Shell Composition:
Gelatin:
The hydrolysis of collagen prepares it. There are two basic types of gelatin: Type-A and Type-B. The two types can be differentiated by their isoelectric points and by their viscosity and film-forming characteristics.
A combination of pork skin and bone gelatin is often used to optimize shell characteristics. The physicochemical properties of gelatin of most interests to shell manufactures are the bloom strength and viscosity. Colorants: Various soluble synthetic dyes (coal tar dyes) and insoluble pigments are used. Colorants play a role in identifying the product and improving patient compliance—for example, white analgesia, lavender - hallucinogenic effects, orange or yellow - stimulants and antidepressants.
Opaquing agents:
Titanium dioxide may be included to render the shell opaque. Opaque capsules may be employed to provide protection against light or to conceal the contents.
Preservatives:
When preservatives are employed, parabens are often selected.
Shell Manufacturing:
Dipping:
Pairs of the stainless-steel pins are dipped into the dipping solution to form the caps and bodies simultaneously. The pins are at ambient temperature, whereas the dipping solution is maintained at a temperature of about 50°C in a heated, jacketed dipping pan. The length of time to cast the film has been reported to be about 12 sec. Rotation: After dipping, pins are elevated and rotated 2-1/2 times until they face upward. This rotation helps distribute the gelatin over the pins uniformly and avoids forming a bead at the capsule ends.
Drying:
The racks of gelatin-coated pins are then passed into a series of four drying ovens. Drying is mainly done by dehumidification. A temperature elevation to only a few degrees is permissible to prevent film melting. Under drying will leave the films too sticky for subsequent operation.
Stripping:
A series of bronze jaws strip the cap and body portions of the capsules from the pins.
Trimming:
The stripped cap and body portions are delivered to collects in which they are firmly held. As the collects rotate, knives are brought against the shells to trim them to the required length.
Joining:
The cap and body portions are aligned concentrically in channels, and the two portions are slowly pushed together.
Sorting:
The moisture content of the capsules as they are from the machine will be in the range of 15-18% w/w. During sorting, the capsules passing on a lighted moving conveyor are examined visually by inspectors. Defects are generally classified according to their nature and potential to cause problems in use.
Printing:
In general, capsules are printed before filling. Generally, printing is done on offset rotary presses having throughput capabilities as high as three-quarter million capsules per hour.
Sizes and Shapes:
For human use, empty gelatin capsules are manufactured in eight sizes, ranging from 000 to 5. The largest size normally acceptable to patients is a No. 0. Three larger sizes are available for veterinary use: 10, 11, and 12 having capacities of about 30, 15, and 7.5 gm, respectively. The standard shape of capsules is a traditional, symmetrical bullet shape. Some manufactures have employed distinctive shapes. For example, Lilly's pulvule tapers to a bluntly pointed end, Smith Kline Beacham's spansule capsules taper at both the cap and body end.
Sealing:
Capsules are sealed and somewhat reshaped in the Etaseal process. This thermal welding process forms an indented ring around the waist of the capsule, where the cap overlaps the body.
Storage:
Finished capsules normally contain a 13-16% equilibrium moisture content to maintain a 40-60% relative humidity when handling and storing capsules.
Filling of Hard Gelatin Capsules:
Equipment used in capsule filling operations involve one often of two types of filling systems:
(i) Zanasi or Martelli encapsulator:
Forms slugs in a disaster which is a hollow tube with a plunger to eject capsule plug.
(ii) Hofliger-Karg machine:
Forms compacts in a die plate using tamping pins to form a compact. The scale-up process involves bulk density, powder flow, compressibility, and lubricant distribution in both these systems. Overly lubricated granules are responsible for delaying capsule disintegration and dissolution.
Osaka Model R-180 Semi-Automatic Capsule Filling Machine.
I need some money. Please help me.
You must be logged in to post a comment.