Friday, 13 February 2009

Capsule (pharmacy)
From Wikipedia, the free encyclopedia

In the manufacture of pharmaceuticals, encapsulation refers to a range of techniques used to enclose medicines in a relatively stable shell known as a capsule, allowing them to, for example, be taken orally or be used as suppositories. The two main types of capsules are hard-shelled capsules, which are normally used for dry, powdered ingredients, and soft-shelled capsules, primarily used for oils and for active ingredients that are dissolved or suspended in oil. Both of these classes of capsule are made both from gelatine and from plant-based gelling substances like carrageenans and modified forms of starch and cellulose.
Since their inception, capsules have been viewed by consumers as the most efficient method of taking medication. For this reason, producers of drugs such as OTC analgesics wanting to emphasize the strength of their product developed the "caplet" or "capsule-shaped tablet" in order to tie this positive association to more efficiently-produced tablet pills. After the 1982 Tylenol tampering murders, capsules experienced a minor fall in popularity as tablets were seen as more resistant to tampering.[1]
In 1834, Mothes and Dublanc were granted a patent for a method to produce a single-piece gelatin capsule that was sealed with a drop of gelatin solution. They used individual iron moulds for their process, filling the capsules individually with a medicine dropper. Later on, methods were developed that used sets of plates with pockets to form the capsules. Although some companies still use this method, the equipment is not produced commercially any more. All modern soft-gel encapsulation uses variations of a process developed by R.P. Scherer in 1933. His innovation was to use a rotary die to produce the capsules, with the filling taking place by blow molding. This method reduced wastage, and was the first process to yield capsules with highly repeatable dosage.

Two-part gel capsules

Two-part hard gelatin capsules
James Murdock patented the two-part telescoping gelatin capsule in London in 1847.[2] The capsules are made in two parts by dipping metal rods in molten gelatin solution. The capsules are supplied as closed units to the pharmaceutical manufacturer. Before use, the two halves are separated, the capsule is filled with powder (either by placing a compressed slug of powder into one half of the capsule, or by filling one half of the capsule with loose powder) and the other half of the capsule is pressed on. The advantage of inserting a slug of compressed powder is that control of weight variation is better, but the machinery involved is more complex.[3]
Sizing
In Canada, gelatin capsules are available in a range of sizes with designations 000, 00, 0E, 0, 1, 2, 3, and 4. The respective volumetric capacities are 1.37ml, 950ul, 770ul, 680ul, 480ul, 360ul, 270ul, and 200ul.[4]

Wednesday, 11 February 2009


CAPSULES

There are two forms of capsules, hard capsules and soft capsules. Hard capsules are for
powders or semi-solid preparations and soft capsules for liquids.
Sizes of Hard Capsules, From The Art of Dispensing, 1937
Hard capsules were invented in 1833 in France. They were (and are today) made of gelatin
and consist of two parts, a body and a lid (they were supplied ready made but were filled in the
pharmacy). A simple filling apparatus would consist of a wooden base, drilled with holes
equivalent to the size of capsule being used. Weighed powder doses could be introduced
through a small funnel. Semi-solid preparations were rolled into a pipe, a piece cut off and
weighed, trimmed to the correct weight and placed in a capsule. The caps were fitted and the
capsules packed and labelled.
Soft capsules could be made in the pharmacy. The apparatus was called a dipper and
consisted of metal moulds of various sizes which were set into a base. The dipper was inverted
and dipped into a melted glycerin/gelatin mixture, placed on its base and, when cool, the
capsules were removed. The capsules could then be filled with a measured amount of liquid via
a syringe then closed with a blob of the molten glycerin/gelatin mixture applied with a glass rod,
or sealed by careful application of a heated rod.