3. INTRODUCTION:
“Capsules are solid dosage
forms in which medicinal agents
and inert substances are enclosed
in a small shell of gelatin’’
4. CLASSIFICATION:
On the basis of composition of gelatin shells,
capsules are divided into 2 types;
1. Hard shell capsule
2. Soft shell capsule
5. 1. HARD SHELL CAPSULE:
Hard gelatin capsule shells are used in most
commercial medicated capsules. The community
pharmacist also uses hard gelatin capsules in the
extemporaneous compounding of prescriptions. Hard shell
capsules consist of two interconnecting rigid, thin shells
that contain the drug and excipient composition.
Ingredients used for capsule shells should be nontoxic and
soluble in order to release drug formulation and should
additionally demonstrate resistance to mechanical stress
that may be encountered during manufacturing and
shipping of the product.
6. The empty capsule shells are made of gelatin, sugar, and
water. They can be clear, colorless, and essentially tasteless.
Most commercially available medicated capsules contain
combinations of colorants and opaquants to make them
distinctive, many with caps and bodies of different colors. For
human use, eight sizes of capsules are available. The capacity
of each size varies according to the combination of drugs and
their apparent densities.
7. METHODS OF PREPARATION OF HARD
SHELL CAPSULE:
Hard gelatin capsule shells are manufactured in two
sections, the capsule body and a shorter cap. The two parts
overlap when joined, with the cap fitting snugly over the open
end of the capsule body.
STEPS OF PREPARATION:
1. Preparation of gelatin solution.
2. Dipping and spining
3. Drying
4. Stripping and cutting
5. Joining
8. 1. PREPARATION OF GELATIN SOLUTION:
The first step in this process is to prepare the gelatin. Here,
you need to mix gelatin with hot demineralized water under a
vacuum. Once mixed, let the mixture sit for a while to allow the
elimination of air bubbles. Then, transfer the mixture to
a stainless steel service tank and add dyes and water. Note that at
this stage, water (hot) should only be used to adjust the viscosity
of the mixture.
2. DIPPING AND SPINNING:
The shells are produced industrially by the mechanical
dipping of pins or pegs of the desired shape and diameter into a
temperature controlled reservoir of melted gelatin mixture and
The moulds are slowly withdrawn from the solution and then
rotated during their transfer to the upper level of the machine, in
order to form a film of uniform thickness.
9. 3. DRYING:
Groups of ‘pin bars’ are then passed through a series of drying
kilns, in which large volumes of controlled-humidity air are
blown over them. When they reach the rear of the machine, the
bars are transferred back to the lower level and pass through
further drying kilns until they reach the front of the machine.
4. STRIPPING & CUTTING:
The dried films are removed from the moulds and cut to the
correct length.
5. JOINING:
The two parts are joined together and the complete capsule is
delivered from the machine.
10.
11.
12. FILLING OF HARD SHELL CAPSULE:
1. Rectification of capsules (placing empty gelatin capsules on
the removable plate with bodies facing downward).
2. Separation of caps from bodies.
3. Dosing of fill material (The body is filled with the
formulation manually using a plastic spatula, and the excess
powder is removed).
4. Replacement of caps/ closing capsule shells and.
5. Ejection of filled capsules.
13. FILLING OF POWDER FORMULATIONS
INTO HARD GELATIN CAPSULES:
Hard gelatin capsules can be filled by hand for
research or experimental purposes or when filling a small
number of capsules in the pharmacy. This is done by
placing the powder to be filled on a sheet of clean paper
or on a pill tile or porcelain plate and pressing the open
end of the capsule downward until it is filled. The cap is
then placed to close the capsule
14. On a small-scale manufacture, hard gelatin
capsules can be filled manually using a manual or
a hand operating capsule machine. This is done
by directly filling the powder into the capsule
shell and relying on the bulk/tapped density of
the powder to get the correct dose for the
volume of the capsule shell used.
Large scale production involves the use of
machines that come in great variety of shapes
and sizes, varying from semi- to fully automatic
and ranging in output from 3000 to 150 000 per
hour
15. CAPSULE SIZE:
Hard capsules are made in a range of sizes; the standard
industrial ones in use today for human medicines range in size
from 0 to 4.
CAPSULE SIZE BODY VOLUME (mL)
0 0.69
1 0.50
2 0.37
3 0.28
4 0.20
16. 2. SOFT SHELL CAPSULE:
Soft gelatin capsules are made of gelatin to which
glycerin or a polyhydric alcohol such as sorbitol has
been added. They contain preservatives such as
methyl paraben and/or propyl paraben, to retard
microbial growth due to presence of water. They may
be single colored or two-toned, oblong, oval or round
in shape. Soft gelatin capsules are pharmaceutically
elegant and are easily swallowed, as compared to
hard gelatin capsules.
17. METHODS OF PREPARATION OF SOFT
GELATIN CAPSULES:
Soft gelatin capsules are typically manufactured
by first melting the gelatin and then incorporating
plasticizers and colorants to form a hot gelatin mass
There are many ways of producing soft gelatin
capsules:
• Rotary die process
• Plate process
• Reciprocating die
• Accogel machine
18. PLATE PROCESS:
o A warm sheet of prepared gelatin is laid over the lower plate
and the liquid is poured on it
o The second sheet of gelatin is carefully put in place and this
followed by the top plate of mold.
o The set is placed under the press were pressure is applied to
form a capsule which are washed of with volatile solvent to
remove any trace of oil from exterior
19. ADVANTAGES OF CAPSULE:
1. When medications are to be administered orally to adults, capsules and
tablets usually are preferred because they are conveniently carried,
readily identifi ed, and easily taken compared with doses of a liquid
medication. With capsules and tablets, there is no need for spoons or
other measuring devices, which may be inconvenient and may result in
less than accurate dosing.
2. Most capsules and tablets are tasteless when swallowed, which is not the
case with oral liquid medications.
3. From a pharmaceutical standpoint, solid dosage forms are effi ciently and
productively manufactured; they are packaged and shipped by
manufacturers at lower cost and with less breakage than comparable
liquid forms. They are also more stable and have a longer shelf life than
their liquid counterparts.
4. Dosage forms that must be left intact include enteric coated tablets,
designed to pass through the stomach for drug release and absorption in
the intestine; extended-release dosage forms, designed to provide
prolonged release of the medication; and sublingual or buccal tablets,
formulated to dissolve under the tongue or in the mouth.
20. DISADVANTAGES OF CAPSULE:
1. Gelatin present in the Hard gelatin capsules is stable in air when
dry but is subject to microbial decomposition when it becomes
moist. if stored in an environment of high humidity, additional
moisture is absorbed by the capsules, and they may become
distorted and lose their rigid shape. In an environment of extreme
dryness, some of the moisture normally present in the gelatin
capsules is lost, and the capsules may become brittle and crumble
when handled.many capsules are packaged along with a small
packet of a desiccant material to protect against the absorption of
atmospheric moisture.
2. In dry formulations, the active and inactive components must be
blended thoroughly to ensure a uniform powder mix for the fill.
Care in blending is especially important for low-dose drugs, since
lack of homogeneity in blending may result in significant
therapeutic consequences.
3. Sometimes a patient who is unconscious cannot swallow a solid
dosage form, so in this case pharmacists can suggest a chewable
or liquid form of the drug.
21. REFERENCE:
Ansel’s Pharmaceutical Dosage Forms And Drug Delivery
System
Aultons’s Pharmaceutics (fifth edition)
Martin’s Physical Pharmacy and Pharmaceutical Sciences
(sixth edition)
AAPS Introductions In The Pharmaceutical Sciences
