, opacifier and a plasticiser such as glycerin or sorbitol.

Material used for Soft Gelatin Capsule

The composition of soft gelatin capsule is differed from the hard gelatin capsule in which the sugar is replaced by Plasticizer (like glycerin, sorbitol). Plasticizer is imparting the elasticity property of soft gelatin capsule. The plasticizer (glycerol, sorbitol) make the capsule flexible. The soft gelatin capsule is generally content a preservative to prevent the growth of bacteria and fungi.

Nature of Capsule Shell

The soft gelatin capsule shell is basically composed of gelatin, plasticizer and water, it also contain a additional ingredient like preservative, coloring agent and opacifying agent etc. Iron is always present in the raw gelatin and it concentration is usually depend on the iron content of large quantities of water use in the manufacture. Gelatin is used in the manufacture of soft capsule should not contain more than 15ppm of this element, because of its effect on Food, Drug and Cosmetics (FD&C)certified dyes and its possible color reactions with organic compounds.

The ratio by weight of dry plasticizer to dry gelatin determine the “hardness” of the gelatin shell, assuming that there is a no effect of capsulated material. Some example of glycerin/gelatin ratio are shown in following table-

Table- Shell Hardness Ratio

Method of Filling of Soft Gelatin Capsule

Soft gelatin capsules are is generally prepared by-

1. The Plate process
2. The Die process

Component of the Soft Gelatin Capsule

The soft gelatin capsule can be used to dispense a variety of liquids and semi-solids.

There are following types of liquids are encapsulated…

1- Liquids Oily: Oily liquid drug are cord liver oil.

2- Solution fills: It contains essential oil, volatile oil, oil such as soybean oil, polyethylene glycol(PEG).

Optional ingredient for solution is-

1. Water/Alcohol- Upto 10% w/w.
2. Glycerin- Upto 1-4% w/w.
3. Polyvinyl pyrolidone- Upto 10% w/w

3- Suspension fills: They are following-

• Oily Mixture
  1. Soyabin oil with beeswax & lecithin.
  2. Gellyfied oil
• Polyethylene Glycol
  1. PEG 800-1000 for Semi-solids fills.
  2. PEG 200-400 for other fills.
  3. Preservation for encapsulated should have pH range 2.5-7.5.