FORMULATION AND FILLING OF HARD GELATIN CAPSULES - EXPERIMENT

EXPT NO: 06                                                                                                            DATE:

FORMULATION AND FILLING OF HARD GELATIN CAPSULES

DEFINITION

Capsules are solid dosage form in which drug or drugs with or without excipients are enclosed in a hard or soft water-soluble shell or a container of gelatin or of any other suitable substance.

ADVANTAGES

·         Capsules are tasteless, odorless, and can be easily administered.

·         They are very attractive in appearance.

·         The drugs having unpleasant odor and taste are enclosed in a tasteless shell.

·         They can be filled quickly and conveniently therefore the physician can change the dose and combination of drugs to suit the individual patients.

·         They are economical.

·         They are easy to handle and carry

DISADVANTAG ES

·         The drugs, which are hygroscopic, are not suitable for filling into capsules. They will absorb the water present in capsule shell rendering the shell very brittle and ultimately lead to crumble into pieces.

·         The concentrated solutions which require previous dilution are unsuitable for capsules because if administered as such lead to irritation in the stomach

·         Capsules should not be used for highly efflorescent or deliquescent materials. Efflorescent material may cause the capsules to soften, whereas deliquescent powders may dry the capsule shell to excessive brittleness.

CAPSULES ARE CLASSIFIED AS

1.       Hard gelatin Capsules.

2.       Soft gelatin capsules.

Hard gelatin Capsules:

They are used particularly for administration of solid, medicaments. They are prepared from gelatin blends, plasticizers, and preservatives and with certified dyes and opacifying agents. Shells can also be prepared from methylcellulose, polyvinyl alcohols and denatured gelatin

Soft gelatin capsules:

They are used for powders, non-aqueous liquids or pastes. They may be spherical (also known as pearls), avoid U cylindrical with hemispherical ends. Soft capsules are sometimes used as containers for eye ointment. Single application eye ointment is filled in the soft capsule. After piercing just by pressing, the contents can be transferred in the eye cavity. The composition of shell is similar to that of hard gelatin capsules with a larger proportion of plasticizers.

Sizes:

Capsules are available in about eight different sizes identified according to numbers ranging from 000 (largest) to 5 (smallest). Their capacities to accommodate the contents vary with the bulk density of the substances and pressure applied during the operation. But approximate capacities are given in the following table.

Different Capsule Sizes

Size of Capsules	Capacity to Fill (mg)
000	950
00	600
1	450
2	300
3	200
4	150
5	100

Method of Filling Of Hard gelatin capsules: The capsule can be filled either by hand or by semiautomatic device or by automatic filling machine.

Capsule filling Machine (Hand operated):

It consists of: -

·         A bed having 200- 3000 holes.

·         A loading tray having 200-300 holes.

·         A power tray.

·         A pin plate having 200-300 pins.

·         A sealing plate having rubber top.

·         A lever.

·         A cam handle.

The empty capsules are filled in the loading tray and it is placed over the bed. The cam handle is operated to separate capsule cap from its bodies. The powder tray is placed in proper position and filled it with accurate quantity of powder with scraper. The excess of powder is collected on the platform of powder tray. The pin plate is lowered and the filled powder is pressed by moving the pin downwards. After pressing, the pin plate is raised and remaining powder is filled in to the bodies of the capsules. The powdered tray is removed after complete filling. The cap holding tray is again placed in position. The plate with rubber top is lowered and the lever is operated to lock the caps and bodies. The loading tray is removed and filled capsules are collected.

Cleaning of capsules:

All capsules whether they have been filled by hand or machine will require cleaning. Small quantities of capsules can be wiped individually with soft cloth. But in case of large quantities, capsule are rotated or shaken with crystalline NaCl. The capsule is then rolled on cloth-covered surfaces.

Sealing of capsules:

The capsules are then sealed, to ensure that the medicaments may not come out of the capsule due to rough handling. This can be done by bonding with molten gelatin, laid around the joint in a strip and dried. Capsules can be sealed spot welded, means heated metal pin, pressed against the cap, fusing it to the body.